Abstracts [medikamente_implantate] 11.201

Dental endosseous implants in the medically compromised patient.
Eastman Dental Institute, University College London, London, UK. [email protected] Abstract
The literature contains numerous observations on the significance of systemic disorders as contraindications to dental endosseous implant treatment, but the justification for these statements is often apparently allegorical. Although implants are increasingly used in healthy patients, their appropriateness in medically compromised patients is less equivocal. Perhaps surprisingly, the evidence of their efficacy in these groups of patients is quite sparse. Indeed, there are few if any randomized controlled trials (RCTs) in this field. Furthermore, any health risks from the placement of implants are unclear. We review the current evidence for the risks associated with endosseous implants in a range of systemic disorders. There is clearly a need for prospective systematic trials. The degree of disease-control may be far more important that the nature of the disorder itself, and individualized assessment, including the medical condition, quality of life and life expectancy is indicated. The benefits of implants to many of these patients may outweigh any risks. However, proper informed consent is mandatory. Consensus statements and recommended clinical procedures regarding risk
factors in implant therapy.
Cochran DL, Schou S, Heitz-Mayfield LJ, Bornstein MM, Salvi GE, Martin WC. Int J Oral Maxillofac Implants. 2009;24 Suppl:86-9. Department of Periodontics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MSC 7894, San Antonio, TX 78229-3900, USA. [email protected] http://www.iti.org/?a=1&t=0&y=3102&r=0&n=185&i=&c=25&v=list2&o=&s= (www.iti.org -> Publications -> Proceedings of the fourth ITI Consensus Conference) Systemic conditions and treatments as risks for implant therapy.
Int J Oral Maxillofac Implants. 2009;24 Suppl:12-27. Department of Oral Surgery and Stomatology, School of Dental Medicine, Univerity of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland. [email protected] Abstract
PURPOSE: To evaluate whether systemic diseases with/without systemic medication increase the risk of implant failure and therefore diminish success and survival rates of dental implants. MATERIALS AND METHODS: A MEDLINE search was undertaken to find human studies reporting implant survival in subjects treated with osseointegrated dental implants who were diagnosed with at least one of 12 systemic diseases. RESULTS: For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. For most systemic diseases there are only case reports or case series demonstrating that implant placement, integration, and function are possible in affected patients. For diabetes, heterogeneity of the material and the method of reporting data precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged. The data from papers reporting on osteoporotic patients were also heterogeneous. The evidence for an association between osteoporosis and implant failure was low. Nevertheless, some reports now tend to focus on the medication used in osteoporotic patients, with oral bisphosphonates considered a potential risk factor for osteonecrosis of the jaws, rather than osteoporosis as a risk factor for implant success and survival on its own. CONCLUSIONS: The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Studies comparing patients with and without the condition in a controlled setting are sparse. Especially for patients with manifest osteoporosis under an oral regime of bisphosphonates, prospective controlled studies are urgently needed. http://www.iti.org/?a=1&t=0&y=3102&r=0&n=185&i=&c=25&v=list2&o=&s= (www.iti.org -> Publications -> Proceedings of the fourth ITI Consensus Conference) Medical contraindications to implant therapy: Part II: Relative
contraindications.
Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA. Abstract
Systemic conditions and habits influence dental implant survival to varying degrees. Illnesses that impair the normal healing cascade worsen surgical success. The mere presence of a disease, however, does not necessarily preclude implant therapy or affect significantly long-term outcomes. Certain disorders, when controlled, or other situations allow implant survival rates that match those in health. This paper reviews these relative contraindications, which include adolescence, aging, osteoporosis, smoking, diabetes, positive interleukin-1 genotype, human immunodeficiency virus positivity, cardiovascular disease, and hypothyroidism. Medical contraindications to implant therapy: part I: absolute
contraindications.
Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA. Abstract
In order to ensure implant success, it is essential to select patients who do not possess local or systemic contraindications to therapy. Hence, it is the purpose of this paper to review the medical diseases that reportedly preclude conventional dental implant treatment. Absolute contraindications to implant rehabilitation include recent myocardial infarction and cerebrovascular accident, valvular prosthesis surgery, immunosuppression, bleeding issues, active treatment of malignancy, drug abuse, psychiatric illness, as well as intravenous bisphosphonate use. Any of these conditions bar elective oral surgery, and require judicious monitoring by the physician as well as the dental provider. Noncompliance to the suggested protocol may, in the worst possible case, result in patient mortality. [Surgical dilemmas. Medical restrictions and risk factors]
Ned Tijdschr Tandheelkd. 2008 Dec;115(12):643-51. Mondziekten, Kaak- en Aangezichtchirurgie van het Universitair Medisch Centrum St Radboud Nijmegen, Nijmegen. [email protected] Abstract
In principle, only patients with an ASA (American Society of Anaesthesiologists)-score I or II qualify for an elective surgical procedure, such as an implantation treatment. Surgical risks are weighed against the potential benefits offered by oral implants. Counter-indications to implant rehabilitation include recent myocardial infarction and cerebrovascular accident, immunosuppression, active treatment of malignancy, drug abuse, as well as long-standing intravenous bisphosphonate use. In the case of patients with an endocarditis risk, and also in the case of patients with an orthopedic prosthesis, implants should be placed with some reluctance. If the decision is made for treatment, then consultation with the treating specialist is recommended. Beside absolute counter-indications, there are also conditions which compromise the success of an implant treatment, such as radiation of the jaw or long-term smoking. Concerning the effect which medical conditions have on the life-expectancy of the implant, little is known. There appear to be few existing factors which actually have a negative influence on the chance that an implant will survive. Patient selection for endosseous dental implants: oral and systemic
considerations.
Int J Oral Maxillofac Implants. 2002 Mar-Apr;17(2):191-201. AstraZeneca R&D Boston, Waltham, Massachusetts 02451, USA. [email protected] Abstract
This paper reviews the literature and discusses patient selection for endosseous dental implants and the effect of systemic and local pathology on the success rate of dental implants. Endosseous dental implants may be preferable to conventional dentures in patients with compromised supporting bone or mucosa, xerostomia, allergy to denture materials, severe gag reflex, susceptibility to candidiasis, diseases affecting orofacial motor function or in patients who demand optimal bite force, esthetics, and phonetics. Conventional dentures or fixed partial prostheses may be preferable to endosseous dental implants in growing and epileptic patients and patients at risk of oral carcinoma, anaphylaxis, severe hemorrhage, steroid crisis, endocarditis, osteoradionecrosis, myocardial infarction, or peri-implantitis. A systematic approach to dental implant patient selection is outlined and centralized reporting of dental implant outcomes is recommended. Impact of local and systemic factors on the incidence of oral implant failures,
up to abutment connection.
Alsaadi G, Quirynen M, Komárek A, van Steenberghe D. J Clin Periodontol. 2007 Jul;34(7):610-7. Epub 2007 Apr 13. Department of Periodontology, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Catholic University of Leuven, Leuven, Belgium. Abstract
AIM: The aim of this retrospective study was to assess the influence of systemic and local bone and intra-oral factors on the occurrence of early implant failures, i.e. up to the abutment connection. MATERIAL AND METHODS: The surgical records of 2004 consecutive patients from the total patient population who had been treated in the period 1982-2003 (with a total of 6946 Brånemark system implants) at the Department of Periodontology of the Catholic University Leuven were evaluated. For each patient the medical history was carefully checked. Data collection and analysis mainly focused on endogenous factors such as hypertension, coagulation problems, osteoporosis, hypo-hyperthyroidy, chemotherapy, diabetes type I or II, Crohn's disease, some local factors [e.g. bone quality and quantity, implant (length, diameter, location), type of edentulism, Periotest value at implant insertion, radiotherapy], smoking habits and breach of sterility during surgery. RESULTS: A global failure rate of 3.6% was recorded. Osteoporosis, Crohn's disease, smoking habits, implant (length, diameter and location) and vicinity with the natural dentition were all significantly associated with early implant failures (p<0.05). CONCLUSION: The indication for the use of oral implants should sometimes be reconsidered when alternative prosthetic treatments are available in the presence of possibly interfering systemic or local factors. Dental implant failure rates and associated risk factors.
Int J Oral Maxillofac Implants. 2005 Jul-Aug;20(4):569-77. Oral and Maxillofacial Surgery, University of California at Los Angeles, School of Dentistry, Los Angeles, California, USA. Abstract
PURPOSE: To guide treatment planning by analyzing the rates of dental implant failure to determine associated risk factors. MATERIALS AND METHODS: All consecutively treated patients from January 1982 until January 2003 were included in a retrospective cohort study, as defined in the hierarchy of evidence for dental implant literature. Data regarding gender, age, implant location, bone quality, bone volume, and medical history were recorded. Correlations between these data and implant survival were calculated to establish relative risk (RR) ratios. RESULTS: Increasing age was strongly associated with the risk of implant failure. Compared to patients younger than 40 years, patients in the 60-to-79 age group had a significantly higher risk of implant failure (RR = 2.24; P < .05). Gender, hypertension, coronary artery disease, pulmonary disease, steroid therapy, chemotherapy, and not being on hormone replacement therapy for postmenopausal women were not associated with a significant increase in implant failure. Smoking (RR = 1.56), diabetes (RR = 2.75), head and neck radiation (RR = 2.73), and postmenopausal estrogen therapy (RR = 2.55) were correlated with a significantly increased failure rate. Overall, implant failure was 8.16% in the maxilla and 4.93% in the mandible (P < .001). DISCUSSION: Patients who were over age 60, smoked, had a history of diabetes or head and neck radiation, or were postmenopausal and on hormone replacement therapy experienced significantly increased implant failure compared with healthy patients. CONCLUSION: Overall, dental implant failure is low and there are no absolute contraindications to implant placement. Conditions that were found to be correlated with an increased risk of failure should be considered during treatment planning and factored into the informed consent process. Effects of steroid-induced osteoporosis on osseointegration of titanium
implants.
Int J Oral Maxillofac Implants. 1998 Mar-Apr;13(2):183-9. Department of Oral Surgery, Nagoya University School of Medicine, Japan. Abstract
The purpose of this study was to clarify the effects of steroid administration on the osseointegration of pure titanium implants. Twelve female New Zealand white rabbits, 8 weeks of age, were divided into two groups: a prednisolone-treated group (Group P) and a control group (Group C). In each rabbit, two implants were placed into the mandible and two into the tibial metaphyses with bone tapping. The six steroid-treated rabbits received three courses of 4 days of prednisolone injections (10 mg/kg per day) before implant placement, 1 month and 2 months after implant placement. The six control rabbits received no administration of prednisolone. Three months after implant placement, all rabbits were sacrificed. Bone density of the femur and removal torque of the implants placed in the tibia were significantly lower in Group P than in Group C. In addition, there were significant correlations between the bone density of the femur and the removal torque of the implants placed in the tibia. There was no significant difference in removal torque of the implants placed in the mandible between Group P and Group C, and there was no significant correlation between the bone density of the femur and the removal torque of the implants placed in the mandible. These results suggest that steroid administration could have less effect on the osseointegration of titanium implants in the mandible than in the skeletal bone. Risk factors associated with dental implants in healthy and medically
compromised patients.
Int J Oral Maxillofac Implants. 1992 Fall;7(3):367-72. Department of Oral and Maxillofacial Surgery, University of California, San Francisco 94143. Abstract
A total of 104 consecutive patients treated with 313 Nobelpharma implants was studied to determine the medical risks associated with dental implants. There did not appear to be an increased implant failure rate or an increase in perioperative morbidity in patients with a compromised medical status. Age; sex; and concurrent use of hypoglycemic agents, supplemental female hormones, or steroids also did not correlate with increased implant failure or perioperative morbidity. Implant procedures using a variety of pain-/anxiety-control agents failed to reveal any increase in anesthetic-related complications. However, the number of implants placed per patient did correlate with implant failure. It appears that implant surgery and the required anesthetic appear to be safe procedures even in the medically compromised patient. Endosteal implants in a patient with corticosteroid dependence.
Brookdale Hospital Medical Center, Brooklyn 11212-3198. Endosseous dental implants and the glucocorticoid-dependent patient.
School of Medicine, University of Louisville, KY 40292. Effect of glucocorticoid-induced osteoporotic-like conditions on osteoblast cell
attachment to implant surface microtopographies.
Cho P, Schneider GB, Kellogg B, Zaharias R, Keller JC. Abstract
OBJECTIVES: The objectives of this work were to: (1) establish methodology for pretreating osteoblast-like cells in vitro with dexamethasone to cause glucocorticoid-induced osteoporosis, (2) perform quantitative and qualitative assessments of cellular attachment of osteoporosis-like osteoblasts when grown on implant surfaces of differing roughness, (3) and explore the hypothesis that dexamethasone-treated osteoblasts have altered cell attachment properties by focal adhesion disassembly and decreased tyrosine phosphorylation of the focal adhesion tyrosine kinase. METHODS: Osteoblasts were cultured with dexamethasone (10(-7) and 10(-6) M) for up to 4 days of incubation to induce osteoporosis-like conditions. Cellular attachment assays demonstrated the effect of dexamethasone treatments on cellular attachment properties of osteoblasts. Qualitative data were obtained utilizing immunofluorescent microscopy and Western blotting. Focal adhesion kinase (FAK) immunoprecipitation and tyrosine-phosphorylation Western blots were obtained from dexamethasone-treated human embryonic palatal mesenchymal- 1486 osteoblast cultures supplemented with ascorbate and beta-glycerol phosphate medium. RESULTS: Cellular attachment was significantly greater (P < 0.05) with non-dexamethasone-treated osteoblasts (92%) as compared to dexamethasone-treated osteoblasts after 1 (72%), 2 (63%), and 4 days (53%) of exposure. Dexamethasone-treated osteoblasts were viable and capable of proliferation, suggesting that the reduction of cellular attachment may be related to these cell adhesion processes. Immunofluorescent microscopy of both dexamethasone-treated osteoblasts and non-dexamethasone-treated osteoblasts failed to show any relative difference in the disassembly of focal adhesions and actin filaments. Extended dexamethasone treatment periods (up to 3 weeks) showed changes in the levels of FAK and FAK-phosphotyrosine in human embryonic palatal mesenchymal-1486 osteoblasts. CONCLUSIONS: The protocol used in this study demonstrated a glucocorticoid-induced osteoporosis-like suppression of osteoblasts. FAK disassembly was not a significant factor in short period; however, FAK protein levels and phosphotyrosine signaling on FAK were affected after 1-week exposure to dexamethasone. Phosphorylated FAK was not associated with the rise in the level of FAK, further indicating the possibility of FAK involvement in reduced cell attachment. Treatment with dental implants in patients with severe osteoporosis: a case
report.
Int J Periodontics Restorative Dent. 1994 Aug;14(4):348-53. Abstract
The case report of a woman with severe osteoporosis who was treated with dental implants is presented. Polyarthritis was diagnosed in 1955, and a corticosteroid medication treatment was started in 1960. During the years, the patient has undergone multiple joint surgeries. Dental implants were inserted in the maxilla in 1987 and in the mandible in 1988. Due to a compression of the spine, the patient lost 12 cm in body height between 1991 and 1993; a spontaneous femur fracture was diagnosed in December 1992. However, the arch bone has been stable; the 6- and 5-year follow-up results of the maxillary and mandibular implants, respectively, are presented. Bisphosphonat-assoziierte Kiefernekrosen
Leitliniengruppe "Septische Chirurgie" der Deutschen Gesellschaft für Mund-, Kiefer- und Gesichtschirurgie Zahnärztliche Betreuung von Patienten unter/nach Bisphosphonat-Medikation
Wissenschaftliche Stellungnahme der DGZMK Outcomes of placing dental implants in patients taking oral bisphosphonates:
a review of 115 cases.
Grant BT, Amenedo C, Freeman K, Kraut RA. J Oral Maxillofac Surg. 2008 Feb;66(2):223-30. • J Oral Maxillofac Surg. 2008 Jul;66(7):1558; author reply 1558-9. • J Evid Based Dent Pract. 2008 Dec;8(4):229-31. Abstract
PURPOSE: In recent years, numerous cases of bisphosphonate-associated osteonecrosis of the jaw have been reported involving both intravenous and oral therapy regimens. The majority of these cases have involved intravenous bisphosphonates. Subsequently, drug manufacturers and the US Food and Drug Administration issued warnings about possible bisphosphonate-associated osteonecrosis of the jaw. The American Dental Association and the American Association of Oral and Maxillofacial Surgeons assembled expert panels to formulate treatment guidelines. Both panels differentiated between patients receiving bisphosphonates intravenously and those receiving the drugs orally. However, the recommendations were based on limited data, especially with regard to patients taking oral bisphosphonates. We wanted to ascertain the extent to which bisphosphonate-associated necrosis of the jaw has occurred in our dental implant patients. We also wanted to determine whether there was any indication that the bisphosphonate therapy affected the overall success of the implants as defined by Albrektsson and Zarb. PATIENTS AND METHODS: We identified 1,319 female patients over the age of 40 who had received dental implants at Montefiore Medical Center between January 1998 and December 2006. A survey about bisphosphonate therapy was mailed to all 1,319 patients. Responses were received from 458 patients of whom 115 reported that they had taken oral bisphosphonates. None had received intravenous bisphosphonates. All 115 patients were contacted and informed about the risk of bisphosphonate-associated osteonecrosis of the jaw. Seventy-two patients returned to the clinic for follow-up clinical and radiological evaluation. RESULTS: A total of 468 implants were placed in the 115 patients who reported that they had received oral bisphosphonate therapy. There is no evidence of bisphosphonate-associated osteonecrosis of the jaw in any of the patients evaluated in the clinic and those contacted by phone or e-mail reported no symptoms. Of the 468 implants, all but 2 integrated fully and meet criteria for establishing implant success. Implant success rates were comparable for patients receiving oral bisphosphonate therapy and those not receiving oral bisphosphonate therapy. CONCLUSIONS: Guidelines for treatment of dental patients receiving intravenous bisphosphonate treatments should be different than for patients taking the oral formulations of these medications. In this study, oral bisphosphonate therapy did not appear to significantly affect implant success. Implant surgery on patients receiving bisphosphonate therapy did not result in bisphosphonate-associated osteonecrosis of the jaw. Nevertheless, sufficient evidence exists to suggest that all patients undergoing implant placement should be questioned about bisphosphonate therapy including the drug taken, the dosage, and length of treatment prior to surgery. For patients having a history of oral bisphosphonate treatment exceeding 3 years and those having concomitant treatment with prednisone, additional testing and alternate treatment options should be considered. What impact do systemically administrated bisphosphonates have on oral
implant therapy? A systematic review.
Clin Oral Implants Res. 2009 Sep;20 Suppl 4:87-95. Abstract
OBJECTIVES: The aim of this systematic review is to evaluate, analysing the dental literature, whether: * Patients on intravenous (IV) or oral bisphosphonates (BPs) can receive oral implant therapy and what could be the risk of developing bisphosphonate-related osteonecrosis of the jaw (BRONJ)? * Osseointegrated implants could be affected by BP therapy. MATERIAL AND METHODS: A Medline search was conducted and all publications fulfilling the inclusion and exclusion criteria from 1966 until December 2008 were included in the review. Moreover, the Cochrane Data Base of Systematic Reviews, and the Cochrane Central Register of Controlled Trials and EMBASE (from 1980 to December 2008) were searched for English-language articles published between 1966 and 2008. Literature search was completed by a hand research accessing the references cited in all identified publications. RESULTS: The literature search rendered only one prospective and three retrospective studies. The prospective controlled non-randomized clinical study followed patients with and without BP medication up to 36 months after implant therapy. The patients in the experimental group had been on oral BPs before implant therapy for periods ranging between 1 and 4 years. None of the patients developed BRONJ and implant outcome was not affected by the BP medication. The three selected retrospective studies (two case-controls and one case series) yielded very similar results. All have followed patients on oral BPs after implant therapy, with follow-up ranging between 2 and 4 years. BRONJ was never reported and implant survival rates ranged between 95% and 100%. The literature search on BRONJ including guidelines and recommendations found 59 papers, from which six were retrieved. Among the guidelines, there is a consensus on contraindicating implants in cancer patients under IV-BPs and not contraindicating dental implants in patients under oral-BPs for osteoporosis. CONCLUSIONS: From the analysis of the one prospective and the three retrospective series (217 patients), the placement of an implant may be considered a safe procedure in patients taking oral BPs for <5 years with regard to the occurrence of BRONJ since in these studies no BRONJ has been reported. Moreover, the intake of oral-BPs did not influence short-term (1-4 years) implant survival rates. Dental implants in patients treated with oral bisphosphonates: a bibliographic
review.
Montoya-Carralero JM, Parra-Mino P, Ramírez-Fernández P, Morata-Murcia IM, Mompeán-Gambín Mdel C, Calvo-Guirado JL. Med Oral Patol Oral Cir Bucal. 2010 Jan 1;15(1):e65-9. Abstract
Bisphosphonates inhibit bone resorption and are used to treat a range of pathologies, including Paget disease, osteoporosis, multiple myeloma and metastases associated with breast or prostate cancer. At present, there is no effective treatment for bisphosphonate induced osteonecrosis, so prevention is extremely important. Since quality of life deteriorates for those suffering osteonecrosis, maximum precautions should be taken with patients at risk, and especially whenever oral surgery, including dental implant placement, is contemplated. Dentists and oral or maxillofacial surgeons must keep up to date with the latest approaches to prevention, particularly when treating patients who are presently taking, or who will be taking bisphosphonates and are also candidates for dental implants. Effect of Long-Term Oral Bisphosphonates on Implant Wound Healing:
Literature Review and a Case Report
Hom-Lay Wang, Daniel Weber, Laurie K. McCauley March 2007, Vol. 78, No. 3, Pages 584-594 Background: Bisphosphonates suppress osteoclast activity, and their intravenous use has been reported in hundreds of cases to be associated with osteonecrosis in the jaw. Little is known of the risks associated with long-term use of oral bisphosphonates despite their use for >10 years by an oral mode of delivery for the treatment of osteopenia, osteoporosis, and Paget's disease of bone. The purpose of this report is to review the literature associated with bisphosphonate use that could impact bone healing and to report a case of bone necrosis in a patient on long-term oral bisphosphonates. Methods: A Medline search was carried out to find relevant articles from both medical and dental literature between 1960 and 2006. A patient, who had been taking an oral bisphosphonate for >10 years, developed unexplained clinical signs of bone necrosis after routine dental implant placement. This case was followed, documented, and the treatment of the osteonecrosis described. Results: A summary of how bisphosphonates may play a role in wound healing is presented. The compromised healing noted in a patient, who was under long-term oral bisphosphonate use, was successfully treated with systemic antibiotics, local microbial mouthrinse, and aggressive defect management (detoxification and mixture of bone graft and tetracycline). Conclusions: This case suggests that patients under long-term oral bisphosphonate use should be treated with caution. Well-controlled, prospective clinical trials on the effect of oral bisphosphonates on bone are warranted to determine which patients may be at risk for such complications Dental endosseous implants in patients on bisphosphonate therapy.
About a decade ago, bisphosphonates were introduced as an alternative to hormone replacement therapies for osteoporosis and to treat osteolytic tumors. More recently, it has became evident that the bisphosphonates used intravenously such as pamidronate (Aredia; Novartis Pharmaceuticals Corp., East Hanover, NJ) and zoledronate (Zometa; Novartis Pharmaceuticals Corp.), in particular, could lead to painful refractory bone exposure (sometimes termed osteochemonecrosis or osteonecrosis) in the jaws. Patients with osteonecrosis of the jaws usually present after dental treatment with oral signs and symptoms of painful, exposed, and necrotic bone, primarily of the mandible and, to a lesser extent, the maxilla. Although the precipitating event that produces this complication may be spontaneous, there is little doubt that oral surgery and endosseous implants can be responsible. Exodontia is the main precipitant. The present postulated mechanism of osteonecrosis of the jaws is that prolonged use of bisphosphonates may suppress bone turnover to the point that the repair function of physiologic microdamage of bone is abolished. Such a mechanism could presumably interfere with the healing process after implant placement. Although, to our knowledge, there is no evidence that bone disorders are a contraindication to implants, there is evidence that bisphosphonate therapy is a contraindication. Where possible, extractions should be avoided, and it is best to avoid all elective oral surgery in patients on bisphosphonates, including endosseous implant placement, or the treatment should be performed well before commencing bisphosphonates. If surgery is essential on a patient taking bisphosphonate therapy, the patient must be counseled about the risks. Osteonecrosis of the Posterior Mandible after Implant Insertion: A Clinical and
Histological Case Report.
Favia G, Piattelli A, Sportelli P, Capodiferro S, Iezzi G. Clin Implant Dent Relat Res. 2009 Aug 3. [Epub ahead of print] Abstract
ABSTRACT Background: In the past few years, the occurrence of an oral lesion, called osteonecrosis of the jaw (ONJ), has been increasingly reported in patients undergoing treatment with bisphosphonates (BPs); however, few published histological studies of ONJ can be found in the literature. Purpose: The aim of the present case was to report an occurrence of ONJ after implant insertion. Materials and Methods: Multiple myeloma was diagnosed to a 65-year-old female. After 5 years of treatment with intravenous clodronate, two dental implants were inserted in the mandibular molar region. No preexisting bone lesions were present at a preoperative panoramic radiography. Before implant insertion, the patient had suspended the treatment with clodronate for 3 months. Four months after the implant insertion, a breakdown of the oral mucosa covering the implants occurred with a purulent discharge; periapical radiolucency was present around both implants. An en-block resection on the alveolar bone including the two implants was performed. No signs of recurrence of the lesion were observed after a follow-up of 20 months. Results: At the interface of one of the implants, a gap was observed between bone and implant. This bone was nonvital, and many osteocyte lacunae were empty. Moreover, this bone appeared to be partially demineralised. No newly formed bone or osteoblasts were present. Bone trabeculae were observed, on the other hand, within the apical implant threads of the other implant. A close connection was observed between this bone and the implant surface. Discussion: The histological findings showed some areas with osseointegration in patients undergoing BP treatment for malignant disease; however, any invasive procedure can determine the onset of osteonecrosis. Conclusion: In conclusion, there is certainly a temporal association between BP use and development of ONJ, but a correlation does not necessarily mean causation. Moreover, generalizations about this complex relationship cannot be made on the basis of a single case report. In patients undergoing intravenous treatment, clinicians must be aware of the increased risk of implant failure and, probably, implant insertion should be avoided at all until more conclusive data are available. Complex prosthodontic treatment with dental implants for a patient with
polymyalgia rheumatica: a clinical report.
Bencharit S, Reside GJ, Howard-Williams EL. Int J Oral Maxillofac Implants. 2010 Nov-Dec;25(6):1241-5. Abstract
Prosthodontic and implant treatment for a patient with polymyalgia rheumatica can be complicated not only by its symptoms, but also by the side effects of long-term use of certain medications, particularly systemic glucocorticoids. This clinical report presents a polymyalgia rheumatica patient who required full-mouth rehabilitation with dental implants. The patient had a sensitive gag reflex and refused the use of any removable prostheses. She presented clinically with a skeletal Class II malocclusion with severe overbite and overjet. All her remaining dentition was determined to be unrestorable. Full-mouth extractions and immediate placement of implants followed by early implant loading were performed. The use of systemic glucocorticoids might have exacerbated her type 4 maxillary bone and compromised her healing capacity and consequently made implant surgery challenging. Her treatment with full-arch fixed implant-supported dentures to correct her severe overbite and overjet and manage misaligned dental implants is summarized here. The effects of polymyalgia rheumatica in prosthodontic and dental implant treatments are reviewed and discussed. Implant prosthodontic rehabilitation of patients with rheumatic disorders: a
case series report.
Weinlander M, Krennmair G, Piehslinger E. Int J Prosthodont. 2010 Jan-Feb;23(1):22-8. Abstract
PURPOSE:
This retrospective study assessed implant and prosthodontic treatment outcomes of patients suffering from rheumatic disorders such as rheumatoid arthritis (RA) and connective tissue diseases (CTDs). MATERIALS AND METHODS:
This study included 22 patients (all women) suffering from autoimmune rheumatic disorders such as isolated RA (n = 16), RA with concomitant CTDs (n = 5), or isolated CTDs (n = 1). Overall, 89 implants were placed for rehabilitations such as single-tooth replacement (n = 8), fixed partial dentures (n = 14), complete dentures (n = 5), and overdentures (n = 2), and were evaluated after a mean of 42.6 +/- 25.2 months. The cumulative implant survival and success rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and Calculus Index) were evaluated with a special focus on RA and CTDs. In addition, incidence and type of prosthodontic maintenance were evaluated. RESULTS:
A high implant survival rate was noted during follow-up with a cumulative 3-year implant success rate of 96.1%. Patients with RA demonstrated acceptable marginal bone resorption (mean: 2.1 +/- 0.5 mm) and good soft tissue conditions, while CTD patients showed increased bone resorption (mean: 3.1 +/- 0.7 mm). This was especially noted in scleroderma patients, as were major peri-implant soft tissue alterations (Bleeding Index) in patients suffering from Sjogren syndrome. CONCLUSIONS:
A high implant and prothodontic success rate can be anticipated even for patients suffering from autoimmune rheumatic disorders such as RA and CTDs. A scrupulous maintenance program that includes optimal oral hygiene could assist in ensuring stable long-term results for CTD patients with more vulnerable soft tissue conditions. Int J Prosthodont 2010;23:22-28. Systemic conditions and treatments as risks for implant therapy.
Int J Oral Maxillofac Implants. 2009;24 Suppl:12-27. To evaluate whether systemic diseases with/without systemic medication increase the risk of implant failure and therefore diminish success and survival rates of dental implants. A MEDLINE search was undertaken to find human studies reporting implant survival in subjects treated with osseointegrated dental implants who were diagnosed with at least one of 12 systemic diseases. For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. For most systemic diseases there are only case reports or case series demonstrating that implant placement, integration, and function are possible in affected patients. For diabetes, heterogeneity of the material and the method of reporting data precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged. The data from papers reporting on osteoporotic patients were also heterogeneous. The evidence for an association between osteoporosis and implant failure was low. Nevertheless, some reports now tend to focus on the medication used in osteoporotic patients, with oral bisphosphonates considered a potential risk factor for osteonecrosis of the jaws, rather than osteoporosis as a risk factor for implant success and survival on its own. The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Studies comparing patients with and without the condition in a controlled setting are sparse. Especially for patients with manifest osteoporosis under an oral regime of bisphosphonates, prospective controlled studies are urgently needed. (www.iti.org -> Publications -> Proceedings of the fourth ITI Consensus Conference Mineral status of COPD patients under long-term inhaled corticosteroid therapy.
Buyukkaplan US, Akkaya A, Yildiz M, Bircan A, Aksoy Dogan A, Ozturk O. J Prosthodont. 2008 Aug;17(6):462-7. Epub 2008 Jun 28. Abstract
The aim of this study was to determine the mineral status of mandibles, femurs, and spines in chronic obstructive pulmonary disease (COPD) patients under long-term inhaled corticosteroid therapy. Pulmonary function tests were conducted on patients (n = 30) with COPD under inhaled corticosteroid therapy for at least 1 year. The results were compared to sex- and age-matched controls (n = 30). Analyses of blood gases were also carried out relative to COPD, and bone mineral densities (BMD) of the mandible, lumbar spine, femoral neck, trochanter, and Ward's triangle were also measured by dual-energy X-ray absorptiometry (DEXA). Levels of serum osteocalcin, alkaline phosphatase, calcium, phosphorus, and cortisol were also assessed. In accordance with the Global Initiative for Chronic Obstructive Lung Disease criteria, 8 of the COPD patients had moderate, 11 patients had severe, and 11 patients had very severe forms of the disease. All BMD measurements were lower in the COPD patients than in the control group. The serum osteocalcin levels in COPD patients were significantly lower than those in the control group (p < 0.0001). Serum calcium (p < 0.004) and cortisol levels (p < 0.026) in the COPD patients were also significantly lower than those in the control subjects. Although serum alkaline phosphatase level was higher and the phosphorus level was lower in the treatment group than in the control group, the differences were not statistically significant. Regular evaluation of the biochemical markers of bone metabolism and BMD would be helpful for detecting any detrimental changes of bone in COPD patients under long-term inhaled corticosteroid therapy. In this study, mandibular BMD was observed to be lower in COPD patients under long-term inhaled corticosteroid therapy than in healthy subjects. Thus, dental implant treatment may require preventive measures in COPD patients under long-term inhaled corticosteroid therapy. Resolution of an active peri-implantitis in a chronic steroid user by bone
augmentation with PepGen P-15 and a barrier membrane.
Abstract
Dental implant treatment can be complicated with infection. A list of possible causes includes overheating during the osteotomy, bacterial contamination from an adjacent tooth, residual bacteria from the infected tooth that previously occupied the site, bone microfractures from overloading or loading too soon, and residual space left around the implant after it is seated. Most treatments entail surgical debridement of the lesion and chemical detoxification of the apical or exposed portion of the implant surface with citric acid, tetracycline, or chlorhexidine gluconate as well as guided tissue regenerative or guided bone regenerative procedures. This article describes the case of an active labiolateral peri-implantitis from a previous infectious site at tooth 12 in a patient who was a chronic steroid user. The patient was treated with surgical debridement and no implant surface detoxification and regenerative procedures with xenograft of PepGen P-15 and an absorbable collagen membrane. The patient was advised to discontinue steroid therapy. This resulted in resolution of the associated signs and symptoms of infection and new bone formation in the radiograph. The negative effect of corticosteroids on calcium metabolism and bone regeneration is discussed. The potential implications of steroid use for implant dentistry are critically appraised, and guidelines are proposed for pre- and postoperative management that may assist in the successful implant-supported rehabilitation of this patient category. Effect of glucocorticoid-induced osteoporotic-like conditions on osteoblast cell
attachment to implant surface microtopographies.
Cho P, Schneider GB, Kellogg B, Zaharias R, Keller JC. Abstract
The objectives of this work were to: (1) establish methodology for pretreating osteoblast-like cells in vitro with dexamethasone to cause glucocorticoid-induced osteoporosis, (2) perform quantitative and qualitative assessments of cellular attachment of osteoporosis-like osteoblasts when grown on implant surfaces of differing roughness, (3) and explore the hypothesis that dexamethasone-treated osteoblasts have altered cell attachment properties by focal adhesion disassembly and decreased tyrosine phosphorylation of the focal adhesion tyrosine kinase. Osteoblasts were cultured with dexamethasone (10(-7) and 10(-6) M) for up to 4 days of incubation to induce osteoporosis-like conditions. Cellular attachment assays demonstrated the effect of dexamethasone treatments on cellular attachment properties of osteoblasts. Qualitative data were obtained utilizing immunofluorescent microscopy and Western blotting. Focal adhesion kinase (FAK) immunoprecipitation and tyrosine-phosphorylation Western blots were obtained from dexamethasone-treated human embryonic palatal mesenchymal- 1486 osteoblast cultures supplemented with ascorbate and beta-glycerol phosphate medium. Cellular attachment was significantly greater (P < 0.05) with non-dexamethasone-treated osteoblasts (92%) as compared to dexamethasone-treated osteoblasts after 1 (72%), 2 (63%), and 4 days (53%) of exposure. Dexamethasone-treated osteoblasts were viable and capable of proliferation, suggesting that the reduction of cellular attachment may be related to these cell adhesion processes. Immunofluorescent microscopy of both dexamethasone-treated osteoblasts and non-dexamethasone-treated osteoblasts failed to show any relative difference in the disassembly of focal adhesions and actin filaments. Extended dexamethasone treatment periods (up to 3 weeks) showed changes in the levels of FAK and FAK-phosphotyrosine in human embryonic palatal mesenchymal-1486 osteoblasts. The protocol used in this study demonstrated a glucocorticoid-induced osteoporosis-like suppression of osteoblasts. FAK disassembly was not a significant factor in short period; however, FAK protein levels and phosphotyrosine signaling on FAK were affected after 1-week exposure to dexamethasone. Phosphorylated FAK was not associated with the rise in the level of FAK, further indicating the possibility of FAK involvement in reduced cell attachment. Dental implants for patients who have had radiation treatment for head and
neck cancer.
Spec Care Dentist. 2003 Nov-Dec;23(6):223-9. Abstract
Implant therapy is no longer considered impossible for patients who have received radiation treatment. However, the risk of osteoradionecrosis and failed osseointegration are barriers to implant therapy for this population. This paper reviews the published literature on the effects of radiation on tissue, such as osteoradionecrosis, hyperbaric oxygen therapy, and evaluates implant therapy in patients who have received radiation treatment, focusing on treatment of the mandible. Recommendations for dentists planning implant therapy for patients who have had radiation treatments are presented. Histometric study of alveolar bone healing in rats treated with the nonsteroidal
anti-inflammatory drug nimesulide.
Teófilo JM, Giovanini GS, Fracon RN, Lamano T. Abstract
There is extensive experimental and clinical evidence in the orthopedic area that prolonged use of nonselective (inhibitor of both cyclooxygenases 1 and 2) nonsteroidal anti-inflammatory drugs can hinder long bone fracture healing, spinal fusion rate, and new bone formation around implants. The purpose of the present study was to investigate whether nimesulide (Nimesulida, Medley S.A., Campinas, SP, Brazil), a preferential cyclooxygenase-2 inhibitor, can hinder alveolar bone healing, in rats. Treated rats received oral doses (5 mg/kg/rat/day) of nimesulide from the day of tooth extraction until euthanasia 2 weeks later and control rats received tap water (n = 5 per group). The volume of neoformed bone inside the alveolar socket was estimated in semiserial longitudinal histological sections by a differential point-counting method, and the significance of the difference between groups was analyzed by Student t test (P < 0.05 for statistical significance). Histometric data confirmed histological observation that the volume fraction of new bone trabeculae in treated rats was not significantly different from that in control rats. Short-term treatment with nimesulide, although its capacity to inhibit preferentially the enzyme cyclooxygenase-2, does not interfere with alveolar bone healing in rats. Effects of chemotherapy in patients with dental implants.
Steiner M, Windchy A, Gould AR, Kushner GM, Weber R. Abstract
Endosseous implant placement is generally considered to be contra-indicated in patients undergoing chemotherapy for the treatment of cancer. A case is presented where a patient was diagnosed with cancer and began chemotherapy four weeks after endosseous implants were placed. The impact of chemotherapeutic agents on endosseous implant acceptance as well as upon oral tissue is examined. Interventions for replacing missing teeth: antibiotics at dental implant
placement to prevent complications.
Esposito M, Worthington HV, Loli V, Coulthard P, Grusovin MG. Cochrane Database Syst Rev. 2010 Jul 7;(7):CD004152. Abstract
Some dental implant failures may be due to bacterial contamination at implant insertion. Infections around biomaterials are difficult to treat and almost all infected implants have to be removed. In general, antibiotic prophylaxis in surgery is only indicated for patients at risk of infectious endocarditis, for patients with reduced host-response, when surgery is performed in infected sites, in cases of extensive and prolonged surgical interventions and when large foreign materials are implanted. To minimise infections after dental implant placement various prophylactic systemic antibiotic regimens have been suggested. More recent protocols recommended short term prophylaxis, if antibiotics have to be used. With the administration of antibiotics adverse events may occur, ranging from diarrhoea to life-threatening allergic reactions. Another major concern associated with the widespread use of antibiotics is the selection of antibiotic-resistant bacteria. The use of prophylactic antibiotics in implant dentistry is controversial. To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic/placebo administration and, if antibiotics are of benefit, to find which type, dosage and duration is the most effective. The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to 2nd June 2010. Several dental journals were handsearched. There were no language restrictions. Randomised controlled clinical trials (RCTs) with a follow up of at least 3 months comparing the administration of various prophylactic antibiotic regimens versus no antibiotics to patients undergoing dental implant placement. Outcome measures were prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity, etc). Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Results were expressed as random-effects models using risk ratios (RRs) for dichotomous outcomes with 95% confidence intervals (CIs). Heterogeneity was to be investigated including both clinical and methodological factors. Four RCTs were identified: three comparing 2 g of preoperative amoxicillin versus placebo (927 patients) and the other comparing 1 g of preoperative amoxicillin plus 500 mg 4 times a day for 2 days versus no antibiotics (80 patients). The meta-analyses of the four trials showed a statistically significant higher number of patients experiencing implant failures in the group not receiving antibiotics: RR = 0.40 (95% CI 0.19 to 0.84). The number needed to treat (NNT) to prevent one patient having an implant failure is 33 (95% CI 17 to 100), based on a patient implant failure rate of 5% in patients not receiving antibiotics. The other outcomes were not statistically significant, and only two minor adverse events were recorded, one in the placebo group. There is some evidence suggesting that 2 g of amoxicillin given orally 1 hour preoperatively significantly reduce failures of dental implants placed in ordinary conditions. No significant adverse events were reported. It might be sensible to suggest the use of a single dose of 2 g prophylactic amoxicillin prior to dental implant placement. It is still unknown whether postoperative antibiotics are beneficial, and which is the most effective antibiotic. Oral implants in radiated patients: a systematic review.
Colella G, Cannavale R, Pentenero M, Gandolfo S. Int J Oral Maxillofac Implants. 2007 Jul-Aug;22(4):616-22. Oral malignancy is often treated with a combination of surgery and radiation therapy (RT). The aim of this systematic review was to examine the effects of pre- and postimplantation RT on dental implant failure. The literature published from 1990 through 2006 was reviewed for studies assessing pre- and postimplantation RT. Potential studies were identified by searches of PubMed, SCIRUS, and the Cochrane Central Register of Controlled Trials (CENTRAL). The incidence of implant failure has been linked to the following variables: post- versus preimplantation RT, site of implant placement, RT dose, delay from RT to implant placement, and timing of implant failure after placement. Similar failure rates were found for implants placed post-RT compared to those placed pre-RT (3.2% and 5.4%). In preimplantation RT, the implant failure rate was lower for the mandible (4.4%) in comparison to the maxilla (17.5%; OR = 4.63; 95% CI: 2.25 to 9.49). Other results did not reach statistical significance. No failures were observed in association with an RT dose lower than 45 Gy. All implant failures observed occurred within 36 months after RT, and most occurred between 1 and 12 months after placement. Notwithstanding the low number of implants evaluated, this review showed similar failure rate for implants placed post-RT and those placed pre-RT (3.2% and 5.4%, respectively). Impact of local and systemic factors on the incidence of late oral implant loss.
Clin Oral Implants Res. 2008 Jul;19(7):670-6. Epub 2008 May 19. Alsaadi G, Quirynen M, Komárek A, van Steenberghe D. This retrospective study was set to assess the influence of systemic and local bone and intra-oral factors on the occurrence of implant loss from abutment connection up to 2 years. The files of 700 patients, have been collected randomly from the total patient group treated by means of endosseous Brånemark system implants (Nobel Biocare, Gothenburg, Sweden) at the Department of Periodontology of the University Hospital of the Catholic University of Leuven. The end point observation was evaluating the loss of the implants 2 years after abutment installation. The study involved all implants that did not encounter early loss and implants for which it was possible to evaluate its status 2 years after abutment surgery. Thus, data of 412 patients (240 females) provided with 1514 implants were analyzed. For each patient, the medical history was carefully checked. Data collection and analysis were mainly focused on endogenous factors such as hypertension, coagulation problems, osteoporosis, hypo- hyperthyroidism, chemotherapy, diabetes type I or II, Crohn's disease, some local factors [e.g. bone quality and quantity, implant (length, diameter, location), type of edentulism, PTV, radiotherapy], smoking habits, and breach of sterility during surgery. Radiotherapy, implant (diameter and location), and higher PTV at implant insertion and abutment connection, all affected significantly the implant loss. Implant location in the oral cavity and radiotherapy seem predominant to explain the occurrence of implant loss. On the other hand, smoking and systemic health factors do not seem to be prominent players in the etiology of late implant loss. Implant location and radiotherapy are the only factors linked to 2-year implant
failure.
J Evid Based Dent Pract. 2010 Mar;10(1):49-51. The subjects in this retrospective case series were derived from a review of 700 patient files within the implant practice of the Department of Periodontology, University Hospital, Catholic University of Leuven. Inclusion criteria were met by 412 patients (240 females, 172 males) receiving a total of 1514 Nobel Biocare dental implants. These patients were included based on data availability for the time period 2 years after abutment surgery (considered to represent late implant failure). KEY EXPOSURE/STUDY FACTOR: Given the concern of the authors to assess the probability of late implant failure among clinic patients with certain local and systemic factors, the potential factors were multiple. The local factors included the following: implant length and diameter, bone quality and quantity, insertion site, type of edentulism, antibiotic use perioperatively, dehiscence and/or perforation of the site during surgery, and stability at insertion (measured by Periotest values). The related health and behavioral factors included the following: medications, smoking (<10 cigarettes/day, 10-20 cigarettes/ day, >20 cigarettes/day), hypertension, ischemic cardiac problems, coagulation anomalies, gastric ulcers, thyroid disorders, hypercholesterolemia,rheumatoid arthritis, asthma, diabetes (types 1 and 2), Crohn's disease, and chemotherapy. Main Outcome Measure: The primary outcome was described as "late implant failure." The current study, which follows a similar study on early implant failure, aims to identify negative influences on maintenance of integration. The authors used the clinical experience related to the 412 patients with 1514 implants to identify whether the observed failure rates were influenced by local and systemic factors. Failure was defined as "late" when occurring between abutment connection surgery and 2 years after this date. Patients/implants that were not available for this interval of time were not included. However, even when records were available, not all patient records provided all data sought. Regarding local factors, the authors reported that implant diameter and location were relevant to late implant loss, whereas implant length was not (P value = .01, = .34, respectively; univariate generalized estimating equation [GEE] logistic regression). Regarding implant diameter, significantly more loss was noted for 5.00-mm implants when compared with the 4.00-mm or 4.75-mm implants. Failure related to location revealed that the maxilla compared with the mandible, posterior jaws compared with anterior jaws, and the posterior maxilla compared with all other oral locations were associated with more late failures (Table 1). Assessment of systemic factors revealed radiotherapy to be related to more late implant loss (P = .003). Neither systemic disease nor smoking exposure was associated with late failure. The authors concluded that late implant failure was influenced by the local factor "implant location" and the systemic factor "radiotherapy." Neither smoking nor systemic health factors were found to adversely influence implant integration from abutment connection through 2 years' performance. Comparison of five parameters as risk factors for peri-mucositis.
Karbach J, Callaway A, Kwon YD, d'Hoedt B, Al-Nawas B. Int J Oral Maxillofac Implants. 2009 May-Jun;24(3):491-6. The aim of this study was to identify risk factors for the development of clinical signs of peri-implant mucositis and for the presence of periodontal pathogens and to determine a possible correlation between these clinical signs and the presence of periodontal pathogens. In 100 patients, a modified Plaque Index (PI), a modified Sulcular Bleeding Index (BOP), and pocket probing depth (PPD) were recorded. Patients with one implant site that scored positive for PI, BOP, and PPD greater than or equal to 5 mm were considered to have peri-implant mucositis. A sample taken at the implant with the deepest pocket was analyzed for periodontal pathogens. Implant surface roughness, smoking, augmentation at the implant site, type of dentition, and radiation therapy were recorded as possible cofactors in the disease process. Thirty-one patients showed clinical signs of peri-implant mucositis and, in 25 implant sites, periodontal pathogens were found. Smoking showed a statistically significant correlation with clinical signs of peri-implant mucositis (univariate analysis). For periodontal pathogens at the implant site, the type of dentition was statistically significant. In the multivariate analysis of the clinical signs of peri-implant mucositis, smoking and radiation therapy were significant explanatory variables. Seventy-two percent of the patients showed agreement for finding either clinical signs of peri-implant mucositis and periodontal pathogens or for no clinical signs and no pathogens. The sensitivity for diagnosis of peri-implant mucositis was 45%, and the specificity was 84%. Smoking was the most important risk factor in the formation of peri-implant mucositis. Radiation therapy was an explanatory variable for the occurrence of inflammation. Implant surface roughness, augmentation at the implant site, and type of dentition had little influence on clinical signs of peri-implant mucositis. The type of dentition influences the periodontal microbiota at the implant site. Head and neck cancer, dental implants, and dental oncology.
Dent Implantol Update. 2011 Jan;22(1):1-8. Abstract
Head and neck cancer is a real presence in the dental-implant world--patients who undergo surgery, chemotherapy, and/or radiation often seek the assistance of dental-implant practitioners to restore them to better function; other patients who have had implants in place for years will return with questions regarding how their treatment will be affected by the presence of their dental implant. As oral-cancer treatment modalities are rapidly changing, practitioners struggle to keep up with the literature surrounding this important subset of the dental-implant population. This month, we look at the numbers of patients suffering from oral cancers, consider the different treatment options for patients with oral cancers, and investigate the role that implants play in improving therapeutic outcomes or changing treatment course. Rehabilitation with dental implants of oral cancer patients.
Werkmeister R, Szulczewski D, Walteros-Benz P, Joos U. J Craniomaxillofac Surg. 1999 Feb;27(1):38-41. Abstract
The aim of this study was to evaluate the risks and complications of rehabilitation with dental implants after tumour surgery and radiotherapy. After a disease-free survival of 18 months, 29 patients who had undergone oral cancer treatment were rehabilitated with dental implants. The complication rate of implants in irradiated, non-irradiated and grafted bone was analyzed at least 3 years after implant placement. In the healing period, 28.6% of the implants in irradiated bone and 8.4% in non-irradiated bone showed soft tissue complications. Of the implants, 26.7% in the irradiated and 14.7% in the non-irradiated mandibular bone were lost in the first 36 months after placement. Thirty-one point two percent of implants inserted in non-irradiated bone grafts were affected and did not osseointegrate. Of 109 inserted implants, 70 were suitable for prosthetic rehabilitation. There are high complication rates after implant placement in oral cancer patients. Irradiation adversely affects soft tissue healing. Osseointegration is frequently disturbed, especially when implants were placed in non-vascularized bone grafts. Implant survival in mandibles of irradiated oral cancer patients.
Yerit KC, Posch M, Seemann M, Hainich S, Dörtbudak O, Turhani D, Ozyuvaci H, Watzinger F, Ewers R. Clin Oral Implants Res. 2006 Jun;17(3):337-44. The aim of this study was to analyze long-term implant survival in the mandible after radiotherapy and radical surgery in oral cancer patients. Between 1990 and 2003, 71 patients (15 females, 56 males; average age 57.8 years, range 16-84.1 years) were treated with dental implants after radiochemotherapy and ablative surgery of oral cancer. Radiation therapy was delivered in daily fractions of 2 Gy given on 25 days (total dose of 50 Gy). Oral defects were reconstructed microsurgically with jejunal, iliac crest or radial forearm grafts. Thereafter 316 dental implants were placed in the non-irradiated residual bone (84; 27%), irradiated residual bone (154; 49%) or grafted bone (78; 25%) at various intervals (mean interval 1.41 (+/- 1.01) years, range 0.34-6.35 years). The mean follow-up time after implant insertion was 5.42 (+/- 3.21) years (range 0.3-13.61 years). The overall 2-, 3-, 5-, and 8-year survival rates of all implants were 95%, 94%, 91% and 75%. Forty-four implants were lost in 21 patients during the observation period. Irradiation of the mandibular bone showed significantly (P = 0.0028) lower implant survival compared with non-irradiated mandibular bone. The 8-year survival rate in the non-irradiated residual bone (two loss), irradiated residual bone (29 loss) or grafted bone (13 loss) were 95%, 72% and 54%, respectively. Time of implantation after irradiation showed no statistically significant influence. Implant brand, length or diameter or the incidence of resective surgery on the mandible and gender of patients had no statistically significant influence on implant survival. Radiation therapy with 50 Gy was significantly related to shorter implant survival in mandibular bone. Survival was lowest in grafted bone. Time of implant placement had no statistically significant influence on survival under the conditions of this study. Although implant survival is lower in irradiated mandibles, implants significantly facilitate prosthodontic treatment and enhance outcome of oral rehabilitation in cancer patients. Oral rehabilitation with dental implants after cancer treatment.
Aust Dent J. 2011 Jun;56(2):160-5. doi: 10.1111/j.1834-7819.2011.01318.x. Abstract
Background: Patients who undergo surgical management of oral cancer may greatly benefit from an implant-supported prosthesis. This study reports on the clinical experience of dental implant placement in patients following resection of oral cancer over a 15-year period. Controversies including the use of dental implants in irradiated tissues, and hyperbaric oxygen treatment will also be discussed. Methods: Thirty-one patients who had dental implants placed as part of their oral rehabilitation between 1992 and 2007 were investigated. Demographic data and factors including implant survival, type of prosthesis provided, radiotherapy and the hyperbaric oxygen therapy were analysed. Results: In this retrospective study, there was a retention rate of 110 implants from a total of 115 implants placed. A high rate of implant retention was found, with 5 implant failures from a total of 115 implants placed. The 5 failed implants occurred in free flap bone that had been irradiated. Conclusions: Dental implants provide an important role in the oral rehabilitation of oral cancer patients. There may be an increased risk of implant failure in free flap bone that has been irradiated. Interventions for replacing missing teeth: hyperbaric oxygen therapy for
irradiated patients who require dental implants.
Esposito M, Grusovin MG, Patel S, Worthington HV, Coulthard P. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD003603. Abstract
Dental implants offer one way to replace missing teeth. Patients who have undergone radiotherapy and those that have also undergone surgery for cancer in the head and neck region may benefit particularly from reconstruction with implants. Hyperbaric oxygen therapy (HBO) has been advocated to improve the success of implant treatment in patients who have undergone radiotherapy but this remains a controversial issue. To compare success, morbidity, patient satisfaction and cost effectiveness of dental implant treatment carried out with and without HBO in irradiated patients. We searched the Cochrane Oral Health Group's Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Handsearching included several dental journals. We checked the bibliographies of relevant clinical trials and review articles for studies outside the handsearched journals. We wrote to authors of the identified randomised controlled trials (RCTs), to more than 55 oral implant manufacturers; we used personal contacts and we asked on an internet discussion group in an attempt to identify unpublished or ongoing RCTs. No language restriction was applied. The last electronic search was conducted on 13 June 2007. Randomised controlled trials of HBO therapy for irradiated patients requiring dental implants. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Only one RCT was identified and included. Thirteen patients received HBO therapy while other 13 did not. Two to six implants were placed in fully edentulous mandibles to be rehabilitated with bar-retained overdentures. One year after implant loading four patients died from each group. One patient, treated with HBO, developed an osteoradionecrosis and lost all implants so the prosthesis could not be provided. Five patients in the HBO group had at least one implant failure versus two in the control group. There were no statistically significant differences for prosthesis and implant failures, postoperative complications and patient satisfaction between the two groups. Despite the limited amount of clinical research available, it appears that HBO therapy in irradiated patients requiring dental implants may not offer any appreciable clinical benefits. There is a definite need for more RCTs to ascertain the effectiveness of HBO in irradiated patients requiring dental implants. These trials ought to be of a high quality and reported as recommended by the CONSORT statement (http://www.consort-statement.org/). Each clinical centre may have limited numbers of patients and it is likely that trials will need to be multicentred. Survival analysis and clinical evaluation of implant-retained prostheses in oral
cancer resection patients over a mean follow-up period of 10 years.
Abstract
Dental implants have been increasingly used for prosthodontic rehabilitation of patients following oral tumor resection and postsurgical radiotherapy. However, only a few long-term studies have examined the implant survival rate and other factors related to prosthodontic treatment in oral tumor resection patients. The purpose of this study was to evaluate the long-term survival of dental implants and implant-retained prostheses in oral cancer resection patients. Ninety-three patients (63 men, 30 women) with a mean age of 59 years (range of 26-89 years) received 435 implants after the resection of a head and neck tumor. Twenty-nine patients received postsurgical radiotherapy prior to implant placement. The factors related to implant survival or failure were monitored over a mean observation period of 10.3 years (range of 5 to 161 months). Prosthodontic rehabilitation was evaluated with respect to the rates of technical failures and complications. Data were analyzed using a Kaplan-Meier curve and comparisons were made with the log-rank test or the Wilcoxon test (a=.05). Of the 435 implants, 43 implants were lost; the cumulative survival rate was 92%, 84%, and 69% after 3.5, 8.5, and 13 years, respectively. Twenty-eight implants in 6 patients were counted as lost since the patients had died. Twenty-nine irradiated patients received 124 implants, of which 6 implants were lost prior to prosthodontic rehabilitation. In 68 patients with 78 rigid bar-retained dentures, only minor technical complications were identified. However, all 25 fixed implant-supported restorations had no technical component failures and did not require technical maintenance. This study demonstrates that implant-retained and -supported prostheses in oral cancer resection patients, irrespective of the cancer treatment procedure, show lower long-term survival rates than those in patients without prior cancer surgery. Rigid fixation of the implant-supported prosthesis appears to minimize the complication rates. The poor implant survival rate was due to the higher mortality rate among these patients, and not to a lack of osseointegration. Life table analysis and clinical evaluation of oral implants supporting prostheses after
resection of malignant tumors.
Int J Oral Maxillofac Implants. 1999 Sep-Oct;14(5):673-80. Seventeen mostly elderly patients, 13 men and 4 women, were consecutively admitted for implant-prosthodontic treatment after they had undergone resection of malignant tumors in the oral cavity. A total of 53 dental implants (ITI-Straumann) was placed, 12 in the maxilla, 41 in the mandible. The prosthetic rehabilitation consisted of overdenture therapy in 15 patients, and 2 patients were treated with fixed partial prostheses. Thirty-three implants were prescribed for patients who received radiotherapy either before or after implant placement. The average dose varied between 50 and 74 Gy. Eighteen implants were located in grafted bone from the fibula, scapula, or hip. For 2 patients, hyperbaric oxygen therapy was also prescribed after osteoradionecrosis had developed. One implant was lost before prosthetic loading. During an observation period of up to 7 years after loading, 3 more implants were removed. All implant losses occurred in the mandibles of patients who had received radiotherapy. A life table analysis was performed, and the cumulative survival rates, calculated for 2, 3, and 5 years, were 93%, 90%, and 90% respectively. No failures or complications were observed with technical components of the implants or prostheses. All prostheses could be maintained during the entire observation time. Although in the present investigation the survival rate of implants was slightly lower than under standard conditions, the treatment with implant-supported prostheses seemed to be advantageous for patients who had undergone intraoral resections. Kaufunktion und orofaziale Rehabilitation nach Tumor-therapeutischerKopf-
Hals-Bestrahlung
Dtsch Zahnärztl Z. 2001 Apr;56(4):222-39. Zusammenfassung:
Die infizierte Osteoradionekrose (IORN) ist die schwerste lokale Strahlenfolge. Das Ausmaß
der chirurgischen Zahnsanierung vor Bestrahlung legitimiert sich deshalb durch die
Verminderung des IORN-Risikos. Die retrospektive Analyse der IORN zeigte 62%
Infektionsursachen aus dem ZMK-Bereich. Zusätzlich war diese Ursachen-Gruppe bei
periradiotherapeutisch nicht betreuten IORN-Patienten um den Faktor 3 häufiger. Die
Wertigkeit zahnärztlicher Betreuung ist damit bestätigt. Die drei späten Strahlenfolgen
,,Strahlenkaries", ,,Radioxerostomie" und ,,IORN" limitieren Kaufunktion und orofaziale
Rehabilitation erheblich. Aus diesem Grund wurden ätiopathogenetische Faktoren und
Möglichkeiten therapeutischer und rehabilitierender Maßnahmen untersucht. Die konfokale
Laser-Scanning-Mikroskopie (CLSM) zeigte eine Retraktion der Odontoblastenfortsätze, die
als direkt radiogene Läsion an der Schmelz-Dentin-Grenze die typische, den Schmelz
unterminierende Strahlenkaries plausibel zu erklären vermag. Daraus resultiert ein neues
Konzept für die Ätiologie der Strahlenkaries, die als Ergebnis eines synergistischen
Kombinationsschadens direkt radiogener Folgen an der Schmelz-Dentin-Grenze und indirekt
radiogener Schmelzläsion durch die veränderte Mundhöhlenökologie aufzufassen ist. Da die
Pathogenese der radiogenen Sialadenitis weitgehend geklärt ist, wurde in einer
Doppelblindstudie die_Prophylaxe mit Cumarin/Troxerutin überprüft. Es zeigte sich eine
signifikante Verminderung früher Strahlenfolgen an Schleimhäuten und Speicheldrüsen.
Radiogene Knochenveränderungen wurden mit der CLSM bei manifester IORN und nach
unterschiedlichen Bestrahlungsmodi untersucht. Dabei konnte der ,,primäre Osteozytentod"
erstmals für humane Knochenproben bestätigt werden. Das Konzept der kaufunktionellen
Wiederherstellung durch enossale Implantate vermag viele onkochirurgische und
radioonkologische Folgen zu kompensieren. Die Implantatprognose war nach retrospektiver
Analyse (1988--97) günstig und zeigte im Literaturvergleich bessere Überlebenszeiten als
natürliche Zähne. Weitergehende Behandlungen werden sich durch mikromorphologische
und prospektiv klinische Daten aus kausal orientierten Therapien früher Strahlenfolgen an
Speicheldrüsen und Zahn(pulpa) ergeben.
Eine tierexperimentelle Studie zum Einheilverhalten enossaler Implantate im
bestrahlten Knochen
Dtsch Zahnärztl Z. 1993 Aug;48(8):512-4. Zusammenfassung: Die Ergebnisse unserer tierexperimentellen Studie zeigen, daß bereits eingeheilte Implantate trotz tumortherapeutischer Bestrahlung fest im Knochen verbleiben können. Eine Implantation im zeitlichen Umfeld der Bestrahlung sowohl kurz vorher als auch wenige Monate danach erscheint nicht erfolgversprechend. Wir können jedoch nachweisen, daß auch ein im Tiermodell voll ausbestrahlter Knochen nach einer gewissen Zeit, bei unseren Untersuchungen nach 8 Monaten, wieder ausreichend osteogene Potenzen aufweist, um ein Implantat knöchern einzubauen. Klinische Evaluation von Implantaten bei Tumorpatienten
Linsen S, Schmidt-Beer U, Martini M, Koeck B. Dtsch Zahnärztl Z. 2008 May;63(5):306-316. Zusammenfassung:
Ziel dieser Studie war es, den Langzeiterfolg von Implantaten bei Patienten nach operativer
Entfernung von Tumoren im Kiefer-Gesichtsbereich mit und ohne begleitende
Strahlentherapie zu analysieren. Im Zeitraum von 1997 bis 2006 wurden 51 Patienten mit
insgesamt 188 Implantaten versorgt. 30 Implantate wurden im Ober- und 158 Implantate im
Unterkiefer inseriert. 79 Implantate wurden in radiogen belasteten Knochen, 126 Implantate
in ortständigen, 62 Implantate in transplantierten Knochen und 108 Implantate in einer
Region mit Weichgewebstransplantat inseriert. Als prothetische Versorgung wurden 13
festsitzende Brücken und 38 herausnehmbare Konstruktionen (24 steg-, 7 teleskop- und 7
knopfverankert) eingegliedert. Bei 6 Patienten kam es zum Verlust von insgesamt 10
Implantaten. 5 Implantate gingen während der Einheilphase nach Strahlentherapie und vor
der prothetischer Versorgung, die anderen 5 Implantate infolge einer rezidivbedingten
Nachresektion verloren. Während des Beobachtungszeitraumes konnten bei rezidivfreien
Patienten alle belasteten Implantate und prothetischen Versorgungen erhalten werden. Die
kumulative 1-, 5- und 10-Jahres-Erfolgsrate betrug für alle Implantate 98 %, 97 % bzw. 80 %.
Die prothetische Belastung osseointegrierter Implantate scheint bei Patienten nach
operativer Entfernung von Tumoren im Kiefer-Gesichtsbereich mit und ohne begleitende
Strahlentherapie nicht weniger erfolgreich zu sein, als bei gesunden Patienten.

Source: http://www.straumann.de/content/dam/internet/straumann_de/resources/referentenmaterial/Abstraktsammlungen/Abstracts_Medikamente_Implantate%2011.2011.pdf