The medically compromised patient: Are dental implants a feasible option?

In healthy subjects, dental implants have evolved to be a common therapy to solve problems related to stability and retention of dentures as well as to replace failing teeth. Although dental implants are applied in medically compromised patients, it is often not well known whether this therapy is also feasible in these patients, whether the risk of implant failure and developing peri‐implantitis is increased, and what specific preventive measures, if any, have to be taken when applying dental implants in these patients. Generally speaking, as was the conclusion by the leading review of Diz, Scully, and Sanz on placement of dental implants in medically compromised patients (J Dent, 41, 2013, 195), in a few disorders implant survival may be lower, and the risk of a compromised peri‐implant health and its related complications be greater, but the degree of systemic disease control outweighs the nature of the disorder rather than the risk accompanying dental implant treatment. So, as dental implant treatment is accompanied by significant functional benefits and improved oral health‐related quality of life, dental implant therapy is a feasible treatment in almost any medically compromised patient when the required preventive measures are taken and follow‐up care is at a high level.     

Long‐term implant survival and success: a 10–16‐year follow‐up of non‐submerged dental implants

Objectives: The aim of the present study was to evaluate the long‐term results of dental implants using implant survival and implant success as outcome variables. Methods: Of the 76 patients who received 162 implants of the Straumann Dental Implant System during the years 1990–1997, 55 patients with 131 implants were recalled 10–16 years after implant placement for a complete clinical and radiographic examination, followed by a questionnaire that examined the degree of satisfaction. The incidence of biological and technical complications has been carefully analysed for each implant. Success was defined as being free of all these complications over the entire observation period. Associated factors related to peri‐implant lesions were analysed for each implant. Results: The long‐term implant cumulative survival rate up to 16 years was 82.94%. The prevalence of biological complications was 16.94% and the prevalence of technical complications was 31.09%. The cumulative complication rate after an observation period of 10–16 years was 48.03%, which meant that substantial amounts of chair time were necessary following implant placement. The majority of implant losses and biological complications were concentrated in a relatively small number of patients. Conclusion: Despite a relatively high long‐term survival rate, biological and technical complications were frequent. Patients with a history of periodontitis may have lower implant survival rates than patients without a history of periodontitis and were more prone to biological complications such as peri‐implant mucositis and peri‐implantitis. To cite this article :
Simonis P, Dufour T, Tenenbaum H. Long‐term implant survival and success: a 10–16‐year follow‐up of non‐submerged dental implants.
Clin. Oral Impl. Res. 21 , 2010; 772–777
doi: 10.1111/j.1600‐0501.2010.01912.x     

Prosthodontic considerations designed to optimize outcomes for single-tooth implants. A review of the literature

Background: The aim of this study was to review the literature on the restoration of single‐tooth implants, and to develop evidence‐based conclusions to optimize aesthetic, biologic and patient‐related outcomes. Methods: An electronic and hand search was conducted using the search terms ‘dental implants, single‐tooth; dental restoration, temporary; dental impression materials; dental impression technique; dental prosthesis, implant‐supported; dental prosthesis design; dental abutments; dental occlusion; maintenance; survival; and survival analysis’. Resultant titles were screened, and full text was obtained where relevant. The authors selected the most appropriate articles, giving preference to systematic reviews and long‐term, patient‐based outcome data. Results: Thirty‐nine articles were selected and critiqued by the authors. Conclusions: There was strong suggestion by several authors that peri‐implant soft tissue aesthetics can be sculpted through provisional restoration contour, but there are no clinical outcome studies to define or support this claim. Laboratory studies demonstrate that pick‐up type impression copings in conjunction with elastomeric impressions are the most accurate means for transferring implant position to a dental cast. Laboratory and finite‐element analysis studies suggest implants with an internal‐type connection show improved stress distribution, but supportive clinical data are lacking. The authors of this review favour a screw‐retained prosthesis for retrievability. Clinical and histological studies show that gold, titanium and zirconia ceramic abutment materials exhibit excellent biological responses, although there is insufficient data on the clinical service provided by zirconia as an implant‐substructure material. The literature does not associate any particular occlusal scheme with superior clinical outcomes. Implant‐borne single crowns offer comparable clinical service to tooth‐borne fixed dental prostheses. However, single‐tooth implant restorations are associated with an increased incidence of biological and technical complications.     

A study of dental implants in medically treated hypothyroid patients

Purpose: The purpose of this study was to investigate the success outcomes of implants and prosthodontic treatment placed in patients with a previous history of hypothyroidism that was being controlled with medications. Materials and Methods: Twenty‐seven female patients with a medically confirmed history of primary hypothyroid disease who were on replacement medications at the time of implant surgery were selected as the study group. They were matched with 29 control patients by age, gender, location (jaw and zone) of implants, type of prosthesis, and dental status of the opposing arch. Additional factors studied were medical history, medications, smoking habits, and bone quality and quantity. Results: There was no statistical difference in the number of implant failures between the two groups (p =.781). The hypothyroid patients had more soft tissue complications (p =.018) following stage 1 surgery. More bone loss around implants in the hypothyroid patients was recorded after year 1 of loading when compared with loss in their matched controls (p =.017). Conclusions: This study suggests that medically controlled hypothyroid female patients treated with dental implants are not at higher risk of implant failure when compared with matched controls, and that a history of controlled hypothyroidism does not appear to be a contraindication for implant therapy with endosseous implants.     

Multivariate study of factors influencing primary dental implant stability

Objectives: The purpose was to determine by multivariate analysis in a large series of dental implants the variables associated with primary endosseous dental implant stability (DIS). Material and methods: A 10‐year retrospective study was conducted of 1084 Brånemark^® implants placed in 316 patients. Clinical variables (age, gender, smoking habit, and periodontal status), implant diameter, implant length, and Periotest^® values (PTVs) were analyzed in bivariate and multivariate studies in order to determine their influence on DIS, using a cut‐off PTV value of ?2. Results: The site of implant insertion showed the strongest association with primary DIS failure among the study variables. Implants in the anterior mandible had a 6.43‐fold lower risk of primary DIS risk vs. those at other sites [95% confidence interval (CI) 3.28–12.61], and implants in the maxillary had a 2.70‐fold higher risk of primary DIS failure vs. those in the mandible (95% CI 1.82–4). Among other variables, females had a 1.54‐fold higher risk of primary DIS failure vs. males (95% CI 1.88–2.22) and implants <15 mm in length had a 1.49‐fold higher risk of failure vs. longer implants (95% CI 1.09–2.04). Conclusion: According to these findings, primary DIS failure is more likely in females, at sites other than the anterior mandible, and with dental implants shorter than 15 mm, at least when non‐threaded titanium implants are used. These data may be of value in the identification of patients at a high risk of primary DIS failure with immediate implant loading.     

Are Short Dental Implants (<10 mm) Effective? A Meta‐Analysis on Prospective Clinical Trials

Background: This study aims to compare the survival rate of short (<10 mm) and standard (≥10 mm) rough‐surface dental implants under functional loading. Methods: An electronic literature search using PubMed and Medline databases was conducted. Prospective clinical human trials, published in English from January 1997 to July 2011, that examined dental implants of <10 mm with a 12‐month follow‐up were included in this meta‐analysis. The following data were retrieved from the included articles: the number of implants, implant dimensions, implant locations, types of prostheses, follow‐up periods, and implant survival rates. Kaplan‐Meier survival estimates and the hazard rates were analyzed and compared between short and standard implants. Results: Thirteen studies were selected, examining 1,955 dental implants, of which 914 were short implants. Short dental implants had an estimated survival rate of 88.1% at 168 months, when standard dental implants had a similar estimated survival rate of 86.7% (P = 0.254). The peak failure rate of short dental implants was found to occur between 4 and 6 years of function. This occurred at an earlier time point compared with standard dental implants, where the peak failure rate occurred between 6 and 8 years of function. Conclusions: This study shows that in the long term, implants of <10 mm are as predictable as longer implants. However, they fail at an earlier stage compared with standard implants.     

Implant treatment of patients with edentulous jaws: a 20-year follow-up

Background: Implant‐supported prostheses are today often used in rehabilitation of partially or totally edentulous patients. Both patients and the dental profession often regard implant treatment as successful in a life perspective. Therefore, studies with a long‐term follow‐up are important. Purpose: The aim was to investigate the outcome of implant treatment with fixed prostheses in edentulous jaws after 20 years, with special reference to survival rate of implants and prostheses and frequency of peri‐implantitis. Materials and Methods: The patient material was a group of patients treated in the early 1980s. The original patient group comprised the first 48 consecutive patients treated with implant‐supported prostheses at Umeå University. All patients were edentulous in one or two jaws. The patients had a mean age at the implant insertion of 54.3 years (range 40–74). At the planning of this study 20 years after treatment, 19 of the 48 patients were found to be deceased. Of the 29 patients still alive, 21 patients with altogether 23 implant‐supported prostheses could be examined clinically and radiographically. All patients were treated ad modum Brånemark® (Nobel Biocare AB, Göteborg, Sweden) with a two‐stage surgical procedure. The implants had a turned surface. Abutment connections were performed 3 to 4 months after fixture insertion in the mandible, and after a minimum of 6 months in the maxilla. The prostheses were fabricated with a framework of gold alloy and acrylic artificial teeth. Results: The 21 patients (with 23 implant prostheses) examined had at the time of treatment got 123 implants (27 in the upper jaw and 96 in the lower jaw) inserted. Only one of these implants had been lost (about 2 years after loading) giving a survival rate of 99.2%. Very small changes occurred in the marginal bone level. Between the 1 and 20‐year examinations, the mean bone loss was 0.53 mm and the mean bone level at the final examination was 2.33 mm below the reference point. Conclusions: This follow‐up over two decades of implant‐supported prostheses demonstrates a very good prognosis for the treatment performed. The frequencies of peri‐implantitis, implant failures, or other complications were very small, and the original treatment concept with a two‐stage surgery and a turned surface of the implants will obviously give very good results.     

The effect of smoking on osseointegrated dental implants. Part I: implant survival

PURPOSE: Recent studies implicate smoking as a significant factor in the failure of dental implants. The purpose of this long-term retrospective study was to evaluate the survival of Br?nemark endosseous dental implants in relation to cigarette smoking. MATERIALS AND METHODS: The sample consisted of 464 consecutively treated completely and partially edentulous patients who had a total of 1852 implants placed between 1979 and 1999, and who were part of a surgical/prosthodontic prospective treatment outcomes study. The effect of cigarette smoking on implant survival in relation to the time of implant failure, gender, age, surgeon, date and site of implant placement, implant length and diameter, prosthesis design, and occlusal loading considerations was assessed in bivariate and multivariate survival analyses. RESULTS: The overall implant failure rate was 7.72%. Patients who were smokers at the time of implant surgery had a significantly higher implant failure rate (23.08%) than nonsmokers (13.33%). Multivariate survival analysis showed early implant failure to be significantly associated with smoking at the time of stage 1 surgery and late implant failure to be significantly associated with a positive smoking history. Short implants and implant placement in the maxilla were additional independent risk factors for implant failure. CONCLUSION: Cigarette smoking should not be an absolute contraindication for implant therapy; however, patients should be informed that they are at a slightly greater risk of implant failure if they smoke during the initial healing phase following implant insertion or if they have a significant smoking history.     

Dental implant failure rates and associated risk factors

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.     

Dental implants in patients at high risk for infective endocarditis: a preliminary study

The safety of dental implant placement in patients at high risk for infective endocarditis (IE) has never been shown. The outcome of osseointegrated implants in patients with artificial heart valves or with a history of an infected valve is not known. In this article we describe our experience of dental implant placement in patients at high risk for IE. A retrospective study was conducted on patients at high risk for IE who underwent dental implant placement. All the patients received prophylactic antibiotic treatment before the surgical procedure, in accordance with the relevant American Heart Association guidelines. A total 13 patients underwent 16 surgical procedures for the placement of 57 dental implants over a period of 17 years. Within the follow-up period, no case of IE was reported. Two implants failed before exposure in one patient, one patient suffered from mitral valve thrombosis 14 days after the dental procedure, and another patient suffered a stroke 6 months following treatment. Despite the limitation of the small group of patients and the known low incidence of IE, dental implants may be regarded as a legitimate procedure for patients at high risk for IE.     

Fracture of the body of an implant and its management--a case history

The increasing use of endosseous osseointegrated implants to replace natural teeth will inevitably lead to an increase in patients presenting in general dental practice with failing implants. A fractured implant body is not a common cause of failure, however it is a common cause of late failure. There is evidence that careful treatment planning can reduce the incidence of fracture. This paper describes a case demonstrating the management of implant fracture and discussing a possible mechanism for this failure. Some of the previously described factors that have been thought to contribute towards fracture are also discussed.     

Oral rehabilitation with dental implants after cancer treatment

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.     

Proton Pump Inhibitors and the Risk of Osseointegrated Dental Implant Failure: A Cohort Study

Proton pump inhibitors (PPIs) have a negative impact on bone accrual. Because osseointegration is influenced by bone metabolism, this study investigates the association between PPIs and the risk of osseointegrated implant failure. This retrospective cohort study included a total of 1,773 osseointegrated dental implants in 799 patients (133 implants in 58 PPIs users and 1,640 in 741 non‐users) who were treated at the East Coast Oral Surgery Clinic in Moncton, Canada, from January 2007 to September 2015. Kaplan‐Meier estimator was used to describe the hazard function of dental implant failure by PPIs usage. Multilevel mixed effects parametric survival analyses were used to test the association between PPIs exposure and risk of implant failure adjusting for potential confounders. The failure rates were 6.8% for people using PPIs compared to 3.2% for non‐users. Subjects using PPIs had a higher risk of dental implant failure (HR = 2.73; 95% CI = 1.10–6.78) compared to those who did not use the drugs. The findings suggest that treatment with PPIs may be associated with an increased risk of osseointegrated dental implant failure.     

Risk of Implant Failure and Marginal Bone Loss in Subjects with a History of Periodontitis: A Systematic Review and Meta‐Analysis

Background: A number of studies have suggested that implant failure and associated bone loss is greater in subjects with a history of periodontitis. Purpose: To evaluate the risk for marginal bone loss around implants and implant failure in subjects with a history of periodontitis compared with periodontally healthy subjects in studies with a minimum 3‐year follow‐up. Materials and Methods: Data sources: The MEDLINE, EMBASE, and PubMed databases and relevant journals were searched up to July 1, 2008, with restriction to English language. Review Methods: Prospective and retrospective longitudinal observational clinical studies comparing periodontal/peri‐implant variables among subjects with periodontitis and subjects who were periodontally healthy were included. Screening of studies, quality assessment, and data extraction were conducted independently and in duplicate. Clarification of missing and unclear information was not sought. Outcome measures were: implant survival/failure, peri‐implant parameters, changes in radiographic marginal bone level, probing pocket depth, and gingival index. Results: Seventeen potential studies were identified and six studies were accepted comparing patients with periodontitis and periodontally healthy patients treated with implants. Five studies were eligible for meta‐analysis of implant survival and four studies were eligible for meta‐analysis of bone loss around implants. The odds ratio for implant survival was significantly in favor of periodontally healthy patients (3.02, 95% confidence intervals 1.12–8.15). A random effects model showed more marginal bone loss in periodontitis subjects compared with periodontally healthy subjects (standard mean difference 0.61, 95% confidence interval 0.14–1.09). Conclusions: Within the limitations of the heterogenous studies available, a moderate level of evidence indicates that periodontitis subjects were at significantly higher risk for implant failure and greater marginal bone loss as compared with periodontally healthy subjects. Prospective observational studies with subject‐based designs are recommended.     

Peri‐implant squamous cell carcinoma

Peri‐implant squamous cell carcinoma is an uncommon pathological manifestation, whereas peri‐implantitis is commonly found in association with dental implants. Both present similarly with loss of supporting soft and hard tissue around dental implants; therefore, a careful differential diagnosis is required. The present case concerns a 62‐year‐old Japanese man who had a dental implant which had been in the left maxillary incisor region for 4 years who apparently developed peri‐implantitis. This did not respond to localized therapy and antibiotics so was referred for specialist surgical management. A biopsy confirmed it to be a squamous cell carcinoma rather than an inflammatory lesion. A literature review shows that this is an unusual presentation without a previous history of malignancy, mucosal disease or risk factors for cancers. Although rare, the possibility of peri‐implant squamous cell carcinoma should be borne in mind by all practitioners who monitor implant patients.     

Crestal Bone Changes at Teeth and Implants in Periodontally Healthy and Periodontally Compromised Patients. A 10‐Year Comparative Case‐Series Study

Background: Limited data exist on the longitudinal crestal bone changes around teeth compared with implants in partially edentulous patients. This study sought to compare the 10‐year radiographic crestal bone changes (bone level [BL]) around teeth and implants in periodontally compromised (PCPs) and periodontally healthy (PHPs) patients. Methods: A total of 120 patients were evaluated for the radiographic crestal BL around dental implants and adjacent teeth at time of implant crown insertion and at the 10‐year follow‐up. Sixty patients had a previous history of periodontitis (PCPs), and the remaining 60 were PHPs. In each category (PCP and PHP), two different implant systems were used. The mean BL change at the implant and at the adjacent tooth at the interproximal area was calculated by subtracting the radiographic crestal BL at the time of crown cementation from the radiographic crestal BL at the 10‐year follow‐up. Results: At 10 years after therapy, the survival rate ranged from 80% to 95% for subgroups for implants, whereas it was 100% for the adjacent teeth. In all eight different patient categories evaluated, teeth demonstrated a significantly more stable radiographic BL compared with adjacent dental implants (teeth BL, 0.44 ± 0.23 mm; implant BL, 2.28 ± 0.72 mm; P <0.05). Radiographic BL changes around teeth seemed not to be influenced by the presence or absence of advanced bone loss (≥3 mm) at the adjacent implants. Conclusions: Natural teeth yielded better long‐term results with respect to survival rate and marginal BL changes compared with dental implants. Moreover, these findings also extend to teeth with an initial reduced periodontal attachment level, provided adequate periodontal treatment and maintenance are performed. As a consequence, the decision of tooth extraction attributable to periodontal reasons in favor of a dental implant should be carefully considered in partially edentulous patients.     

Factors associated with dental implant survival: a 4-year retrospective analysis

Background: Dental implants are a predictable treatment option for replacing missing teeth and have strong survival and success outcomes. However, previous research showed a wide array of potential risk factors that may have contributed to dental implant failures. The objectives of this study are to study if implant survival rates were affected by known risk factors and risk indicators that may have contributed to implant failures. The secondary outcome measures were whether the level of expertise of the periodontal residents affected success rates and how the rate of implant success at the Harvard School of Dental Medicine (HSDM) compared to published standards. Methods: A retrospective chart review of patients at the HSDM who had one of two types of rough‐surface implants (group A or B) placed by periodontology residents from 2003 to 2006 was performed. Demographic, health, and implant data were collected and analyzed by multimodel analyses to determine failure rates and any factors that may have increased the likelihood of an implant failure. Results: The study cohort included 341 dental implants. The odds ratio for an implant failure was most clearly elevated for diabetes (2.59 implant surface group B (7.84), and male groups (4.01). There was no significant difference regarding the resident experience. The success rate for HSDM periodontology residents was 96.48% during the 4‐year study period. Conclusions: This study demonstrates that implant success rates at HSDM fell within accepted published standards, confirmed previously identified risk factors for a failure, and potentially suggested that other acknowledged risk factors could be controlled for. Furthermore, the level of experience of the periodontology resident did not have an impact on survival outcomes.     

Long‐Term Outcomes of Immediate Implant Placement Into Infected Sockets in Association With Immediate Loading: A Retrospective Cohort Study

Background: There is a paucity of studies examining long‐term outcomes of immediate loading of dental implants immediately placed into infected sites. This study aims to evaluate long‐term outcomes of immediate loading of postextraction implants placed in infected sites. Methods: Patients were selected if they had postextraction implants in the anterior maxilla that were inserted in the period from December 2006 to June 2015 and immediately loaded. Information collected about patients included: 1) demographic data; 2) implant details; 3) soft tissue stability; and 4) prosthodontics data. Marginal bone loss (BL) and implant and prosthesis survival rates were calculated. Results: Thirty patients (mean age: 56 years) had 43 implants immediately inserted into infected sites and immediately loaded. Implants were inserted at torque ≥35 Ncm. Mean follow‐up time was 6 years (range: 1 to 8 years), and 65% of implants had a follow‐up time >5 years. No implant failure occurred, and implant success rate was 93%. Proximal BL was 1.42 mm (range: 0.21 to 5.61 mm). Three prosthetic complications (all fracture of veneer material) occurred. Conclusions: Immediate loading of implants inserted into fresh and infected extraction sockets is not a risk factor for implant survival. However, stability of peri‐implant soft and hard tissues indicates the need to take measures that minimize loss.     

Reasons for failures of oral implants

This study reviews the literature regarding the factors contributing to failures of dental implants. An electronic search was undertaken including papers from 2004 onwards. The titles and abstracts from these results were read to identify studies within the selection criteria. All reference lists of the selected studies were then hand‐searched, this time without time restrictions. A narrative review discussed some findings from the first two parts where separate data from non‐comparative studies may have indicated conclusions different from those possible to draw in the systematic analysis. It may be suggested that the following situations are correlated to increase the implant failure rate: a low insertion torque of implants that are planned to be immediately or early loaded, inexperienced surgeons inserting the implants, implant insertion in the maxilla, implant insertion in the posterior region of the jaws, implants in heavy smokers, implant insertion in bone qualities type III and IV, implant insertion in places with small bone volumes, use of shorter length implants, greater number of implants placed per patient, lack of initial implant stability, use of cylindrical (non‐threaded) implants and prosthetic rehabilitation with implant‐supported overdentures. Moreover, it may be suggested that the following situations may be correlated with an increase in the implant failure rate: use of the non‐submerged technique, immediate loading, implant insertion in fresh extraction sockets, smaller diameter implants. Some recently published studies suggest that modern, moderately rough implants may present with similar results irrespective if placed in maxillas, in smoking patients or using only short implants.