Factors affecting the survival of implants placed in grafted maxillary sinuses: a clinical report

Many factors affect the survival rate of osseointegrated implants placed in grafted maxillary sinuses. This clinical report describes the retrospective evaluation of 60 patients with 228 implants placed in 84 grafted maxillary sinuses at the Loma Linda University School of Dentistry. The factors used to determine the survival rates of these implants were implant type, simultaneous/delayed implant placement, pretreatment bone height, oral hygiene, and cigarette smoking habits. Out of the total 228 implants, 205 (89.9%) remained in function after a mean follow-up period of 41.6 months (range 0 to 60 months). A higher failure rate was associated with the use of non-threaded implants, poor oral hygiene, and smoking. This information may facilitate treatment planning and enhance communication between the dentist and patient regarding the risk/benefit ratio and outcomes of implants placed in grafted maxillary sinuses.     

Effects of smoking on the outcome of implant treatment: a literature review.

STATEMENT OF PROBLEM: The use of osseointegrated implants as a foundation for the prosthetic replacement of missing teeth has become widespread in the last decade. Owing to the remarkable success of dental implants, there has been growing interest in identifying the factors associated with implant failure. Given the well-documented deleterious effect of smoking on wound healing after tooth extraction and its association with poor quality bone and periodontal disease, a negative effect of tobacco use on implant success is to be expected. PURPOSE: To establish the relationship between smoking and implant-related surgical procedures (i.e, sinus lift procedures, bone grafts and dental implants), including the incidence of complications related to these procedures and the long-term survival and success rates of dental implants among smokers and nonsmokers based on relevant literature.MATERIALS AND METHODS: Relevant clinical studies published in English between 1990 and 2006 were reviewed. The articles were located through Medline and, manually, through the references of peer-reviewed literature. This was supplemented with a hand search of selected dental journals and text books.RESULTS: The majority of the past and current literature implicates smoking as one of the prominent risk factors affecting the success rate of dental implants with only a handful of studies failing to establish a connection. Most of the studies report the failure rate of implants in smokers as being more than twice that in nonsmokers. These findings are difficult to ignore. There is a statistically significant difference between smokers and nonsmokers in the failure rates of dental implants. Smoking also has a strong influence on the complication rates of implants: it causes significantly more marginal bone loss after implant placement, it increases the incidence of peri-implantitis and affects the success rates of bone grafts. The failure rate of implants placed in grafted maxillary sinuses of smokers is again more than twice that seen in nonsmokers.Conclusion: Smokers have higher failure rates and complications following dental implantation and implant-related surgical procedures. The failure rate of implants placed in grafted maxillary sinuses of smokers is more than twice that seen in nonsmokers.     

The effect of cigarette smoking and native bone height on dental implants placed immediately in sinuses grafted by hydraulic condensation

The purpose of this study was to determine the effect of cigarette smoking and residual native bone height on the survival of dental implants placed immediately in grafted sinuses. In this retrospective study, 334 subject records were screened, and 75 subjects (155 implants) were included. Data collection based on treatment notes and radiographs included age, sex, smoking status, sinus floor bone height, dental implant information, and implant survival. The survival rates of implants for nonsmokers and smokers at stage-two surgery were 93% and 84%, respectively. After 12 months of functional loading, the survival rates of implants for nonsmokers and smokers were 87% (81 of 93) and 79% (49 of 62), respectively (P < .000). Analysis revealed that the effect of smoking on implant survival is significant when the preoperative bone height is less than 4 mm, with an 82.4% implant survival rate in nonsmokers compared to 60% in smokers (P < .05). Smoking should be considered as a high risk factor when implants are placed immediately in grafted sinuses, particularly in areas of limited bone height.     

Healing in smokers versus nonsmokers: survival rates for sinus floor augmentation with simultaneous implant placement

PURPOSE: Evidence suggests that smoking is detrimental to the survival of dental implants placed in grafted maxillary sinuses. Studies have shown that improving bone quantity and quality, using rough-surfaced implants, and practicing good oral hygiene may improve outcomes. In this prospective study, the long-term survival rates of implants placed simultaneously with sinus grafting in smokers and nonsmokers were compared. MATERIALS AND METHODS: Implants with roughened surfaces were immediately placed into maxillary sinus grafts in patients with 1 to 7 mm of residual bone. A total of 2132 simultaneous implants were placed into the grafted sinuses of 226 smokers (627 implants) and 505 nonsmokers (1505 implants). A majority of the patients received a composite graft consisting of 50% autogenous bone. In both smokers and nonsmokers, approximately two thirds of the implants had microtextured surfaces; the remainder had hydroxyapatite-coated surfaces. The implants were restored and monitored during clinical follow-up for up to 9 years. RESULTS: Cumulative survival of implants at 9 years was 97.9%. There were no statistically significant differences in implant failure rates between smokers and nonsmokers. DISCUSSION: Implant survival was believed to depend on the following aspects of the technique used: creation of a large buccal window to allow access to a large recipient site; use of composite grafts consisting of at least 50% autogenous bone; meticulous bone condensation; placement of long implants (i.e., 15 mm); use of implants with hydroxyapatite-coated or microtextured surfaces; use of a membrane to cover the graft and implants; antibiotic use and strict oral hygiene; use of interim implants and restricted use of dentures; and adherence to a smoking cessation protocol.     

Private practice results of screw-type tapered implants: survival and evaluation of risk factors

PURPOSE: The aims of this study were to examine the long-term survival and the prosthetic treatment outcome of screw-type, tapered implants placed in a private practice setting and to explore potential risk factors of implant failures. MATERIALS AND METHODS: In this retrospective analysis of patients treated with endosseous screw-type tapered implants, data relative to implant placement and failure, implant length, location, prosthetic treatment, medical history, smoking habits, and oral health behavior were gathered by chart review and questionnaire. An oral examination was also conducted. Cumulative survival rates were estimated through Kaplan-Meier methods. Comparisons between subgroups of patients were made using the log-rank statistical test. The association between several factors and implant failures was analyzed using Cox regression analyses (random and dependent models). Differences were considered significant when P < .05. RESULTS: The survival rate of 663 implants placed in 159 patients (65 men, 94 women; 80.7% of 197 eligible patients) was 91.8% after 120 months. Mandibular implants had a higher survival rate than maxillary implants (96% versus 89%, P = .011). The failure rates for implants were 15.0% among current smokers, 9.6% among former smokers, and 3.6% among nonsmokers. The differences between nonsmokers, former smokers, and current smokers were significant (nonsmokers versus former smokers: P = .036, nonsmokers versus current smokers: P < .001, former smokers versus current smokers: P = .003). Only number of years of smoking was significantly associated with an increased risk of implant failures (P = .036 using dependent estimation; P = .004 using independent estimation). The HR increased to 6.6 for patients who had smoked for 45 years. Loosening of prosthetic components were rare (n=12). No fractures of screws or implants were found. DISCUSSION: Higher failure rates for former smokers and a dose-response effect between duration of smoking and implant failure rates suggested that permanent tissue damage from smoking may occur in addition to immediate local and systemic effects. The frequency of prosthetic complications was comparable to other studies. CONCLUSIONS: Screw-type tapered implants placed in a private dental office demonstrated a cumulative survival rate of 91.8%. The relative risk of implant failure increased with the duration of smoking.     

A 1- to 12-year clinical evaluation of 106 endosseous implants supporting fixed and removable prostheses

The purpose of this article is to report on the long-term clinical evaluation of patients treated with dental implants. A total of 106 implants were placed in 34 patients and restored with fixed partial dentures and overdentures. The 12-year cumulative implant survival and success rates were 95.2% and 90.2%, respectively. Probing depths around mandibular implants were significantly lower than those around maxillary implants (P < .05). The cumulative implant success rate in nonsmokers was 97.7%, but this dropped to 75.81% in smokers. Also, patients rehabilitated with implant-supported overdentures had more peri-implant tissue inflammation than patients with fixed prostheses.     

The effect of smoking on achieving osseointegration of surface-modified implants: a clinical report

PURPOSE: The present study evaluated the effect of smoking on achieving initial osseointegration when surface-modified dental implants were used. MATERIALS AND METHODS: During an 18-month period in a private practice setting 1,183 implants were placed in 461 patients. The group of smokers consisted of patients who smoked a half pack or more of cigarettes per day. RESULTS: The overall success rate for smokers and non-smokers in achieving osseointegration was 98.1%. Ninety-seven percent of the implants placed in smokers osseointegrated successfully, and 98.4% of implants placed in non-smokers osseointegrated successfully (P < .05). DISCUSSION: The surface of an implant may be a critical determinant for achieving osseointegration in patients who smoke. CONCLUSION: It appears from this short-term retrospective study that smoking does not play a significant role in achieving the osseointegration of surface-modified dental implants.     

Osseointegrated oral implants. A Swedish multicenter study of 8139 consecutively inserted Nobelpharma implants

Fourteen Swedish teams outside the University of Gothenburg, each with minimally three years' experience in the Nobelpharma osseointegrated implant participated in a retrospective multiclinic study. The total number of consecutively inserted implants at the 14 clinics was 8139. The outcome of every implant was reported and all implant failures, irrespective of when they occurred, were published. The success criteria included absence of implant mobility, absence of radiolucent zones on x-rays, and an annual bone loss after the first year of less than 0.2 mm. In the mandible 334 implants were followed for five to eight years, with only three failures, for a success rate of 99.1%. In the maxilla 106 implants were followed for five to seven years, with a success rate of 84.9%. In irradiated and grafted mandibles, 56 implants were inserted and none was lost during a follow-up of up to five years. In the irradiated maxilla there were 16 implants inserted with three reported failures and in the grafted upper jaw 71 implants were inserted with 12 failures. The proportions of mandibular and maxillary sleeping implants were 0.8 and 0.3%, of patient drop-out implants 0.3 and 0.6%, and of patient death implants 0.9 and 1.2%, respectively. It was concluded that the osseointegrated implant, if inserted according to the guidelines of Br?nemark, results in a very high degree of clinical success, thereby meeting any published oral implant success criteria.     

Impact of smoking on marginal bone loss

PURPOSE: To compare marginal implant bone loss (MBL), survival, and radiographic evidence of success of dental implants among smokers and nonsmokers. MATERIALS AND METHODS: Consecutive records of 161 patients (aged 23 to 89 years, mean 57 years) treated with a total of 646 implants between the years 1995 and 1998 were examined. Patients were divided into 3 groups: nonsmokers, moderate smokers, and heavy smokers. Tobacco exposure was calculated by cigarettes per day and by pack-years. Follow-up ranged from 1 to 7 years (mean 3.8 years). Postoperative panoramic radiographs obtained before implant exposure and annually thereafter were analyzed for MBL changes. The influence of smoking and other variables on MBL was analyzed at all implant sites. RESULTS: Generally, smokers had more MBL than nonsmokers (0.153 +/- 0.092 mm and 0.047 +/- 0.048 mm, respectively; P < .001). When each jaw was examined separately, smoking had a greater effect on MBL in the maxilla than in the mandible (0.158 +/- 0.171 mm versus 0.146 +/- 0.158 mm, respectively; P < .001). Furthermore, in the maxilla, heavy smokers had the greatest amount of MBL (0.1897 +/- 0.1825 mm), followed by moderate smokers (0.123 +/- 0.156 mm) and nonsmokers (0.0460 +/- 0.070 mm) (P < .001). In the mandible, there was no distinction between heavy and moderate smokers, and both had greater MBL than nonsmokers (P < .001). Only 3 of the 646 implants failed; the cumulative survival rate was 99.5%. Overall radiographic success rate was 93.2%. Nonsmokers had a higher radiographic success rate (97.1%) than smokers (87.8%) (P < .001). CONCLUSIONS: This study demonstrated a relationship between MBL and smoking habits. A higher incidence of MBL was found in the smoking group, and this was more pronounced in the maxilla.     

A 3- to 6-year study of overdentures supported by hydroxyapatite-coated endosseous dental implants

PURPOSE: The purpose of this study was to evaluate the clinical effectiveness of hydroxyapatite-coated cylindrical implants to support overdentures. These implants were placed between 1990 and 1994 and have been followed up over a period of 3 to 6 years. MATERIALS AND METHODS: One hundred thirty-nine Calcitek dental implants were placed in 43 patients to support 14 maxillary and 30 mandibular overdentures. Standardized clinical review procedures were used. RESULTS: At exposure all the implants were found to be osseointegrated. To date only 7 implants (5%) have completely failed and two associated overdentures (5%) have been lost. The cumulative survival rate of all implants over 6 years was 92%. However, if failure is defined by the loss of more than 4 mm of cervical bone, 33 implants could be classified as being in the process of failing. Using these figures, interval success rates as low as 82% were found by year 6, and the cumulative success rate would fall to 39%. Maxillary survival and success rates were significantly lower than mandibular rates, at 38% and 10%, respectively, by year 5. CONCLUSION: Failure rates were higher in the maxillary arch, in poor quality bone, in smokers, and where implants were opposed by a natural dentition or an implant-supported prosthesis. The results suggest that the cervical bone level adjacent to the Calcitek cylindrical hydroxyapatite-coated implant failed to establish a steady state, particularly in the maxillary arch. Doubts remain regarding the long-term prognosis of these cylindrical implants.     

自体胫骨骨松质移植提升上颌窦与骨内牙种植

本文通过8例自体胫骨骨松质移植提升上颌窦的成功．认为上颌窦底自体胫骨骨松质移植对于解决上颌后区牙槽嵴萎缩、上颌窭与牙槽嵴接近而又需要进行骨内种植牙的病人提供了一种良好的方法。胫骨近中外上髁作为供骨区有明显的优点，可以获得质量高、数量较多的骨质．骨面与皮肤接近．创口小，并发症少。     

Long-term evaluation of implant survival in augmented sinuses: a case series

This study compared bone grafting regimens and different implant surfaces used for sinus augmentation and presented long-term implant success rates in augmented sinuses. Two hundred fifty-seven consecutive patients with 625 implants were evaluated retrospectively. In phase 1, 188 sinuses were grafted with (1) autograft alone; (2) autograft + demineralized freeze-dried bone allograft (DFDBA) + absorbable hydroxyapatite (AHA) in a ratio of approximately 1:3:3; or (3) DFDBA + AHA + nonabsorbable HA (NHA) in a ratio of approximately 1:1:1. In phase 2, grafting regimen 3 (combination of DFDBA + AHA + NHA) was used in another 69 patients. Data were analyzed based on bone grafting regimen, implant surface texture, and time of implant placement (immediate or delayed). In phase 1, graft type 3 had the lowest implant failure rate (2.7%), followed by type 2 (14.3%) and type 1 (44.4%). The overall implant failure rate was 3.6%. Smooth implants showed the highest failure rate (21.8%), followed by titanium plasma-sprayed (2.9%) and HA-coated (0.7%) implants. In phase 2, the overall implant survival rate was 92.5% after 3 years. Smooth implants showed the highest failure rate (41.7%), followed by sand-blasted, large-grit, acid-etched (6.8%) and HA-coated (3.4%) implants. All failures occurred when implants were placed simultaneously with sinus grafts. This study suggests that long-term implant success can be obtained when maxillary sinuses are augmented with a combination of DFDBA + AHA + NHA. Rough surfaces and delayed implant placement seem to increase implant success in these areas.     

Three-year analysis of tapered screw vent implants placed into maxillary sinuses grafted with mineralized bone allograft

With an increase in the number of patients presenting for dental implant treatment, it is becoming more common for clinicians to encounter inadequate bone volume. Several surgical techniques have been advocated for placing dental implants in the posterior maxilla, including the lateral window sinus elevation technique. This article reports the results of implants placed into maxillary sinuses grafted with particulate mineralized cancellous bone allograft alone or in combination with resorbable hydroxyapatite over a 3-year period. A total of 56 sinuses were grafted, and 136 dental implants were placed into the grafted sites after a 4- to 8-month healing period. All reentries revealed a bony hard structure acceptable for osteotomy preparation. Of these implants, 124 have been restored with fixed prosthesis and 12 with removable overdentures for a total of 136 loaded implants. A total of 3 implants required removal (failure) resulting in a 97.7% implant success rate (2.3% failure rate). A conclusion was made that mineralized human allograft, placed into lateral window sinus elevations, is a clinically predicable method acceptable for implant placement and restoration.     

Autologous bone graft to augment the maxillary sinus in conjunction with immediate endosseous implants: a retrospective study up to 5 years.

This study reports the successful use of osseointegrated implants to replace posterior teeth combined with the autogenous bone graft technique in the sinus. Preliminary data (1 to 6 years experience) of this one-stage procedure are presented. A total of 33 patients were treated--44 sinus grafts were augmented with bone from the anterior iliac crest. Reconstruction was completed with ceramic fixed partial dentures, and there was a follow-up of 3 to 80 months (mean 40.2 months) after loading. None of the 44 sinus grafts was lost. Of the 121 implants placed, eight failed, resulting in a failure rate of 6.6% and a cumulative failure rate of 6.8%. Of the 44 prostheses placed in the 44 sinuses, one failed, resulting in a prosthesis stability of 97.7%. Complications were encountered in three patients (three sinuses, eight implants); treatments were administered, symptoms subsided, and the implants integrated in two patients (two sinuses, six implants). One patient lost the two implants and the prosthesis, but the graft integrated. No other complications have since occurred. The results compare favorably with previous reports in terms of implant survival and stability. The implant survival rate approached that of implants placed in uncompromised maxillary bone.     

Success and failure rates of osseointegrated implants in function in regenerated bone for 72 to 133 months

PURPOSE: Guided bone regenerative therapy has become a significant component of clinical implant practice. Initial reports have demonstrated success rates of implants in regenerated bone under function comparable to the success rates of implants placed in native nonregenerated host bone. This report documents the success and failure rates of osseointegrated implants placed in regenerated bone for up to 133 months in function. MATERIALS AND METHODS: A retrospective analysis of a group of 607 titanium plasma-sprayed cylindric implants placed in regenerated bone, the success and failure rates of which were previously reported at 6 to 51 months in function, were assessed. RESULTS: The implants demonstrated cumulative success rates of 97.2% for the maxilla and 97.4% for the mandible, yielding an overall cumulative success rate of 97.4% for up to 133 months in function. DISCUSSION AND CONCLUSIONS: Titanium plasma-sprayed osseointegrated implants of various diameters, lengths, and designs, utilized in a variety of clinical scenarios, demonstrated functional cumulative success rates comparable to those of implants placed in nonregenerated host bone for extended periods of time in this patient population.     

Long-term clinical effectiveness of oral implants in the treatment of partial edentulism. Seven-year life table analysis of a prospective study with ITI dental implants system used for single-tooth restorations

One hundred and eight-seven ITI implants were prospectively followed from November 1992 to July 2000, in order to evaluate the clinical efficiency and the long-term prognosis in 109 partially edentulous patients (69 women and 40 men; average age 41.3 years). Of these 187 implants, 69.5% were placed in the mandible and 30.5% in the maxilla. After a healing period that ranged from three to six months, the osseointegrated implants (n = 184) were restored with single crowns. Three implants were extracted prior to loading the fixture and were considered early failures. Each implant was reassessed on a yearly basis, both clinically and radiographically. The results of the investigation, which were evaluated according to predefined success criteria, were reviewed in accordance with a life table method. During the follow-up, six cases were deemed to be late failures. In each of these cases, a suppurative infection of the peri-implant tissue was diagnosed: in one implant, the infection could not be eradicated and the implant was removed. When 11 drop-outs were included in the analysis, the cumulative survival and success rates for the whole sample group were 96.77% and 93.6%, respectively. When only prosthetically loaded implants were considered, the results increased to 99.35% for the cumulative survival rate and 96.18% for the cumulative success rate. The analysis on disaggregated data showed better results for maxillary restorations (survival rate 100%) in comparison to mandible restorations (survival rate 95.11%). It was concluded that, under standard anatomic conditions (bone site height > 8 mm, thickness > 6 mm), prosthetic restoration of partially edentulous patients with the ITI system can be described as a reliable and efficient therapy in the long term.     

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.     

The effect of cigarette smoking on dental implants and related surgery

Cigarette smoking is still considered a common habit. Of smokers, increased plaque accumulation, higher incidence of gingivitis and periodontitis, higher rate of tooth loss, and increased resorption of the alveolar ridge have been found in the oral cavity. Cigarette smoking may adversely affect wound healing, and, thus, jeopardize the success of bone grafting and dental implantation. Bone grafts and sinus lift operations are both common and well-documented procedures before dental implant placement. Heat as well as toxic by-products of cigarette smoking, such as nicotine, carbon monoxide, and hydrogen cyanide, have been implicated as risk factors for impaired healing, and, thus, may affect the success and complications of those surgical procedures. An association among dental implants, grafting procedures (i.e., bone grafts, maxillary sinuses augmentation), and history of smoking has been reported. A higher degree of complication, or implant failure rates, were found in smokers with and without bone grafts. The relationship between cigarette smoking and implant-related surgical procedures, including the incidence of complications associated with these procedures, will be described and discussed based on relevant literature and results of our recent studies.     

Influence of smoking on osseointegrated implant failure: a meta-analysis

The aim of this study was to examine the influence of smoking on osseointegrated implant failure by performing a meta-analysis. A computerized literature search using PubMed database (in English) and Japana Centra Revuo Medicina (in Japanese) was carried out to identify all relevant studies. Among 175 studies identified and chosen for detailed review, 19 were appropriate for inclusion in our meta-analysis. When smokers were compared with non-smokers, odds ratio (OR) for osseointegrated implant failure was significantly elevated (OR 2.17, 95% confidence intervals (CI), 1.67-2.83). Seven studies were appropriate to examine the influence of intra-oral location (maxillary arch vs. mandibular arch) of implant failure on smoking. The OR for implant failure occurring in the maxillary arch was significantly elevated (OR 2.06, 95% CI, 1.61-2.65), whereas the OR in the mandibular arch did not demonstrate a significant increased risk associated with smoking (OR 1.32, 95% CI, 0.72-2.4). Our meta-analysis revealed a significant relationship between smoking and the risk of osseointegrated implant failure, more particularly those implants located in the maxillary arch.     

ITI implant use in private practice: clinical results with 5,526 implants followed up to 72+ months in function

PURPOSE: To evaluate the success and failure rates over time of ITI implants placed in 3 private practices and used in a variety of clinical situations. MATERIALS AND METHODS: ITI solid-screw implants (n = 5,526) were placed in 3 private practices and restored by a variety of clinicians. Numerous clinical scenarios were treated with the implants, which were in function for between 0 and 72+ months. RESULTS: After 72+ months the cumulative success rates were 94.8% for maxillary implants and 97.5% for mandibular implants. The overall cumulative implant success rate was 96.1%. Implants that failed to osseointegrate were included in the data as failures in the 0- to 12-month interval. The criteria of Albrektsson and associates were used to assess implant success or failure. DISCUSSION: The results, which were achieved in conjunction with numerous restorative clinicians, were comparable to those reported by other authors. The clinical viability of ITI implant use was thus reinforced. CONCLUSION: ITI solid-screw implants were a predictable treatment modality in 3 private practices for a variety of clinical applications.