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.     

Effects of smoking on implant success in grafted maxillary sinuses.

STATEMENT OF THE PROBLEM: Cigarette smoking has been identified as a significant risk factor for dental implant treatment. PURPOSE: This retrospective study evaluated the effect of smoking and the amount of cigarette consumption on the success rates of the implants placed in grafted maxillary sinuses. MATERIAL AND METHODS: Sixty patients (16 smokers and 44 nonsmokers) were evaluated for the effects of smoking on osseointegrated implants placed in 84 grafted maxillary sinuses that contained a total of 228 endosseous root-form implants. Seventy implants were placed in 26 maxillary sinuses in smokers, whereas 158 implants were placed in 58 sinuses in nonsmokers. The number of implant failures and the amount of cigarette consumption were recorded. RESULTS: Of the 228 implants, 205 (89.9%) remained in function, after a mean follow-up period of 41.6 months (2 to 60 months). There was a significantly higher cumulative implant success rate in nonsmokers (82.7%) than in smokers (65.3%) (P =.027). Overall cumulative implant success rate was 76%. There was no correlation between implant failures and the amount of cigarette consumption (P >.99). CONCLUSION: Within the limitations of this study, cigarette smoking appeared to be detrimental to the success of osseointegrated implants in grafted maxillary sinuses regardless of the amount of cigarette consumption.     

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.     

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.     

Postoperative maxillary cyst following sinus bone graft: report of a case

Sinus bone grafting with autogenous bone is routinely performed to allow placement of endosseous dental implants. Although numerous maxillary sinuses have been successfully grafted, some complications of this procedure have been reported. These include maxillary sinusitis, resorption, infection and possible failure of grafts, loss of implants after 1-stage surgery, and oroantral fistulae. Only one case of postoperative maxillary cyst developing in the graft has been reported in the literature. Here, the authors report a similar case that necessitated grafting of the cyst with autologous iliac bone.     

Dental implants placed in grafted maxillary sinuses: a retrospective analysis of clinical outcome according to the initial clinical situation and a proposal of defect classification

Objective of the study: To present a classification of maxillary defects necessitating sinus floor elevation procedures (SFEPs) with two objectives: (a) to propose a standardization of surgical procedures according to initial type of atrophy and (b) to allow the evaluation of the success/survival rates of implants placed in the grafted areas according to the initial situation. Materials and methods: Nine‐hundred and fifty‐two consecutive SFEP were performed on 692 patients. Initial defects were classified according to a new classification, which considered not only residual bone height below the sinus but also the width of the alveolar crest and horizontal/vertical intermaxillary relationship. Results were evaluated according to the different classes. The sinuses were grafted with autogenous bone taken from intra‐oral or extra‐oral sites: 579 SFEP were associated with vertical and/or horizontal onlay grafts to correct concomitant alveolar ridge deficits. A total of 2037 implants were inserted into the grafted sinuses either immediately or 4–6 months later. Three to 6 months afterwards, implants were loaded. The mean follow‐up was 59 months (range: 12–144 months). Results: The success rate of the reconstructive procedures varied between 93.2% and 100%, according to class of atrophy; the overall survival and success rates of implants were 95.8% and 92.5%, respectively, whereas the survival and success rates according to class of atrophy varied between 90% and 97.6%, and between 85.4% and 95.5%, respectively. Lower success rates were found in classes presenting with more severe atrophy. Conclusion: The results obtained demonstrated that sinus floor elevation, alone or in association with reconstructive procedures with autogenous bone grafts, is a reliable procedure to allow implant placement in atrophic edentulous maxillae, irrespective of the initial clinical situation. However, it must be underlined that the success rates of reconstructive procedures and implants differ according to class of atrophy, showing lower success rates in classes presenting with more severe atrophy.     

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.     

Systematic review of survival rates for implants placed in the grafted maxillary sinus

Based on a systematic review of the literature from 1986 to 2002, this study sought to determine the survival rate of root-form dental implants placed in the grafted maxillary sinus. Secondary goals were to determine the effects of graft material, implant surface characteristics, and simultaneous versus delayed placement on survival rate. A search of the main electronic databases was performed in addition to a hand search of the most relevant journals. All relevant articles were screened according to specific inclusion criteria. Selected papers were reviewed for data extraction. The search yielded 252 articles applicable to sinus grafts associated with implant treatment. Of these, 39 met the inclusion criteria for qualitative data analysis. Only 3 of the articles were randomized controlled trials. The overall implant survival rate for the 39 included studies was 91.49%. The database included 6,913 implants placed in 2,046 subjects with loaded follow-up time ranging from 12 to 75 months. Implant survival was 87.70% with grafts of 100% autogenous bone, 94.88% when combining autogenous bone with various bone substitutes, and 95.98% with bone grafts consisting of bone substitutes alone. The survival rate for implants having smooth and rough surfaces was 85.64% and 95.98%, respectively. Simultaneous and delayed procedures displayed similar survival rates of 92.17% and 92.93%, respectively. When implants are placed in grafted maxillary sinuses, the performance of rough implants is superior to that of smooth implants. Bone-substitute materials are as effective as autogenous bone when used alone or in combination with autogenous bone. Studies using a split-mouth design with one variable are needed to further validate the findings.     

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.     

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.     

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。     

Maxillary Sinus Membrane Repair With Amnion–Chorion Barriers: A Retrospective Case Series

Background: Schneiderian membrane perforation is the most common complication of maxillary sinus augmentation procedures and has been associated with a variety of post‐surgical problems. Multiple techniques to repair perforated Schneiderian membranes with materials such as connective tissue, buccal fat pads, and resorbable collagen membranes have been reported in the dental literature. Although these reparative options have proven successful, they are technique sensitive and time consuming. The aim of this case series is to present a simplified method of Schneiderian membrane perforation repair with amnion–chorion membranes and results obtained from nine cases using this technique. Methods: A consecutive retrospective record review was performed of all maxillary sinus augmentation cases performed during the past 5 years by the same board‐certified private practice periodontist (DH). Results: Seventy‐seven cases were identified, with a total of 104 sinus augmentations, in which nine perforations were noted. None of the perforation cases were aborted midprocedure, and all perforations were repaired with amnion–chorion membranes. All cases were augmented with a combination of allograft and xenograft particulate bone. After an average healing time of 4.9 months, dental implants were placed in the grafted sinuses. Conclusions: This retrospective case series shows nine perforations during 104 lateral window maxillary sinus augmentation procedures. A total of 23 dental implants were placed in the augmented sinuses with perforated Schneiderian membranes, and one failure was noted according the Albrektsson success criteria. A total of 158 dental implants were placed in non‐perforated augmented sinuses, with a total of three failures noted.     

Smoking as a risk factor for dental implants and implant-related surgery

Cigarette smoking is known to adversely affect wound healing, and thus may jeopardize the success of dental implantation and implant-related oral surgery. The present study is aimed to present the influence of cigarette smoking on the success and survival of dental implantation as well as on the complication and success of implant-related surgery. We conclude that smokers undergoing both implant-related surgical procedures and dental implantation should be encouraged by their dentists, oral and maxillofacial surgeons, or treating physicians to cease smoking, emphasizing that smoking can increase complications and reduce the success rate of these procedures.     

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.     

Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis

AIM: This systematic literature review was performed to investigate if smoking interferes with the prognosis of implants with and without accompanying augmentation procedures compared with non-smokers. METHODS: A systematic electronic and handsearch (articles published between 1989 and 2005; English and German language; search terms "dental or oral implants and smoking"; "dental or oral implants and tobacco") was performed to identify publications providing numbers of failed implants, related to the numbers of smokers and non-smokers for meta-analysis. Publications providing statistically examined data of implant failures or biologic complications among smokers compared with non-smokers were included for systematic review. RESULTS: Of 139 publications identified, 29 were considered for meta-analysis and 35 for systematic review. Meta-analysis revealed a significantly enhanced risk for implant failure among smokers [implant-related odds ratio (OR) 2.25, confidence interval (CI(95%)) 1.96-2.59; patient-related OR 2.64; CI(95%) 1.70-4.09] compared with non-smokers, and for smokers receiving implants with accompanying augmentation procedures (OR 3.61; CI(95%) 2.26-5.77, implant related). The systematic review indicated significantly enhanced risks of biologic complications among smokers. Five studies revealed no significant impact of smoking on prognosis of implants with particle-blasted, acid-etched or anodic oxidized surfaces. CONCLUSION: Smoking is a significant risk factor for dental implant therapy and augmentation procedures accompanying implantations.     

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.     

Maxillary sinus augmentation with deproteinated bovine bone and platelet rich plasma with simultaneous insertion of endosseous implants.

PURPOSE: To investigate the clinical applicability of using deproteinated bovine bone mixed with autologous platelet rich plasma (PRP) in human maxillary sinus augmentations in severely resorbed posterior maxillary alveolar processes with simultaneous insertion of endosseous dental implants. MATERIALS AND METHODS: Fifteen patients with less than 5 mm of residual alveolar bone height in the posterior maxillary alveolus underwent a total of 24 maxillary sinus augmentations. Seventy endosseous implants were inserted simultaneously in the grafted sinuses. The implants were uncovered and loaded 4 months after insertion and the sinus augmentation. An osseous biopsy specimen was obtained from the augmented maxillary sinus in 1 patient. In 3 patients, computed tomography scans of the grafted maxillae were obtained and the bone density quantified and compared with native bone density using SIMPlant 7 (Columbia Scientific, Columbia, MD) software 4 months postoperatively. RESULTS: Although a total of 5 implants in 4 patients were lost, this did not result in the loss of any of the restorations, for an overall success rate of 92.9 %. Follow-up for patients in this study after insertion of the permanent restoration was between 6 and 36 months. The bone biopsy from the patients showed evidence of viable new bone formation in close approximation to the xenograft. The bone density of the grafted bone was similar or exceeded the bone density of the surrounding native maxillary bone. CONCLUSION: Based on our clinical experience, we believe that the use of platelet rich plasma in combination with deproteinated bovine bone is effective for maxillary sinus augmentation with simultaneous insertion of endosseous dental implants in severely resorbed posterior maxillae.     

Osseointegrated dental implants in private practice: a long-term case series study

BACKGROUND: Osseointegrated dental implants have become a routinely recommended procedure in the clinical practice of dentistry and periodontics. Due to their predictability, they have changed the way many cases are treatment planned. The purpose of this paper is to report the results of a prospective study of factors affecting the successes and failures of a large group of dental implants and compare them to published literature. METHODS: A total of 1,003 consecutively placed pure titanium dental implants placed from August 1987 to January 2002 and followed to October 2003 are reported. All implants were placed in one private practice by the same surgeon. RESULTS: Success rates statistically were influenced only by the age of the implant, although when the raw data are examined, some trends are seen. Success was unaffected by patient age, gender, surface roughness of implant, site of placement, smoking, bone type, arch, screw versus press-fit, diameter, length, manufacturer, reason for tooth loss, site bony augmentation and timing, placement timing, one-versus two-stage placement, or torque testing of implants; 75% of failures occurred before restoration. CONCLUSIONS: Osseointegrated dental implants are a highly predictable procedure with proper case selection. Failure rates vary for a number of factors reviewed, although only the age of the implant was statistically important in predicting failure. Male smokers, maxillary first molars, and type 4 bone had increased failure rates. Threaded, surface-roughened implants had the highest success rates.     

Implant marginal bone loss in maxillary sinus grafts

PURPOSE: The marginal bone loss (MBL) around implants placed in maxillary sinus grafts was evaluated. MATERIALS AND METHODS: The study consisted of 70 patients who had undergone 81 sinus-graft procedures (total 212 screw-type implants). Complete radiographic records were available for 160 implants, which were used to calculate MBL (follow-up 6 to 56.5 months). Habits (smoking, bruxism), surgical phase parameters (preoperative residual bone, grafting material, implant characteristics, and complications), and prosthetic parameters (crown-implant ratio, marginal fit, and opposite-arch restoration) were recorded for each patient and statistically analyzed regarding MBL. RESULTS: Cumulative survival and overall radiographic success rates were 95.5% and 83.7% for 4.5 years, respectively. Smoking, small implant surface area, and a delayed implantation approach were related to enhanced MBL, with mean MBL values of 0.24 mm/y (P < .011), 0.21 mm/y (P < .031), and 0.31 mm/y (P = .052), respectively. In residual bone of < or =4 mm, the relation to enhanced MBL was stronger (P < .018) for delayed implantation. DISCUSSION: Survival and radiographic success rates compare well with other reports. However, most studies modify success criteria regarding MBL. Smoking may be a primary risk factor regarding implant success. Implants with greater surface area values could compensate for problematic bone characteristics (e.g., in grafted maxillary sinuses). The effect of delayed implantation on MBL was surprising and may prompt simultaneous implantation whenever primary stability can be achieved. CONCLUSIONS: Smoking and implant surface area affected MBL in this patient population. Criteria for long-term implant success should be revised to a standard.     

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.