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.     

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.     

Tobacco as a risk factor for survival of dental implants

BACKGROUND: It has been shown that smoking habits represent an increased risk for impaired bone healing and implant failure. This study aimed to evaluate the implant survival rates among non-smokers (NS) and different kinds of smokers (S). METHODS: A retrospective analysis was made over a 5-year period of the clinical and radiographic findings corresponding to 66 consecutive patients who had received a total of 165 dental implants. Patients were divided into two groups: S, 40 patients (95 implants; 58% of the sample); and NS, 26 patients (70 implants; 42% of the sample). Also, S and NS were classified into four different categories according to daily tobacco use: NS, 26 patients and 70 implants; light smokers (LS), 23 patients and 44 implants; moderate smokers (MS), 11 patients and 25 implants; and heavy smokers (HS), six patients and 26 implants. RESULTS: Sixteen implants (9.7%) failed and had to be removed. Group S showed 15 failures and a success rate of 84.2%. Group NS had only one failure, giving a success rate of 98.6%. The risk of implant failure was approximately 31% in those who smoked more than 20 cigarettes per day. HS showed statistical differences from NS or LS. However, they did not show any differences from MS. CONCLUSIONS: Within the limits of the present study, the use of tobacco involves a 15.8% risk of implant failure, with a 13.1 odds ratio. LS or MS tobacco use involves a 10.1% relative risk of implant loss, whereas the consumption of >20 cigarettes per day increases this risk to 30.8%.     

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 relationship between cigarette smoking and dental implant failure

This paper examines the effect of tobacco use on the failure rates of dental implants. A review of 56 dental implant patients with a total of 187 endosseous dental implants, placed over a four year period, demonstrated a significant association between increased implant failure rates and cigarette smoking with failure rates of 16.6% in smokers compared to 6.9% in non-smokers. Also implant length was shown to be a significant factor with shorter implants (< or = 10 mm) being more susceptible to failure in smokers. A chi-square test was used for data analysis. Current recommendations that should be given to implant patients who smoke are included.     

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.     

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.     

The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth

BACKGROUND: Studies concerning immediate implantation describe its use in the anterior and premolar regions. However, its clinical effectiveness in immediately replacing molar teeth has rarely been challenged. The purpose of this study was to evaluate the survival rate of implants placed immediately after extraction of molar teeth to support a fixed ceramo-metal prosthesis. METHODS: From 1989 to 1996, 56 immediate implants were placed in 43 patients following extraction of 51 molars; 46 molars were replaced by 1 implant and 5 molars replaced by 2 implants. All implants were restored with fixed prostheses (4 single crowns and 52 splinted). Mean follow-up period was 15 months (range, 4 to 60 months). The influence of the following parameters on implant failure was evaluated: gender, arch, smoking, pre-extraction vertical bone loss, implant length, and severity of complications between the two stages of surgery. RESULTS: The 5-year cumulative survival rate (5-year CSR) was 89%. The 5-year CSR among men was 84% compared to 93.5% among women. The maxillary 5-year CSR was 82% and the mandibular 92%. Among non-smokers (50 implants), the 5-year CSR was 90% compared to 83% among smokers (6 implants). Complications were evident in 8 (6 minor, 2 major) out of 50 non-failing implants compared to 2 (minor) of the 6 failing implants. No differences were evident in the other study variables. CONCLUSIONS: Immediate implantation in the molar region is an alternative, predictable surgical treatment. Immediate implantation in the posterior mandible has a better prognosis than in the posterior maxilla.     

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.     

100例牙列缺损患者口腔种植修复并发症及其危险因素探讨

目的:通过对我院100例种植修复患者进行随访研究,探讨种植修复后种植体的存留率、并发症的发生情况及其危险因素,以期预防和减少种植修复并发症的发生。方法:纳入本院口腔科2017年1月至2019年9月行种植修复的患者100例作为研究对象,记录患者的入院信息、基本临床资料、种植修复和并发症发生情况,并探讨并发症发生的相关危险因素。结果:本研究共纳入本院口腔科2017年1月至2019年9月行种植修复的患者100例,种植体143枚。种植体累计取出、脱落3颗,存留率为97.90%,不同分类种植体留存率与并发症发生率无统计学差异(均P>0.05)。按照修复并发症类型统计各修复并发症总体发生率,具体结果如下表所示,其中发生率前三的的并发症分别是食物嵌塞(45.0%)、基台或基台螺丝松动(6.0%)和邻接丧失(5.0%)(均P<0.05)。Logistic回归分析发现,年龄>50岁的患者发生并发症的危险性较≤18岁的患者更高;相较于骨量充足的患者,骨量不足患者发生并发症的危险性升高,糖尿病是并发症发生的独立危险因素,在糖尿病患者中并发症的发生率更高。性别和吸烟对并发症发生无显著影响。结论:食物嵌塞和基台或基台螺丝松动是较常见的并发症,后牙区、高龄、骨量不足和糖尿病患者的并发症发生率相对较高。     

Complication rates for various retention types in anterior implant-supported prostheses: A retrospective clinical study

Statement of problemImplant-supported prostheses have typically been retained by cement or screws, each of which has advantages and disadvantages. Two new types of prosthesis with complementary advantages and disadvantages have been proposed: the screw- and cement-retained prosthesis, which combines cement and screw retention, and the antiloosening inner-post screw (ALIPS) type, which uses lateral screws. Both esthetic and functional factors should be considered for anterior prostheses; however, clinical studies of the complication rates of these designs are lacking.PurposeThe purpose of this retrospective clinical study was to evaluate the complications of dental implant-supported restorations with various prosthetic types in the anterior region and to analyze other factors that affect complications.Material and methodsThis study included 51 patients who had 83 implants placed in the anterior region by a single clinician between August 2009 and December 2016. Surgical and prosthetic features were recorded, and implant complications were analyzed.ResultsThere were 45 (55.4%) cement-retained implants, 5 (6.0%) screw- and cement-retained prosthesis implants, and 32 (38.6%) ALIPS-retained implants. Peri-implant mucositis was observed most frequently in the ALIPS type (21.9%), but the biological complications did not differ significantly with the prosthetic type. The most common mechanical complication was loss of retention in the cement type of prosthesis (30.4%) and screw loosening in the ALIPS type (43.8%). Implant complications varied with position (maxilla or mandible) and implantation timing (period from tooth extraction to implant placement).ConclusionsThe complications of implants placed in the anterior region were affected by different factors but did not differ significantly with the type of the retention.     

Impact of IL-1 genotype and smoking status on the prognosis of osseointegrated implants

AIM: This study evaluated the impact of the IL-1 genotype and smoking status on the prognosis and development of complications of osseointegrated implants. MATERIAL AND METHODS: The clinical charts of 180 consecutively admitted patients were analyzed with respect to the occurrence of biological complications in conjunction with oral implants. Biologic complications were defined as clinical conditions with suppuration from the peri-implant sulcus, development of a fistula or peri-implantitis with radiologic bone loss. All patients had received one or more ITI dental implants, which had been in function for at least 8 (range: 8-15) years. This patient population had received 292 implants. From these, 51 implants in 34 patients showed late (infectious) biologic complications, and 241 implants had survived without any biologic complications at all. RESULTS: Of the 180 patients, 53 were smokers, who were subdivided in a series of classes according to their intensity of smoking and 127 were never smokers. Sixty-four of 180 (36%) patients tested positive for the IL-1 genotype polymorphism. This prevalence corresponds to previous reports for the prevalence of European descent populations. The results for the non-smoking group indicated no significant correlation between implant complications and a positive IL-1 genotype. However, there was a clear association for heavy smokers between a positive IL-1 genotype and implant complications. 6 of 12 or half of the heavy smokers and IL-1 genotype-positive patients had either an implant failure, i.e. loss of implant, or a biologic complication during the follow-up period. CONCLUSIONS: These findings have led to the conclusion that there is a synergistic effect between a positive IL-1 genotype and smoking that puts dental implants at a significantly higher risk of developing biologic complications during function.     

Effect of washers on reverse torque displacement of dental implant gold retaining screws.

STATEMENT OF THE PROBLEM: Gold screw loosening is a frequent problem that affects dental implants. PURPOSE: This study determined the effect of spring washers on gold screw displacements during applied removal torque in dental implants. MATERIAL AND METHODS: A 3-unit fixed partial denture was cast in semiprecious alloy and fixed to 2 dental implants with gold-retaining screws. Implants were embedded in acrylic resin and restrained from movement. A miniature load sensor was attached to a torque controller handpiece to accurately measure the time and torque needed to completely loosen the gold screws. Rotational displacements were calculated for 4 experimental setups, involving washers placed on (a) both, (b) the mesial, (c) the distal, and (d) no implants. Screw displacement data were compared between implants in all 4 combinations by means of paired t tests. RESULTS: Gold screws with underlying conical spring washers underwent on average up to 35% (14.1 microm) more rotational displacement during applied removal torque than those without washers. CONCLUSION: Inclusion of a conical spring washer significantly increased the amount of rotational displacement needed to completely loosen an implant gold retaining screw.     

The challenge of endosseous implants placed in the posterior partially edentulous maxilla: a clinical report

The survival rate of implants placed in the maxillary molar area in a 2-stage procedure was evaluated. Between 1990 and 1997, 60 consecutive patients (32 females and 28 males, mean age 51 years) received 87 implants to replace missing maxillary molar teeth. Radiographs were evaluated preoperatively for bone quantity (mesiodistal width, potential implant length not compromising the integrity of adjacent vital structures). Second-stage surgery was performed in a mean of 7.9 months postimplantation. The 5-year cumulative implant survival rate and the influence of implant characteristics (type, length, diameter, and coating) on implant failure and complication rates (between the 2 stages of surgery) were evaluated. The total 5-year cumulative survival rate was 95.4% (4 implants were lost). There were a total of 17 "complications" (premature spontaneous implant exposure) in non-failing implants, 11 with high and 6 with flat cover screws, respectively. Implantation in the edentulous maxillary molar area is a predictable procedure with a considerably high survival rate. The type of implant cover screw used can affect the complication rate.     

口腔环境中纯钛及钛75合金种植体覆盖螺丝缝隙腐蚀的研究

目的 :研究口腔环境中纯钛及钛 75合金种植体覆盖螺丝的缝隙腐蚀 ,及同一环境中纯钛及钛 75合金之间有无电偶腐蚀现象。方法 :将纯钛 (TA2 )及钛 75合金机加工成直径 3.5mm、长10mm的柱状螺纹种植钉及相对应覆盖螺丝 ,清洗、钝化、消毒。选择杂种实验狗6条 ,随机分A、B、C组,A组每条狗口腔中植入纯钛钉4个,B组每条狗植入钛 75合金种植钉4个,C组口内同时植入2个纯钛、2个钛75合金种植钉 ,种植体与对牙合无接触。每组以 12周为时间点 ,扫描电镜观察覆盖螺丝。结果 :A组纯钛机加工处理不清晰、走向改变 ,但未发现点蚀坑 ,B组钛75合金覆盖螺丝机加工纹理清晰、密度细、未发现腐蚀 ,C组未发现纯钛及钛 75合金种植覆盖螺丝的点蚀坑。结论 :钛75合金与纯钛在同一口腔环境中未发现电偶腐蚀 ,提示临床应用中可用钛75合金代替纯钛做上部结构与纯钛匹配 ;钛75合金在口腔中耐磨损性能优于纯钛。     

种植体植入15年内种植体周围炎和种植周黏膜炎发生率调查

目的:探讨种植体植入15年中种植体周围炎(peri-implantitis,PI)和种植体周围黏膜炎(peri-implant mucosi-tis,PM)的发生率.方法:回顾性分析南昌大学附属口腔医院2001年1月-2005年12月收治的口腔种植修复患者507例(共1162颗种植体),随访12～15年,收集患者临床资...     

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.     

Cigar, pipe, and cigarette smoking as risk factors for periodontal disease and tooth loss

BACKGROUND: Our purpose was to test the hypotheses that cigar and pipe smoking have significant associations with periodontal disease and cigar, pipe, and cigarette smoking is associated with tooth loss. We also investigated whether a history of smoking habits cessation may affect the risk of periodontal disease and tooth loss. METHODS: A group of 705 individuals (21 to 92 years-old) who were among volunteer participants in the ongoing Baltimore Longitudinal Study of Aging were examined clinically to assess their periodontal status and tooth loss. A structured interview was used to assess the participants' smoking behaviors with regard to cigarettes, cigar, and pipe smoking status. For a given tobacco product, current smokers were defined as individuals who at the time of examination continued to smoke daily. Former heavy smokers were defined as individuals who have smoked daily for 10 or more years and who had quit smoking. Non-smokers included individuals with a previous history of smoking for less than 10 years or no history of smoking. RESULTS: Cigarette and cigar/pipe smokers had a higher prevalence of moderate and severe periodontitis and higher prevalence and extent of attachment loss and gingival recession than non-smokers, suggesting poorer periodontal health in smokers. In addition, smokers had less gingival bleeding and higher number of missing teeth than non-smokers. Current cigarette smokers had the highest prevalence of moderate and severe periodontitis (25.7%) compared to former cigarette smokers (20.2%), and non-smokers (13.1%). The estimated prevalence of moderate and severe periodontitis in current or former cigar/pipe smokers was 17.6%. A similar pattern was seen for other periodontal measurements including the percentages of teeth with > or = 5 mm attachment loss and probing depth, > or = 3 mm gingival recession, and dental calculus. Current, former, and non- cigarette smokers had 5.1, 3.9, and 2.8 missing teeth, respectively. Cigar/pipe smokers had on average 4 missing teeth. Multiple regression analysis also showed that current tobacco smokers may have increased risks of having moderate and severe periodontitis than former smokers. However, smoking behaviors explained only small percentages (<5%) of the variances in the multivariate models. CONCLUSION: The results suggest that cigar and pipe smoking may have similar adverse effects on periodontal health and tooth loss as cigarette smoking. Smoking cessation efforts should be considered as a means of improving periodontal health and reducing tooth loss in heavy smokers of cigarettes, cigars, and pipes with periodontal disease.     

Screw loosening for standard and wide diameter implants in partially edentulous cases: 3- to 7-year longitudinal data

Screw loosening is considered to be a common problem with both screw-retained and cemented implant restorations. A wider abutment platform, as well as using a torque driver to tighten specifically designed screws may help prevent this loosening. However, there has been no clinical study evaluating either of these. To longitudinally compare the frequency of screw loosening in standard diameter, (3.75 and 4.0 mm) implant supported prostheses to that of wide diameter, (5.0 and 6.0 mm) implant supported prostheses that were hand tightened, and to evaluate whether using a torque driver would minimize or prevent this problem, if screw loosening occurred. A total of 213 dental implants in 106 patients were included in this prospective longitudinal study. Of the implants 68 were wide diameter and 145 were standard diameter implants. Wide diameter implants showed 5.8% screw loosening, while standard diameter implants showed 14.5% screw loosening after insertion with only hand torquing. When these loose screws were tightened with a torque driver, there was no more loosening of screws. Within the limitations of this study, the wide diameter implants tested showed less screw loosening than the standard diameter implants when hand torqued. Additionally, within the scope of our study, using a torque driver to tighten the screws with the recommended force prevented this loosening from reoccurring in all cases.     

Oral rehabilitation using Camlog screw-cylinder implants with a particle-blasted and acid-etched microstructured surface. Results from a prospective study with special consideration of short implants

OBJECTIVES: The purpose of the present clinical study was to report on the clinical performance of screw-cylinder implants with special consideration of the survival rate of short implants. MATERIAL AND METHODS: In this prospective study with consecutive patient recruitment, Camlog screw-cylinder implants with a particle-blasted and acid-etched microstructured surface and a triple-cam tube-in-tube implant-abutment connection have been used only. Two groups of implants were evaluated: implants of 9 and 11 mm in length were considered short, those of 13 and 16 mm were considered long. Besides clinical and radiographic parameters, data of complications, patients' subjective evaluation of treatment outcome, general medical history and smoking habits were recorded. RESULTS: Three hundred and thirty-three Camlog screw-cylinder implants were inserted in 133 patients. One hundred and twenty-nine patients were available for follow-up, representing 325 implants. The median observation period was 33 months (Q(25%) 26; Q(75%) 38). After a maximum observation period of 55 months, the Kaplan-Meier-survival analysis revealed no significant difference between the mean survival probabilities of 98.3% (n=59, patient-related) of short implants, and of 95.7% of long implants (n=70, patient-related) (P=0.162). No significant difference was found between implant survival rates considering maxilla (98.7%) and mandible (98.2%). A stratified analysis of short implants revealed a significant influence of premature cover screw exposures (P=0.02) and smoking (P=0.008) on implant survival. These influences were not found significant for long implants. CONCLUSIONS: The prognosis of short Camlog implants is comparable with that of long implants. Therefore, their clinical use instead of performance of sophisticated vertical augmentation procedures before installation of long implants might be considered as alternative treatment option. In smokers, the use of short implants should be considered cautiously, however. The risk of premature cover screw exposure should be minimized.