***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND To date only a few studies have evaluated the long-term influence of smoking and smoking cessation on periodontal health . The present study , therefore , was undertaken with the aim to prospect ively investigate the influence of smoking exposure over time on the periodontal health condition in a targeted population before and after a follow-up interval of 10 years . METHODS The primary study base consisted of a population of occupational musicians that was investigated the first time in 1982 and scheduled for reinvestigation in 1992 and 2002 . The 1992 investigation included 101 individuals from the baseline study constituting a prospect i ve cohort including 16 smokers , who had continued to smoke throughout the entire length of the 10-year period ; 28 former smokers who had ceased smoking an average of approximately 9 years before the commencement of the baseline study ; 40 non-smokers , who denied ever having smoked tobacco ; and 17 individuals whose smoking pattern changed or for whom incomplete data were available . The clinical and radiographic variables used for the assessment of the periodontal health condition of the individual were frequency of periodontally diseased sites ( probing depth > or = 4 mm ) , gingival bleeding ( % ) , and periodontal bone height ( % ) . The oral hygiene st and ard was evaluated by means of a st and ard plaque index . RESULTS The changes over the 10 years with respect to frequency of diseased sites indicated an increased frequency in continuous smokers versus decreased frequencies in former smokers and non-smokers . Controlling for age and frequency of diseased sites at baseline , the 10-year change was significantly associated with smoking ( P < 0.001 ) . The differences between current smokers and non-smokers , and between current and former smokers , respectively , were statistically significant ( P<0.001 ) . Moreover , the 10-year change increased significantly with increasing smoking exposure controlling for age ( P= 0.01 ) . In terms of periodontal bone height , the 10-year changes implied statistically significant reductions within current as well as former smokers ( P < 0.001 and P < 0.05 , respectively ) , but not within non-smokers . The overall change was significantly associated with smoking controlling for age and bone height level at baseline ( P<0.01 ) , including statistically significant differences between current smokers and non-smokers and between current and former smokers , respectively ( P<0.05 ) . Moreover , the 10-year bone height reduction increased significantly with increasing smoking exposure controlling for age ( P < 0.05 ) . With regard to gingival bleeding , the 10-year differences between smoking groups were not statistically significant . Plaque index remained low throughout in all smoking groups at an overall average level of about 0.8 . CONCLUSIONS The results suggest that periodontal health is compromised by chronic smoking as evidence d by an increase of periodontally diseased sites concomitant with loss of periodontal bone height , as compared to non-smokers whose periodontal health condition remained unaltered throughout the 10-year period of investigation . The periodontal health condition in former smokers , similar to that of non-smokers , remained stable , suggesting that smoking cessation is beneficial to periodontal health PURPOSE This r and omized controlled clinical trial aim ed to evaluate the efficacy of splinted implants versus unsplinted implants in overdenture therapy over a 10-year period . MATERIAL S AND METHODS The study sample comprised 36 completely edentulous patients , 17 men and 19 women ( mean age 63.7 years ) . In each patient , 2 implants ( Brånemark System , Nobel Biocare , Göteborg , Sweden ) were placed in the interforaminal area . Three to 5 months after placement , they were connected to st and ard abutments . The patients were then rehabilitated with ball-retained overdentures , magnet-retained overdentures , or bar-retained overdentures ( the control group ) . Patients were followed for 4 , 12 , 60 , and 120 months post-abutment connection . Group means as well as linear regression models were fitted with attachment type and time as classification variables and corrected for simultaneous testing ( Tukey ) . RESULTS After 10 years , 9 patients had died and 1 was severely ill . Over 10 years , no implants failed . Mean Plaque Index , Bleeding Index , change in attachment level , Periotest values , and marginal bone level at the end of the follow-up period were not significantly different among the groups . DISCUSSION The annual marginal bone loss , excluding the first months of remodeling , was comparable with that found around healthy natural teeth . CONCLUSION The fact that no implants failed and that overall marginal bone loss after the first year of bone remodeling was limited suggested that implants in a 2-implant m and ibular overdenture concept have an excellent prognosis in this patient population , irrespective of the attachment system used Introduction Little is known about the effect of cigarette smoking cessation on risk of tooth loss . We examined how risk of tooth loss changed with longer periods of smoking abstinence in a prospect i ve study of oral health in men . Methods Research subjects were 789 men who participated in the Veterans Administration Dental Longitudinal Study from 1968 to 2004 . Tooth status and smoking status were determined at examinations performed every 3 years , for a maximum follow-up time of 35 years . Risk of tooth loss subsequent to smoking cessation was assessed sequentially at 1-year intervals with multivariate proportional hazards regression models . Men who never smoked cigarettes , cigars , or pipes formed the reference group . Hazard ratios were adjusted for age , education , total pack-years of cigarette exposure , frequency of brushing , and use of floss . Results The hazard ratio for tooth loss was 2.1 ( 95 % confidence interval [ CI ] , 1.5–3.1 ) among men who smoked cigarettes during all or part of follow-up . Risk of tooth loss among men who quit smoking declined as time after smoking cessation increased , from 2.0 ( 95 % CI , 1.4–2.9 ) after 1 year of abstinence to 1.0 ( 95 % CI , 0.5–2.2 ) after 15 years of abstinence . The risk remained significantly elevated for the first 9 years of abstinence but eventually dropped to the level of men who never smoked after 13 or more years . Conclusion These results indicate that smoking cessation is beneficial for tooth retention , but long-term abstinence is required to reduce the risk to the level of people who have never smoked BACKGROUND , AIMS In 1973 , a r and om sample of 574 dentate individuals aged 15 , 20 , 30 , 40 , 50 , and 60 years in the city of Jönköping , Sweden , were examined clinical ly and radiographically to assess oral health and overall treatment needs .  Periodontal examination included registration of plaque , gingivitis , probing depths at four aspects of each tooth , and interproximal bone height measurements on full-mouth intraoral radiographs . In 1990 , 17 years later , the same individuals were invited to participate in a new investigation . Of these , 433 ( 75 % ) agreed to participate in the investigation and were re-examined ( Hugoson & Laurell 2000 ) . The proximal alveolar bone height at all interproximal sites was measured and expressed as per cent of tooth length . Only teeth that were present in both 1973 and 1990 were included in the assessment of changes in bone score . From the age of 30 years , about 80 % of the population had one or more sites with a bone loss of 2 - 3 mm or more . Seventeen per cent of the individuals had more than six such sites , indicating destructive periodontal disease . Bone loss occurred at sites both with and without previous bone loss . The present study was undertaken to test the hypothesis that sites with a bone loss of 10 % or more of the tooth length ( 2 - 3 mm ) during the 17 years were r and omly distributed in the dentition . MATERIAL AND METHODS Of the 13,197 sites examined in individuals 20 - 60 years at baseline , 1201 sites ( 9.0 % ) in 998 teeth with a bone loss  corresponding to 10 % or more of the tooth length were found and included in the analysis . A probability test for binomial distribution was used to test the null hypothesis that all teeth had the same risk of losing bone regardless of its position in the dentition . The valid risk for each tooth was 3.571 % and the null hypothesis was rejected at the 95 % confidence interval . RESULTS Although all tooth types were affected by tooth loss , some teeth , namely 17 , 16 , 42 , 41 , and 31 , showed a higher incidence of sites losing bone , whereas 46 , 45 , 44 , and 36 had a lower incidence . Loser sites in smokers appeared more at r and om . CONCLUSION Sites that will develop periodontal break-down over time may appear at r and om , although with higher risk at maxillary molars and lower incisors . For the early detection of destructive periodontitis , periodontal examination that includes all teeth should be made routine in every dental check-up BACKGROUND Dental implants with moderately rough surfaces are commonly used in the treatment of edentulous patients . However , long-term data on survival rates and marginal bone conditions are lacking . PURPOSE This prospect i ve study evaluated the cumulative survival rate of the TiOblast implant ( Astra Tech AB , Mölndal , Sweden ) after 10 years of prosthetic loading . MATERIAL S AND METHODS A total of 199 TiOblast implants were placed in 36 consecutive edentulous patients ( 23 males and 13 females ) . All patients were treated at one clinic and by the same team . The patients were edentulous in either the maxilla ( n = 16 ) or the m and ible ( n = 20 ) . The average age of the patients at the start of the trial was 64 years ( range , 59 - 82 years ) . Of the 199 implants inserted 108 were in the m and ible and 91 were in the maxilla . Clinical evaluations were undertaken after completion of the prosthetic superstructure ( baseline ) and after 6 months , 1 year , 3 years , 5 years , 7 years , and 10 years . Mean marginal bone level was evaluated for the first 100 placed implants for up to 7 years . RESULTS Six implants failed during the study ( 3 in the m and ible and 3 in the maxilla ) . All failures occurred within the first year , giving a cumulative survival rate of 96.9 % ( 96.6 % in the maxilla and 97.2 % in the m and ible ) after 10 years of follow-up . The survival rate for the superstructures was 100 % . The mean marginal bone level in the measured sample was 0.2 mm ( st and ard deviation [ SD ] , 0.31 ) below the reference point at baseline , 0.28 mm ( SD , 0.20 ) and 1.27 mm ( SD , 1.15 ) below the same point 7 years later ( mean , 0.15 mm per year ) . CONCLUSION This study showed that titanium dioxide-blasted implants offer predictable long-term results as supports for fixed prostheses in both the maxilla and m and ible STATEMENT OF THE PROBLEM The clinical success of implant-supported fixed partial dentures has been documented . However , few studies have reported long-term results or any association between implant outcomes and host determinants . PURPOSE This study reports on implant and prosthesis outcomes in a group of partially edentulous patients treated with Brånemark implants in the posterior zones . It also examines factors described in the medical history that may influence implant survival . MATERIAL AND METHODS The charts of patients treated with implants from 1983 and followed prospect ively through December 2001 at the University of Toronto were review ed . One hundred thirty partially edentulous patients treated with implant-supported restorations in the posterior zones ( area distal to mental foramen ) were selected .  Implant and prosthesis treatment outcomes were recorded and analyzed through the Kaplan-Meier and Cox regression methods ( P<.05 ) . RESULTS A total of 130 patients received 432 Brånemark dental implants in 174 posterior edentulous spans . The mean age of the patients at the time of insertion of the implants was 50.97 + /- 13.27 years . At 15 years , the overall implant and prosthesis survival rates were 91.6 % and 89 % , respectively . At 5 years , the survival rate of the wide-platform 5-mm-diameter implants was 76.3 % . Implant diameter ( P=.0001 ) and a history of a chronic medical condition ( P=.01 ) were correlated with implant survival outcomes . CONCLUSIONS High success of implant-supported prostheses in the posterior zones of both the maxilla and m and ible . It corroborated other studies that have shown higher failure rates for wide-platform implants , emphasizing the need for proper establishment of clinical trials prior to marketing of new implant design BACKGROUND Numerous investigators have used osseointegrated dental implants as retention for m and ibular overdentures , but few have reported 10-year outcomes or incorporated carefully st and ardized radiographs to document crestal bone loss . PURPOSE The purpose of this study was to use a prospect i ve clinical trial design to assess the performance of short sintered porous-sur 
    Output:
    
In clinical ly well-maintained patients , the loss rate at teeth was lower than that at implant .
Bone level changes appeared to be small at teeth as well as at implants in well-maintained patients .