***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: PURPOSE The aim of the study was to compare the differences in the long-term clinical and radiologic effects for three different treatment strategies with implant-supported overdentures in the edentulous m and ible , with a special emphasis on smoking . MATERIAL S AND METHODS In a r and omized- controlled clinical trial , 110 edentulous patients participated . Thirty-six patients were treated with an overdenture supported by two implants with ball attachments ( 2IBA ) , 37 patients with an overdenture supported by two implants with a bar ( 2ISB ) and 37 patients with an overdenture supported by four implants with a triple bar ( 4ITB ) . After a mean evaluation period of 8.3 years , the clinical and radiographic parameters were evaluated . RESULTS Ninety-four out of the original 110 patients ( = 85 % ) were evaluated . In the 2IBA group , the plaque index was significantly lower ( vs. 2ISB , P=0.013 ; vs. 4ITB , P=0.001 ) than in the other groups , but there was no correlation with the other peri-implant parameters . In the 4ITB group , the marginal bone loss was significantly higher than that in the two implant groups . The maximal probing depth was correlated with peri-implant bone loss ( P=0.011 ) . Smoking almost doubled marginal bone loss irrespective of the treatment strategy chosen . CONCLUSIONS Patients with two implants show less marginal bone loss than those with four implants . Smoking is a risk factor for the survival of dental implants in the long run AIM This 1-year prospect i ve RCT compared the outcome of minimally ( turned ) and moderately rough ( TiUnite ) implant surfaces . MATERIAL AND METHODS Two subgroups of patients were formed ; one group ( n = 10 ) where all teeth had been extracted due to severe periodontitis , another group ( n = 8) with teeth in the antagonistic jaw with a history of periodontitis and some remaining medium pockets ( 4 - 6 mm ) .  Implants ( n = 85 , 43 turned & 42 TiUnite ) were installed r and omly in each patient . After 3 - 6 months of submerged healing , healing abutments were connected , followed by final abutments 2 weeks later , all with the same surface characteristics as the supporting implant . Peri-implant parameters and intra-oral radiographs were recorded up to 1 year after abutment connection . RESULTS Two turned implants  failed in the partial edentulous group during the initial healing period ( CSR : 95 % ) and none of the TiUnite ( CSR : 100 % ) surface . No statistically significant differences in clinical parameters could be observed between both surfaces . The partial edentulous subgroup showed more bone loss compared to the full edentulous subgroup . CONCLUSION Moderately rough implants have a similar clinical outcome ( at 1 year of loading in periodontitis susceptible patients ) compared to minimally rough implants The aim of this prospect i ve longitudinal study of patients treated for generalized aggressive periodontitis ( GAP ) was the clinical , microbiologic , and radiologic longitudinal evaluation of implants placed into bone regenerated by the guided bone regeneration ( GBR ) technique . Ten patients with GAP who had lost either one or two maxillary incisors or premolars through periodontal disease and whose alveolar bone was neither high nor wide enough for implant placement were enrolled in the study .  GBR was carried out in a two-stage procedure using titanium-reinforced extended polytetrafluoroethylene membranes and titanium screws . No bone graft or bone substitute material s were used . After 6 to 8 months , the membranes and supporting screws were removed , and a total of 15 implants ( Nobel Biocare ) were placed . The control group comprised 10 periodontally healthy patients who had a total of II implants ( Nobel Biocare ) placed in the maxilla ( incisor and premolar region ) without GBR because of aplasia , trauma , or endodontic lesions . All patients were examined 2 to 4 weeks before extraction of the nonretainable teeth ( baseline ) and again immediately after placement of the superstructure . Further examinations were performed within the framework of a 3-month recall schedule over a 3-year period . At each session , clinical parameters ( probing pocket depths , bleeding on probing , gingival recession , clinical attachment level , Gingival Index , and Plaque Index ) were recorded at teeth and implants , and the composition of the subgingival microflora was determined by dark-field microscopy and DNA probe . Intraoral radiographs were taken for control purpose s at baseline , immediately after insertion of the superstructure , and 1 and 3 years later . The GBR technique yielded a horizontal and vertical bone gain of 4.5 to 7.0 mm in the GAP patients . The clinical , microbiologic , and radiologic findings indicated healthy periodontal and periimplant conditions in both patient groups throughout the study . However , a slightly increased attachment loss ( 0.65 mm ) and bone loss ( 1.78 mm ) were recorded at the implants in the regenerated bone after 3 years of loading . The 3-year implant survival rate was 100 % in both groups . The possibility of continuous attachment loss and bone loss occurring at teeth and implants in regenerated bone can not be ruled out in patients treated for aggressive periodontitis . The prognosis for the retention of the teeth and implants is thus open to question The relationship between periodontitis and peri-implantitis remains a matter of debate . The present study compared , " within " r and omly chosen partially edentulous patients ( n=84 subjects , 97 jaws ) , the marginal bone loss around teeth and implants during 5 years ( range 3 to 11 years ) following the first year of bone remodelling . The patients had all been rehabilitated by means of screw-shape c.p . titanium implants with a machined surface ( Brånemark system ) . During the 5 years observation interval , periodontal parameters ( marginal bone and attachment loss , the latter for teeth only ) were collected together with data on confounding factors ( smoking , oral hygiene , tooth loss ) . Marginal bone loss was measured through long-cone intra-oral radiographs . The mean " interval " bone loss was significantly ( P=0.0001 ) higher around teeth ( 0.48+/-0.95 mm ) than around implants ( 0.09+/-0.28 mm ) . The corresponding data for the " worst " performing tooth ( 0.99+/-1.25 mm ) and implant ( 0.19+/-0.32 mm ) per subject showed the same tendency . Neither attachment nor bone loss around teeth correlated with marginal bone loss around implants . This study indicated that the rate of bone loss around screw-shape c.p . titanium implants with a machined surface ( Brånemark system implants ) was not influenced by the progression rate of periodontal destruction around the remaining teeth within the same jaw The roughness of intraoral hard surfaces plays an important role in bacterial adhesion and colonization . Earlier studies have shown that rough surfaces accumulate up to 25 times more subgingival plaque than do smooth sites . In the present study , the influence of surface smoothing was studied . In six partially edentulous patients waiting for a fixed prosthesis supported by endosseous titanium implants , four titanium abutments with different surface roughness were r and omly placed . After 1 month of intraoral exposure , subgingival plaque sample s from each abutment were compared within each patient by means of differential phase-contrast microscopy . After 3 months , supragingival and subgingival plaque sample s were taken from all abutments for differential phase-contrast microscopy and culturing . Probing depth , recession , and bleeding upon probing were scored at the same visit . Differential phase-contrast microscopy showed that subgingivally , only the two roughest abutments harbored spirochetes after 1 month . After 3 months , subgingivally , the composition of the flora showed little variation on the different abutment types , although spirochetes were only noticed around the roughest abutments . Anaerobic culturing result ed in comparable amounts of colony-forming units for all abutment types , both supragingivally and subgingivally . Subgingivally , the microbiologic composition did not show major interabutment differences . Clinical ly , small differences in probing depth were observed . The roughest abutment showed some attachment gain ( 0.2 mm ) during 3 months , whereas all other abutments had an attachment loss ranging from 0.8 to greater than 1 mm . The results indicate that a reduction in surface roughness ( less than a roughness of 0.2 micron ) had no major effect on the microbiologic composition , supragingivally or subgingivally . These observations indicate the existence of a threshold roughness below which no further impact on the bacterial adhesion and /or colonization should be expected . However , clinical evaluation seems to indicate that a certain surface roughness is necessary for increased resistance to clinical probing Bacterial adhesion to intra-oral , hard surfaces is firmly influenced by the surface roughness to these structures . Previous studies showed a remarkable higher subgingival bacterial load on rough surfaces when compared to smooth sites . More recently , the additional effect of a further smoothening of intra-oral hard surfaces on clinical and microbiological parameters was examined in a short-term experiment . The results indicated that a reduction in surface roughness below R(a ) = 0.2 microns , the so-called " thresholds R(a ) " , had no further effect on the quantitative/qualitative microbiological adhesion or colonisation , neither supra- nor subgingivally . This study aims to examine the long-term effects of smoothening intra-oral hard transgingival surfaces . In 6 patients expecting an overdenture in the lower jaw , supported by endosseus titanium implants , 2 different abutments ( transmucosal part of the implant ) : a st and ard machined titanium ( R(a ) = 0.2 microns ) and one highly polished and made of a ceramic material ( R(a ) = 0.06 microns ) were r and omly installed . After 3 months of intra-oral exposure , supra- and subgingival plaque sample s from both abutments were compared with each other by means of differential phase-contrast microscopy ( DPCM ) . Clinical periodontal parameters ( probing depth , gingival recession , bleeding upon probing and Periotest-value ) were recorded around each abutment . After 12 months , the supra- and subgingival sample s were additionally cultured in aerobic , CO2-enriched and anaerobic conditions . The same clinical parameters as at the 3-month interval were recorded after 12 months . At 3 months , spirochetes and motile organisms were only detected subgingivally around the titanium abutments . After 12 months , however , both abutment-types harboured equal proportions of spirochetes and motile organisms , both supra- and subgingivally . The microbial culturing ( month 12 ) failed to detect large inter-abutment differences . The differences in number of colony- forming units ( aerobic and anaerobic ) were within one division of a logarithmic scale . The aerobic culture data showed a higher proportion of Gram-negative organisms in the subgingival flora of the rougher abutments . From the group of potentially " pathogenic " bacteria , only Prevotella intermedia and Fusobacterium nucleatum were detected for anaerobic culturing and again the inter-abutment differences were negligible . Clinical ly , the smoothest abutment showed a slightly higher increase in probing depth between months 3 and 12 , and more bleeding on probing . The present results confirm the findings of our previous short-term study , indicating that a further reduction of the surface roughness , below a certain " threshold R(a ) " ( 0.2 microns ) , has no major impact on the supra- and subgingival microbial composition AIM This 3-year prospect i ve r and omized controlled trial compared the clinical , microbiological and biochemical outcome of minimally ( Turned , Tur ) and moderately rough ( TiUnite ( ® ) , TiU ) implant surfaces in a split-mouth design . MATERIAL AND METHODS The study population included 14 subjects : nine fully edentulous and five partially edentulous subjects with a history of periodontitis .  Implants ( n = 78 , 39 Tur and 39 TiU ) were installed r and omly in each patient . Peri-implant clinical parameters and intra-oral radiographs were recorded after 3 years of loading . Subgingival plaque and peri-implant crevicular fluid sample s were collected and analysed using culture and quantitative polymerase chain reaction for the biofilm , and enzyme-linked immunosorbent assay for the concentration of osteoprotegerin and receptor activator of nuclear factor kappa-B lig and , respectively . RESULTS No statistically significant differences in clinical , microbiological and biochemical parameters could be observed when comparing the Tur and TiU implant surfaces . CONCLUSION After 3 years of loading , in periodontitis susceptible patients , the moderately rough , TiU implants demonstrated a similar clinical outcome compared with the smoother , turned implants . Longer follow-up and studies using different implant types are needed to confirm the statement that minimally and moderately rough implant surfaces perform similar , both from a clinical and from a microbiological point of view BACKGROUND Many longitudinal studies of different implant systems have been published but few controlled r and omized investigations have been reported . A 1-year report of a comparative study of ITI Dental Implant System implants ( Straumann AG , Waldenburg , Switzerl and ) and Brånemark System implants ( Nobel Biocare AB , Gothenburg , Sweden ) has been published by the present authors . This paper is a 3-year follow-up of that r and omized study . PURPOSE The aim of the study was to compare the outcome of fixed partial 
    Output:
    
Implant with rough surfaces were more favourable for plaque accumulation during short-term follow-up .
On a long-term , turned implants surfaces were associated with more plaque and higher peri-implant bone loss .
Conclusions Within the limitations of the present study , rough implant surface does not seem to increase the incidence of peri-implantitis in comparison to turned implants surface