human
***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: The aim of this study of the present experiment was to study the marginal periimplant tissues at intentionally non-submerged ( 1-stage implants ) and initially submerged and subsequently exposed implants ( 2-stage implants ) . 5 beagle dogs , about 1-year-old , were used , 3 months after the extraction of the m and ibular premolars , fixtures of the Astra Tech Implants Dental System , the Brånemark System and the Bonefit -- ITI system were installed . In each m and ibular quadrant , 1 fixture of each implant system was installed in a r and omised order . The installation procedure followed the recommendations given in the manuals for each system . Thus , following installation , the bone crest coincided with the fixture margin of the Astra Tech Implants Dental System and the Brånemark System , whereas the border between the plasma sprayed and the machined surface of the Bonefit-ITI implant system was positioned at the level of the bone crest . Following a healing period of 3 months , abutment connection was carried out in the 2-stage systems ( the Astra Tech Implants Dental System and the Brånemark system ) . A 6-month period of plaque control was initiated . The animals were sacrificed and biopsies representing each important region dissected . The tissue sample s were prepared for light microscopy and exposed to histometric and morphometric measurements . The mucosal barrier which formed to the titanium surface following 1-stage and 2-stage implant installations comprised an epithelial and a connective tissue component , which for that 3 systems studied , had similar dimensions and composition . The amount of lamellar bone contained in the periimplant region close to the fixture part of the 3-implant systems was almost identical . It is suggested that correctly performed implant installation may ensure proper conditions for both and hard tissue healing , and that the geometry of the titanium implant seems to be of limited importance This paper describes the 5-year results of a comparative study between Astra Tech and Brånemark system implants . The aim was to compare the systems primarily with regard to bone level changes , and also with regard to other variables of interest . Sixty-six patients with edentulous jaws were included in the study . R and omisation schedules were used to allocate the patients to the two implant systems . 184 Astra Tech implants with a titanium-blasted surface and 187 Brånemark implants with a turned surface were used . The implants were inserted with a two-stage technique and the insertion followed the routines for the respective implant system . All patients were provided with full-arch fixed bridges . All patients were followed up with clinical and radiographic examinations from fixture insertion to the 5-year follow-up . The total mean bone level change in the upper jaw between fixture insertion and the 5-year examination was -1.74+/-0.45 mm at the Astra implants and -1.98+/-0.21 at the Brånemark implants . The corresponding values for the lower jaw were -1.06+/-0.19 for Astra and -1.38+/-0.17 for Brånemark . The major postoperative changes of the marginal bone level took place between fixture insertion and baseline . During this period , there was also a different pattern of bone remodelling between the implant systems . Between baseline ( prosthesis connection ) and the 5-year examination , the marginal bone level changes were small , with no difference between the implant systems . The implant stability was examined with the supraconstructions removed . At the 5-year examination , the survival rate for Astra Tech implants was 98.4 % and for the Brånemark implants it was 94.6 % . The difference was not statistically significant Previous papers in this series on evidence -based dentistry have discussed the first 2 steps in seeking answers to clinical problems formulating a clear question and strategically search ing for evidence . The next step , critical appraisal of the evidence , is made easier if one underst and s the basic concepts of clinical research design . The strongest design , especially for questions related to therapeutic or preventive interventions , is the r and omized , controlled trial . Questions relating to diagnosis , prognosis and causation are often studied with observational , rather than experimental , research design s. The strongest study design should be used whenever possible . Rules have been established to grade research evidence . This paper , the fourth in the series , presents an overview of research methodology most commonly used in the dental literature The purpose of the investigation was to gain more underst and ing of marginal inflammatory reactions around osseointegrated implants . The significance of the lacking periodontal ligament of implants was examined in the initial breakdown phase of supporting tissues by comparing clinical and radiographic manifestations of ligature-induced marginal inflammation related to osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys ( Macaca fascicularis ) . Bilateral extraction of the first and second m and ibular molars was carried out initially , and 12 weeks later 2 implants were placed in each side . Ankylosis of the second maxillary molars was established by extracting and replanting the teeth after a drying period . When ankylosis and osseointegration were established , ligature-induced marginal inflammation was induced in the right or left side at r and om around implants , ankylosed teeth and normal control teeth ( second maxillary premolar ) for 7 weeks . Although the clinical manifestations as expressed by plaque score , gingival score , probing depth and attachment loss were quite similar , the radiographic features differed . Significant loss of bone height was limited to implants and ankylosed teeth and did not occur in relation to normal control teeth . Furthermore , the bone loss around implants was significantly greater than the loss around ankylosed teeth . Bone loss was limited to implants and ankylosed teeth ; the study therefore suggests that the presence of marginal inflammation around implants and ankylosed teeth may have more serious implication s than does marginal inflammation around teeth with a periodontal ligament . However , variations in microbiota and susceptibility of different jaw positions to periodontal breakdown may influence the results of this study The aim of the present experiment was to study the location and composition of plaque associated lesions in the mucosa adjacent to implant systems that differed with respect to both geometry and dimension . At day 0 extraction of the m and ibular premolars were performed . After a healing period of 3 months , fixtures of the Astra Tech Implants , Dental System , the Brånemark System and the ITI Dental Implant System were installed . In each m and ibular quadrant 1 fixture of each implant system was installed in a r and omized order . A period of plaque control was initiated . Following another 3 months of healing , abutment connection was performed in the 2-stage systems ( the Astra Tech Implants , Dental System and the Brånemark System ) . After 1 month , the plaque control measures were ab and oned and plaque formation was allowed for 5 months . The animals were killed and biopsies representing each implant region obtained . The tissue sample s were prepared for light microscopy and exposed to histometric and morphometric measurements . The present study demonstrated that plaque formation result ed in the establishment of an ICT lateral to a pocket epithelium . The lesion was found to be similar regarding extension and composition in the peri-implant mucosa of the 3 implant systems tested . The vertical extension of the ICT was in all systems within 91 - 99 % of the vertical dimension of the junctional epithelium . The marginal bone level , measured from the abutment/fixture ( PS ) border , did not differ between the three systems This investigation is the result of a multicenter research project between the Catholic University of Leuven and the University of Madrid with the purpose of study ing histometrically and ultrastructurally periimplant marginal tissue reactions in mendium-term Brånemark implants . 12 patients were selected and distributed according to predefined clinical and radiological parameters into a periimplant infection group ( A ) and a non-periimplant infection group ( B ) . Biopsies were taken from these patients and analyzed by means of microscopy ( LM ) , histometry ( HM ) and transmission electron microscopy ( TEM ) . With LM group A showed pathological features consistent with an advanced gingivitis lesion , while group B showed signs of healthy gingiva in the connective tissue and vauolae formation in the epithelium . With HM , group A showed significantly higher transmigration of inflammatory cells in the epithelium than group B. In the connective tissue , group A showed a higher % of inflammatory infiltrate with significantly higher numbers of plasma cells and mononuclear cells than group B. With TEM , group A showed an ultrastructural picture consistent with plaque-induced periodontitis , while group B showed a rather healthy connective tissue and vacuolae formation in the epithelium . These results suggest that supracrestal marginal tissues around osseointegrated implants react to plaque bacteria similarly to periodontal tissues around teeth by chronic inflammation BACKGROUND Progressive peri-implant bone losses , which are accompanied by inflammatory lesions in the soft tissues , are referred to as peri-implantitis . The aim of this study was to compare the effects of photodynamic therapy ( PDT ) and conventional technique on microbial reduction in ligature-induced peri-implantitis in dogs . METHODS Eighteen third premolars from nine Labrador retriever dogs were extracted and the implants were submerged . After osseointegration , peri-implantitis was induced . After 4 months , ligature was removed and natural bacterial plaque was allowed to form for another 4 months . The animals were then r and omly divided into two groups . In the conventional group , they were treated using mucoperiosteal flaps for scaling the implant surface and chlorexidine ( conventional ) irrigation . In the PDT group , only mucoperiosteal scaling was carried out before photodynamic therapy . Inside the peri-implant pocket , a paste-based azulene photosensitizer was placed and then a GaAlAs low-power laser ( lambda=660 nm , P=40 mW , E=7.2 J for 3 minutes ) was used . Microbiological sample s were obtained before and immediately after treatment . Before treatment , one implant was removed and analyzed by scanning electron microscopy to vali date the contamination . RESULTS The results of this study showed that Prevotella sp. , Fusobacterium sp. , and S. Beta-haemolyticus were significantly reduced for both groups . After treatment , no significant differences were observed between the groups . CONCLUSION These findings suggest that photodynamic therapy is a non-invasive method that could be used to reduce microorganisms in peri-implantitis After 3 years , 82 of the original 92 patients remain in this prospect i ve multicenter study of single-tooth restorations supported by Brånemark implants . Since the 1-year follow-up , 6 more patients have been lost , but no additional implants have failed in those patients examined at the 3-year follow-up visit . After 1 year of function , 97.2 % of the implants survived in 88 patients , and between the 1- and 3-year follow-up , 100 % survived in 82 patients , giving a 3-year cumulative success rate of 97.2 % . No changes were observed in the status of gingivitis , pocket depth , periodontal pocket bleeding index , and tooth and implant mobility from those reported after 1 year . Marginal bone resorption remained at a low level -- less than 0.1 mm annually during the second and third years . Abutment screw loosening continued , but at a significantly reduced rate from that reported after 1 year . When used , gold rather than titanium abutment screws remained secure BACKGROUND Today , implants are placed using both non-submerged and submerged approaches , and in 1- and 2-piece configurations . Previous work has demonstrated that peri-implant crestal bone reactions differ radiographically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of the interface ( microgap ) between the implant and abutment/restoration in 2-piece configurations . The purpose of this investigation was to examine histometrically crestal bone changes around unloaded non-submerged and submerged 1- and 2-piece titanium implants in a side-by-side comparison . METHODS A total of 59 titanium implants were r and omly placed in edentulous m and ibular areas of 5 foxhounds , forming 6 different implant subgroups ( types A-F ) . In general , all implants had a relatively smooth , machined coronal portion as well as a rough , s and blasted and acid-etched ( SLA ) apical portion . Implant types A-C were placed in a non-submerged approach , while types D-F were inserted in a submerged fashion . Type A and B implants were 1-piece implants with the rough/smooth border ( r/s ) at the alveolar crest ( type A ) or 1.0 mm below ( type B ) . Type C implants had an abutment placed at the time of surgery with the interface located at the bone crest level . In the submerged group , types D-F , the interface was located either at the bone crest level ( type D ) , 1 mm above ( type E ) , or 1 mm below ( type F ) . Three months after implant placement , abutment connection was performed in the submerged implant groups . At 6 months , all animals were sacrificed . Non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels . RESULTS For types A and B , mean crestal bone levels were located adjacent ( within 0.20 mm ) to the rough/smooth border ( r/s ) . For type C implants , the mean distance ( + /- st and ard deviation ) between the interface and the crestal bone level was 1.68 mm ( + /- 0.19 mm ) with an r/s border to first bone-to-implant contact ( fB 
    Output:
    
agent
Evidence analysis shows that the present knowledge about biologic width around implants is mainly derived from animal studies and that clinical controlled human studies are insufficient
***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: The aim of this study of the present experiment was to study the marginal periimplant tissues at intentionally non-submerged ( 1-stage implants ) and initially submerged and subsequently exposed implants ( 2-stage implants ) . 5 beagle dogs , about 1-year-old , were used , 3 months after the extraction of the m and ibular premolars , fixtures of the Astra Tech Implants Dental System , the Brånemark System and the Bonefit -- ITI system were installed . In each m and ibular quadrant , 1 fixture of each implant system was installed in a r and omised order . The installation procedure followed the recommendations given in the manuals for each system . Thus , following installation , the bone crest coincided with the fixture margin of the Astra Tech Implants Dental System and the Brånemark System , whereas the border between the plasma sprayed and the machined surface of the Bonefit-ITI implant system was positioned at the level of the bone crest . Following a healing period of 3 months , abutment connection was carried out in the 2-stage systems ( the Astra Tech Implants Dental System and the Brånemark system ) . A 6-month period of plaque control was initiated . The animals were sacrificed and biopsies representing each important region dissected . The tissue sample s were prepared for light microscopy and exposed to histometric and morphometric measurements . The mucosal barrier which formed to the titanium surface following 1-stage and 2-stage implant installations comprised an epithelial and a connective tissue component , which for that 3 systems studied , had similar dimensions and composition . The amount of lamellar bone contained in the periimplant region close to the fixture part of the 3-implant systems was almost identical . It is suggested that correctly performed implant installation may ensure proper conditions for both and hard tissue healing , and that the geometry of the titanium implant seems to be of limited importance This paper describes the 5-year results of a comparative study between Astra Tech and Brånemark system implants . The aim was to compare the systems primarily with regard to bone level changes , and also with regard to other variables of interest . Sixty-six patients with edentulous jaws were included in the study . R and omisation schedules were used to allocate the patients to the two implant systems . 184 Astra Tech implants with a titanium-blasted surface and 187 Brånemark implants with a turned surface were used . The implants were inserted with a two-stage technique and the insertion followed the routines for the respective implant system . All patients were provided with full-arch fixed bridges . All patients were followed up with clinical and radiographic examinations from fixture insertion to the 5-year follow-up . The total mean bone level change in the upper jaw between fixture insertion and the 5-year examination was -1.74+/-0.45 mm at the Astra implants and -1.98+/-0.21 at the Brånemark implants . The corresponding values for the lower jaw were -1.06+/-0.19 for Astra and -1.38+/-0.17 for Brånemark . The major postoperative changes of the marginal bone level took place between fixture insertion and baseline . During this period , there was also a different pattern of bone remodelling between the implant systems . Between baseline ( prosthesis connection ) and the 5-year examination , the marginal bone level changes were small , with no difference between the implant systems . The implant stability was examined with the supraconstructions removed . At the 5-year examination , the survival rate for Astra Tech implants was 98.4 % and for the Brånemark implants it was 94.6 % . The difference was not statistically significant Previous papers in this series on evidence -based dentistry have discussed the first 2 steps in seeking answers to clinical problems formulating a clear question and strategically search ing for evidence . The next step , critical appraisal of the evidence , is made easier if one underst and s the basic concepts of clinical research design . The strongest design , especially for questions related to therapeutic or preventive interventions , is the r and omized , controlled trial . Questions relating to diagnosis , prognosis and causation are often studied with observational , rather than experimental , research design s. The strongest study design should be used whenever possible . Rules have been established to grade research evidence . This paper , the fourth in the series , presents an overview of research methodology most commonly used in the dental literature The purpose of the investigation was to gain more underst and ing of marginal inflammatory reactions around osseointegrated implants . The significance of the lacking periodontal ligament of implants was examined in the initial breakdown phase of supporting tissues by comparing clinical and radiographic manifestations of ligature-induced marginal inflammation related to osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys ( Macaca fascicularis ) . Bilateral extraction of the first and second m and ibular molars was carried out initially , and 12 weeks later 2 implants were placed in each side . Ankylosis of the second maxillary molars was established by extracting and replanting the teeth after a drying period . When ankylosis and osseointegration were established , ligature-induced marginal inflammation was induced in the right or left side at r and om around implants , ankylosed teeth and normal control teeth ( second maxillary premolar ) for 7 weeks . Although the clinical manifestations as expressed by plaque score , gingival score , probing depth and attachment loss were quite similar , the radiographic features differed . Significant loss of bone height was limited to implants and ankylosed teeth and did not occur in relation to normal control teeth . Furthermore , the bone loss around implants was significantly greater than the loss around ankylosed teeth . Bone loss was limited to implants and ankylosed teeth ; the study therefore suggests that the presence of marginal inflammation around implants and ankylosed teeth may have more serious implication s than does marginal inflammation around teeth with a periodontal ligament . However , variations in microbiota and susceptibility of different jaw positions to periodontal breakdown may influence the results of this study The aim of the present experiment was to study the location and composition of plaque associated lesions in the mucosa adjacent to implant systems that differed with respect to both geometry and dimension . At day 0 extraction of the m and ibular premolars were performed . After a healing period of 3 months , fixtures of the Astra Tech Implants , Dental System , the Brånemark System and the ITI Dental Implant System were installed . In each m and ibular quadrant 1 fixture of each implant system was installed in a r and omized order . A period of plaque control was initiated . Following another 3 months of healing , abutment connection was performed in the 2-stage systems ( the Astra Tech Implants , Dental System and the Brånemark System ) . After 1 month , the plaque control measures were ab and oned and plaque formation was allowed for 5 months . The animals were killed and biopsies representing each implant region obtained . The tissue sample s were prepared for light microscopy and exposed to histometric and morphometric measurements . The present study demonstrated that plaque formation result ed in the establishment of an ICT lateral to a pocket epithelium . The lesion was found to be similar regarding extension and composition in the peri-implant mucosa of the 3 implant systems tested . The vertical extension of the ICT was in all systems within 91 - 99 % of the vertical dimension of the junctional epithelium . The marginal bone level , measured from the abutment/fixture ( PS ) border , did not differ between the three systems This investigation is the result of a multicenter research project between the Catholic University of Leuven and the University of Madrid with the purpose of study ing histometrically and ultrastructurally periimplant marginal tissue reactions in mendium-term Brånemark implants . 12 patients were selected and distributed according to predefined clinical and radiological parameters into a periimplant infection group ( A ) and a non-periimplant infection group ( B ) . Biopsies were taken from these patients and analyzed by means of microscopy ( LM ) , histometry ( HM ) and transmission electron microscopy ( TEM ) . With LM group A showed pathological features consistent with an advanced gingivitis lesion , while group B showed signs of healthy gingiva in the connective tissue and vauolae formation in the epithelium . With HM , group A showed significantly higher transmigration of inflammatory cells in the epithelium than group B. In the connective tissue , group A showed a higher % of inflammatory infiltrate with significantly higher numbers of plasma cells and mononuclear cells than group B. With TEM , group A showed an ultrastructural picture consistent with plaque-induced periodontitis , while group B showed a rather healthy connective tissue and vacuolae formation in the epithelium . These results suggest that supracrestal marginal tissues around osseointegrated implants react to plaque bacteria similarly to periodontal tissues around teeth by chronic inflammation BACKGROUND Progressive peri-implant bone losses , which are accompanied by inflammatory lesions in the soft tissues , are referred to as peri-implantitis . The aim of this study was to compare the effects of photodynamic therapy ( PDT ) and conventional technique on microbial reduction in ligature-induced peri-implantitis in dogs . METHODS Eighteen third premolars from nine Labrador retriever dogs were extracted and the implants were submerged . After osseointegration , peri-implantitis was induced . After 4 months , ligature was removed and natural bacterial plaque was allowed to form for another 4 months . The animals were then r and omly divided into two groups . In the conventional group , they were treated using mucoperiosteal flaps for scaling the implant surface and chlorexidine ( conventional ) irrigation . In the PDT group , only mucoperiosteal scaling was carried out before photodynamic therapy . Inside the peri-implant pocket , a paste-based azulene photosensitizer was placed and then a GaAlAs low-power laser ( lambda=660 nm , P=40 mW , E=7.2 J for 3 minutes ) was used . Microbiological sample s were obtained before and immediately after treatment . Before treatment , one implant was removed and analyzed by scanning electron microscopy to vali date the contamination . RESULTS The results of this study showed that Prevotella sp. , Fusobacterium sp. , and S. Beta-haemolyticus were significantly reduced for both groups . After treatment , no significant differences were observed between the groups . CONCLUSION These findings suggest that photodynamic therapy is a non-invasive method that could be used to reduce microorganisms in peri-implantitis After 3 years , 82 of the original 92 patients remain in this prospect i ve multicenter study of single-tooth restorations supported by Brånemark implants . Since the 1-year follow-up , 6 more patients have been lost , but no additional implants have failed in those patients examined at the 3-year follow-up visit . After 1 year of function , 97.2 % of the implants survived in 88 patients , and between the 1- and 3-year follow-up , 100 % survived in 82 patients , giving a 3-year cumulative success rate of 97.2 % . No changes were observed in the status of gingivitis , pocket depth , periodontal pocket bleeding index , and tooth and implant mobility from those reported after 1 year . Marginal bone resorption remained at a low level -- less than 0.1 mm annually during the second and third years . Abutment screw loosening continued , but at a significantly reduced rate from that reported after 1 year . When used , gold rather than titanium abutment screws remained secure BACKGROUND Today , implants are placed using both non-submerged and submerged approaches , and in 1- and 2-piece configurations . Previous work has demonstrated that peri-implant crestal bone reactions differ radiographically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of the interface ( microgap ) between the implant and abutment/restoration in 2-piece configurations . The purpose of this investigation was to examine histometrically crestal bone changes around unloaded non-submerged and submerged 1- and 2-piece titanium implants in a side-by-side comparison . METHODS A total of 59 titanium implants were r and omly placed in edentulous m and ibular areas of 5 foxhounds , forming 6 different implant subgroups ( types A-F ) . In general , all implants had a relatively smooth , machined coronal portion as well as a rough , s and blasted and acid-etched ( SLA ) apical portion . Implant types A-C were placed in a non-submerged approach , while types D-F were inserted in a submerged fashion . Type A and B implants were 1-piece implants with the rough/smooth border ( r/s ) at the alveolar crest ( type A ) or 1.0 mm below ( type B ) . Type C implants had an abutment placed at the time of surgery with the interface located at the bone crest level . In the submerged group , types D-F , the interface was located either at the bone crest level ( type D ) , 1 mm above ( type E ) , or 1 mm below ( type F ) . Three months after implant placement , abutment connection was performed in the submerged implant groups . At 6 months , all animals were sacrificed . Non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels . RESULTS For types A and B , mean crestal bone levels were located adjacent ( within 0.20 mm ) to the rough/smooth border ( r/s ) . For type C implants , the mean distance ( + /- st and ard deviation ) between the interface and the crestal bone level was 1.68 mm ( + /- 0.19 mm ) with an r/s border to first bone-to-implant contact ( fB 
    Output:
    