***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 was to compare the short-term performance of a session of single photodynamic therapy ( PDT ) and of a conventional ultrasonic debridement ( UST ) in persistent pockets of maintenance patients . In a prospect i ve , r and omized , controlled , single-blind clinical study , patients with chronic periodontitis with at least two persistent pockets ( > 4 mm ) were enrolled . They were treated either with UST ( n = 29 ) or PDT ( n = 25 ) . Clinical and microbiological examinations were performed at baseline and after 3 month . For UST , the mean probing depth was reduced from 5.3 to 4.5 mm ( p = < 0.001 ) and for PDT from 5.3 to 4.7 mm ( p < 0.001 ) with no difference between the two treatment modalities . Microbial counts were significantly reduced about 30 % to 40 % immediately after debridement but returned to baseline values at month 3 irrespective of treatment . PDT is not superior to conventional mechanical treatment of persistent pockets , but it may be a meaningful therapeutic alternative ; the clinical effects were too minor to draw a definitive conclusion BACKGROUND Single photodynamic therapy ( PDT ) has been effective in initial periodontal therapy , but only improved bleeding on probing ( BoP ) in maintenance patients after a single use . Repeated PDT has not been addressed . OBJECTIVES To study the possible added benefits of repeated adjunctive PDT to conventional treatment of residual pockets in patients enrolled in periodontal maintenance . MATERIAL AND METHODS Ten maintenance patients with 70 residual pockets [ probing pocket depth (PPD)>or=5 mm ] were r and omly assigned for treatment five times in 2 weeks ( Days 0 , 1 , 2 , 7 , 14 ) with PDT ( test ) or non-activated laser ( control ) following debridement . The primary outcome variable was PPD , and the secondary variables were clinical attachment level ( CAL ) and BoP. These were assessed at 3 , 6 and 12 months following the interventions . RESULTS Greater PPD reductions were observed in the test ( -0.67 + /- 0.34 ; p=0.01 ) compared with the control patients ( -0.04 + /- 0.33 ; NS ) after 6 months . Significant CAL gain ( + 0.52 + /- 0.31 ; p=0.01 ) was noted for the test , but not in the control ( -0.27 + /- 0.52 ; NS ) patients after 6 months . BoP percentages decreased significantly in test ( 97 - 64 % , 67 % , 77 % ) , but not control patients after 3 , 6 and 12 months . CONCLUSIONS Repeated ( five times ) PDT adjunctive to debridement yielded improved clinical outcomes in residual pockets in maintenance patients . The effects were best documented after 6 months AIM A r and omized-controlled clinical pilot trial was design ed to evaluate photodynamic therapy ( PDT ) for its bactericidal potential and clinical effect in the treatment of periodontitis . MATERIAL AND METHODS Fifty-eight subjects with chronic periodontitis were included . Each subject exhibited at least three active periodontal pockets 5 mm or deeper , bleeding on probing and the presence of Porphyromonas gingivalis . Subjects were r and omly assigned to a control group treated by subgingival ultrasound only or to a study group additionally treated by PDT .  Baseline clinical values of gingival index , bleeding on probing , probing pocket depths and clinical attachment levels were recorded and re-evaluated 90 days later . Pathogen screening for P. gingivalis , Tannerella forsythia and Treponema denticola was conducted at baseline as well as 10 , 42 and 90 days after treatment . RESULTS P. gingivalis was significantly reduced in both groups ( laser group : p=0.020 ; control group : p=0.042 ) . No significant reductions of T. forsythia and T. denticola were observed in either group . For the microbial parameters , no significant difference was found between the laser and the control group . All clinical parameters were significantly reduced in both groups after treatment . The mean probing pocket depths decreased from 5.79 to 4.55 mm in the laser group and from 5.54 to 4.51 in the control group . The intergroup difference was not significant ( p=0.82 ) . Bleeding on probing was reduced from 100 % evaluated at baseline to 47 % in the laser group and 59 % in the control group . The intergroup difference was not significant ( p=0.28 ) . No significant differences were observed in any other parameters . CONCLUSION Application of a single cycle of PDT was not effective as an adjunct to ultrasonic periodontal treatment . There were no extra reductions in pocket depths and bleeding on probing . With regard to eradicating bacteria , however , there are no additional effects as compared with conventional treatment alone In recent years , the combination of laser light and photosensitizer known as photodynamic therapy ( PDT ) has been used in periodontal therapy . However , there are not enough clinical studies to fully evaluate the effects of PDT on the periodontal tissues . This microbiological study examined the effects of PDT on the periodontal bacteria in combination with scaling and root planing ( SRP )  in the same group of patients by r and omly selecting PDT or SRP for use in different quadrants of the mouth . For the present study , PDT was compared with a diode laser ( 980 nm ) and an Nd : YA G laser ( 1,064 nm ) . Microbiological sample s were examined and evaluated over a period of three months . Significant bacterial reduction has been observed in all cases . The diode laser with SRP presented long-term positive results , while PDT showed a significant bacteria reduction during the entire observation period Recent pre clinical and clinical data have suggested the potential benefit of photodynamic therapy ( PDT ) in the treatment of periodontitis . However , currently , there are very limited data from controlled clinical trials evaluating the effect of PDT in the treatment of periodontitis . The aim of the present study was to evaluate the clinical and microbiological effects of the adjunctive use of PDT in non-surgical periodontal treatment in patients receiving supportive periodontal therapy . Twenty-four patients receiving regularly supportive periodontal therapy were r and omly treated with either subgingival scaling and root planing followed by a single episode of PDT ( test ) or subgingival scaling and root planing alone ( control ) . The following parameters were evaluated at baseline and at 3 months and 6 months after therapy : full mouth plaque score ( FMPS ) , full mouth bleeding score ( FMBS ) , bleeding on probing ( BOP ) at experimental sites , probing pocket depth ( PPD ) , gingival recession ( REC ) , and clinical attachment level ( CAL ) . Primary outcome variables were changes in PPD and CAL . Microbiological evaluation of Aggregatibacter actinomycetemcomitans ( A.a . ) , Porphyromonas gingivalis ( P.g . ) , Prevotella intermedia ( P.i . ) , Tannerella forsythensis ( T.f . ) , Treponema denticola ( T.d . ) , Peptostreptococcus micros ( P.m . ) , Fusobacterium nucleatum ( F.n . ) , Campylobacter rectus ( C.r . ) , Eubacterium nodatum ( E.n . ) , Eikenella corrodens ( E.c . ) , and Capnocytophaga species ( C.s . ) was also performed at baseline and at 3 months and 6 months after therapy , using a commercially available polymerase chain reaction test . No differences in any of the investigated parameters were observed at baseline between the two groups . At 3 months and 6 months after treatment , there were no statistically significant differences between the groups in terms of PPD , CAL and FMPS . At 3 months and 6 months , a statistically significantly higher improvement of BOP was found in the test group . At 3 months after therapy , the microbiological analysis showed a statistically significant reduction of F.n . and E.n . in the test group . At 6 months , statistically significantly higher numbers of E.c . and C.s . were detected in the test group . The additional application of a single episode of PDT to scaling and root planing failed to result in an additional improvement in terms of PPD reduction and CAL gain , but it result ed in significantly higher reduction of bleeding scores than following scaling and root planing alone OBJECTIVE The aim of the present study was to compare the effectiveness of a photodisinfection process to that of scaling and root planing ( SRP ) for non-surgical periodontal treatment . METHODOLOGY Thirty-three subjects with moderate to advanced periodontal disease were r and omly treated in one of three study arms with either photodisinfection ( PD ) alone ( Group 1 ) using a diode laser and photosensitizer combination , with SRP alone ( Group 2 ) , or with SRP and PD combined ( Group 3 ) . Clinical assessment s of bleeding on probing ( BOP ) , probing pocket depth ( PPD ) , and clinical attachment level ( CAL ) were made at baseline , three weeks , six weeks , and 12 weeks following therapy . RESULTS No difference in any of the investigated parameters was observed at baseline between the three groups . The mean value of BOP decreased in the PD group ( Group 1 ) from baseline by 71 % at six weeks and 73 % at 12 weeks , and in the SRP alone group ( Group 2 ) from baseline by 43 % at six weeks and 56 % at 12 weeks . The BOP in the combined SRP + PD group ( Group 3 ) decreased from baseline by 65 % at six and 59 % at 12 weeks . The sites treated with PD alone demonstrated mean CAL gains of 0.09 + /- 0.38 mm and 0.14 + /- 0.65 mm at six and 12 weeks , respectively . Those sites treated with SRP alone demonstrated mean CAL gains of 0.37 + /- 0.34 mm and of 0.36 + /- 0.35 mm at six and 12 weeks , respectively . The final group of SRP + PD demonstrated mean CAL gains of 0.92 + /- 0.62 mm and 0.86 + /- 0.61 mm at six and 12 weeks , respectively ( p < 0.01 for six weeks and p < 0.02 for 12 weeks when compared to SRP alone ) . The sites treated with PD alone demonstrated mean PPD reductions of 0.69 + /- 0.33 mm and of 0.67 + /- 0.44 mm at six and 12 weeks , respectively . Those sites treated with SRP alone demonstrated mean PPD reductions of 0.78 + /- 0.47 mm and 0.74 + /- 0.43 mm at six and 12 weeks , respectively . The final group of SRP + PD demonstrated mean PPD reductions of 1.16 + /- 0.39 mm and 1.11 + /- 0.53 at six and 12 weeks , respectively ( p < 0.06 for six weeks and p < 0.05 for 12 weeks when compared to SRP alone ) . CONCLUSION Within the limits of the present study , it can be concluded that SRP combined with photodisinfection leads to significant improvements of the investigated parameters over the use of SRP alone The aim of this trial was to investigate changes occurring in the subgingival microbiological composition of subjects with aggressive periodontitis , treated with antimicrobial photodynamic therapy ( aPDT )  , in a single episode , or scaling and root planing ( SRP )  , in a split-mouth design on −7 , 0 , and + 90 days . Ten patients were r and omly assigned to either aPDT using a laser source in conjunction with a photosensitizer or SRP with h and instruments . Subgingival plaque sample s were collected and the counts of 40 subgingival species were determined using checkerboard DNA-DNA hybridization . The data were analyzed using the method of generalized estimating equations ( GEE ) to test the associations between treatments , evaluated parameters , and experimental times ( α = .05 ) . The results indicated that aPDT and SRP  affects different bacterial species , with aPDT being effective in reducing numbers of A. actinomycetemcomitans than SRP . On the other h and , SRP was more efficient than  aPDT in reducing the presence of periodontal pathogens of the Red Complex . Additionally , a recolonization in the sites treated by aPDT was observed , especially for T. forsythia and P. gingivalis . Under our experimental conditions , this trial demonstrates that aPDT and SRP affected different groups of bacteria , suggesting that their association may be beneficial for the non-surgical treatment of aggressive periodontitis The aim of this study was to evaluate the effects of the photodynamic therapy ( PDT ) on the inflammatory infiltrate and on the collagen network organization in human advanced chronic periodontitis . Two different drug delivery systems ( DDS ) were tested ( liposomes and nanoemulsions ) to determine if the effects of PDT could differ according to the DDS used . Sixteen patients presenting two teeth with chronic advanced periodontitis and important tooth mobility with clinical indication of extraction were included in the group liposomes ( group L , n=8 ) or in the group nanoemulsions ( group N , n=8 ) in order to compare the effects of each DDS . Seven days before extraction s one tooth of each patient was treated with PDT using phthalocyanine derivatives as photosensitizers and the contralateral tooth was taken as control . In group L the density of gingival collagen fibers ( 66±19 % ) was significantly increased ( p<0.02 ) when compared to controls ( 35±21 % ) . Concerning the antigen-presenting cells , PDT had differential effects depending on the drug delivery system 
    Output:
    
Neither heterogeneity nor publication bias was detected .
The use of antimicrobial photodynamic therapy adjunctive to conventional treatment provides short-term benefits , but microbiological outcomes are contradictory .
There is no evidence of effectiveness for the use of antimicrobial photodynamic therapy as alternative to scaling root planing .