***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 Freeze-dried acellular dermal matrix ( ADM ) allograft , originally used for full-thickness burn wounds , was recently introduced as an alternative to the autogenous free gingival graft ( FGG ) in achieving increased attached keratinized tissue . The aim of part 1 of this study was to investigate the clinical efficacy of the ADM allograft for this particular purpose . METHODS Twelve patients , 7 males and 5 females , with attached gingiva < or = 1 mm on the facial aspect of m and ibular anterior teeth demonstrating a tendency of progressive marginal tissue recession , were r and omly assigned to either test or control treatment . Six patients received ADM graft ( test ) and 6 patients received an autogenous FGG harvested from the hard palate ( control ) . Clinical variables including plaque index ( PI ) , gingival index ( GI ) , probing depth ( PD ) , attached tissue width ( AT ) , and gingival recession ( GR ) were recorded immediately before surgery and at the 6-month postoperative visit . Patients were seen at 2 , 4 , 6 , 8 , and 12 weeks to monitor wound healing and oral hygiene performance ( PI and GI ) . Graft width was also measured , in corono-apical direction , on individually involved teeth during the surgery . RESULTS When values between baseline and 6 months were compared in both groups , there was no statistically significant difference in changes of PI , GI , PD , and GR ( P>0.05 ) with the exception of PD in the FGG group ( 1.01 + /- 0.03 versus 1.27 + /- 0.20 mm , P= 0.042 ) . There was a statistically significant ( P < 0.05 ) increase in AT in both groups . Although the ADM group received wider grafts than the FGG group ( 8.81 + /- 0.46 versus 6.70 + /- 0.89 mm ) , the AT gain was significantly smaller ( 2.59 + /- 0.92 versus 5.57 + /- 0.44 mm ) and the graft shrinkage significantly greater ( 71 + /- 10 % versus 16 + /- 12 % ) in the ADM group than in the FGG group ( P<0.01 ) . CONCLUSIONS The results of this study suggest that in procedures aim ing at increasing the width of attached gingiva : 1 ) the ADM allograft was less effective and less predictable than the autogenous FGG in terms of increasing attached keratinized tissue due to considerable shrinkage and inconsistent quality of the attached tissue gained and 2 ) the esthetic results using the ADM allograft might be better than those using the autogenous FGG BACKGROUND Periodontists have found the gingival autograft to be an effective and predictable technique to increase the amount of attached gingiva around teeth , but this technique requires the surgeon to harvest donor tissue from a remote surgical site . The present study seeks to evaluate the safety and effectiveness of a tissue-engineered skin equivalent , a living human fibroblast-derived dermal substitute ( HF-DDS ) , compared to a gingival autograft ( GA ) consisting of donor tissue harvested from the patient 's palate in a procedure design ed to increase the amount of keratinized tissue around teeth that do not require root coverage . METHODS Twenty-five patients with insufficient attached gingiva associated with at least two teeth in contralateral quadrants of the same jaw were treated . One tooth in each patient was r and omized to receive either a GA ( control ) or a HF-DDS graft ( test ) . Clinical parameters measured at baseline and 3 , 5 , 7 , 9 , and 12 months included recession , clinical attachment level , keratinized tissue height , and plaque index . Probing depth was measured at 7 , 9 , and 12 months . Inflammation of each site was scored and texture and color of the grafted tissue were compared to the surrounding tissue . Resistance to muscle pull was evaluated and a question naire was used to determine patient preference . Surgical position of the graft and alveolar bone level were recorded at the surgical visit and patients were evaluated weekly for the first 4 weeks at which time recession and level of oral hygiene were measured . Biopsies and persistence studies were performed on a subset of the patients . RESULTS Results for both test and control groups were similar for all measured clinical parameters with the exception of amount of keratinized tissue and percent shrinkage of keratinized tissue . The control group exhibited an average of 1.0 to 1.2 mm more keratinized tissue over time than the test group ( P < 0.001 ) and the control group had about half as much shrinkage as the test group over time ( P < 0.001 ) . Test sites demonstrated significantly better color match over time compared to control sites . Similarly , tissue texture for test sites was significantly better than control sites over time . CONCLUSIONS Based on the results of this investigation , the tissue engineered HF-DDS graft was safe and capable of generating keratinized tissue without the morbidity and potential clinical difficulties associated with donor site surgery . The GA generated more keratinized tissue and shrank less than the HF-DDS graft , but the test graft generated tissue that appeared more natural BACKGROUND This study evaluated the safety and effectiveness of a tissue-engineered skin product composed of viable neonatal keratinocytes and fibroblasts and compared it to a free gingival graft ( FGG ) in a procedure to enhance keratinized tissue ( KT ) and wound healing around teeth that do not require root coverage . METHODS Twenty-five subjects were enrolled who had at least two non-adjacent teeth in contralateral quadrants exhibiting an insufficient zone of attached gingiva requiring soft tissue grafting where root coverage was not desired . One tooth was r and omized to receive an FGG , and the other was r and omized to receive bilayered cell therapy ( BCT ) . The amount of KT was measured at baseline and 3 and 6 months , and the texture and color of the grafted tissue were compared to the surrounding tissue at months 1 , 3 , and 6 . A question naire was used to determine subject preference at 6 months . Biopsies and persistence studies were performed on a subset of the subjects . RESULTS The FGG generated statistically significantly ( P < 0.001 ) more KT than the test device ( BCT ) ( 4.5 + /- 0.80 mm versus 2.4 + /- 1.02 mm ) ; no significant difference in recession or clinical attachment level was detected between treatment groups ( P = 0.212 and P = 0.448 , respectively ) ; and no significant differences were detected at any time point for bleeding on probing ( BOP ) , resistance to muscle pull , or inflammation . The BCT group had significantly better color and texture match with surrounding tissue ( P < 0.001 ) , and subject preference was significantly greater for the BCT group ( P = 0.041 ) . No device-related adverse events or safety issues occurred during the course of the study . CONCLUSIONS The tissue-engineered graft BCT was safe and capable of generating de novo KT without the morbidity and potential clinical difficulties associated with donor-site surgery . The amount of KT generated with FGG was greater than generated with BCT ; however , 24 of 25 test sites demonstrated an increase in KT at 6 months , with more than three-quarters of the sites yielding > or = 2 mm b and s of KT Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more This study was conducted to compare the efficacy and feasibility of an extracellular matrix membrane ( DynaMatrix ) with that of an autogenous gingival graft in increasing the width of attached keratinized tissue . Six patients with an inadequate amount of attached keratinized gingiva on the bilateral facial aspect of the m and ibular posterior teeth were recruited for this study . The defect sites were r and omly subjected to receive either test ( DynaMatrix membrane ) or control ( autogenous gingival graft ) treatment . Both test and control sites achieved a clinical ly significant increase in the amount of keratinized gingiva , and the DynaMatrix membrane-treated sites blended well with the surrounding tissue , with a better appearance when compared to the autogenous gingival grafted sites . The biopsy specimens of both test and control sites appeared to be similar histologically , with mature connective tissue covered by keratinized epithelium . The results of both clinical and histologic evaluations have suggested a potential application of an extracellular matrix membrane in achieving gingival augmentation BACKGROUND The aim of this study was to evaluate clinical ly , histologically , and ultrastructurally the integration process of the acellular dermal matrix used to increase the b and of keratinized tissue while achieving gingival inflammation control . METHODS Ten patients exhibiting a mucogingival problem with b and s of keratinized tissue < or=1 mm and gingival inflammation of the related teeth were included in the study . The surgical procedures were performed to augment the gingival tissue using acellular dermal matrix . Clinical measurements were assessed at baseline and after 3 months . A specimen of the allograft and surrounding tissues was obtained immediately before the surgery and 4 minutes and 1 , 2 , 3 , 4 , 6 , and 10 weeks after grafting . RESULTS Clinical ly , a gain of keratinized tissue of 2.92 + /- 0.65 mm was observed after 3 months . Histologically and ultrastructurally , many macrophages were observed phagocytosing preexisting collagen fibers in the first weeks . From week 2 on , fibroblasts synthesizing new collagen , epithelial cells colonizing the graft surface , and revascularization were noticed . After 6 weeks it was difficult to find the acellular dermal matrix preexisting collagen fibers . This process of substitution was completed after 10 weeks , when the reepithelialization of the entire graft throughout a well-structured basement membrane was achieved . CONCLUSION The acellular dermal matrix graft seemed to be an easily h and led material for use in keratinized tissue augmentation that , in humans , was substituted and completely reepithelialized in 10 weeks according to histologic and ultrastructural results This prospect i ve split-mouth pilot case series compared the use of a bilayer collagen matrix ( CM ) to an autogenous gingival graft ( AGG ) in the ability to increase the zone of keratinized attached gingiva .  Five patients with inadequate amounts of keratinized attached gingiva bilaterally in the posterior m and ible were enrolled using a split-mouth design . There were statistically significant increases in attached gingiva at all test ( CM ) and control ( AGG ) sites . The CM sites at 12 months blended well with surrounding tissues , while the AGG sites were morphologically dissimilar to the adjacent areas . Biopsy results showed intrapatient histologic similarity between CM and AGG treatments , with all sites exhibiting mature connective tissue covered by keratinized epithelium . Thus , the obtained data support further investigations in evaluating the role of CM as a viable alternative to AGG in augmenting areas deficient in keratinized gingiva BACKGROUND The importance of keratinized tissue is a controversial subject . However , in some situations most clinicians would agree that surgical procedures to increase the amount of keratinized tissue without root coverage are indicated . In this study , 3 surgical procedures were compared in their ability to increase the width of keratinized tissue . They are : the epithelized autogenous masticatory mucosa graft ( free gingival graft ) , autogenous predominately connective tissue graft ( connective tissue graft ) , and acellular dermal matrix . METHODS Forty-five patients referred for treatment of areas with inadequate keratinized tissue were r and omly assigned into 1 of 3 groups of 15 each . Each group was treated with 1 of the 3 surgical procedures to increase the width of keratinized tissue . The width of keratinized tissue pre- and postsurgery was evaluated . RESULTS All 3 groups started with a similar width of keratinized tissue . All of the surgical procedures result ed in a statistically significant increase in the width of keratinized tissue :  free gingival graft , 4.1 mm ; connective tissue graft , 3.6 mm ; and acellular dermal matrix , 4.1 mm . CONCLUSION A statistically significant increase in the amount of keratinized tissue was obtained with all 3 surgical procedures evaluated AIM The aim of this study was to test a new collagen matrix ( CM ) aim ed to increase keratinized gingiva/mucosa when compared with the free connective tissue graft ( CTG ) . MATERIAL AND METHODS This r and omized longitudinal parallel controlled clinical trial studied 20 patients with at least one location with minimal keratinized tissue ( < or=1 mm ) . MAIN OUTCOME MEASURE The 6-month width of keratinized tissue . As secondary outcomes , the aesthetic outlook , the maintenance of periodontal health and the patient morbidity were assessed pre-operatively at 1 , 3 and 6 months . RESULTS At 6 months , the CTG attained a mean width of keratinized tissue of 2.6 ( 0.9 ) mm , while the CM was 2.5 ( 0.9 ) mm , these differences being insignificant . In both groups , there was a marked contraction ( 60 % and 67 % , respectively ) although the periodontal parameters were not affected . The CM group had a significantly lower patient morbidity ( pain and medication intake ) as well as reduced surgery time . CONCLUSIONS These results prove that this new CM was as effective and predictable as the CTG for attaining a b and of keratinized tissue , but its use was associated with a significantly 
    Output:
    
Conclusions Based on the clinical outcomes , the results of this systematic review and meta‐ analysis showed that soft tissue alternatives result in an increased width of KT .