Xenogenous Collagen Matrix and/or Enamel Matrix Derivative for Treatment of Localized Gingival Recessions: A Randomized Clinical Trial. Part II: Patient-Reported Outcomes

Clinical and patient-reported outcomes of tissue engineering strategies for periodontal and peri-implant reconstruction

Scientific advancements in biomaterials, cellular therapies, and growth factors have brought new therapeutic options for periodontal and peri-implant reconstructive procedures. These tissue engineering strategies involve the enrichment of scaffolds with living cells or signaling molecules and aim at mimicking the cascades of wound healing events and the clinical outcomes of conventional autogenous grafts, without the need for donor tissue. Several tissue engineering strategies have been explored over the years for a variety of clinical scenarios, including periodontal regeneration, treatment of gingival recessions/mucogingival conditions, alveolar ridge preservation, bone augmentation procedures, sinus floor elevation, and peri-implant bone regeneration therapies. The goal of this article was to review the tissue engineering strategies that have been performed for periodontal and peri-implant reconstruction and implant site development, and to evaluate their safety, invasiveness, efficacy, and patient-reported outcomes. A detailed systematic search was conducted to identify eligible randomized controlled trials reporting the outcomes of tissue engineering strategies utilized for the aforementioned indications. A total of 128 trials were ultimately included in this review for a detailed qualitative analysis. Commonly performed tissue engineering strategies involved scaffolds enriched with mesenchymal or somatic cells (cell-based tissue engineering strategies), or more often scaffolds loaded with signaling molecules/growth factors (signaling molecule-based tissue engineering strategies). These approaches were found to be safe when utilized for periodontal and peri-implant reconstruction therapies and implant site development. Tissue engineering strategies demonstrated either similar or superior clinical outcomes than conventional approaches for the treatment of infrabony and furcation defects, alveolar ridge preservation, and sinus floor augmentation. Tissue engineering strategies can promote higher root coverage, keratinized tissue width, and gingival thickness gain than scaffolds alone can, and they can often obtain similar mean root coverage compared with autogenous grafts. There is some evidence suggesting that tissue engineering strategies can have a positive effect on patient morbidity, their preference, esthetics, and quality of life when utilized for the treatment of mucogingival deformities. Similarly, tissue engineering strategies can reduce the invasiveness and complications of autogenous graft-based staged bone augmentation. More studies incorporating patient-reported outcomes are needed to understand the cost-benefits of tissue engineering strategies compared with traditional treatments.

Efficacy of biologics in root coverage and gingival augmentation therapy: An American Academy of Periodontology best evidence systematic review and network meta-analysis

BACKGROUND

The aim of this systematic review was to assess the efficacy of three biologics, namely autologous blood-derived products (ABPs), enamel matrix derivatives (EMD) and recombinant human platelet-derived growth factor BB (rhPDGF-BB), in root coverage and gingival augmentation therapy.

METHODS

The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42021285917). After study selection, data of interest were extracted. A network meta-analysis (NMA) was conducted to assess the effect of different surgical interventions on the main clinical outcomes of interest (i.e., mean root coverage [MRC%], complete root coverage [CRC%], keratinized tissue width [KTW], gingival thickness [GT] change, and recession depth [RD] reduction).

RESULTS

A total of 48 trials reported in 55 articles were selected. All studies reported on the treatment of gingival recession defects for root coverage purposes. Forty-six treatment arms from 24 trials were included in the NMA. These arms consisted of treatment with coronally advanced flap (CAF) alone, EMD + CAF, platelet-rich fibrin (PRF) + CAF, and subepithelial connective tissue graft (SCTG) + CAF. Regarding MRC%, SCTG+CAF was associated with a significant higher estimate (13.41%, 95% CI [8.06-18.75], P <  0.01), while EMD+CAF (6.68%, 95% CI [-0.03 to 13.4], P = 0.061) and PRF+CAF (1.03%, 95% CI [-5.65 to 7.72], P = 0.71) failed to show statistically significant differences compared with CAF alone (control group) or with each other. Similarly, only SCTG+CAF led to a significantly higher CRC% (14.41%, 95% CI [4.21 to 24.61], P < 0.01), while treatment arms EMD + CAF (13.48%, 95% CI [-3.34 to 30.32], P = 0.11) and PRF+CAF (-0.91%, 95% CI [-15.38, 13.57], p = 0.81) did not show significant differences compared with CAF alone or with each other. Differences in the CI of PRF+CAF (symmetrical around a zero adjunctive effect) and EMD+CAF (non-symmetrical) suggest that EMD could have some additional value compared with PRF. Treatment with SCTG+CAF led to a statistically significant higher RD reduction (-0.39 mm, 95% CI [-0.55 to 0.22], P < 0.01), however EMD+CAF (-0.13 mm, 95% CI [-0.29 to 0.01], P = 0.08) and PRF+CAF (-0.06 mm, 95% CI [-0.23 to 0.09], P = 0.39) failed to show significant differences compared with CAF or with each other. While SCTG+CAF was associated with a statistically significant higher gain of KTW (0.71 mm, 95% CI [0.48 to 0.93], P < 0.01), EMD+CAF (0.24 mm, 95% CI [-0.02 to 0.51], P = 0.08) and PRF+CAF (0.08 mm, 95% CI [-0.23 to 0.41], P = 0.58) did not result into significant changes compared with CAF alone or with each other. Regarding the use of rhPDGF-BB+CAF, although available studies have reported equivalent results compared with SCTG+CAF, evidence is very limited.

CONCLUSIONS

The use of ABPs, EMD, or rhPDGF-BB in conjunction with a CAF for root coverage purposes is safe and generally promotes significant improvements respective to baseline clinical parameters. However, the adjunctive use of ABPs and EMD does not provide substantial additional improvements in terms of clinical outcomes and patient-reported outcome measures to those achieved using CAF alone, when baseline KTW is >2 mm. Both PRF+CAF and EMD+CAF rendered inferior MRC%, CRC%, RD reduction, and KTW gain compared with SCTG+CAF, which should still be considered the gold-standard in root coverage therapy. Although some studies have reported equivalent results for rhPDGF-BB+CAF compared with the gold-standard intervention, limited evidence precludes formal comparisons with CAF or SCTG+CAF that could be extrapolated to guide clinical practice.

Recombinant human platelet-derived growth factor improves root coverage of a collagen matrix for multiple adjacent gingival recessions: A triple-blinded, randomized, placebo-controlled trial

AIM

To evaluate the efficacy of recombinant human platelet-derived growth factor (rhPDGF)-BB combined with a cross-linked collagen matrix (CCM) for the treatment of multiple adjacent gingival recession type 1 defects (MAGRs) in combination with the coronally advanced flap (CAF).

MATERIALS AND METHODS

Thirty patients were enrolled in this triple-blind, randomized, placebo-controlled trial and treated with either CAF + CCM + rhPDGF, or CAF + CCM + saline. The primary outcome was mean root coverage (mRC) at 6 months. Complete root coverage, gain in gingival thickness (GT), keratinized tissue width, volumetric and ultrasonographic changes, and patient-reported outcome measures were also assessed. Mixed-modelling regression analyses were used for statistical comparisons.

RESULTS

At 6 months, the mRC of the CCM + rhPDGF and CCM alone groups were 88.25% and 77.72%, respectively (p = .02). A significant gain in GT was consistently observed for both treatment arms, and more so for the patients receiving the matrix containing rhPDGF through time (0.51 vs. 0.80 mm, on average, p = .01). The rhPDGF + CCM treated patients presented greater volume gain, higher soft tissue thickness, and a superior aesthetic score.

CONCLUSION

rhPDGF enhances the clinical, volumetric, and aesthetic outcomes of MAGRs above the results achieved with CAF + CCM alone (ClinicalTrials.gov NCT04462237).

Comparison between connective tissue graft and xenogeneic acellular dermal matrix to treat single gingival recession: A data reanalysis of randomized clinical trials

OBJECTIVES

There are few studies comparing xenogeneic acellular dermal matrixes (XDMs) with connective tissue graft (CTG) to treat single gingival recession (GR). The present study involved a reanalysis of previous studies and comparison of CTG or XDM to treat single RT1/GR.

MATERIALS AND METHODS

Fifty patients from three previous randomized clinical trials treated either by CTG (n = 25) or XDM (n = 25) were evaluated after 6-month. Clinical, patient-centered, and esthetic parameters were assessed. Pearson's correlation and regression analyses were also performed.

RESULTS

Greater recession reduction (RecRed), percentage of root coverage (%RC), and complete root coverage (CRC) were observed in the CTG group (p ≤ 0.02). Gingival thickness (GT) and keratinized tissue width (KTW) gains were higher in the CTG group. The CTG group showed better esthetic at 6-month. Logistic analyses reported that GT([OR] = 1.647³ ) and papilla height (PH) (OR = 8.20) are predictors of CRC. GT*XDM interaction was a negative predictor of CRC (OR = 7.105^-5 ). GT at baseline acted as a predictor of RecRed in both groups (p = 0.03). The XDM graft impacted RecRed and %RC negatively. Baseline PH was a predictor of %RC for both grafts.

CONCLUSION

CTG was superior for treating RT1/GR, providing better root coverage outcomes and tissue gains over time. GT, PH, and graft type were classified as predictors of CRC.

CLINICAL SIGNIFICANCE

CTG presented better outcomes to treat single RT1 gingival recession when compared to the XDM.

Does the subepithelial connective tissue graft in conjunction with a coronally advanced flap remain as the gold standard therapy for the treatment of single gingival recession defects? A systematic review and network meta-analysis

BACKGROUND

The aim of this systematic review and network meta-analysis was to assess the efficacy of a bilaminar root coverage technique consisting of the combination of an autogenous subepithelial connective tissue graft (SCTG) and a coronally advanced flap (CAF) compared to the five most indicated alternative approaches for the treatment of single gingival recession defects (GRD).

METHODS

The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42020221362). Three electronic databases were searched up to September 30^th , 2021 to identify randomized controlled trials that involved the treatment of single GRD without interproximal tissue loss via root coverage procedures. A frequentist network meta-analysis was conducted for complete root coverage (CRC), mean root coverage (MRC) and keratinized tissue width (KTW) changes.

RESULTS

A total of 38 studies reporting on 830 patients and 1,265 GRD were included. SCTG+CAF was ranked as the most efficient treatment approach for MRC, CRC and KTW gain at 6 and 12 months after surgery, except for MRC at the 12-month follow-up where enamel matrix derivative (EMD) plus CAF exhibited superior results.

CONCLUSIONS

SCTG+CAF can be considered the gold standard for the treatment of single GRD. This article is protected by copyright. All rights reserved.

Single gingival recession associated with non-carious cervical lesion treated by partial restoration and coronally advanced flap with or without xenogenous collagen matrix: A randomized clinical trial evaluating the coverage procedures and restorative protocol

BACKGROUND

Evaluate the use of collagen matrix (CM) as adjunctive to coronally advanced flap (CAF versus CAF + CM) to treat gingival recession (GR) associated with non-carious cervical lesion-combined defects (CDs).

METHODS

Sixty-two patients presenting 62 CDs (RT1 GR and non-carious cervical lesion (NCCLs) were randomly allocated to either CAF group (n = 31): partial restoration of the NCCL and CAF; or to CAF + CM group (n = 31): partial restoration of the NCCL and CAF associated with CM. Clinical, esthetic, patient-centered outcomes, and restorative parameters were assessed.

RESULTS

After 12 months, CD coverage were 55.2% for CAF and 54.4% for CAF + CM (P = 0.8). Recession reduction were 1.9 ± 0.8 mm for CAF and 2.0 ± 0.7 mm for CAF + CM (P = 0.6). CAF+CM resulted in higher increase in keratinized tissue (KT) width (CAF: 0.3 ± 0.7 mm; CAF + CM: 0.9 ± 0.8 mm; P = 0.004) and KT thickness gain (CAF: 0.1 ± 0.3 mm; CAF + CM: 0.7 ± 0.2 mm; P = 0.001). Both treatments presented low postoperative pain and resulted in esthetics improvements. In addition, no restoration was lost, 27.4% showed a reduction of the superficial polishing, and 8% showed marginal staining, but still clinically acceptable.

CONCLUSION

Partial resin composite restoration (with the apical limit up to 1 mm of the estimated CEJ) and CAF alone or combined with CM are suitable for treating CDs. The use of CM provided additional benefits in terms of KT width and thickness gain. (NCT03341598).

Prevalence and severity of non-carious cervical lesions and dentin hypersensitivity: association with oral-health related quality of life among Brazilian adults

Objectives

To assess the association between dentin hypersensitivity (DH) (with or without non-carious cervical lesions (NCCL)) and physical and psychosocial oral health impact.

Methods

A cross-sectional population-based study with one-stage random sample of adults living in a Brazilian municipally was conducted between 2018 and 2019. Interviews and oral examinations were performed by calibrated examiners (Kappa ≥0.7). The participant was considered as having physical and psychosocial impact if at least one item of the Oral Health Impact Profile (OHIP-14) was experienced fairly often or very often. NCCL was assessed by the Tooth Wear Index (codes 2 to 4) and DH was evaluated by a tactile test with a probe in the cervical area of teeth. The combination of these clinical variables resulted in categories of the independent variable: without DH or NCCL, NCCL without DH, DH without NCCL, and both DH with NCCL. The covariables were sociodemographic and economic factors, health habits, and oral conditions. Associations were investigated by Poisson Regression models using Direct Acyclic Graph (Stata 17).

Results

Of 197 adults, 59.3% had oral health impact and 31.3% had DH with NCCL. Higher frequency of oral health impact was observed in adults with DH alone. A higher impact on the physical pain dimension of the OHIP-14 was observed in adults with DH and NCCL (PR: 2.46; 95% CI: 1.21–5.00) and with DH alone (PR: 2.03; 95% CI: 1.21–3.41).

Conclusion

NCCL and DH are common conditions in adults and the presence of DH is associated with higher oral health impact. Regardless the presence of NCCL, DH is associated with the physical pain dimension of OHRQoL.

Clinical, radiographic, and patient-centered outcomes after use of enamel matrix proteins for the treatment of intrabony defects in patients with aggressive periodontitis: A 12-month multicenter clinical trial

BACKGROUND

The aim of this study was to evaluate the clinical, radiographic and patient-centered results of enamel matrix derivative (EMD) therapy in intrabony defects in aggressive periodontitis (AgP) patients and compare them with those in chronic periodontitis (CP) patients.

METHODS

Sixty intrabony defects in AgP and CP patients associated with ≥ 6 mm residual probing pocket depth (PPD) were included and randomly assigned to one of three groups: AgP+CS (conservative surgery) (n = 20); AgP+CS/EMD (n = 20); CP+CS/EMD (n  =  20). Clinical parameters were measured at baseline and after 6 and 12 months. Defect resolution (DR) and bone filling (BF) were used for radiographic analysis. The quality of life was recorded at baseline and 6 months using OHIP-14 and VAS scale in the early post-therapy period.

RESULTS

PPD and relative clinical attachment level (rCAL) improved for all groups during follow-up (P ≤ 0.05), and AgP+CS/EMD presented a higher rCAL gain (2.4 ± 1.0 mm) when compared to AgP control patients (1.6 ± 1.6 mm, P ≤ 0.05) after 12 months. No difference was observed between AgP+CS/EMD and CP+CS/EMD groups (P > 0.05). No radiographic differences were observed among groups at any time point (P > 0.05). All the groups reported a positive impact on OHIP-14 total score, without differences among them.

CONCLUSIONS

EMD therapy of intrabony defects promotes additional benefits in AgP patients, presenting a similar regeneration rate compared to CP patients, and has proven to be a viable therapy for the treatment of individuals with AgP.

Patient experience of autogenous soft tissue grafting has an implication for future treatment: A 10- to 15-year cross-sectional study

BACKGROUND

Patient-reported outcomes have received a great deal of interest in periodontal plastic procedures. However, their evaluation has mainly been short-term. Thus, the aim of this study was to evaluate the impact of soft tissue grafting procedures conducted over a decade ago on the willingness of a patients to undergo the surgery again.

METHODS

Subjects that received an autogenous soft tissue graft over 10 years ago were screened and invited for a survey. Their response was only analyzed if they were able to correctly identify the sites of the surgical procedures. Dichotomous questions and visual analogue scales (VASs) were used to assess self-reported pain, willingness to retreat and satisfaction.

RESULTS

Fifty-two patients were included in the analyses. Higher pain was reported for mandibular sites, and treated areas including ≥ 3 teeth (P < 0.01). Willingness to retreatment was 84.6% and it was negatively associated with self-reported pain measures, the arch location (mandible), and number of treated sites (≥3 teeth) (P < 0.01). Mean satisfaction rate was 86.9 ± 13.65 (VAS) and showed a positive correlation with willingness to retreat (P < 0.01). Having a complete root coverage at the recall visit was also significantly associated with higher patient satisfaction scores (P < 0.01).

CONCLUSIONS

Patient experience of previous autogenous soft tissue grafting has an influence on their decision to undergo future treatment. Willingness to retreat was negatively affected by mandibular sites, larger treated areas and the perceived pain, while presenting with complete root coverage was significantly associated with patient satisfaction.

Aesthetic-And patient-related outcomes following root coverage procedures: A systematic review and network meta-analysis

BACKGROUND

Aim of this systematic review (SR) of randomized controlled trials (RCTs) was to evaluate effect of different flap designs and graft materials for root coverage, in terms of aesthetics, patient satisfaction and self-reported morbidity (post-operative pain/discomfort).

MATERIAL AND METHODS

A comprehensive literature search was performed. A mixed-modelling approach to network meta-analysis was utilized to formulate direct and indirect comparisons among treatments for Root Coverage Esthetic Score (RES), with its individual components, and for subjective patient-reported satisfaction and post-operative pain/discomfort (visual analogue scale (VAS) of 100).

RESULTS

Twenty-six RCTs with a total of 867 treated patients (1708 recessions) were included. Coronally Advanced Flap (CAF) + Connective Tissue Graft (CTG) (0.74 (95% CI [0.24, 1.26], p = .005)), Tunnel (TUN) + CTG (0.84 (95% CI [0.15, 1.53]), p = .01) and CAF + Graft substitutes (GS) (0.55 (95% CI [0.006, 1.094], p = .04)) were significantly associated with higher RES than CAF. No significant difference between CAF + CTG and TUN + CTG was detected (0.09 (95% CI [-0.54, 0.72], p = .77)). Addition of CTG resulted in less natural tissue texture (-0.21 (95% CI [-0.34, -0.08]), p = .003) and gingival colour (-0.06 (95% CI [-0.12, -0.03], p = .03)) than CAF. CTG techniques were associated with increased morbidity.

CONCLUSIONS

Connective tissue graft procedures showed highest overall aesthetic performance for root coverage, although graft integration might impair soft tissue colour and appearance. Additionally, CTG-based techniques were also correlated with a greater patient satisfaction and morbidity.

Treatment of dehiscence-type defects with collagen matrix and/or enamel matrix derivative: Histomorphometric study in minipigs

BACKGROUND

This study aimed to evaluate, histomorphometrically, the use of collagen matrix (CM) and/or enamel matrix derivative (EMD) for the treatment of dehiscence-type recession defects in minipigs.

METHODS

Eight healthy, male, young BR-1 minipigs, with no periodontal disease were treated. Bilateral dehiscence-type defects were surgically created on the buccal of the mandibular premolars (PI and PII). After 30 days, the defects were randomly assigned to four groups: coronally advanced flap (CAF); CAF + CM; CAF + EMD; and CAF + CM + EMD (split-mouth design). The evaluated parameters (mm): total defect length; new cementum (NC); new bone (NB); gingival margin position; total epithelium length; epithelium on the root; connective tissue adaptation; and soft tissue thickness (STT).

RESULTS

The EMD-treated groups showed a superior length of NC [4.13 ± 1.22 (CAF + EMD); 3.95 ± 1.11 (CAF + CM + EMD); 2.94 ± 0.77 (CAF + CM); 2.72 ± 0.81 (CAF), P = 0.02] and NB [3.21 ± 0.68 (CAF + CM + EMD); 3.01 ± 0.56 (CAF + EMD); 2.15 ± 0.47 (CAF + CM); 2.29 ± 0.82 (CAF), P = 0.005]. The CAF and CAF + CM groups showed a superior epithelial length when compared to EMD-treated groups after 3 months. A superior STT was observed for CAF + CM + EMD group (1.5 ± 0.33) when compared with the other groups [1.09 ± 0.26 (CAF + EMD); 1.04 ± 0.34 (CAF + CM); and 1.14 ± 0.29 (CAF), P = 0.03].

CONCLUSION(S)

The results of the present study indicate that EMD application, irrespective of the combination with CM, may improve the periodontal regeneration of dehiscence-type defects in this animal model.

Biologics-based regenerative technologies for periodontal soft tissue engineering

This manuscript provides a state-of-the-art review on the efficacy of biologics in root coverage procedures, including enamel matrix derivative, platelet-derived growth factor, platelet concentrates, and fibroblast-growth factor-2. The mechanism of action and the rationale for using biologics in periodontal plastic surgery, as well as their anticipated benefits when compared with conventional approaches are discussed. Although the clinical significance is still under investigation, preclinical data and histologic evidence demonstrate that biologic-based techniques are able to promote periodontal regeneration coupled with the provision of tooth root coverage.

Efficacy of Enamel Derivatives to Improve Keratinized Tissue as Adjunct to Coverage of Gingival Recessions: A Systematic Review and Meta-Analysis

Background: The systematic review was designed to answer the following focused question: Are enamel matrix derivatives able to improve the quantity of keratinized tissue (KT) around natural dentition in patients with recessions defects after their treatment with periodontal plastic procedures? Methods: Only Randomized Clinical Trials (RCT) in English language evaluating root coverage procedures in combination with enamel matrix derivatives (commercially known as Emdogain^®—EMD), with at least 10 subjects and a minimum duration of six months, were included. The search was applied to PUBMED and SCOPUS and it consists of a combination of MeSH terms and free text words (from January 2000 to June 2019). Risk of bias in individual studies and across studies was also evaluated. Results: After the full text analysis and the exclusion of further 18 articles, 12 articles were finally included. In total 639 recessions were treated (334 tests and 305 control). The recessions defects were classified according to the classification of Miller (Class I, II, III, IV). Only one trial included Miller Class III recessions (7 in total). Enamel matrix derivatives were applied in conjunction with Coronally Advanced Flap (CAF), Coronally Advanced Flap + Sub Epithelial Connective Tissue Graft (CAF + CTG), Semilunar Flap (SF). For the group CAF vs CAF + EMD the mean difference between the keratinized tissue gain in the two procedures was 0.40 mm (95% Confindence Interval Lower/Upper: 0.014–0.81) (p < 0.058); for the comparison CAF + CTG + EMD vs. CAF + CTG the mean difference between the two groups resulted in −0.06 mm (95% Confindence Interval Lower Upper −0.45 to 0.33) (p = 0.7603). Discussion: Randomized clinical trials included medium-low quality evidence. The application of Enamel Matrix Derivatives to surgical procedures aimed to cover gingival recessions does not add robust clinical benefit to conventional plastic procedure alone.

Root coverage procedures for treating localised and multiple recession-type defects

BACKGROUND

Gingival recession is defined as the oral exposure of the root surface due to a displacement of the gingival margin apical to the cemento-enamel junction and it is regularly linked to the deterioration of dental aesthetics. Successful treatment of recession-type defects is based on the use of predictable root coverage periodontal plastic surgery (RCPPS) procedures. This review is an update of the original version that was published in 2009.

OBJECTIVES

To evaluate the efficacy of different root coverage procedures in the treatment of single and multiple recession-type defects.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 15 January 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 12) in the Cochrane Library (searched 15 January 2018), MEDLINE Ovid (1946 to 15 January 2018), and Embase Ovid (1980 to 15 January 2018). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials (15 January 2018). No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) only of at least 6 months' duration evaluating recession areas (Miller's Class I or II ≥ 3 mm) and treated by means of RCPPS procedures.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, data extraction and risk of bias assessment were conducted independently and in duplicate. Authors were contacted for any missing information. We expressed results as random-effects models using mean differences (MD) for continuous outcomes and odds ratios (OR) for dichotomous outcomes with 95% confidence intervals (CI). We used GRADE methods to assess the quality of the body of evidence of our main comparisons.

MAIN RESULTS

We included 48 RCTs in the review. Of these, we assessed one as at low risk of bias, 12 as at high risk of bias and 35 as at unclear risk of bias. The results indicated a greater reduction in gingival recession for subepithelial connective tissue grafts (SCTG) + coronally advanced flap (CAF) compared to guided tissue regeneration with resorbable membranes (GTR rm) + CAF (MD -0.37 mm; 95% CI -0.60 to -0.13, P = 0.002; 3 studies; 98 participants; low-quality evidence). There was insufficient evidence of a difference in gingival recession reduction between acellular dermal matrix grafts (ADMG) + CAF and SCTG + CAF or between enamel matrix protein (EMP) + CAF and SCTG + CAF. Regarding clinical attachment level changes, GTR rm + CAF promoted additional gains compared to SCTG + CAF (MD 0.35; 95% CI 0.06 to 0.63, P = 0.02; 3 studies; 98 participants; low-quality evidence) but there was insufficient evidence of a difference between ADMG + CAF and SCTG + CAF or between EMP + CAF and SCTG + CAF. Greater gains in the keratinized tissue were found for SCTG + CAF when compared to EMP + CAF (MD -1.06 mm; 95% CI -1.36 to -0.76, P < 0.00001; 2 studies; 62 participants; low-quality evidence), and SCTG + CAF when compared to GTR rm + CAF (MD -1.77 mm; 95% CI -2.66 to -0.89, P < 0.0001; 3 studies; 98 participants; very low-quality evidence). There was insufficient evidence of a difference in keratinized tissue gain between ADMG + CAF and SCTG + CAF. Few data exist on aesthetic condition change related to patients' opinion and patients' preference for a specific procedure.

AUTHORS' CONCLUSIONS

Subepithelial connective tissue grafts, coronally advanced flap alone or associated with other biomaterial and guided tissue regeneration may be used as root coverage procedures for treating localised or multiple recession-type defects. The available evidence base indicates that in cases where both root coverage and gain in the width of keratinized tissue are expected, the use of subepithelial connective tissue grafts shows a slight improvement in outcome. There is also some weak evidence suggesting that acellular dermal matrix grafts appear as the soft tissue substitute that may provide the most similar outcomes to those achieved by subepithelial connective tissue grafts. RCTs are necessary to identify possible factors associated with the prognosis of each RCPPS procedure. The potential impact of bias on these outcomes is unclear.

Xenogenous Collagen Matrix and/or Enamel Matrix Derivative for Treatment of Localized Gingival Recessions: A Randomized Clinical Trial. Part I: Clinical Outcomes

BACKGROUND

Considering xenogeneic collagen matrix (CM) and enamel matrix derivative (EMD) characteristics, it is suggested that their combination could promote superior clinical outcomes in root coverage procedures. Thus, the aim of this parallel, double-masked, dual-center, randomized clinical trial is to evaluate clinical outcomes after treatment of localized gingival recession (GR) by a coronally advanced flap (CAF) combined with CM and/or EMD.

METHODS

Sixty-eight patients presenting one Miller Class I or II GRs were randomly assigned to receive either CAF (n = 17); CAF + CM (n = 17); CAF + EMD (n = 17), or CAF + CM + EMD (n = 17). Recession height, probing depth, clinical attachment level, and keratinized tissue width and thickness were measured at baseline and 90 days and 6 months after surgery.

RESULTS

The obtained root coverage was 68.04% ± 24.11% for CAF; 87.20% ± 15.01% for CAF + CM; 88.77% ± 20.66% for CAF + EMD; and 91.59% ± 11.08% for CAF + CM + EMD after 6 months. Groups that received biomaterials showed greater values (P <0.05). Complete root coverage (CRC) for CAF + EMD was 70.59%, significantly superior to CAF alone (23.53%); CAF + CM (52.94%), and CAF + CM + EMD (51.47%) (P <0.05). Keratinized tissue thickness gain was significant only in CM-treated groups (P <0.05).

CONCLUSIONS

The three approaches are superior to CAF alone for root coverage. EMD provides highest levels of CRC; however, the addition of CM increases gingival thickness. The combination approach does not seem justified.