Clinical efficacy of xenogeneic collagen matrix in the treatment of gingival recession: a systematic review and meta-analysis

The quality of life after keratinized mucosa augmentation around dental implants using xenogenic collagen matrix with or without stent

BACKGROUND

The substitution of missing teeth with implants is a dependable and anticipated therapeutic approach. Despite numerous studies affirming long-term success rates, there exists a spectrum of potential biological and aesthetic complications.

OBJECTIVE

The primary objective of this study was to assess patient responses subsequent to surgical interventions, with a specific emphasis on the utilization of xenogenic collagen matrix (XCM), both with and without the application of a stent secured over healing abutments, in the context of keratinized gingival mucosa augmentation. The principal aim was to evaluate and draw comparisons between the clinical outcomes resulting from these two procedural approaches, with a particular focus on critical parameters encompassing post-operative complications, patient comfort, and the overall efficacy in achieving successful keratinized tissue augmentation.

methods

Sixty patients were selected for this study. The patients were divided into three groups: A, B, and a control group, with each group comprising 20 participants. We used XCM in experimental group A, XCM covered with surgical stent in experimental group B, and free gingival graft (FGG) in the control group. After the surgical procedure, patients were required to complete a visual analogue scale (VAS) questionnaire for post-operative complications, and a quality of life (QOL) questionnaire on days 1, 3, and 7.

RESULTS

Patients in the experimental groups A and B demonstrated markedly improved outcomes when compared with the control group. Assessments conducted on days 1, 3, and 7 demonstrated diminished levels of pain, bleeding, and swelling in both experimental groups, with experimental group B showing the least discomfort. The incorporation of XCM, either with or without stents, was associated with a reduction in analgesic consumption, underscoring its favorable influence on post-operative comfort, notwithstanding the exception of halitosis in experimental group B.

CONCLUSION

Using XCM with or without a stent for keratinized tissue augmentation has better post-operative outcomes associated with reduced swelling, bleeding, and pain based on the QOL survey. This study provides data to support the clinical application of XCM and stents.

Xenogeneic collagen matrix vs. connective tissue graft for the treatment of multiple gingival recession: a systematic review and meta-analysis

The aim of this systematic review (SR) compared the effect of xenogeneic collagen matrix (XCM) vs. connective tissue graft (CTG) for the treatment of multiple gingival recession (MGR) Miller Class I and II or Cairo type I. Five databases were searched up to August 2022 for randomized clinical trials (RCTs) comparing the clinical effects of XCM vs. CTG in the treatment of MGR. The random effects model of mean differences was used to determine reduction of gingival recession (GR), gain in keratinized tissue width (KTW), gain in gingival thickness (GT) and gain in clinical attachment level (CAL). The risk ratio was used to complete root coverage (CRC) at 6 and 12 months. 10 RCTs, representing 1095 and 649 GR at 6 and 12 months, respectively, were included in this SR. The meta-analysis showed no statistically significant difference in GR reduction, KTW gain GT gain or CAL gain between groups at 6 months. However, at 12 months of follow-up, differences favoring the control group were observed (p < 0.05). CRC was significantly higher in the CTG group at 6 and 12 months. Regarding dentine hypersensitivity (DH), no statistically significant differences were found between groups at 6 and 12 months of follow-up (p < 0.05). At 12 months, CTG showed significantly superior clinical results in the treatment of MGR: however, this difference was not observed in the decrease of DH.

Hyaluronic Acid as an Adjunct to Coronally Advanced Flap Procedures for Gingival Recessions: A Systematic Review and Meta—Analysis of Randomized Clinical Trials

Previous systematic reviews have reported that coronally advanced flap (CAF) + connective tissue graft (CTG) are the gold standard in root coverage procedures (RCP). Nevertheless, adjunctive treatment with hyaluronic acid (HA) has been proposed to aim at improving clinical outcomes and reducing patient morbidity. The aim of this systematic review and meta-analysis is to compare the use of HA as an adjunctive treatment to CAF procedures in Miller class I and II (recession type 1; RT1) gingival recession (GR) defects treatment with no adjunctive/other treatments. MEDLINE, The Cochrane Central Register of Controlled Trials, Web of Science, Scopus databases and gray literature were searched up to April 2022. The primary outcome variables were mean recession coverage (MRC) and reduction of the recession depth (RecRed). Weighted mean differences and 95% confidence intervals between treatments were estimated using a random-effect mode. From 264 titles identified, 3 RCTs reporting 90 GR defects in 60 patients were included. Overall analysis of MRC and RecRed were 0.27% (p = 0.01) and 0.40 mm (p = 0.45) in favor of CAF + HA compared to CAF alone/CAF + subepithelial connective tissue graft (SCTG), respectively, with a statistically significant difference only for MRC values. Nevertheless, due to the limited number and heterogeneity of the included studies, well-performed RCTs are needed to clarify a potential advantage of HA in RCPs in the future.

A New Matrix for Soft Tissue Management

Gingival recession is a mucogingival defect defined as the apical shifting of the gingival margin in relation to the CEJ. The use of connective tissue autografts allows for the obtention of very satisfactory results but is associated with undoubted disadvantages. The aim of the present work is to carry out a systematic review of the literature using a meta-analysis to investigate the clinical efficacy of xenogeneic collagen matrix (XCM) in the treatment of gingival recessions. This revision was carried out strictly following the guidelines published in the Cochrane Handbook. Thus, a meta-analysis was performed to calculate relative risks and standardized mean differences for each of the variables considered. The results of the meta-analysis show that CAF + CTG was statistically better than CAF + XCM in almost all the variables analyzed: complete root coverage (RR 0.46), mean root coverage (SMD −0.89), recession reduction (SMD −0.98), clinical attachment level (SMD −0.63) and gingival thickness (SMD −1.68). Meanwhile, CAF + XCM was slightly better than CAF alone in regard to: mean root coverage (SMD 0.51), recession reduction (SMD 0.47) and gingival thickness (SMD 0.56). It is possible to conclude that CAF + CTG still remains the gold standard in radicular coverage.

Peri-implant keratinized gingiva augmentation using xenogeneic collagen matrix and platelet-rich fibrin: A case report

BACKGROUND

Keratinized gingival insufficiency is a disease attributed to long-term tooth loss, can severely jeopardizes the long-term health of implants. A simple and effective augmentation surgery method should be urgently developed.

CASE SUMMARY

A healthy female patient, 45-year-old, requested implant restoration of the her left mandibular first molar and second molar. Before considering a stage II, as suggested from the probing depth measurements, the widths of the mesial, medial, and distal buccal keratinized gingiva of second molar (tooth #37) were measured and found to be 0.5 mm, 0.5 mm, and 0 mm, respectively. This suggested that the gingiva was insufficient to resist damage from bacterial and mechanical stimulation. Accordingly, modified apically repositioned flap (ARF) surgery combined with xenogeneic collagen matrix (XCM) and platelet-rich fibrin (PRF) was employed to increase the width of gingival tissue. After 1 mo of healing, the widths of mesial, medial, and distal buccal keratinized gingiva reached 4 mm, 4 mm, and 3 mm, respectively, and the thickness of the augmented mucosa was 4.5 mm. Subsequently, through the second-stage operation, the patient obtained an ideal soft tissue shape around the implant.

CONCLUSION

For cases with keratinized gingiva widths around implants less than 2mm，the soft tissue width and thickness could be increased by modified ARF surgery combined with XCM and PRF. Moreover, this surgery significantly alleviated patients’ pain and ameliorated oral functional comfort.

Stability of biomaterials used in adjunct to coronally advanced flap: A systematic review and network meta-analysis

AIM

The objective of this network meta-analysis was to rank different biomaterials used in adjunct to coronally advanced flap (CAF), based on their performance in root-coverage for Miller's Class I and II gingival recessions.

MATERIALS AND METHODS

An electronic database search was carried out in PUBMED, CENTRAL, SCOPUS, and EMBASE to identify the eligible articles and compiled into the citation manager to remove the duplicates. The primary outcome was keratinized gingival tissue width (KGW) and percentage of root coverage (%RC). The treatment effect of different biomaterials was estimated using predictive interval plots and ranked based on biomaterials performance, using multidimensional scale ranking.

RESULTS

CAF + connective tissue graft (CTG), CAF + platelet concentrate matrix (PCM) and acellular dermal matrix (ADM) ranked at the top positions in performance in improving KGW. The highest ranked materials in improving percentage of root coverage in gingival recession were CAF + collagen matrix (CM) + gingival fibroblasts (GF), CAF + ADM + platelet rich plasma (PRP) and CAF + ADM, as compared to CAF alone.

CONCLUSION

CTG, ADM, platelet concentrates, and CM + GFs, when used in adjunct to CAF, showed improved stability over ≥12 months of follow-up, better percentage of root coverage, and improved keratinized gingival width.

Is there any biomaterial substitute for peri-implant soft tissue phenotype modification? A network meta-analysis of the appraisal literature

Evidence shows that an increased width and thickness of the keratinized mucosa favours peri-implant health. The aim of this network meta-analysis was to compare the clinical effects of alternative biomaterials for peri-implant soft tissue phenotype modification (PSPM) in patients with dental implants when compared to autologous tissue grafts. An electronic search without language or date limitations was performed in four databases and the grey literature for articles published until November 2020. The eligibility criteria included randomized clinical trials (RCTs) evaluating the clinical outcomes of biomaterials for PSPM. A pairwise and network meta-analysis was conducted for each parameter to assess and compare the outcomes between the different treatment arms for the primary and secondary outcomes. A total of 11 RCTs were included in this review. The free gingival graft (FGG) showed the best clinical effect for increasing keratinized mucosa width (KMW). When compared in a network, the FGG demonstrated the best treatment ranking of probability results, followed by connective tissue graft (CTG), acellular dermal matrix (ADM), and xenogeneic collagen matrix (XCM). For the parameters 'mucosa thickness' and 'participant satisfaction with aesthetics', the results were CTG > ADM > XCM and XCM > ADM > CTG, respectively. Autogenous tissue grafts (FGG/CTG) demonstrate the best results in increasing KMW and mucosa thickness when compared to the other biomaterials.

Collagen Matrix vs. Autogenous Connective Tissue Graft for Soft Tissue Augmentation: A Systematic Review and Meta-Analysis

Soft tissues have been shown to be critical for the maintenance of both teeth and implants. Currently, regenerative soft tissue techniques propose the use of collagen matrices, which can avoid the drawbacks derived from the obtainment of autogenous tissue graft. A systematic review and meta-analysis were conducted to ascertain the efficacy of collagen matrices (CM) compared to autogenous connective tissue graft (CTG) to improve soft tissue dimensions. An electronic and manual literature searches were performed to identify randomized clinical trials (RCT) or controlled clinical trials (CCT) that compared CTG and CM. Pooled data of width of keratinized tissue (KT) and mucosal thickness (MT) were collected and weighted means were calculated. Heterogeneity was determined using Higgins (I²). If I² > 50% a random-effects model was applied. Nineteen studies were included based on the eligibility criteria. When using CTG a higher MT gain (0.32 mm, ranging from 0.49 to 0.16 mm) was obtained than when employing CM. Similar result was obtained for the width of KT gain, that was 0.46 mm higher (ranging from 0.89 to 0.02 mm) when employing CTG. However, it can be stated that, although autogenous CTG achieves higher values, CM are an effective alternative in terms of total width of KT and MT gain.