Clinical Outcomes of Comparing Soft Tissue Alternatives to Free Gingival Graft: A Systematic Review and Meta-Analysis

Oral host-microbe interactions investigated in 3D organotypic models

The oral cavity is inhabited by abundant microbes which continuously interact with the host and influence the host's health. Such host-microbe interactions (HMI) are dynamic and complex processes involving e.g. oral tissues, microbial communities and saliva. Due to difficulties in mimicking the in vivo complexity, it is still unclear how exactly HMI influence the transition between healthy status and disease conditions in the oral cavity. As an advanced approach, three-dimensional (3D) organotypic oral tissues (epithelium and mucosa/gingiva) are being increasingly used to study underlying mechanisms. These in vitro models were designed with different complexity depending on the research questions to be answered. In this review, we summarised the existing 3D oral HMI models, comparing designs and readouts, discussing applications as well as future perspectives.

Electrospun methacrylated natural/synthetic composite membranes for gingival tissue engineering

New functional materials for engineering gingival tissue are still in the early stages of development. Materials for such applications must maintain volume and have advantageous mechanical and biological characteristics for tissue regeneration, to be an alternative to autografts, which are the current benchmark of care. In this work, methacrylated gelatin (GelMa) was photocrosslinked with synthetic immunomodulatory methacrylated divinyl urethanes and defined monomers to generate composite scaffolds. Using a factorial design, with the synthetic monomers of a degradable polar/hydrophobic/ionic polyurethane (D-PHI) and GelMa, composite materials were electrospun with polycarbonate urethane (PCNU) and light-cured in-flight. The materials had significantly different relative hydrophilicities, with unique biodegradation profiles associated with specific formulations, thereby providing good guidance to achieving desired mechanical characteristics and scaffold resorption for gingival tissue regeneration. In accelerated esterase/collagenase degradation models, the new materials exhibited an initial rapid weight loss followed by a more gradual rate of degradation. The degradation profile allowed for the early infiltration of human adipose-derived stromal/stem cells, while still enabling the graft's structural integrity to be maintained. In conclusion, the materials provide a promising candidate platform for the regeneration of oral soft tissues, addressing the requirement of viable tissue infiltration while maintaining volume and mechanical integrity. STATEMENT OF SIGNIFICANCE: There is a need for the development of more functional and efficacious materials for the treatment of gingival recession. To address significant limitations in current material formulations, we sought to investigate the development of methacrylated gelatin (GelMa) and oligo-urethane/methacrylate monomer composite materials. A factorial design was used to electrospin four new formulations containing four to five monomers. Synthetic immunomodulatory monomers were crosslinked with GelMa and electrospun with a polycarbonate urethane resulting in unique mechanical properties, and resorption rates which align with the original design criteria for gingival tissue engineering. The materials may have applications in tissue engineering and can be readily manufactured. The findings of this work may help better direct the efforts of tissue engineering and material manufacturing.

The use of platelet-rich fibrin in vestibuloplasty: A 36-month follow-up technique report

INTRODUCTION

Vestibuloplasty is a mucogingival procedure that aims to increase the vestibule and the amount of keratinized tissue (KT) around teeth and dental implants. Currently, the gold standard in this procedure is still represented by free gingival grafts (FGGs); however, they require a second surgical site, which means more morbidity for the patient and a higher risk of surgical complications, as well as surgical time and chromatic alteration of the recipient area.

CASE PRESENTATION

This is a description of the vestibuloplasty technique with platelet-rich fibrin (PRF) in a 35-year-old female patient with a thin gingival phenotype and no medical history of interest. The reason for consultation was tooth sensitivity during brushing and the presence of recessions in the fifth sextant.

CONCLUSIONS

The use of PRF as a graft biomaterial in vestibuloplasty is a valid and effective option as an alternative to secondary epithelialization of the surgical site, as well as to FGGs, with acceptable results in terms of KT gain and root coverage, and with minimal postoperative discomfort.

KEY POINTS

Why is this case new information? The use of PRF is an interesting option as an alternative to second-intention healing, as FGGs in vestibuloplasty. What are the keys to successful management of this case? The most important part of the membranes is the part that was in close relation to the erythrocyte fraction in the blood collection tube, so this part must be oriented toward the recipient bed. A minimum of four membranes should be obtained, overlapping one on top of the other. What are the primary limitations to success in this case? The stability of the PRF.

The Structure and Function of Next-Generation Gingival Graft Substitutes-A Perspective on Multilayer Electrospun Constructs with Consideration of Vascularization

There is a shortage of suitable tissue-engineered solutions for gingival recession, a soft tissue defect of the oral cavity. Autologous tissue grafts lead to an increase in morbidity due to complications at the donor site. Although material substitutes are available on the market, their development is early, and work to produce more functional material substitutes is underway. The latter materials along with newly conceived tissue-engineered substitutes must maintain volumetric form over time and have advantageous mechanical and biological characteristics facilitating the regeneration of functional gingival tissue. This review conveys a comprehensive and timely perspective to provide insight towards future work in the field, by linking the structure (specifically multilayered systems) and function of electrospun material-based approaches for gingival tissue engineering and regeneration. Electrospun material composites are reviewed alongside existing commercial material substitutes’, looking at current advantages and disadvantages. The importance of implementing physiologically relevant degradation profiles and mechanical properties into the design of material substitutes is presented and discussed. Further, given that the broader tissue engineering field has moved towards the use of pre-seeded scaffolds, a review of promising cell options, for generating tissue-engineered autologous gingival grafts from electrospun scaffolds is presented and their potential utility and limitations are discussed.

Outcomes of alveolar segmental 'sandwich' osteotomy with interpositional particulate allograft for severe vertical defects in the anterior maxilla and mandible

The purpose of this study was to report the outcomes of interpositional osteotomy with mineralized allograft in the treatment of alveolar vertical defects in preparation for implant placement. Thirteen defects (11 maxillary and two mandibular) were treated with osteotomy segments ranging in length from two to five missing teeth. The segments were positioned 5-7 mm coronally, with the gap space filled with allograft and then fixated with titanium hardware. Vertical bone augmentation was analyzed by superimposing pre- and post-surgical cone beam computed tomography images and stratified based on the length and number of missing teeth in each edentulous segment. The mean vertical bone gain was 3.7 ± 1.6 mm in the area of greatest vertical defect and the mean length of the transport segment was 20.5 ± 8.1 mm. These segments represented two-, three-, four-, or five-tooth edentulous sites; the mean vertical bone gain for these segments was 1.7 ± 0.5 mm, 3.8 ± 1.0 mm, 4.6 ± 0.9 mm, and 6.7 ± 0.0 mm, respectively. Stability of vertical height gain was found to be directly proportional to the span length of the osteotomy segment, with the largest five-tooth segment achieving the greatest gain. Vertical bone gain in two-tooth segments was minimal, indicating a moderate amount of resorption.

Clinical and Histological Differences between Guided Tissue Regeneration with Acellular Dermal Matrix of Porcine Origin and Autologous Connective Tissue: An Animal Study

This research aims to evaluate the clinical and histological parametric differences concerning keratinized tissue that result from two regeneration techniques, the subepithelial autologous connective tissue graft (ACTG) and the acellular dermal matrix (MD) of porcine origin, performed on surgical beds on edentulous spaces in an animal model. The parameters of the MD and ACTG groups were compared with samples of the control group (CG) after 15, 45, and 90 days. Nine female white pigs (Sus scrofa domestica) were used, and each animal provided 20 study areas (12 MD and 8 ACTG). At 15 days, the keratin layer thickness in the MD group was greater than those of the ACTG (25.27 vs. 19.95 μm) and the CG (21.2 μm). After 45 days, the MD and ACTG thickness values decreased but were higher than the CG. At 90 days, MD (19.46 μm) obtained a value close to that of CG, and the ACTG decreased to CG (15.53 μm, p < 0.001). The use of an MD may be a viable alternative to the ACTG because of its ability to provide increased keratinized tissue in comparison to the ACTG.

Effect of A-PRF Application on Palatal Wound Healing after Free Gingival Graft Harvesting: A Prospective Randomized Study

Objective  The aim of this study was to investigate the healing effect of advanced platelet-rich fibrin (A-PRF) clot membranes in palatal wounds, resulting from free gingival graft (FGG) harvesting, on the reepithelization rate and on the pain experience after surgery.

Materials and Methods  Twenty-five patients requiring FGG have participated in this prospective cohort study. After FGG harvesting, the test group ( n = 14) received A-PRF clot membranes at the palatal wound and the control group ( n = 11) received a gelatin sponge. Epithelialization rate of the palatal wound, wound healing area, correspondent percentage of reduction, and postsurgical pain experience were assessed at 2, 7, 14, 30, and 90 days.

Results  A-PRF group had higher palatal wound reduction than the control group, at 7, 14, and 30 days of follow-up. The highest difference between the groups was attained at 30 days (91.5% for A-PRF vs. 59.0% control group). At 14 days, a significant difference in the proportion of patients showing total epithelization was found: 64.3% for A-PRF versus 9.1% for the control group. At 90 days, both groups showed total recovery. The control group experienced higher pain level and discomfort until the 14th day, being notably higher on the second day.

Conclusion  The results suggest that A-PRF membranes haste the healing process, and promote greater reduction along the recovery period and less painful postoperative period.

Use of Mucograft Collagen Matrix® versus Free Gingival Graft to Augment Keratinized Tissue around Teeth: A Randomized Controlled Clinical Trial

Objectives

This study aimed to evaluate the mucograft collagen matrix (CM) to increase keratinized tissue around teeth compared to free gingival graft (FGG).

Materials and Methods

The present double-blind, randomized, controlled clinical trial studied 12 patients who had 2 mm or less keratinized gingiva bilaterally around mandibular premolars. The 6-month width of keratinized tissue, periodontal parameters (preoperatively and 1, 3, and 6 months postoperatively), color match, pain, and total surgical time were measured.

Results

The mean dimensional change of keratinized gingiva 6 months postoperatively was 4.1±0.7 mm for FGG and 8±1.7 mm for CM. Periodontal parameters were not affected in the two groups. The CM group had a significantly lower pain, experienced less surgery time, and gained better aesthetics compared to the FGG group.

Conclusion

CM appears to be a suitable substitute for FGG in procedures designed to increase keratinized tissue around teeth. It has remarkable benefits, such as acceptable keratinized tissue gain, less pain, less surgical chair time, and better aesthetics.

Vestibuloplasty covering titanium mesh with grafted free gingiva on anterior mandible: technical report and rationale

This paper describes a patient with an insufficient vestibular depth for a removable partial denture who underwent vestibuloplasty with a free gingival graft using a titanium mesh in the anterior mandible. Free gingiva was harvested from the palatal mucosa, and a partial thickness flap was elevated at the recipient site. After minimal suturing for the graft, a titanium mesh was fixed over the graft. The mesh was removed four weeks after surgery. The patient obtained an adequate vestibular depth and keratinized gingiva eight weeks after surgery without any complications. In this case, an appropriate vestibular depth and keratinized gingiva were easily obtained by vestibuloplasty using a titanium mesh.

Stabilization Techniques for Soft Tissue Grafting Around Dental Implants: Case Report

INTRODUCTION

Implants that lack keratinized tissue (KT) have been associated with increased plaque accumulation, gingival inflammation or hue of metal showing through the tissue. Free gingival grafts (FGGs) are a predictable treatment for minimal or lack of KT. FGGs can increase the zone of KT around teeth and implants alike. Despite predictability of FGGs, stabilizing the graft around implants can be challenging, but is critical for success. Little information is available regarding ways to stabilize FGGs around implants. Acrylic or composite stents are a viable option for obtaining graft stability and support during the healing process.

CASE PRESENTATION

This case report highlights the practicality of using acrylic or composite stents for FGG stabilization with successful outcomes. Two patients presented with dental implants, with minimal or lack of KT requiring soft tissue augmentation. FGGs were harvested from the palate and fitted around implant carriers allowing stabilization and adequate suturing. Custom-made acrylic or composite stabilization stents were fabricated to fit around implant carriers, which were screwed into the implant platform, and hollowed out internally to provide space for the graft. Postoperative visits showed healthy, stable zones of KT in both cases.

CONCLUSION

The customized acrylic or composite stents allowed stabilization of the FGGs with successful outcome.

Adjunctive benefit of a xenogenic collagen matrix associated with coronally advanced flap for the treatment of multiple gingival recessions: A superiority, assessor-blind, randomized clinical trial

AIM

To evaluate the superiority of coronally advanced flaps (CAFs) when used in combination with a xenogeneic collagen matrix (CMX) for root coverage of multiple adjacent gingival recessions.

MATERIALS AND METHODS

Participants with at least 2 upper adjacent teeth exhibiting gingival recession depth ≥2 mm were recruited and randomized to CAF with (test) or without (control) CMX, respectively. Mean and complete root coverage, amount of keratinized tissue (KTw), gingival thickness (GThick) and patient-reported outcomes (PROMs) were recorded at baseline, 3, 6 and 12 months.

RESULTS

Twenty-four patients providing 61 gingival recessions were analysed. After 1 year, gingival recession depth decreased from 2.3 ± 0.7 to 0.3 ± 0.4 mm in the CAF + CMX group (2.0 ± 0.8 mm meanRC) and from 2.6 ± 1.0 to 0.6 ± 0.3 mm in the control group (2.0 ± 1.1 mm meanRC). No difference was observed between the two groups (p = 0.2023). Nineteen (63%) of the test and 16 (52%) of control defects showed complete root coverage (p = 0.4919). GThick greatly increased in the test group (0.5 mm; 0.2-0.8 mm, 95% CI; p = 0.0057). No difference between the two groups was observed for KTw (p = 0.5668) and PROMs.

CONCLUSION

At 1 year, CAF + CMX provided similar root coverage to CAF alone, but a significant increase in gingival thickness.