Impact of a collagen matrix on early healing, aesthetics and patient morbidity in oral mucosal wounds - a randomized study in humans

Posterior open wound healing in immediate implant placement using reactive soft tissue versus absorbable collagen sponge: a retrospective cohort study

The soft and hard tissue healing of open wounds in immediate implant placement are yet to be explored. The aim of this study was to compare the clinical outcomes of open wound healing using reactive soft tissue (RST) and absorbable collagen sponge (ACS). Forty implants placed immediately in posterior sockets were included; autologous RST was used in 20 and ACS substitute was used in 20. Soft tissue healing was primarily assessed through a novel scoring system and the evaluation of gingival recession. The horizontal bone width (HBW) and interproximal marginal bone level (MBL) were measured on radiographs to observe the hard tissue healing. No significant difference in total soft tissue healing score was observed at 2 weeks postoperatively. Notably, the ACS group showed better tissue colour (P = 0.016) but worse fibrous repair (P = 0.043) scores than the RST group. Gingival recession levels were comparable in the two groups, both before tooth extraction and after placement of the restoration. Regarding hard tissue, HBW and MBL changes showed no intergroup differences. Within the limitations of this study, both RST and ACS seemed effective for open wound closure, achieving ideal soft and hard tissue healing in immediate implant placement.

Efficacy of a Novel Melatonin-Loaded Gelatin Sponge in Palatal Wound Healing

OBJECTIVES

The aim of this research was to assess both clinically and histologically the effect of a topically applied melatonin-loaded gelatin sponge on palatal wound healing after graft harvesting.

METHODS

Twenty-six patients for whom free palatal graft procurement was indicated were divided equally into 2 groups. In the test group, the donor site was covered by a melatonin-loaded gelatin sponge, and in the control group the site was covered by a placebo-loaded gelatin sponge. Wound healing was evaluated on the day of surgery and at 7 and 14 days postsurgery using photo-digital planimetry. Histologic specimens were taken to verify healing type and rate. Pain was assessed via Visual Analogue Scale (VAS) for 7 days from the day of the surgery.

RESULTS

At the 7-day interval, photo-digital planimetry showed a significant decrease in the traced raw area (P = .04) in the test group compared with the control group and a significant increase in the mean area of immature epithelia (P = .04). At the 14-day interval, there was no statistically significant difference in any area of interest. Histologically, the application of melatonin was associated with accelerated healing and superior maturation at all follow-up time points. No significant differences were noted in VAS scores between the 2 groups.

CONCLUSIONS

Melatonin-treated tissue showed marked clinical improvement in the first week postsurgery, indicating an increased rate of healing. Similarly, histologic analysis revealed significant maturation at both time intervals. A melatonin-loaded gelatin sponge is a novel palatal wound dressing that can be used to improve wound healing outcomes and reduce patient morbidity.

Chitosan-based dressing for management of palatal donor site: A randomized clinical trial

AIMS

This study aimed to evaluate the effectiveness of a chitosan-based dressing (CD) in achieving early wound healing and hemostasis at palatal donor sites in patients undergoing free gingival graft (FGG) surgery.

METHODS

Thirty-two patients requiring FGG were treated in this randomized controlled clinical trial. Complete epithelialization (CE) and color match (CM) at donor sites were assessed by a blinded examiner on postoperative days 7, 14, 21, and 28. Donor sites were compressed for 2 min with wet gauze (WG) alone in control group (CG) or WG + CD in test group (TG) immediately after graft harvesting, and immediate bleeding (IB) was recorded (yes/no). Delayed bleeding (DB) (for 1 week), and number of analgesic tablets consumed, and VAS scores for pain (for 2 weeks) were recorded by patient every day.

RESULTS

Twenty-eight patients (14 in each group) were included in final analysis. The prevalence of CE (at weeks 2 and 3) and VAS scores for CM scores were higher in TG but the intergroup differences were statistically significant only for CM (at week 4). Number of patients exhibiting IB and DB was significantly fewer in the TG (p < .05). Although average pain scores and analgesic consumption were higher in TG up to 5 days, differences between two groups were not statistically significant at any time point.

CONCLUSION

Our data suggests that the application of CD increased re-epithelialization and accelerated wound healing process, although it did not reach statistical significance. Moreover, CD was found to significantly reduce bleeding complications, but it did not decrease the pain levels.

Early implant placement in sites with ridge preservation or spontaneous healing: histologic, profilometric, and CBCT analyses of an exploratory RCT

PURPOSE

The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion.

METHODS

Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis. Patients were followed up after the final crown insertion and again at 1 year post-procedure.

RESULTS

Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by -2.11 mm for the DBBM-C/CM group, -1.62 mm for the DBBM-C group, and -1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by -0.27 mm for the DBBM-C/CM group, -2.73 mm for the DBBM-C group, and -1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were -0.19 mm in the DBBM-C/CM group, -0.09 mm in the DBBM-C group, and -0.29 mm in the SH group.

CONCLUSIONS

Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.

Comparison of the Effectiveness of a Novel Matrix-Modified Bovine Collagen Membrane With a Conventional Bovine Collagen Membrane for Oral Mucosal Defects: A Single-Center Study

Background Surgical procedures such as excision of a growth or lesion lead to soft tissue or oral mucosal defects. These defects require a proper surgical dressing to promote better wound healing and to avoid infection and scarring. A collagen membrane is one of the most commonly used surgical dressings because of its ease of adaptability to defects and its inherent ability to promote epithelialization and inhibition of pain through the indirect mechanism of preventing infection of the surgical site. Collagen also serves as a reservoir of regenerative factors. The regenerative potential increases as porosity decreases. The novel bovine-derived collagen membrane used in this current study has an average porosity of 20 microns which increases the availability of regenerative factors. Objective  The aim of this study was to compare the effectiveness between a novel matrix-modified bovine collagen membrane (SurgiColl) and a conventional bovine collagen membrane for promoting wound healing for oral mucosal or soft tissue defects. Materials and methods This clinical trial was conducted in the Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospital. The sample size of the study was 20, divided into two groups: novel bovine collagen (Surgicoll-Mesh) (Group 1) and conventional bovine collagen (Group 2) with 10 participants in each group. The randomization process was adopted. The parameters assessed were epithelialization, granulation, and wound contraction at the end of two weeks. All the parameters were assessed using a standardized visual assessment scale. Statistical analysis was done using IBM SPSS Statistics for Windows, Version 23.0 (Released 2015; IBM Corp., Armonk, New York, United States), and an independent sample t-test was done at 95% confidence interval. A p-value of less than 0.05 was considered statistically significant. Results The difference in epithelialization between the two groups was statistically significant with a p-value of 0.015 (<0.05). The difference in granulation tissue formation between the two groups was statistically significant with a p-value of 0.015 (<0.05). The difference in wound contraction at the end of two weeks between the two groups was also statistically significant with a p-value of 0.005 (<0.05). Group 1 showed superior results compared to Group 2 for all the outcomes assessed. Conclusion  The novel bovine-derived collagen membrane (SurgiColl-Mesh) was superior in its properties of wound healing for oral mucosal or soft tissue defects than the conventional bovine collagen membrane.

Pre-operative, chair-side Zn-containing surgical stents affect morbidity and wound healing after free gingival graft harvesting: a randomized clinical trial

OBJECTIVE

To compare a pre-operatively, chair-side made, zinc-containing surgical stent (ZN) and suturing of a gelatin-based hemostatic agent (HA) on palatal wound healing and patient morbidity after free gingival graft surgery (FGG).

MATERIALS AND METHODS

Sixty patients requiring FGG were randomly divided into two groups to receive either a ZN or a sterile HA sutured on the surgical area. Patients were evaluated at 1st, 3rd, 7th, 14th, 28th, and 56th days following surgery. Overall surgical time, donor site surgical time, postoperative pain (PP), delayed bleeding (DB), changes in dietary habits (DH), burning sensation (BS), completion of re-epithelialization (CE), and patients' discomfort (PD) were evaluated.

RESULTS

Donor site surgical time, PP, DB, DH, BS were statistically significantly lower in the ZN group together with faster completion of re-epithelialization compared to the HA group.

CONCLUSION

Pre-operatively, chair-side made, zinc-containing surgical stents provided significant benefits for wound healing parameters and patients' postoperative morbidity after FGG harvesting.

CLINICAL RELEVANCE

The results show that using Zn-containing palatal stent after free gingival graft surgery significantly reduces pain and patient morbidity during the postoperative period.

Evaluation of low-level laser therapy and platelet-rich fibrin on donor site healing after vascularized interpositional periosteal connective tissue flap: a randomized clinical study

AIM

To evaluate the effectiveness of platelet-rich fibrin (PRF) and low-level laser therapy (LLLT) on donor site healing after vascularized interpositional periosteal connective tissue (VIP-CT) flap.

MATERIALS AND METHODS

For the present clinical study, the selected patients requiring VIP-CT flap were randomly assigned into either of the two treatment groups (VIP-CT/PRF and VIP-CT/LLLT). For VIP-CT/PRF, palatal donor site treated with platelet-rich fibrin (PRF, n = 15) after harvesting VIP-CT flap; and for VIP-CT/LLLT, palatal donor site treated with low-level laser therapy (LLLT, n = 16) after harvesting VIP-CT flap.

RESULTS

The mean thickness of palatal mucosa at surgical site was increased from 2.91 ± 0.65 to 2.93 ± 0.55 mm after 1 week and to 3.02 ± 0.55 mm after 12 weeks while in PRF-treated site, while in LLLT-treated sites, palatal mucosal thickness decreased after 1 week from 3.35 ± 0.56 mm to 1.83 ± 0.48 mm and then increase to 3.35 ± 0.55 mm after 12 weeks, and the mean difference was significantly higher for PRF-treated group compared to LLLT-treated group. In regard to contour, absence of hypertrophic tissue was observed in VIP-CT/LLLT compared with VIP-CT/PRF group (40% of patients, p = 0.003) at 4 weeks. "Absence" of pain and burning sensation were observed as early as at 1 week in LLLT-treated palatal donor sites compared to PRF-treated palatal donor site after VIP-CT. Improvement in post-surgical complications like ecchymosis, tissue necrosis, swelling, and infection were observed almost 100% at 4 weeks in both the groups.

CONCLUSION

Favourable clinical outcomes in terms of tissue thickness, consistency, color, contour, scar, pain, and burning sensation and patient comfort were obtained in both LLLT- and PRF-treated donor palatal sites at 12 weeks. Non-significant increase in tissue thickness was observed compared to baseline in PRF-treated donor sites at 12 weeks compared to LLLT-treated donor sites.

CLINICAL SIGNIFICANCE

Both low-level laser therapy (LLLT) using 940 nm wavelength and autologous platelet-rich fibrin (PRF) can be utilized to enhance early wound healing and reduce the palatal donor site morbidity.

Dimensional Influence of Epithelialized Tissue Graft Harvested From Palate on Postoperative Pain: a Systematic Review

Objectives

The aim of the present systematic review was to evaluate the dimensional influence of the epithelialized tissue graft harvested from the palate in the postoperative pain.

Material and Methods

Research was conducted in electronic databases Cochrane Library, Embase, LILACS, PubMed, Scopus, and Web of Science upwards May 15, 2022. Studies that reported the influence of graft dimensions of palatal epithelized harvesting on postoperative pain were eligible. The evaluation was made using the methodological quality assessment by Joanna Briggs Institute Critical Appraisal Checklist for randomized clinical trials and non-randomized studies and the level of evidence according to GRADE.

Results

Four studies were included. The clinical and methodological heterogeneity among studies led to an analysed narrative. The postoperative pain was assessed during the period of 1 to 28 postoperative days. It was determined by using visual analog scale in three studies, while the evaluation was performed indirectly based on analgesics intake in one study. According to three studies, bigger graft sizes were associated with higher postoperative pain. The methodological quality assessment categorized two study as high (one randomized control trial and one non-randomized), and two as moderate (one randomized control trial and one non-randomized). The data was considered moderate.

Conclusions

Based on the moderate certainty level, bigger graft sizes of palatal epithelized harvesting appear to promote more postoperative pain. Understanding the postoperative pain as a response to a graft extension may assist some clinical decisions regarding the surgical periodontal and peri-implant planning.

Full-Thickness Oral Mucoperiosteal Defects: Challenges and Opportunities

Regenerative engineering strategies for the oral mucoperiosteum, as may be needed following surgeries, such as cleft palate repair and tumor resection, are underdeveloped compared with those for maxillofacial bone. However, critical-size tissue defects left to heal by secondary intention can lead to complications, such as infection, fistula formation, scarring, and midface hypoplasia. This review describes current clinical practice for replacing mucoperiosteal tissue, including autografts and allografts. Potentially paradigm-shifting experimental regenerative engineering strategies for mucoperiosteal wound healing, such as hybrid grafts and engineered matrices, are also discussed. Throughout the review, the advantages and disadvantages of each replacement or regeneration strategy are outlined in the context of clinical outcomes, quality of life for the patient, availability of materials, and cost of care. Finally, future directions for research and development in the area of mucoperiosteum repair are proposed, with an emphasis on identifying globally available and affordable solutions for promoting mucoperiosteal regeneration. Impact statement Unassisted oral mucoperiosteal wound healing can lead to severe complications such as infection, fistulae, scarring, and developmental abnormalities. Thus, strategies for promoting wound healing must be considered when mucoperiosteal defects are incident to oral surgery, as in palatoplasty or tumor resection. Emerging mucoperiosteal tissue engineering strategies, described in this study, have the potential to overcome the limitations of current standard-of-care donor tissue grafts. For example, the use of engineered mucoperiosteal biomaterials could circumvent concerns about tissue availability and immunogenicity. Moreover, employment of tissue engineering strategies may improve the equity of oral wound care by increasing global affordability and accessibility of materials.

Effect of GaAlAs 940 nm Photobiomodulation on palatal wound healing after free gingival graft surgery: a split mouth randomized controlled clinical trial

Background

The aim of this study was to evaluate the effects of photobiomodulation (PBM) on wound healing, pain, and discomfort at free gingival graft (FGG) donor sites.

Methods

Sixteen patients in need of bilateral FGG were selected for this randomized, controlled, triple-blinded, and split mouth clinical trial. The FGG donor sites in test group were treated with LLLT GaAlAs 940 nm, 5 J/cm² immediately after surgery and every other day within the following ten days. The control group received sham irradiation. Remaining Wound Area (RWA), Epithelialization and color match were evaluated on the day of surgery and 7, 14, 21, 28, and 60 days after surgery. A questionnaire was administered to measure pain and bleeding in the first ten days after surgery.

Results

RWA was significantly smaller in the test than control group on the days 7 (p < 0.001) and 14 (p = 0.048) after the surgery. Bleeding was higher in the test group than in the control group on the day of surgery (p = 0.046). Pain and discomfort at the palatal donor site, however, had no significant difference between laser and control group during 11 days after the surgery (p > 0.05), nor did the Color match scores on the 28th and 60th days after the surgery (p > 0.05).

Conclusions

It can be concluded that PBM enhances FGG donor site wound healing one and two weeks after the surgery.

Trial registration

IRCT2017092036203N2, registered 01.11.2017.

Outcome measures and methods of assessment of soft tissue augmentation interventions in the context of dental implant therapy: A systematic review of clinical studies published in the last 10 years

AIM

To identify and report outcome measures and methods of assessment on soft tissue augmentation interventions in the context of dental implant therapy reported in clinical studies published in the last 10 years.

MATERIAL AND METHODS

The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42021252214). A literature search was conducted to identify articles that met the pre-established eligibility criteria. Data of interest, with an emphasis on outcome measures, were extracted. For each outcome, specific methods and timing of assessment were described in detail. Following a critical qualitative analysis of the data, outcome measures were categorized. Primary outcomes were identified and frequency of reporting in the selected articles was calculated. Additionally, risk of bias assessments were performed for individual articles and primary outcomes.

RESULTS

Ninety-two articles, of which 39 reported randomized controlled trials (RCTs), 20 reported non-RCTs, and 33 reported case series studies, were selected. Outcome measures were categorized into either investigator-evaluated outcome measures (i.e., clinical, digital imaging, esthetic, histologic, biomarker, and safety) or patient-reported outcome measures (PROMs). Clinical outcomes were the most frequently reported type of outcome. Considering all categories, the most frequently reported primary outcomes were facial mucosa thickness assessed with clinical methods (22.83%), facial keratinized mucosa width assessed with clinical methods (19.57%), facial mucosal margin position / recession assessed with clinical methods (18.48%), facial mucosa thickness assessed with digital imaging methods (11.96%), facial soft tissue volume assessed with digital imaging methods (9.78%), and supracrestal tissue height assessed with clinical methods (9.78%). No distinguishable patterns of association between specific types or quality (level of bias) of clinical studies and the choice of primary outcomes were observed.

CONCLUSION

Clinical research on peri-implant soft tissue augmentation has progressively increased in the last 10 years. Although clinical outcome measures were the most frequently reported outcomes in the selected literature, trends in the field are indicative of a shift from traditional clinical assessment methods to the use of digital technologies. PROMs were generally underreported but should be considered an integral methodological component in future clinical studies. This article is protected by copyright. All rights reserved.

The effect of different soft-tissue management techniques for alveolar ridge preservation: a randomized controlled clinical trial

PURPOSE

For alveolar ridge preservation, various treatment protocols have been described. While most studies focus on the effect of the bone graft material, the aim of this study was to analyze the influence of different soft-tissue management techniques on the soft and hard tissue.

METHODS

A total of 20 maxillary extraction sockets were grafted with an anorganic xenogenic bone graft and then randomly treated with either a combined epithelialized-subepithelial connective tissue graft (CECG) or a porcine collagen matrix (CM) placed in labial and palatal tunnels. Measurements of soft-tissue thickness were performed at tooth extraction (T0), implant insertion (T1) and second stage surgery (T2).

RESULTS

In the CECG group, gingival thickness was 1.18 ± 0.56 mm (T0), 1.29 ± 0.26 mm (T1) and 1.2 ± 0.32 mm (T3). In the CM group, the measurements were 1.24 ± 0.50 mm (T0), 1.6 ± 0.6 mm (T1) and 1.7 ± 1.06 mm. Thus, there was an overall increase in gingival thickness from T0 to T2 of 0.02 ± 0.66 mm (CECG) compared to 0.46 ± 0.89 mm (CM). The thickness of keratinized soft-tissue was 3.91 ± 1.11 mm (CECG) and 4.76 ± 1.48 mm (CM) before extraction and 3.93 ± 1.17 mm (CECG) and 4.22 mm ± 1.26 mm (CM) at implant follow-up. Mean peri-implant probing depths were 3.15 ± 1.39 mm (CECG) and 3.41 ± 0.99 mm (CM).

CONCLUSIONS

After ridge preservation, comparable soft-tissue parameters were observed in both groups, whether treated with a collagen matrix or a combined autologous connective tissue graft.

Efficacy of keratinized mucosal augmentation with a collagen matrix concomitant to the surgical treatment of peri-implantitis: A dual-center randomized clinical trial

AIM

The aim of this study was to evaluate the efficacy of a xenogeneic collagen matrix to augment the width of keratinized mucosa (KM), concomitantly to the surgical treatment of peri-implantitis, when compared to the use of an autologous soft tissue graft.

MATERIAL AND METHODS

In this 12-month parallel-arm randomized controlled clinical trial, patients with peri-implantitis were randomly assigned, one month after non-surgical therapy, to surgical resective treatment of peri-implantitis consisting on an apically positioned flap (APF) in combination with a KM augmentation procedure, either with an autologous free gingival graft (FGG) or a collagen matrix (CM). Primary outcomes were the increase in the width of KM and probing pocket depth (PPD) reduction at 12 months. As secondary outcomes, peri-implant radiographic and patient-reported outcomes were assessed.

RESULTS

The intention-to-treat population consisted of 49 subjects, assigned to either the APF + FGG (n = 23) or APF + CM (n = 26) group. PPDs were reduced by 1.6 mm (SD 1.0) and 1.7 mm (SD 1.2), respectively, being these differences non statistically significant (p = .782). However, the increase in KM was significantly higher in the APF + FGG compared with APF + CM (2.5 mm [SD 1.6] vs. 1.6 mm [SD 1.2], respectively (p = .033).

CONCLUSION

The tested surgical modalities resulted in similar improvements of the clinical parameters. Both free gingival graft and collagen matrix significantly increased the peri-implant keratinized mucosa, but this KM gain was significantly higher with the free gingival graft. Use of CM, however, was better appreciated by the patients, in terms of pain perception and analgesic consumption, although the surgical time was similar.

Soft tissue metric parameters, methods and aesthetic indices in implant dentistry: A critical review

OBJECTIVES

The primary objective was to provide an overview of soft tissue metric parameters, methods, and aesthetic indices in implant dentistry. The secondary objective was to describe reliability and validity of aesthetic indices.

MATERIALS AND METHODS

Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase, and Cochrane databases up to October 2020 to identify studies on soft tissue metric parameters, methods, and aesthetic indices. Aesthetic indices were evaluated in terms of reliability and validity. Data extraction was performed by the same reviewers.

RESULTS

Five metric parameters (papilla height, linear changes in soft tissue level, color assessment, soft tissue thickness, and profilometric soft tissue changes) registered by means of several methods (intra-oral registrations, radiographic assessments, digital analyses, and ultrasonic assessments), and 15 aesthetic indices (Papilla Index (PI), ad hoc questions scored with Visual Analogue Scales, Pink Esthetic Score (PES), Implant Crown Aesthetic Index (ICAI), Implant Aesthetic Score (IAS), Rompen Index, Subjective Esthetic Score, White Esthetic Score, Copenhagen Index, Complex Esthetic Index, Californian Dental Association Index (CDAI), Peri-Implant, and Crown Index, Functional Implant Prosthodontic Score, Implant Restoration Esthetic Index (IREI), and Mucosal Scarring Index (MSI)) could be identified. With respect to metric parameters and methods, intra-oral registrations were least accurate whereas profilometric soft tissue changes on the basis of digital surface models were most accurate. Six aesthetic indices showed good inter-rater reliability (PI, PES, ICAI, CDAI, IREI, and MSI). Good validity could only be shown for two indices (PES and CEI). Given this and on the basis of ease of use and ease of interpretation, PES qualified best for clinical research on single implants. None of the indices fulfilled the quality criteria for clinical research on multiple implants.

CONCLUSION

Many soft tissue assessment methods with varying reliability and validity have been described and used, which hampers uniform reporting in implant dentistry. Clinical investigators are advised to measure linear and profilometric soft tissue changes using digital surface models, and to use a reliable and validated aesthetic index. Currently, PES qualifies best for aesthetic evaluation of single implants. An index is to be developed to assess the aesthetic outcome of rehabilitations on multiple implants.

Oral wound healing models and emerging regenerative therapies

Following injury, the oral mucosa undergoes complex sequences of biological healing processes to restore homeostasis. While general similarities exist, there are marked differences in the genomics and kinetics of wound healing between the oral cavity and cutaneous epithelium. The lack of successful therapy for oral mucosal wounds has influenced clinicians to explore alternative treatments and potential autotherapies to enhance intraoral healing. The present in-depth review discusses current gold standards for oral mucosal wound healing and compares endogenous factors that dictate the quality of tissue remodeling. We conducted a review of the literature on in vivo oral wound healing models and emerging regenerative therapies published during the past twenty years. Studies were evaluated by injury models, therapy interventions, and outcome measures. The success of therapeutic approaches was assessed, and research outcomes were compared based on current hallmarks of oral wound healing. By leveraging therapeutic advancements, particularly within in cell-based biomaterials and immunoregulation, there is great potential for translational therapy in oral tissue regeneration.

Efficacy of Collagen Membrane Graft in Intraoral Surgery - An Evaluative Study

Introduction

Bovine-derived collagen membrane is usually and regularly used as a temporary cover or dressing for extraoral wounds and burns. It has wide applications because of its usefulness and biocompatibility. This has provoked us to do a study with the use of collagen membrane even for minor intraoral surgical defects. The aim of this evaluative study was to evaluate the clinical efficacy of collagen membrane in intraoral wounds created by removal of various soft tissue lesions.

Materials and Methods

A total of 25 healthy patients (16 males and 9 females) were taken for this study. This study was confined to secondary defects of the oral mucosa, which occur after excision of premalignant lesions and other conditions, such as benign lesions, reactive proliferations, and incisional biopsy wounds. Only those lesions that were sufficiently large and could not be closed primarily were included in the study.

Results

The results were evaluated on the day of surgery and in the postoperative period. The usefulness of collagen membrane as an intraoral temporary wound dressing material to promote haemostasis, relieve pain, induce granulation, and assist in rapid epithelialization at the wound site and prevent infection, contracture, scarring, and donor-site morbidity was evaluated, and finally, the efficacy of collagen membrane was tested by the use of Chi-square test and P < 0.001, which is a statistically and clinically significant value.

Discussion

Collagen membrane was observed as both biological dressing material and drug carrier. It was found to be a suitable alternative to other graft materials mentioned for the repair of defects in the mucous membrane created by surgical excision of lesions. Therefore, when used judiciously in a controlled clinical situation, collagen membrane is biologically acceptable in nature. It is an alternative to autologous grafts rather than a replacement of other grafts used in the oral cavity.

Effect of customized healing abutments on the peri-implant linear and volumetric tissue changes at maxillary immediate implant sites: A 1-year prospective randomized clinical trial

BACKGROUND

Immediate implant placement (IIP) associated with the use of bone substitutes and collagen matrices (CM) seems to reduce the amount of resorption at peri-implant areas. Recently, customized healing abutments (CA) appeared as another solution in order to seal the socket and preserve the original soft tissue contour.

PURPOSE

To evaluate peri-implant tissues dimensional changes after using customized healing abutments compared with the use of xenogeneic collagen matrices as socket sealing options in flapless maxillary immediate implant placement.

MATERIAL AND METHODS

The present study was designed as a prospective, randomized, controlled clinical trial. Patients were allocated into two groups depending on the socket sealing option: in the CM group a collagen matrix was used and in the CA group a customized abutment. Digital impressions were taken prior to extraction, 1, 4, and 12 months after implant insertion and the digital files allowed to evaluate linear buccal changes (MBC) and the buccal volumetric variation (BVv) between the different time points at peri-implant tissue areas. Additionally, mucosa variation was computed assessing the papilla presence and the midfacial mucosa height. Statistical significance was set at 0.05.

RESULTS

Twenty-eight patients were observed during a 12-month period. Significant differences between mean values of BVv at the first month were observed at the CM and CA group (-9.75 ± 6.65% and -4.76 ± 5.29%, respectively) (p = 0.043). At the 1-year follow-up, no significant differences were found in terms of BVv between the two groups, although the thin bone phenotype (≤1 mm) significantly influenced the volumetric variations that occurred in each group. No significant differences were noticed in midfacial mucosa and papillae alteration between groups, after 1 year of treatment.

CONCLUSION

Both treatment options are predictable solutions for socket sealing in IIP, although a higher volumetric variation can be expected in the presence of thin bone phenotypes.

Marginal Bone Resorption Around Dental Implants Placed in Alveolar Socket Preserved Sites: A 5 Years Follow-up Study

Aim

The present study evaluated the clinical and radiological stability of hard and soft tissues following alveolar socket preservation (ASP) procedure with a follow-up of 5 year from implant insertion.

Materials and methods

The initial sample consisted of seven patients who underwent single tooth extraction and ASP procedure by means of demineralized bovine bone mineral particles covered with a porcine-derived non-cross-linked collagen matrix (CM). Each patient received a submerged single implant in the healed site. Mesial and distal peri-implant marginal bone resorption (MBR) rates were assessed radiographically at 1 year (T ₁) and 5 years (T ₂) after implant placement (baseline value).

Results and Statistics

No dropouts occurred up to 5 years. At T ₁, the MBR was 0.08 ± 0.16 mm at the mesial aspect and 0.1 ± 0.12 mm at the distal aspect. This difference was not statistically significant (P = 0.867). At T ₂, the mesial MBR was 0.15 ± 0.17 mm and the distal MBR was 0.11 ± 0.14 mm, with a non-statistically significant difference (P = 0.532). Therefore, no statistically significant differences were detected comparing mesial and distal MBR at any time point. With respect to the intra-group comparisons, no differences were observed comparing the different study periods within each variable. Indeed, the comparison between T ₀, T ₁ and T ₂ was non-statistically significant at both mesial (P = 0.06) and distal (P = 0.06) aspects. After 5 years, the volume of the soft tissues appeared clinically well maintained with a natural aspect around dental implants and adjacent teeth.

Conclusion

ASP using demineralized bovine bone mineral in combination with CM proved to be an effective technique to maintain stable dimensional volumes of both hard and soft tissues.

Early implant placement with or without alveolar ridge preservation in single tooth gaps renders similar esthetic, clinical and patient-reported outcome measures: One-year results of a randomized clinical trial

Objectives

To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient‐reported outcome measures (PROMs) compared with early implant placement without ARP.

Material and methods

Seventy‐five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM‐C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM‐C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post‐loading.

Results

A total of 70 patients were available for re‐examination at one year post‐loading. The median mid‐facial mucosal margin change amounted to −0.02 mm (IQR −0.27–0.46) in the CM group, −0.13 mm (IQR −0.44–0.25) in the PG group and −0.14 mm (IQR −0.29–0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups.

Conclusion

Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

Clinical Outcomes of Free Gingival Graft Following Recipient Bed Preparation with Er,Cr:YSGG Laser Versus Scalpel: A Split-Mouth Randomized Clinical Trial

Objective: Free gingival graft (FGG) procedure is accompanied with a considerable rate of graft shrinkage. This study was aimed to assess the dimensional changes of FGG after recipient site preparation with Er,Cr:YSGG laser and surgical scalpel. Materials and methods: This split-mouth randomized clinical trial evaluated 11 patients with bilateral lack of keratinized gingiva in mandibular premolars. The test side in each patient was prepared with Er,Cr:YSGG laser (3 W power, 300 mJ energy, 10 Hz frequency, long-pulsed mode), whereas the control side was prepared by surgical scalpel. All FGGs were harvested from the palate with standard dimensions of 14 × 9 mm. The graft width, length, surface area, and shrinkage and color match were measured after 1, 3, and 6 months. Postoperative complications, including pain and bleeding were also evaluated using a questionnaire. Results: In both groups, the surface area and width of graft significantly decreased at all time points compared with baseline but the difference in this respect was not significant between the two groups (p > 0.05). In both groups, maximum shrinkage occurred within the first 3 months. In control group, the surface shrinkage in 3 months was significantly greater than the first month (p = 0.025) without significant difference between groups (p = 0.79). The two groups were not significantly different regarding pain score and bleeding score either. On the day of surgery, the test group had slightly lower pain score and higher bleeding score in comparison to the control group without significant difference. The pain and bleeding scores reduced in both groups with no significant difference (p > 0.05). Conclusions: Er,Cr:YSGG laser has promising results for preparation of FGG recipient site and yields results comparable to those of surgical scalpel.

Effects of non-thermal atmospheric pressure plasma on palatal wound healing of free gingival grafts: a randomized controlled clinical trial

OBJECTIVE

The aim of this trial was to evaluate the effects of non-thermal atmospheric pressure plasma (NAPP) on wound healing, epithelization, local pain, bleeding, and alteration of sensation in palatal donor site.

MATERIALS AND METHODS

Forty patients with inadequate attached gingiva were included in the study. Patients were divided into two groups: (i) NAPP group (Free gingival graft [FGG] + NAPP) and (ii) control group (FGG alone). NAPP was performed immediately after the operation and on days 3 and 7. Pain, bleeding, and the amount of medication were recorded by patients every day. Epithelization in donor site, alteration of sensation and color match were assessed weekly for 2 months. Inter-group comparisons of continuous variables by time were performed with two-way repeated measures ANOVA test and a general linear model. Categorical variables were compared using Chi-square exact test. A p value of < 0.05 was considered significant.

RESULTS

At week 2, the number of patients with complete epithelization was greater in the NAPP group compared to the control group (p < 0.05). Additionally, color match in donor site was better in the NAPP group than in the control group (p < 0.05) during the first five follow-up assessments. No significant difference was found between the two groups with regard to bleeding, pain level, drug use, and alteration of sensation.

CONCLUSION

The NAPP application increased the epithelization and accelerated the wound healing process although it did not decrease the level of pain and sensation.

CLINICAL RELEVANCE

Our data suggested that the NAPP application may help epithelization and thus may shorten the recovery time after oral surgeries.

Soft tissue contour and radiographic evaluation of ridge preservation in early implant placement: A randomized controlled clinical trial

Objectives

To compare two ridge preservation techniques and spontaneous healing in terms of hard and soft tissue changes 2 months after tooth extraction.

Material and methods

The study was designed as a randomized controlled trial and included 75 patients. After single tooth extraction in the maxillary incisor/premolar area, patients were randomly allocated to one of the following groups: (a) ridge preservation with a xenogeneic bone substitute covered with a collagen matrix (CM‐group), (b) ridge preservation with a xenogeneic bone substitute covered with a free palatal graft (PG‐group) or (c) spontaneous healing (control). Eight weeks after tooth extraction, implants were placed and clinical, profilometric and radiographic evaluations were performed. In addition, the need for further guided bone regeneration (GBR) at implant placement was assessed. The differences between the treatment groups were compared with the One‐way ANOVA or Kruskal–Wallis test with the corresponding post hoc analysis. The proportions of the categorical parameters were compared with the Fisher´s exact test.

Results

Seventy‐five patients underwent early implant placement 8 weeks after tooth extraction and were evaluated. CM‐group (−0.9 SD 0.6 mm) and PG‐group (−1.0 SD 0.8 mm) showed less horizontal bone resorption compared to the control group (−3.2 SD 2.1 mm) (p < .001). Moreover, the necessity of GBR at implant placement was significantly less in CM‐group (32%) and PG‐group (24%) when compared to control group (72%) (p = .001). Patients in CM‐group experienced less pain than PG‐group, one week after tooth extraction (p = .042). No significant differences were found regarding graft evaluation, post‐operative complications, and soft tissue contour.

Conclusions

Ridge preservation using a xenogeneic bone substitute covered with a collagen matrix or a palatal graft, results in less bone resorption and fewer GBR procedures at early implant placement compared to spontaneous healing.

Topical phenytoin effects on palatal wound healing

BACKGROUND

The clinical benefits of autogenous soft tissue grafts are countered by donor site morbidity. The aim of this prospective split-mouth clinical trial is to assess clinical, histological and patient outcomes following topical phenytoin (PHT) treatment of experimental palatal wounds.

METHODS

Systemically healthy adults were recruited. One 6 mm diameter wound (posterior) and one 4 mm diameter wound (anterior), each 1-1.5 mm deep, were created on both sides of the palate. Wounds on one randomly chosen side received 10% phenytoin USP and contralateral wounds received carrier alone. Biopsies were harvested from anterior wounds (Day 1 or Day 5) and were routinely processed for histology. Posterior wounds were left undisturbed to clinically evaluate healing (using photographs and Healing Score Index) on Days 1, 5, 14, and 21. Questionnaires were used to assess patient-centered outcomes. Data analysis was performed using generalized logistic and generalized linear mixed models.

RESULTS

Twenty participants completed all visits. 30% of participants reported more pain on control side than the PHT side at Day 1 (P = 0.014). PHT treated sites were more likely to not exhibit swelling (OR = 9.35; P = 0.009) and to not experience pain on palpation (OR = 6.278; P = 0.007). PHT significantly and time-dependently affected granulation tissue appearance (P = 0.004). Histologically, there were no significant differences between control and PHT, at any time point (P ≥ 0.853).

CONCLUSIONS

The results of the present study, the first one to report on topical PHT as palatal wound treatment, suggest that PHT application on palatal wounds could result in improved healing outcomes.

Three-Dimensional Volumetric Changes After Socket Augmentation with Deproteinized Bovine Bone and Collagen Matrix

PURPOSE

Socket augmentation decreases the magnitude of alveolar ridge resorption, but the literature is limited in respect to quantifying soft tissue remodeling. The aim of this study was to determine the volumetric and linear dimensional changes at the buccal surface for both hard and soft tissues after socket augmentation treated with a xenogeneic collagen matrix in combination with bone grafting.

MATERIALS AND METHODS

Twenty-four individuals indicated for tooth extraction were enrolled in this investigation. Each participant was randomly assigned to one of two groups: (1) deproteinized bovine bone + collagen plug, or (2) deproteinized bovine bone + xenogeneic collagen matrix. A cone beam computed tomography scan was taken prior to extraction and at 6 months postextraction. Intraoral scanning images were taken at baseline, 3 months, and 6 months postextraction. Hard and soft tissue analyses were performed to compare linear ridge remodeling and volumetric changes by noncontact reverse-engineering software.

RESULTS

Both groups showed bone and soft tissue remodeling. For hard tissue remodeling, there was no significant difference between the collagen plug and collagen matrix groups. For soft tissue remodeling, the collagen matrix group showed a reduced soft tissue loss compared with the collagen plug group. The volumetric analysis demonstrated that the mean buccal soft tissue volume loss for the collagen matrix group was 68.6 mm³ compared with 87.6 mm³ found in the collagen plug group (P = .009) over a 6-month period.

CONCLUSION

This clinical investigation provides early evidence of using the total tissue volume to compare soft and hard tissue remodeling after socket augmentation. The results of this study demonstrated that the use of a xenogeneic collagen matrix reduced the buccal soft tissue loss after tooth extraction, but additional studies are necessary to evaluate the clinical significance of soft tissue augmentation after tooth extraction.

Root coverage using coronally advanced flap with porcine-derived acellular dermal matrix or subepithelial connective tissue graft: a randomized controlled clinical trial

OBJECTIVE

The aim of this study is to investigate the use of a porcine-derived acellular dermal matrix (MD) in root coverage procedures combined with extended coronally positioned flap (eCAF), in comparison to the subepithelial connective tissue graft (SCTG) associated with the eCAF.

MATERIAL AND METHODS

Eighteen adult patients presenting bilateral type 1 gingival recession were randomly assigned to SCTG or MD groups. Clinical and patient-based outcomes were recorded at 3 and 6 months after the surgical procedure.

RESULTS

Both groups showed a significant reduction in the mean recession height of 3.33 ± 0.89 mm to 1.24 ± 1.10 mm (MD) and 3.21 ± 0.8 mm to 0.83 ± 0.86 mm (SCTG) without difference between groups. Six patients in the test group and eight in the control group obtained complete root coverage. The keratinized tissue height and thickness (KTT) showed a significant increase after 3 and 6 months in both groups. The average KTT gains were 0.39 ± 0.4 mm (MD) and 0.51 ± 0.5 mm (SCTG) (p < 0.05). Performing multivariate analysis suggests that MD addition to coronally advanced flaps may be similar to SCTG.

CONCLUSION

The MD had similar results in comparison to SCTG and in the context of reducing patient morbidity it can be used as an alternative for the treatment of gingival recessions.

CLINICAL RELEVANCE

The SCTG is the gold standard therapy for root coverage. The MD has been widely used in mucogingival surgery as a substitute for SCTG and proposed similar results. A substitute is very important for clinicians and patients. It will give a better postoperative and possibilities to treat multiples recession. (Clinicaltrials.gov Identifier: NCT03675334).

Oral Soft Tissue Regeneration Using Nano Controlled System Inducing Sequential Release of Trichloroacetic Acid and Epidermal Growth Factor

BACKGROUND

The effect of nano controlled sequential release of trichloroacetic acid (TCA) and epidermal growth factor (EGF) on the oral soft tissue regeneration was determined.

METHODS

Hydrophobically modified glycol chitosan (HGC) nano controlled system was developed for the sequential release of TCA and EGF, and the release pattern was identified. The HGC-based nano controlled release system was injected into the critical-sized defects created in beagles' palatal soft tissues. The palatal impression and its scanned body was obtained on various time points post-injection, and the volumetric amount of soft tissue regeneration was compared among the three groups: CON (natural regeneration control group), EXP1 (TCA-loaded nano controlled release system group), EXP2 (TCA and EGF individually loaded nano controlled release system). DNA microarray analysis was performed and various soft tissue regeneration parameters in histopathological specimens were measured.

RESULTS

TCA release was highest at Day 1 whereas EGF release was highest at Day 2 and remained high until Day 3. In the volumetric measurements of impression body scans, no significant difference in soft tissue regeneration between the three groups was shown in two-way ANOVA. However, in the one-way ANOVA at Day 14, EXP2 showed a significant increase in soft tissue regeneration compared to CON. High correlation was determined between the histopathological results of each group. DNA microarray showed up-regulation of various genes and related cell signaling pathways in EXP2 compared to CON.

CONCLUSION

HGC-based nano controlled release system for sequential release of TCA and EGF can promote regeneration of oral soft tissue defects.

Chemical Regeneration of Wound Defects: Relevance to the Canine Palatal Mucosa and Cell Cycle Up-Regulation in Human Gingival Fibroblasts

Background

Trichloroacetic acid (TCA) is an agent widely applied in dermatology for skin regeneration. To test whether TCA can offer an advantage for the regeneration of oral soft tissue defects, the cellular events following TCA application were explored in vitro and its influence on the oral soft tissue wound healing was evaluated in a canine palate model.

Methods

The cytotoxicity and growth factor gene expression in human gingival fibroblasts were tested in vitro following the application of TCA at four concentrations (0.005%, 0.05%, 0.5% and 1%) with different time intervals (0, 3, 9 and 21 h). One concentration of TCA was selected to screen the genes differentially expressed using DNA microarray and the associated pathways were explored. TCA was injected in open wound defects of the palatal mucosa from beagle dogs (n = 3) to monitor their healing and regeneration up to day 16-post-administration.

Results

While the 0.5-1% concentration induced the cytoxicity, a significantly higher expression of growth factor genes was observed after 3 and 9 h following the 0.5% TCA application in comparison to other groups. DNA microarray analysis in 0.5% TCA group showed 417 genes with a significant 1.5-fold differential expression, involving pathways of cell cycle, FoxO signaling, p53 signaling, ubiquitin mediated proteolysis and cAMP signaling. In vivo results showed a faster reepithelialization of TCA-treated wounds as compared to spontaneous healing.

Conclusion

TCA promoted the healing and regeneration of oral soft tissue wound defects by up-regulating the cell cycle progression, cell growth, and cell viability, particularly at a concentration of 0.5%.

Augmentation of keratinized tissue at tooth and implant sites by using autogenous grafts and collagen-based soft-tissue substitutes

AIM

To investigate the effect of three treatment modalities on the gain of keratinized tissue (KT) at tooth and implant sites in dogs.

MATERIALS AND METHODS

In five dogs, the distal roots of the mandibular second, third and fourth premolars were extracted, while the mesial roots were maintained. After 2 months of healing, implants were placed with KT excision. After another 2 months of healing, free gingival grafts, collagen-based matrices and apically positioned flap only were applied. The height of KT was measured during implant placement, immediately before soft-tissue grafting and after 10, 30 and 60 days.

RESULTS

Two months after KT excision, spontaneous KT regrowth was greater at tooth sites than at implant sites (median, 2.0 mm vs. 1.1 mm). The outcomes of soft-tissue grafting at implant sites favoured the free gingival graft treatment, with a greater final median height (5.0-5.5 mm) and increase in KT (4.0-4.2 mm). Locations of the recipient sites significantly influenced KT regeneration at both tooth and implant sites.

CONCLUSIONS

At implant sites, the free gingival graft treatment led to higher KT regeneration. At tooth sites, however, the differences between the three treatment modalities seemed clinically irrelevant.

Xenogeneic collagen matrix versus connective tissue graft for the treatment of multiple gingival recessions: A systematic review and meta-analysis

A systematic review and meta‐analysis was performed to understand the efficacy of xenogeneic collagen matrix (CMX) compared with connective tissue graft (CTG) for the treatment of multiple adjacent gingival recessions (MAGRs). A literature search was performed for published randomized controlled trials in adult patients (≥18 years old) with Multiple Adjacent Miller class I and II gingival recessions (MAGRs). The assessments included recession depth, Recession width, complete root coverage, mean root coverage, probing depth, clinical attachment level, and keratinized tissue width. Pooled data were analyzed using fixed‐ and random‐effects models, and Forest plots were constructed. Heterogeneity within studies was calculated to assess publication bias. Four randomized controlled trials were included based on the eligibility criteria. Although the recession depth, complete root coverage, and mean root coverage were significantly lower with CMX (p = .017 and p = .001, p = .001, respectively), there was no statistically significant difference in the Recession width between CMX and CTG (p = .203). CMX showed significantly lower Probing Depth than CTG (p = .023); however, no significant difference in clinical attachment level (p = .060) and keratinized tissue width (p = .052) was observed between the groups. Owing to the heterogeneity in the included studies, firm conclusions cannot be drawn regarding the noninferiority of CMX compared with CTG. Long‐term studies are therefore needed to conclusively establish the relative efficacy of CMX in MAGR.

Soft tissue substitutes to increase gingival thickness: Histologic and volumetric analyses in dogs

OBJECTIVES

To evaluate the histologic and volumetric changes of gingival tissues following grafting with collagen-based matrices at labial aspect of teeth in canines.

MATERIALS AND METHODS

Gingival augmentation was performed in the mandibular incisor area using two types of xenogeneic cross-linked collagen matrices (CCMs), bovine CCM for BCCM group and porcine CCM for PCCM group, whereas the contralateral sides remained untreated (B-control group and P-control group). Descriptive histology, histometric and volumetric analyses were performed after 12 weeks. For statistical comparison between each test group and respective control group, paired t test was used for histometric analysis, and repeated-measured analysis of variance was used for volumetric analysis (p < 0.05).

RESULTS

An increased number of rete pegs and an enhanced formation of new blood vessels were observed at both grafted sites compared to the corresponding control sites. There was statistically significant gain of horizontal thickness only in BCCM group (1.36 ± 0.27 mm vs. 1.26 ± 0.34 mm; p < 0.05) compared to the B-control groups.

CONCLUSION

BCCM was effective for gingival augmentation in terms of horizontal thickness at the labial aspect of teeth at 12 weeks post-surgery.

Topical simvastatin gel as a novel therapeutic modality for palatal donor site wound healing following free gingival graft procedure

OBJECTIVE

Autogenous soft-tissue grafting is a commonly used procedure nowadays in dentistry. However, the prolonged healing time needed for the donor site leads to increase the patient's pain and discomfort. Statin has been observed to be beneficial in reducing bacterial burden, improving epithelization and wound healing. The aim of this study was to evaluate intra-oral topical application of simvastatin/chitosan gel (10 mg/mL) over the palatal donor site following free gingival graft (FGG) procedure.

MATERIAL AND METHODS

Subjects indicated for FGG procedure were divided into four groups. Group I: Simvastatin suspension (S), group II: simvastatin/chitosan gel (SC), group III: chitosan gel (C), group IV: petroleum gel (P). Treatment was applied three times/day for the following 7 days. Wound healing was evaluated at day 3, 7 and 14 post-surgery. A visual analogue scale (VAS) was used to measure the experienced discomfort at 1, 3, 5, 7 and 14 days.

RESULTS

Statistical significant reduction in wound-healing scores was observed after 3 and 7 days for group II compared to other groups (p  = .015). A significant reduction was also observed in VAS score for group II compared to other groups at day 1, 3, 5 and 7.

CONCLUSION

Topical application of S/C gel could be used as a novel therapeutic modality that improved healing and reduced pain in the palatal donor site following FGG procedure.

Alveolar ridge preservation in the esthetic zone

In the esthetic zone, in the case of tooth extraction, the clinician is often confronted with a challenge regarding the optimal decision-making process for providing a solution using dental implants. This is because, after tooth extraction, alveolar bone loss and structural and compositional changes of the covering soft tissues, as well as morphological alterations, can be expected. Ideally, the therapeutic plan starts before tooth extraction and it offers three options: spontaneous healing of the extraction socket; immediate implant placement; and techniques for preserving the alveolar ridge at the site of tooth removal. The decision-making process mainly depends on: (i) the chosen time-point for implant placement and the ability to place a dental implant; (ii) the quality and quantity of soft tissue in the region of the extraction socket; (iii) the remaining height of the buccal bone plate; and (iv) the expected rates of implant survival and success. Based on scientific evidence, three time-periods for alveolar ridge preservation are described in the literature: (i) soft-tissue preservation with 6-8 weeks of healing after tooth extraction (for optimization of the soft tissues); (ii) hard- and soft-tissue preservation with 4-6 months of healing after tooth extraction (for optimization of the hard and soft tissues); and (iii) hard-tissue preservation with > 6 months of healing after tooth extraction (for optimization of the hard tissues).

Alveolar socket preservation with demineralised bovine bone mineral and a collagen matrix

PURPOSE

The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically.

METHODS

Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure.

RESULTS

Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm (P=0.005) and 0.46 mm (P=0.004), respectively. Histologically, residual xenograft particles (31.97%±3.52%) were surrounded by either newly formed bone (16.02%±7.06%) or connective tissue (50.67%±8.42%) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue.

CONCLUSIONS

Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good re-epithelialisation of the soft tissues during a 6-month healing period.

Evaluation of the Biological Behavior of Mucograft® in Human Gingival Fibroblasts: An In Vitro Study

Mucograft(r) is a resorbing porcine matrix composed of type I and type III collagen, used for soft tissue augmentation in guided tissue bony regeneration procedures. This in vitro study aimed to evaluate the biological behavior of Mucograft(r) in human gingival fibroblasts, as well as the ability of the matrix to induce production of extracellular matrix. Six resorbing Mucograft(r) matrices (MCG) were cut into 3 x 2 mm rectangles and 5 x 5 mm squares and were placed in 96- and 24-well plates, respectively. The control group (CTRL) consisted of cells plated on polystyrene without the MCG. After one, two, three and seven days, cell proliferation and viability were assessed using the Trypan exclusion method and MTT test, respectively. Type III collagen (COL 3A1) and vimentin (VIM) expression were also evaluated at 10 and 14 days, using Western blotting. Statistical analysis, using ANOVA with post hoc Bonferroni test, revealed that human gingival fibroblasts from MCG showed similar results (p>0.05) for proliferation and viability as the cells cultured on CTRL. After 14 days, a significant decrease in COL 3A1 expression (p<0.05) was observed when cultured with the MCG. VIM expression showed no significant difference at any time period (p>0.05). Although no increase in extracellular matrix secretion was observed in this in vitro study, Mucograft(r) presented cellular compatibility, being an option for a scaffold whenever it is required.

Palatal wound healing using a xenogeneic collagen matrix - histological outcomes of a randomized controlled clinical trial

AIM

The aim of this study was to test whether or not a collagen matrix can improve early wound healing compared to spontaneous healing based on histological and immunohistologic analyses.

METHODS

In 20 volunteers, 6 mm punch biopsies were harvested at the palate. A xenogeneic collagen matrix (XCM) was sutured in one site; the other one was left untreated (control). Biopsies with a diameter of 8 mm were subsequently obtained at 4, 8, 15 and 29 days and histological and immunohistologic analyses were performed.

RESULTS

At day 4, wound bed keratinization amounted to 12.4 ± 7.5% (control) and 18.0 ± 10.2% (XCM). This increased up to day 8 (19.7 ± 25.5% control; 29.1 ± 8.0% XCM) and reached complete keratinization at day 15 in both groups. The quantitative analyses of the superficial compartment measured an increase in the amount of granulation tissue (32-88% control; 14-41% XCM) from day 4 to day 8. Angiogenesis was first detected at 8 days. At day 29, the amount of connective tissue in all compartments reached values similar to the native tissue at baseline.

CONCLUSIONS

The application of a XCM as a wound dressing on palatal wounds might be beneficial in the early stages of wound healing. Further research with a larger sample size is needed to confirm these results.

Quantitative changes in palatal donor site thickness after free gingival graft harvesting: a pilot study

AIM

The aim of this study was to investigate how donor sites thickness quantitatively change over time and at different points of donor site in spontaneous palatal wound healing after free gingival graft (FGG) harvesting.

MATERIALS AND METHODS

Forty individuals were enrolled and divided into the following two groups based on the residual tissue thickness (RTT) after harvesting: Group 1, <2 mm; and Group 2, ≥2 mm. FGGs were standardized according to their dimensions and thickness and then harvested. Tissue filling was measured at three points of the defect area (mesial, central and distal) at various time points (baseline, after harvesting, and at 1, 3 and 6 months).

RESULTS

The thickness of newly formed tissue from the baseline to 1 month after harvesting was greater in Group 2 than in Group 1, whereas the thickness from 1 to 3 months and from 3 to 6 months after harvesting was greater in Group 1 than in Group 2 (p < 0.005). RTT was positively correlated with tissue filling in all the groups at all time points (p < 0.05).

CONCLUSIONS

The palatal mucosal thickness after FGG harvesting might affect the filling of the defect. Within the study period, the periphery of the palatal wounds filled earlier and to a greater extent compared with the centre of the wounds.

Randomized controlled clinical study evaluating effectiveness and safety of a volume-stable collagen matrix compared to autogenous connective tissue grafts for soft tissue augmentation at implant sites

AIM

To test whether or not the use of a collagen matrix (VCMX) results in short-term soft tissue volume increase at implant sites non-inferior to an autogenous subepithelial connective tissue graft (SCTG), and to evaluate safety and tissue integration of VCMX and SCTG.

METHODS

In 20 patients with a volume deficiency at single-tooth implant sites, soft tissue volume augmentation was performed randomly allocating VCMX or SCTG. Soft tissue thickness, patient-reported outcome measures (PROMs), and safety were assessed up to 90 days (FU-90). At FU-90 (abutment connection), tissue samples were obtained for histological analysis. Descriptive analysis was computed for both groups. Non-parametric tests were applied to test non-inferiority for the gain in soft tissue thickness at the occlusal site.

RESULTS

Median soft tissue thickness increased between BL and FU-90 by 1.8 mm (Q1:0.5; Q3:2.0) (VCMX) (p = 0.018) and 0.5 mm (-1.0; 2.0) (SCTG) (p = 0.395) (occlusal) and by 1.0 mm (0.5; 2.0) (VCMX) (p = 0.074) and 1.5 mm (-2.0; 2.0) (SCTG) (p = 0.563) (buccal). Non-inferiority with a non-inferiority margin of 1 mm could be demonstrated (p = 0.020); the difference between the two group medians (1.3 mm) for occlusal sites indicated no relevant, but not significant superiority of VCMX versus SCTG (primary endpoint). Pain medication consumption and pain perceived were non-significantly higher in group SCTG up to day 3. Median physical pain (OHIP-14) at day 7 was 100% higher for SCTG than for VCMX. The histological analysis revealed well-integrated grafts.

CONCLUSIONS

Soft tissue augmentation at implant sites resulted in a similar or higher soft tissue volume increase after 90 days for VCMX versus SCTG. PROMs did not reveal relevant differences between the two groups.

Versitality of the Use of Collagen Membrane in Oral Cavity

INTRODUCTION

Bovine derived collagen membrane is usually and regularly used as a temporary cover or dressing for the extra oral wounds and for the burns on the body. It has wide applications because of its usefulness and biocompatibility. This has provoked us to do a study with the use of collagen membrane even for the intraoral minor surgical defects.

AIM

The study was conducted to evaluate the clinical efficacy of collagen membrane as a biological dressing material for intraoral wounds, to check for haemostasis, pain control, granulation tissue formation, rapid re-epithelialization and minimal contracture.

MATERIALS AND METHODS

A total of 30 patients 19 male, 11 female were taken for excision of various intraoral lesions like leukoplakia patches, mucocele, epulis growths, irritational fibroma, frenectomy and the surgical defects were closed with collagen membrane. Postoperatively healing was assessed by taking five clinical parameters of Haemostasis, Pain, Granulation tissue, Epithelialization, Contracture.

RESULTS

Among 30 patients, haemostasis score was found to be good in 28 cases, fair in two cases. Pain relief score was good in seven cases, fair in 19 cases, poor in four cases. Granulation tissue formation score was good in eight cases, fair in 13 cases, poor in nine cases. Epithelialization score was good in 19 cases, fair in seven cases, poor in four cases. Contracture score was good in six cases, fair in 16 cases, poor in eight cases. Total score of all the five parameters, which was rated as effectiveness score, was calculated by using a standard scale. Final scoring was very effective in six cases, effective in 20 cases, ineffective in four cases.

CONCLUSION

Reconstituted bovine derived collagen membrane used in our study was found to be an effective intraoral wound dressing material for faster uneventful healing of intraorally also.

Advances in collagen, chitosan and silica biomaterials for oral tissue regeneration: from basics to clinical trials

Different materials have distinct surface and bulk characteristics; each of them potentially useful for the treatment of a particular wound or disease.