Extraction Socket Preservation with or without Membranes, Soft Tissue Influence on Post Extraction Alveolar Ridge Preservation: a Systematic Review

Poly(lactic acid/caprolactone) bilayer membrane achieves bone regeneration through a prolonged barrier function

Guided bone regeneration (GBR) is a treatment strategy used to recover bone volume. Barrier membranes are a key component of GBR protocols, and their properties can impact treatment outcomes. This study investigated the efficacy of an experimental, slow-degrading, bilayer barrier membrane for application in GBR using in vivo animal models. A synthetic copolymer of poly(lactic acid/caprolactone) (PLCL) was used to prepare a slow-degrading bilayer membrane. The biodegradability of PLCL was evaluated by subcutaneous implantation in a rat model. The barrier function of the PLCL membrane was investigated in a rat calvaria defect model and compared with commercially available membranes composed of type I collagen (Col) and poly(lactic-co-glycolic acid) (PLGA). An alveolar bone defect model in beagle dogs was used to simulate GBR protocols to evaluate the bone regeneration ability of the experimental PLCL membrane. The PLCL membrane showed slow biodegradation, resulting in an efficient and prolonged barrier function compared with commercial materials. In turn, this barrier function enabled the space-making ability of PLCL membrane and facilitated bone regeneration. In the alveolar bone defect model, significantly greater regeneration was achieved by treatment with PLCL membrane compared with Col and PLGA membranes. Additionally, a continuous alveolar ridge contour was observed in PLCL-treated bone defects. In conclusion, the PLCL bilayer membrane is a promising biomaterial for use in GBR given its slow degradation and prolonged barrier function.

Post-extraction volumetric analysis of alveolar ridge contour using subepithelial connective tissue graft in esthetic zone: a randomized controlled clinical trial

OBJECTIVES

The aim of this randomized clinical trial was to assess the alveolar ridge contour after soft tissue augmentation using subepithelial connective tissue graft (SCTG) buccal to fresh extraction sockets in patients with thin buccal bone, versus minimally-traumatic extraction followed by spontaneous healing solely.

MATERIALS AND METHODS

Forty non-restorable maxillary teeth in the esthetic zone were randomly assigned into two groups: minimally-traumatic extraction with SCTG (test) and minimally-traumatic extraction followed by spontaneous healing (control). The outcomes assessed included linear volumetric change of buccal soft tissue contour, vertical tissue loss, gingival thickness (GT), and interdental papilla (IDP) height after 6 months.

RESULTS

The SCTG group showed a significant improvement (P < 0.001) in all outcomes after 6 months. The SCTG group showed a statistically significant (P < 0.001) gain in the buccal soft tissue volumetric change compared to the control group. The SCTG group showed a statistically significant increase in GT (P < 0.001) and IDP height (P < 0.05) after 6 months compared to the control group.

CONCLUSIONS

The use of SCTG buccal to extraction sockets in the anterior maxilla might be considered as a predictable approach for preserving the alveolar ridge contour.

CLINICAL RELEVANCE

SCTG buccal to extraction sockets might counteract post-extraction hard and soft tissue alterations in the esthetic zone.

Complications following alveolar ridge augmentation procedures

Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth extraction/loss results in alveolar ridge deficiencies. Although RAP-related surgical techniques and biomaterials have been in practice for several decades, outcomes are not always predictable. Post-surgical complications experienced during the early or late wound healing phases may jeopardize the targeted ideal ridge dimensions, required for implant fixture placement, and may have other consequences, such as negatively impacting the patient's quality of life. This review describes reported post-surgical complications following RAP under the following subtitles: complications by tissue type, complications in function and aesthetics, complications by healing time, complications by biomaterial type, and complications by surgical protocol modalities. Specifically, RAP performed by using particulate bone graft substitutes and related complications are explored. Modalities developed to prevent/manage these complications are also discussed.

Clinical evaluations of alveolar ridge preservation in compromised extraction sockets with cortical-lamina anchoring technique: Case series study

OBJECTIVE

The objective of this study is to retrospectively evaluate the clinical outcomes of alveolar ridge preservation (ARP) in the compromised extraction sockets using autogenous cortical-lamina anchoring technique (CAT).

MATERIAL AND METHODS

Twenty patients were treated with ARP in the compromised extraction sockets by applying CAT. Then implant placement and crown delivery was performed. A planned follow-up was performed by analyzing various outcome measures to evaluate the clinical outcomes, including primary outcome measures [radiographic assessment of residual alveolar ridge height (RARH) and residual alveolar ridge width (RARW)] and secondary outcome measures [clinical assessment of the healing of the soft and hard tissue, survival rates of implants, marginal bone loss (MBL) evaluation of implants, buccal bone thickness (BBT), and esthetic treatment outcomes].

RESULTS

Among the 20 patients, 17 were consecutively treated and 3 dropped out after implant crown delivery because of loss to follow-up. After the ARP, the initial RARH (12.37 mm) significantly increased to 19.29 mm (P < .05). No significant difference was detected in the RARW before (7.92 ± 1.18 mm) and after (7.92 ± 1.18 mm) the ARP, but reduce to 6.99 ± 1.18 mm at the implant placement and 6.64 ± 0.77 mm at the 3-year follow-up (P < .05). The MBL at the implant crown delivery (0.13 ± 0.12 mm) significantly increased to 0.31 ± 0.14 mm at 1-year follow-up and 0.56 ± 0.23 mm at 3-year follow-up, respectively. The bone loss was limited (<1 mm) but statistically significant (P < .05). The BBT at the implant placement (2.53 ± 0.56 mm) significantly reduced to 2.23 ± 0.44 mm at implant crown delivery and 2.14 ± 0.40 mm at 3-year follow-up, respectively. The bone loss was also limited (<0.5 mm) but statistically significant (P < .05). Each implant site showed acceptable aesthetic outcome and the average score was 16.4. The incisions healed uneventful in all patients and the implant survival rate was 100% during the 3-year follow-up.

CONCLUSION

Autogenous CAT was successfully applied to preserve the height and width of alveolar ridge in the compromised extraction sockets.

An Analysis of Different Techniques Used to Seal Post-Extractive Sites—A Preliminary Report

Background: Bone grafting in post-extractive site improves tissue regeneration. Soft tissue sealing of the grafted post-extractive alveolus is supposed to limit microbiological contamination from the oral cavity and to stabilize the coagulum. Several techniques are presented in the literature to reach this goal using different heterologous matrices or autogenous grafts. In addition, recently, a technique based on the use of granulation tissue in the post-extractive alveolus has been proposed. Aim: To compare the effect of different graft sealing approaches in post-extractive sites by qualitatively evaluating their healing process. Materials and Methods: This retrospective investigation included 30 patients requiring post-extractive site regeneration in the aesthetic area. Post-extractive sites were regenerated using a bovine bone matrix and patients were divided into three groups (10 patients in each group) according to the material used to seal the alveolar socket. In the UD group, the granulation tissue was used to seal the defect; in the PC group, epithelial-connective soft tissue graft was used, and in the COLL group, a collagen-based membrane was employed. Images of the post-extractive sites at different follow-up periods (2 and 12 weeks) were taken and the healing process was blindly evaluated by two independent practitioners. The Healing Index (HI) by Landry, Turnbull and Howley was used to assess the quality of the healing process. The combination of presence/absence of five clinical criteria defines an HI ranging from 1 (very poor) to 5 (excellent). Patients’ clinical-pathological variables were recorded. One-way ANOVA was used to explore the dependence of HI on the different socket preservation protocols. Results: Based on clinical-pathological characteristics of the included patients, there were no statistically significant differences among the different sealing techniques. At the 2-week follow-up appointment, HI did not differ among the socket preservation protocols evaluated. Moreover, smoking status and reason for extraction did not influence the HI among the three groups (two-way ANOVA p-value = 0.686, p-value = 0.248 respectively). At the 2-week follow-up appointment, HI was significantly different among the socket preservation protocols investigated. Specifically, the group undergoing collagen-based socket preservation procedure reported the highest HI, compared to the other two techniques (COLL mean 4.60 ± 0.5; PC mean 3.5 ± 1.2; UD mean 3.4 ± 0.5, one-way ANOVA p-value 0.006). Conclusions: The use of collagen porcine membranes may represent a suitable option to improve the patient healing process in grafted post-extractive sites together with reducing the surgical intervention time compared to alternative sealing techniques.

The Use of Biocompatible Membranes in Oral Surgery: The Past, Present & Future Directions. A Narrative Review

The use of biocompatible membranes in periodontal and oral surgery is an important part of regeneration. Over the years, several different membranes have been developed, ranging from non-resorbable membranes that have to be removed in a separate procedure, to collagen membranes that completely resorb on their own, thus avoiding the need for a second surgery. Autogenous membranes are becoming increasingly popular in more recent years. These membranes can be used with a great variety of techniques in the four main hard tissue regenerative procedures: guided tissue regeneration, alveolar ridge preservation, guided bone regeneration and sinus floor augmentation. A review of the literature was conducted in order to identify the most commonly used membranes in clinical practice, as well as the most promising ones for regeneration procedures in the future. The information provided in this review may serve as a guide to clinicians, in order to select the most applicable membrane for the clinical case treated as the correct choice of materials may be critical in the procedure's success.

A Narrative Review on the Effectiveness of Bone Regeneration Procedures with OsteoBiol® Collagenated Porcine Grafts: The Translational Research Experience over 20 Years

Over the years, several bone regeneration procedures have been proposed using natural (autografts, allografts, and xenografts) and synthetic (i.e., metals, ceramics, and polymers) bone grafts. In particular, numerous in vitro and human and animal in vivo studies have been focused on the discovery of innovative and suitable biomaterials for oral and maxillofacial applications in the treatment of severely atrophied jaws. On this basis, the main objective of the present narrative review was to investigate the efficacy of innovative collagenated porcine bone grafts (OsteoBiol^®, Tecnoss^®, Giaveno, Italy), designed to be as similar as possible to the autologous bone, in several bone regeneration procedures. The scientific publications were screened by means of electronic databases, such as PubMed, Scopus, and Embase, finally selecting only papers that dealt with bone substitutes and scaffolds for bone and soft tissue regeneration. A total of 201 papers have been detected, including in vitro, in vivo, and clinical studies. The effectiveness of over 20 years of translational research demonstrated that these specific porcine bone substitutes are safe and able to improve the biological response and the predictability of the regenerative protocols for the treatment of alveolar and maxillofacial defects.

Comparison of the efficacy of different techniques to seal the alveolus during alveolar ridge preservation: Meta-regression and network meta-analysis

AIM

To evaluate the efficacy of different techniques to seal the alveolus (flap advancement [FA], open healing with barrier [OHB], and open healing without barrier [OHNB]) during alveolar ridge preservation (ARP) in terms of horizontal ridge width resorption.

MATERIALS AND METHODS

Randomized trials of at least 2 months duration comparing at least two techniques to seal the alveolus against each other or against spontaneous healing (SH) were eligible. Searches were conducted in MEDLINE via PubMed, EMBASE, Scopus, and Cochrane Central. Conventional meta-analysis, meta-regression, and network meta-analysis (NMA) were conducted, with clinical and tomographic ridge width changes as outcomes. Predictive intervals (95% PI) were reported.

RESULTS

Twenty-two studies were included, accounting for 52 study arms. Meta-regression identified that the socket sealing technique and publication year explained the observed heterogeneity. NMA showed that FA and OHB led to significantly lower ridge resorption than SH, resulting in 1.18 mm (95% PI 0.21-2.13) and 1.10 mm (95% PI 0.49-1.69) wide alveolar ridges, respectively. No significant difference between OHNB and SH was found (0.46 mm, 95% PI -0.70 to 1.64). The treatment with the largest probability for ARP was FA (52.7%), followed by OHB (39.1%) and OHNB (8.2%).

CONCLUSIONS

FA and OHB are efficacious techniques to seal the alveolus during ARP.

Autogenous Dentin Particulate Graft for Alveolar Ridge Augmentation with and without Use of Collagen Membrane: Preliminary Histological Analysis on Humans

(1) Background: The phenomenon of ankylosis of the dental elements has led clinicians to think that properly treated dentin and cement may be a potential graft for alveolar ridge augmentation. Currently, there are no studies in the literature able to histomorphometrically compare the healing patterns of an autogenous dentin particulate graft with the association, or not, of resorbable membranes. The aim of this pilot study is to histologically compare bone after an alveolar ridge augmentation using an autogenous dentin particulate graft with and without a resorbable collagen membrane. (2) Methods: this clinical trial enrolled six patients with defects requiring bone augmentation. Two procedures were performed in all six adult human patients in order to perform a study–control study: in Group 1, a ridge augmentation procedure with an autogenous dentin particulate graft and a resorbable collagen membrane was performed, and, in Group 2, an alveolar ridge preservation without a membrane was performed at the same time (T0). At 4 months, a biopsy of the bone tissues was performed using a 4 mm trephine bur in order to perform a histomorphometric analysis. (3) Results: The histomorphometric analysis demonstrated that Group 1 presented 45% of bone volume, 38% of vital bone, and 7% of residual graft. On the contrary, membrane-free regenerative procedures demonstrated 37% of bone volume, 9% of vital bone, and 27% of non-resorbed graft. In all cases, the regenerated bone allowed the insertion of implants with a standard platform, and no early failures were recorded. (4) Conclusions: Autogenous dentin particulate grafts seem to work best when paired with a membrane.

Autogenous Tooth Bone Grafts for Repair and Regeneration of Maxillofacial Defects: A Narrative Review

Autogenous tooth graft is an innovative and ingenious technique that employs a stepwise approach and utilizes human teeth as an autogenous source of bone graft. The structure of teeth closely resembles bone, both physically and biochemically, and can be efficiently used for the process as it depicts properties of osteoinduction and osteoconduction. Autogenous tooth bone has characteristics similar to bone grafts in terms of healing potential, physical properties, and clinical outcome. Autogenous tooth graft has shown reasonable promise as a graft material for the regeneration of maxillary and mandibular defects. Autogenous tooth bone graft finds its principal application in sinus and ridge augmentations and for socket preservation before implant placement. Additionally, it can be used successfully for alveolar cleft patients and patients with limited periodontal defects. The overall complication rates reported for autogenous tooth grafts are comparable to other graft sources. However, although long-term results are still underway, it is still recommended as a grafting option for limited defects in the cranio-facial region.

The need for socket preservation: a systematic review

The aim of this study was to evaluate the clinical need and impact of socket preservation to protect the bone for future dental implant placement. Moreover, we aimed to list down various methods of socket preservation by going through randomized clinical trials. We searched PubMed, Google Scholar, and Cochrane databases for all relevant publications, where researchers compared various methods and tools for socket preservation. All eight randomized controlled trials mentioned several methods that are helpful in preserving bone levels both horizontally and vertically. The studies included in this systematic review demonstrate that each material has certain efficacy in preserving the socket after tooth extraction for future implant placement. Socket preservation methods and materials are effective in preparing patients for future prostheses.

Buccal periosteal inversion (BUPI) for defect closure and keratinized gingiva width preservation after tooth extraction - technique modification

Introduction

Several techniques and methods have been proposed to cover alveolar bone after tooth extraction when soft tissue is lacking. Some authors recommend soft tissue flap techniques, and others advocate different types of materials for socket covering. In this article, the authors use a modified buccal inversion technique for adequate coverage of the alveolar ridge to ensure its preservation and to minimize soft tissue shrinkage and loss of keratinized gingiva after tooth extraction. This local mucogingival-periosteal plastic procedure was named by the authors the “Buccal Periosteal Inversion technique” or simply BUPI.

Materials and Methods

After extraction of a fractured, endodontically compromised lower right first molar, the BUPI technique was performed to cover the alveolus. After reflecting the two-sided full-thickness flap, the periosteum was split in the cranial direction. The inverted periosteum is used to provide tension-free defect closure of the postextractional defect. Detailed technique implementation and patient postoperative healing are presented here in detail.

Results

Postoperative evaluation at six weeks was presented with photos showing adequate surgical site healing, no signs of infection or dehiscence, and no crestal shift of the keratinized gingiva.

Conclusion

The buccal periosteal inversion (BUPI) technique is a modified technique that allows full socket coverage, avoiding a keratinized gingiva shift in the crestal direction using only the periosteum as a cover material. By inverting the buccal ridge periosteum alone from its normal position, the osteoclastic effect on the buccal bony wall will be eliminated, and this procedure abolishes the need for additional alveolar coverage materials.

Hard and Soft Tissue Augmentation with Single-Implant Restoration in the Esthetic Zone

The removal of the central incisor of the upper jaw is a challenging process, since the restoration of a single implant in the esthetic zone is of great responsibility. When tooth extraction with immediate implant placement is not possible, modern protocols imply the use of the socket preservation technique. This method of preserving socket properties significantly reduces changes that occur during the healing process of the postextracted area and along with soft tissue augmentation allows to achieve a satisfying aesthetic result. The aim of present case report is to assess capabilities of socket preservation concept and application of soft tissue augmentation in the anterior maxillary region. The treatment steps of a 35-year-old woman who needed to remove tooth 11 with further dental implant placement are described. The clinical case is of interest because after socket preservation and soft tissue augmentation, an acceptable aesthetic result was not reached. However, additional soft tissue augmentation made it possible to achieve the desired result, which was stable for 7 years.

Sealing materials for post-extraction site: a systematic review and network meta-analysis

Abstract

Aim

By means of a systematic review and network meta-analysis, this study aims to answer the following questions: (a) does the placement of a biomaterial over an extraction socket lead to better outcomes in terms of horizontal and vertical alveolar dimensional changes and percentage of new bone formation than healing without coverage? And (b) which biomaterial(s) provide(s) the better outcomes?

Materials and methods

Parallel and split-mouth randomized controlled trials treating ≥ 10 patients were included in this analysis. Studies were identified with MEDLINE (PubMed), Embase, Cochrane Central Register of Controlled Trials, and Scopus. Primary outcomes were preservation of horizontal and vertical alveolar dimension and new bone formation inside the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes. For NMA, prediction intervals were calculated to estimate clinical efficacy, and SUCRA was used to rank the materials based on their performance; multidimensional ranking was used to rank treatments based on dissimilarity. The manuscript represents the proceedings of a consensus conference of the Italian Society of Osseointegration (IAO).

Results

Twelve trials were included in the qualitative and quantitative analysis: 312 sites were evaluated. Autologous soft tissue grafts were associated with better horizontal changes compared to resorbable membranes. A statistically significant difference in favor of resorbable membranes, when compared to no membrane, was found, with no statistically significant heterogeneity. For the comparison between crosslinked and non-crosslinked membranes, a statistically significant difference was found in favor of the latter and confirmed by histomorphometric NMA analysis. Given the relatively high heterogeneity detected in terms of treatment approaches, materials, and outcome assessment, the findings of the NMA must be interpreted cautiously.

Conclusions

Coverage of the healing site is associated with superior results compared to no coverage, but no specific sealing technique and/or biomaterial provides better results than others. RCTs with larger sample sizes are needed to better elucidate the trends emerged from the present analysis.

Clinical relevance

Autologous soft tissue grafts and membranes covering graft materials in post-extraction sites were proved to allow lower hard tissue shrinkage compared to the absence of coverage material with sealing effect. Histomorphometric analyses showed that non-crosslinked membranes provide improved hard tissue regeneration when compared to crosslinked ones.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04262-3.

Barrier membranes for tissue regeneration in dentistry

Background: In dentistry, barrier membranes are used for guided tissue regeneration (GTR) and guided bone regeneration (GBR). Various membranes are commercially available and extensive research and development of novel membranes have been conducted. In general, membranes are required to provide barrier function, biosafety, biocompatibility and appropriate mechanical properties. In addition, membranes are expected to be bioactive to promote tissue regeneration.

Objectives: This review aims to organize the fundamental characteristics of the barrier membranes that are available and studied for dentistry, based on their components.

Results: The principal components of barrier membranes are divided into nonbiodegradable and biodegradable materials.

Nonbiodegradable membranes are manufactured from synthetic polymers, metals or composites of these materials. The first reported barrier membrane was made from expanded polytetrafluoroethylene (e-PTFE). Titanium has also been applied for dental regenerative therapy and shows favorable barrier function. Biodegradable membranes are mainly made from natural and synthetic polymers. Collagens are popular materials that are processed for clinical use by cross-linking. Aliphatic polyesters and their copolymers have been relatively recently introduced into GTR and GBR treatments. In addition, to improve the tissue regenerative function and mechanical strength of biodegradable membranes, inorganic materials such as calcium phosphate and bioactive glass have been incorporated at the research stage.

Conclusions: Currently, there are still insufficient guidelines for barrier membrane choice in GTR and GBR, therefore dentists are required to understand the characteristics of barrier membranes.

A Clinical and Histological Study about the Socket Preservation in a Patient under Oral Bisphosphonates Treatment: A Case Report

The aim of the present study is to assess the clinical and histological healing of a post-extractive alveolus following the procedure for socket preservation, in a patient receiving oral bisphosphonates for more than 6 years. After the extraction, enzymatically-deantigenated horse bone granules and an equine pericardium membrane were used to preserve the tooth socket. The patient was placed on a monthly follow-up in order to monitor the healing process. A 3 mm trephine bur was used to drill the bone for implant site preparation and to collect the bone sample. No signs and symptoms related to osteonecrosis of the jaws were reported. Histological data showed that, after 5 months, the mean percentages of trabecular bone, bone marrow and residual bone graft were respectively 45.74 ± 0.09%, 48.09 ± 0.08%, and 6.16 ± 0.01%. The residual graft material appeared to be osteointegrated and none of the particles appeared to be encapsulated. The present case report supports the guidelines that assume that patients undergoing oral bisphosphonate therapy can be eligible for surgical therapy. More clinical studies with larger sample sizes are needed to support this clinical evidence.

Advanced platelet-rich fibrin plus and osseous bone graft for socket preservation and ridge augmentation - A randomized control clinical trial

Objective

To compare the clinical and radiographic effectiveness of A PRF Plus as an adjuctive material to osseous bone graft in socket preservation and ridge augmentation.

Methods

Twenty patients with need to preserve extraction socket in non-molar sites planning for further prosthetic rehabilitation were divided into two groups. Test Group (Group A) was treated with A PRF Plus membrane and Sybograf plus ™ (70% HA and 30 %β TCP) bone graft. The Control Group (Group B) was treated with Sybograf plus ™ (70% HA and 30% βTCP) bone graft. Both groups had same socket preservation surgical technique.

Results

Both Group A and Group B showed significant improvement in clinical and radiographic parameters. Mean socket length, Vertical Resorption reduction in Group A was 1.48 whereas in Group B was 1.67 which is statistically significant. (p ​≤ ​0.05). Changes in Horizontal width reduction at 1,3, and 5 ​mm depth of the socket for both groups were not statistically significant. The Gain in socket fill for Group A and B 6 months postoperatively was 1185.30HU ± 473.21 and 966.60 HU ± 273.27 respectively. But intergroup comparison was not statistically significant. (p ​= ​0.17). There were no significant statistical differences in postoperative pain in Group A and Group B as subjects experienced moderate amount of pain. The assessment of post-operative swelling showed that only 30% subjects in Group A reported with swelling. Whereas 80% subjects in Group B complained of post-operative swelling.

Conclusion

The results of the present study proved utilisation of A PRF Plus as a promising adjunct to conventional regenerative therapy for socket preservation.

Efficacy of different surgical techniques for peri-implant tissue preservation in immediate implant placement: a systematic review and meta-analysis

INTRODUCTION

Preserving peri-implant tissues after immediate implant placement (IIP), especially in aesthetic zones, is a topic of interest.

OBJECTIVES

This systematic review investigated the effects of currently available surgical procedures for preserving peri-implant tissue or ensuring dimensional stability following immediate implant placement.

MATERIALS AND METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement's guidelines were followed, and articles were sought on the PubMed and Cochrane databases with no date restrictions. Only randomised clinical trials that evaluated changes in soft and hard tissues around immediately placed implants were included. Statistical analyses were performed, and the studies´ quality was assessed using the Cochrane Collaboration tool. The agreement between reviewers was assessed based on Cohen's kappa statistics.

RESULTS

Of the 14 studies that met the inclusion criteria, 11 were analysed in the meta-analysis (kappa = 0.814; almost perfect agreement). The use of connective tissue grafts resulted in a significantly greater improvement of the facial gingival level (MD = -0.51; 95% CI: -0.76 to -0.31; p = < .001), and the placement of bone grafts significantly reduced the horizontal resorption of the buccal bone (MD = -0.59; 95% CI: -0.78 to -0.39; p < .001).

CONCLUSION

Connective tissue grafts and bone grafts positively influence tissue preservation around immediately placed implants. Neither the flapless technique nor palatal implant positioning resulted in significant improvements to any of the investigated parameters. Additional longitudinal studies are required.

CLINICAL RELEVANCE

This meta-analysis is useful for discerning the effects of soft tissue augmentation, bone grafting, the flapless technique, and palatal implant positioning on preserving peri-implant tissues after immediate implant placement.

Postextraction Ridge Width Alterations Following Socket Seal Surgery—A Retrospective Study

Background and objectives: Preservation of alveolar ridge contour following tooth extraction is important to allow for restoration with prosthetics and implants. Socket seal surgery was introduced more than two decades ago for preservation of the form, volume and bone quality of the postextraction ridge. The aim of this retrospective study was to assess the changes in alveolar ridge contour following socket seal surgery and to evaluate the survival of the soft tissue grafts sealing the extraction site. Materials and Methods: Digital images of the extraction sites treated with the socket seal surgery were obtained immediately after extraction and after a healing time of 6 months to measure the changes in the alveolar width. In addition, the sites were photographed 1 week postsurgery to evaluate the vitality of the soft tissue grafts. Results: The overall mean loss of buccal width following socket seal surgery was 5.3% (SD = 13.4%). The mean change in width at the incisor area (1.5% ± 13.1) was significantly lesser than those in the canine area (−17.0% ± 2.1, p < 0.01) or premolar area (−10.5% ± 11.2, p < 0.01). One-week post-surgery 69% of the grafts were vital, and 31% were partially vital. Complete necrosis of the grafts did not occur. Conclusions: Our results suggest that socket seal surgery has a beneficial effect on alveolar dimensional changes 6 months following tooth extraction and that the teeth that benefit mostly from socket seal surgery are incisors.

Effects of combined use of recombinant human fibroblast growth factor-2 and β-tricalcium phosphate on ridge preservation in dehiscence bone defects after tooth extraction: A split-mouth study in dogs

BACKGROUND AND OBJECTIVE

Following tooth extraction, bone resorption is especially severe in cases complicated with buccal dehiscence bone defects. To minimize this, various bone graft materials have been used for alveolar ridge preservation. This study aimed to evaluate additional effects of the concomitant use of recombinant human fibroblast growth factor-2 (rhFGF-2) with β-tricalcium phosphate (β-TCP) on ridge preservation in a dehiscence defect model after tooth extraction in dogs.

MATERIALS AND METHODS

The maxillary first premolars of six beagle dogs were extracted and dehiscence defects of 4 × 4 × 5 mm (mesio-distal width × bucco-palatal width × depth) were created. Bilateral defects were filled with β-TCP combined with 0.3% (w/v) rhFGF-2 (test sites) or the scaffold alone (control sites). Twelve weeks post-surgery, histologic and histometric evaluations were performed.

RESULTS

Morphological measurements using micro-computed tomography revealed a significantly greater bone volume at the test sites (48.9 ± 9.06 mm³ ) than at the control sites (38.8 ± 7.24 mm³ ). Horizontal widths of the alveolar ridge at the coronal and middle position at the test sites (2.18 ± 0.71 mm, 2.93 ± 0.53 mm) were significantly greater than those at the control sites (1.47 ± 0.41 mm, 2.36 ± 0.45 mm, respectively). Regarding the histological parameters, the occupation rate of mineralized bone in the original defects was slightly higher at the test sites (44.07 ± 10.19%) than that at the control site (41.15 ± 6.56%).

CONCLUSIONS

These results indicate that the adjunct use of rhFGF-2 with β-TCP is effective for alveolar ridge preservation in fresh extraction sockets with dehiscence defects.

Effectiveness of bilayer porous polyethylene membrane for alveolar ridge preservation: A randomized controlled trial

BACKGROUND

Porous polyethylene has been successfully used in several medical applications with good outcomes. Based on this, a new bilayer porous polyethylene membrane (B-PPM) was developed for possibly being used as a membrane in alveolar ridge preservation.

PURPOSE

To evaluate the clinical efficacy of a new B-PPM in comparison to high-density polytetrafluoroethylene membrane (d-PTFE) in alveolar ridge preservation.

MATERIALS AND METHODS

Thirty patients were randomized into two groups according to the membranes used to cover the socket (B-PPM or d-PTFE). Wound healing was monitored at day 1, 3, 7, 14, 28, and 4 months postoperatively. Dimensional changes of alveolar ridge were measured immediately after tooth extraction and at 4 months later using intraoral scanner and cone beam computed tomography. Bone cores were harvested before implant placement. Implant stability at insertion and prior to prosthesis delivery were also measured.

RESULTS

No significant difference in socket wound closure between groups was observed excepting at day 14 that B-PPM showed a faster wound closure than d-PTFE (P = .03). Greater bone resorptions were seen on buccal than lingual side and on coronal than apical part of the alveolar ridge. No significant difference in dimensional changes of alveolar ridge, new bone formation, connective tissue content, residual bone grafts, and implant stability between two groups.

CONCLUSION

B-PPPM was safe and effective for alveolar ridge preservation.

Evaluation of Collagen Membranes Coated with Testosterone and Alendronate to Improve Guided Bone Regeneration in Mandibular Bone Defects in Minipigs

OBJECTIVES

The purpose of the present in vivo study was to evaluate whether pericard collagen membranes coated with ancillary amounts of testosterone and alendronate in a poly-lactic glycolic acid (PLGA) carrier as compared to uncoated membranes will improve early bone regeneration.

MATERIAL AND METHODS

In each of 16 minipigs, four standardized mandibular intraosseous defects were made bilaterally. The defects were filled with Bio-Oss^® granules and covered with a non-coated or coated membrane. Membranes were spray-coated with 4 layers of PLGA containing testosterone and alendronate resulting in 20, 50 or 125 μg/cm² of testosterone and 20 µg/cm² alendronate (F20, F50, F125). Non-coated membranes served as controls (F0). Animals were sacrificed at 6 and 12 weeks after treatment. Qualitative and quantitative histological evaluations of bone regeneration were performed. Differences between groups were assessed by paired Student's t-test.

RESULTS

Light microscopical analysis showed new bone formation that was in close contact with the Bio-Oss^® surface without an intervening non-mineralized tissue layer. Histomorphometric analysis of newly formed bone showed a significant 20% increase in area in the F125 coated membrane treated defects (40 [SD 10]%) compared to the F0 treated defects after 6 weeks (33 [SD 10]%, P = 0.013). At week 12, the total percentage of new bone was increased compared to week 6, but no increase in newly formed bone compared to F0 was observed.

CONCLUSIONS

The data from this in vivo study indicate that F125 collagen membranes coated with testosterone and alendronate resulted in superior bone formation (+24%) when normalized to control sites using uncoated membranes.

Alveolar ridge preservation with a collagen cone: Histological, histochemical, and immunohistochemical results of a randomized controlled clinical trial

OBJECTIVES

The objective of the present study was to examine the influence of a combination material of a collagen cone and a collagen membrane on the healing process of extraction sockets with regard to histological, histochemical, and immunohistochemical parameters.

MATERIALS AND METHODS

In a prospective randomized clinical study, 10 patients (test group) received a collagen combination material after tooth removal. The extraction sockets of 10 other patients (control group) were left to heal without further intervention. Eleven ±1 weeks after tooth extraction, histological biopsies were performed in both groups at the time of implant placement. Subsequently, the biopsies were evaluated semiquantitatively in terms of histological, histochemical, and immunohistochemical parameters for the identification of factors of bone metabolism and vascularization.

RESULTS

No significant difference between test and control group were found for any parameter. According to the descriptive data, the use of a collagen combination material seems to result in slightly higher values of the osteogenic Runt-related transcription factor 2 (Runx2) and vascularization.

CONCLUSION

The histological, histochemical, and immunohistochemical analysis of ARP with a collagen cone combined with a collagen membrane showed no significant differences in terms of bone metabolism and vascularization.

The Influence of Local Pamidronate Application on Alveolar Dimensional Preservation after Tooth Extraction-An Animal Experimental Study

The aim of this randomized, controlled animal exploratory trial was to investigate the influence of local application of aminobisphosphonate pamidronate during the socket preservation procedure. Mandibular premolars were extracted in five Göttingen minipigs. Two animals underwent socket preservation using BEGO OSS (n = 8 sockets) and three animals using BEGO OSS + Pamifos (15 mg) (n = 12 sockets). After jaw impression, cast models (baseline, eight weeks postoperative) were digitized using an inLab X5 scanner (Dentsply Sirona) and the generated STL data were superimposed and analyzed with GOM Inspect 2018 (GOM, Braunschweig). After 16 weeks, the lower jaws were prepared and examined using standard histological methods. In the test group (BEGO OSS + pamidronate), buccooral dimensional loss was significantly lower, both vestibulary (−0.80 ± 0.57 mm vs. −1.92 ± 0.63 mm; p = 0.00298) and lingually (−1.36 ± 0.58 mm vs. −2.56 ± 0.65 mm; p = 0.00104) compared with the control group (BEGO OSS). The test group showed a significant difference between vestibular and lingual dimensional loss (p = 0.04036). Histology showed cortical and cancellous bone in the alveolar sockets without signs of local inflammation. Adjuvant application of pamidronate during socket preservation reduces alveolar dimensional loss significantly. Further investigations with regard to dose–response relationships, volume effects, side effects, and a verification of the suitability in combination with other bone substitute materials (BSMs) are necessary.

Open-Healing Socket Preservation with a Novel Dense Polytetrafluoroethylene (dPTFE) Membrane: A Retrospective Clinical Study

Background and objectives: Non-resorbable dense polytetrafluoroethylene (dPTFE) membranes are widely used for regeneration procedures, alone or in combination with particulate materials. The aim of this work was to examine the efficacy of a newly developed dPTFE membrane in the management of extraction socket healing. Materials and Methods: The extraction premolar sockets of 44 patients (20 men and 24 women) were preserved. One group received prosthetic rehabilitation with a fixed partial denture (FPD) (PROS group, N = 19) and a second group received immediate implant placement (IMPL group, N = 25). The PROS group sockets were augmented with a bovine derived xenograft and covered with a newly developed dPTFE membrane prior to FPD rehabilitation. Results: In the IMPL group, socket preservation was combined with immediate implant placement. Before (T0) and 6 months after surgery (T1), horizontal and vertical dimensions were measured with customized stents. No significant differences in alveolar bone loss from T0 to T1 were observed between the PROS and IMPL groups in the horizontal dimension for any tooth type. There was a significant difference in alveolar bone loss from T0 to T1 between the two groups for only single-rooted maxillary premolars in the vertical dimension. Conclusions: The use of the examined new dPTFE membrane consistently led to the preservation of hard tissue in the extraction sites.

The 2nd Baltic Osseointegration Academy and Lithuanian University of Health Sciences Consensus Conference 2019. Summary and Consensus Statements: Group II - Extraction Socket Preservation Methods and Dental Implant Placement Outcomes within Grafted Sockets

Introduction

The task of Group II was to review and update the existing data concerning extraction socket preservation with or without membranes and soft tissue influence on post-extraction alveolar ridge preservation; extraction socket preservation using different biomaterials as bone grafts, growth factors, and stem cells. Special interest was paid to the dental implant placement outcomes within grafted sockets.

Material and Methods

The main areas evaluated by this group were as follows: quantitative and qualitative assessment of the effect of different alveolar preservation techniques performed immediately after tooth extraction, with or without membranes and/or soft tissue grafting, and the use of different bone substitutes, stem cells or growth factors in the postextraction socket. Evaluation of the treatment outcomes of dental implants placed in the grafted sockets in terms of primary and secondary outcomes were assessed. The systematic reviews and/or meta-analyses were registered in PROSPERO, an international prospective register of systematic reviews: http://www.crd.york.ac.uk/PROSPERO/. TThe literature in the corresponding areas of interest was screened and reported following the PRISMA guidelines (Preferred Reporting Item for Systematic Review and Meta-Analysis) Statement: http://www.prisma-statement.org/. Method of preparation of the systematic reviews, based on comprehensive search strategies, was discussed and standardized. The summary of the materials and methods employed by the authors in preparing the systematic reviews and/or meta-analyses is presented in the Preface chapter.

Results

The results and conclusions of the review process are presented in the respective papers. Three systematic reviews and one systematic review and meta-analysis were performed. The group's general commentaries, consensus statements, clinical recommendations and implications for research are presented in this article.