Clinical and histologic outcomes of socket grafting after flapless tooth extraction: a systematic review of randomized controlled clinical trials

How effective is dentin autograft for socket preservation and implant site preparation: A systematic review protocol

Background

Socket preservation is a surgical procedure aimed at preserving the dimensions of the alveolar bone following tooth extraction. It is performed by filling the extraction socket with bone graft material with or without a barrier membrane. Recently, dentine obtained from extracted teeth has been tried as an autograft for socket preservation. Studies have compared the use of dentin to other bone grafts, however, systematic reviews evaluating the efficacy of dentin for socket preservation are limited. Hence, this systematic review protocol is proposed to generate evidence on the efficacy of dentin as a viable alternative to other bone graft materials for socket preservation.

Methods

This systematic review protocol was prepared according to the Methodological Expectations of the Cochrane Intervention Reviews (MECIR) guidelines. It will be conducted using the Cochrane Handbook for Systematic Review of Interventions. PubMed, Scopus, Web of Science, EMBASE, Epistemonikos, Cochrane Central, and EBSCO databases and clinical trial registries, will be searched for all randomized controlled trials (RCTs) and non-randomized studies that have used autologous dentin graft (either in particulate/putty, or/matrix form) for socket preservation. The radiographic and clinical assessment of bone and soft tissue healing of the preserved sockets along with patient-related outcomes following surgery will be assessed. The risk of bias assessment of the RCTs and Non-RCTs will be assessed using the 'Cochrane Risk of Bias assessment tool (ROB II) and ROBINS-I respectively. The certainty of evidence will be assessed by the GRADE approach.

Discussion

This evidence is important for dental clinicians and the public to make an informed decision when choosing graft material for socket preservation. The extracted teeth are considered biological waste; however, this evidence provides scope for using a less invasive autograft for bone regenerative procedures.

Systematic review registration

PROSPERO: CRD42021201958 (Registered on 15/02/2021).

Changes of the Alveolar Bone Ridge Using Bone Mineral Grafts and Collagen Membranes after Tooth Extraction: A Systematic Review and Meta-Analysis

BACKGROUND

Alveolar preservation techniques for esthetic or functional purposes, or both, are a frequently used alternative for the treatment of post-extraction sockets, the aim of which is the regeneration of the lesion and the preservation of the alveolar bone crest.

METHODS

Studies published in PubMed (Medline), Web of Science, Embase, and Cochrane Library databases up to January 2024 were consulted. Inclusion criteria were established as intervention studies, according to the PICOs strategy: adult subjects undergoing dental extractions (participants), with alveoli treated with bone mineral grafts and collagen membranes (intervention), compared to spontaneous healing (comparison), and observing the response to treatment in clinical and radiological measures of the alveolar bone crest (outcomes).

RESULTS

We obtained 561 results and selected 12 studies. Risk of bias was assessed using the Cochrane Risk of Bias Tool, and methodological quality was assessed using the Joanna Briggs Institute. Due to the high heterogeneity of the studies (I2 > 75%), a random-effects meta-analysis was used. Despite the trend, no statistical significance (p > 0.05) was found in the experimental groups.

CONCLUSIONS

The use of bone mineral grafts in combination with resorbable collagen barriers provides greater preservation of the alveolar ridge, although more clinical studies are needed.

Comparison of histologic and radiographic changes of sockets grafted with LPRF and sockets without intervention after tooth extraction

OBJECTIVES

After tooth extraction, marked resorption occurs in extraction socket walls, leading to functional and esthetic problems in that area. One of the methods introduced to reduce this resorption is the use of platelet derivatives. This study aimed to evaluate the effects of leukocyte and platelet-rich fibrin (L-PRF) on the changes following tooth extraction.

MATERIALS AND METHODS

The participants were 24 patients who needed to replace at least one single-rooted tooth with an implant. They were randomly divided into test and control groups. After the tooth extraction, the sockets in the test group received LPRF clots, while in the control group, the sockets were left free of any interventions. CBCT scans were obtained from the extraction site both immediately after the tooth extraction and 8 weeks later. The histologic biopsy was also obtained while the implant site was being prepared 8 weeks after the extraction.

RESULTS

The average vertical bone loss in the buccal crest was not significantly different between the two groups (1.67 ± 1.67 in the test group and 2.3 ± 1.36 in the control group; mean difference =  - 0.36, 95% CI: - 1.65-0.93, p-value = 0.57). Nor was the difference in resorption of the palatal wall (mean difference =  - 0.19, 95% CI: - 1.51.12, p-value = 0.76). The mean ridge width resorption in 25% of the coronal aspect of sockets was also measured in the test (1.30 ± 0.66) and control group (0.58 ± 0.95) (mean difference = 0.73, 95% CI: 0.03-1.42, p-value = 0.04). The new bone formation in histologic view was not statistically different between groups (p-value = 0.15).

CONCLUSION

The LPRF neither reduces the rate of ridge resorption in vertical or horizontal dimensions of extraction sockets nor induces more new bone formation.

CLINICAL RELEVANCE

This study helps dentists choose the appropriate material for ridge preservation.

Learn, unlearn, and relearn post-extraction alveolar socket healing: Evolving knowledge and practices

OBJECTIVE

This review was to offer a comprehensive analysis of currently available evidence on post-extraction alveolar socket healing, including i) the histological and molecular events during alveolar socket healing, ii) the dimensional ridge alterations after socket healing and controversies relating to sinus pneumatisation, iii) the patient-specific factors, procedural elements, and site-related variables influencing socket healing, iv) techniques and effectiveness of alveolar ridge preservation (ARP) procedure, and v) the philosophies and cost-effectiveness of ARP in clinical practice.

SOURCES AND STUDY SELECTION

To investigate the dimensional profiles of the alveolar ridge following unassisted healing, an overview of systematic reviews was conducted in February 2024 by two independent reviewers. Four electronic databases were searched in Pubmed, Embase, Web of science and Cochrane Library between 2004 and 2024 to identify all relevant systematic reviews on post-extraction healing. A further manual search of reviews was also conducted. The articles were further reviewed in full text for relevance. The AMSTAR-2 appraisal tool was adopted to assess methodological quality. Current research pertaining to other listed objectives was objectively analysed in narration.

DATA

11 out of 459 retrieved studies were selected and ultimately covered in this review on the dimensional changes of alveolar ridge following natural healing: Seven systematic reviews and four systematic reviews with meta-analyses. The methodological quality of all included reviews was critically low.

CONCLUSION

This review thoroughly examines the healing profiles of post-extraction alveolar sockets and highlights the dynamic process with overlapping phases and the inter-individual variability in outcomes. ARP procedure is a potential strategy for facilitating prosthetic site development, while the current evidence is limited. Herein, an individualised and prosthetically driven approach is crucial. Further well sized and designed trials with novel biomaterials need to be undertaken, and the role of artificial intelligence in predicting healing and assisting clinical decision-making could be explored.

CLINICAL SIGNIFICANCE

By advancing our understanding of alveolar socket healing and its management strategies, clinicians can make more informed decisions regarding patient and site level assessment and selection, surgical techniques, and biomaterial choices, ultimately contributing to the enhanced healing process with reduced complications and improved quality of life for patients undergoing tooth extraction and dental implant treatments.

Application of modified porcine xenograft by collagen coating in the veterinary field: pre-clinical and clinical evaluations

Introduction

This study aimed to identify a collagen-coating method that does not affect the physicochemical properties of bone graft material. Based on this, we developed a collagen-coated porcine xenograft and applied it to dogs to validate its effectiveness.

Methods

Xenografts and collagen were derived from porcine, and the collagen coating was performed through N-ethyl-N'-(3- (dimethylamino)propyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) activation. The physicochemical characteristics of the developed bone graft material were verified through field emission scanning electron microscope (FE-SEM), brunauer emmett teller (BET), attenuated total reflectance-fourier transform infrared (ATR-FTIR), and water absorption test. Subsequently, the biocompatibility and bone healing effects were assessed using a rat calvarial defect model.

Results

The physicochemical test results confirmed that collagen coating increased bone graft materials' surface roughness and fluid absorption but did not affect their porous structure. In vivo evaluations revealed that collagen coating had no adverse impact on the bone healing effect of bone graft materials. After confirming the biocompatibility and effectiveness, we applied the bone graft materials in two orthopedic cases and one dental case. Notably, successful fracture healing was observed in both orthopedic cases. In the dental case, successful bone regeneration was achieved without any loss of alveolar bone.

Discussion

This study demonstrated that porcine bone graft material promotes bone healing in dogs with its hemostatic and cohesive effects resulting from the collagen coating. Bone graft materials with enhanced biocompatibility through collagen coating are expected to be widely used in veterinary clinical practice.

Risk Factors for Early Implant Failure and Selection of Bone Grafting Materials for Various Bone Augmentation Procedures: A Narrative Review

Implant therapy is now an established treatment with high long-term success and survival rates. However, early implant failure, which occurs within one year of superstructure placement, occurs at a higher rate than late failure, which is represented by peri-implantitis caused by bacterial infection. Furthermore, various risk factors for early failure have been reported, including patient-related factors, such as systemic diseases, smoking, and bone quality and quantity, as well as surgery-related factors, such as surgeons' skill, osteogenesis technique, and selection of graft material, and implant-related factors, such as initial implant fixation and implant length diameter. Due to the wide variety of relevant factors reported, it is difficult to identify the cause of the problem. The purpose of this review is to discuss the risk factors associated with various types of bone augmentation which have a close causal relationship with early implant failure, and to determine the optimal bone grafting material for bone augmentation procedures to avoid early implant failure.

Alveolar Ridge Preservation with a Novel Cross-Linked Collagen Sponge: Histological Findings from a Case Report

Alveolar ridge preservation (ARP) is a well-documented procedure to maintain bone volume after tooth extraction in order to place implants. However, at the end of the healing process, the residual biomaterial that is not reabsorbed remains embedded in the bone over time. Ribose cross-linked biomaterials demonstrated their ability to promote osteoconduction and complete resorption. The aim of this study was to evaluate the histological healing pattern of a novel ribose cross-linked collagen sponge used as a grafting material left exposed in human sockets at the time of tooth extraction. On a single patient, non-restorable lower first molars were extracted on both sides, and a ribose cross-linked collagen sponge was placed bilaterally in the cavities and left uncovered at the end of the surgery. After six months, core biopsies were taken immediately prior to implant placement; after the sample preparation, a histological analysis was performed. The results are very promising for substitution with newly formed bone and the amount of residual material. Ribose cross-linked collagen sponge could represent a valid alternative to conventional biomaterials for ARP procedures with no need for flap advancement and/or the addition of a membrane to cover the graft, reducing the invasiveness, complexity, and costs of the treatment.

Prevalence of peri-implantitis after alveolar ridge preservation at periodontitis and nonperiodontitis extraction sites: A retrospective cohort study

INTRODUCTION

Periodontitis is the main indication for dental extraction and often leads to peri-implantitis (PI). Alveolar ridge preservation (ARP) is an effective means of preserving ridge dimensions after extraction. However, whether PI prevalence is lower after ARP for extraction after periodontitis remains unclear. This study investigated PI after ARP in patients with periodontitis.

MATERIALS AND METHODS

This study explored the 138 dental implants of 113 patients. The reasons for extraction were categorized as periodontitis or nonperiodontitis. All implants were placed at sites treated using ARP. PI was diagnosed on the basis of radiographic bone loss of ≥3 mm, as determined through comparison of standardized bitewing radiographs obtained immediately after insertion with those obtained after at least 6 months. Chi-square and two-sample t testing and generalized estimating equations (GEE) logistic regression model were employed to identify risk factors for PI. Statistical significance was indicated by p < 0.05.

RESULTS

The overall PI prevalence was 24.6% (n = 34). The GEE univariate logistic regression demonstrated that implant sites and implant types were significantly associated with PI (premolar vs. molar: crude odds ratios [OR] = 5.27, 95% confidence intervals [CI] = 2.15-12.87, p = 0.0003; bone level vs. tissue level: crude OR = 5.08, 95% CI = 2.10-12.24; p = 0.003, respectively). After adjustment for confounding factors, the risks of PI were significantly associated with implant sites (premolar vs. molar: adjusted OR [AOR] = 4.62, 95% CI = 1.74-12.24; p = 0.002) and implant types (bone level vs. tissue level: AOR = 6.46, 95% CI = 1.67-25.02; p = 0.007). The reason for dental extraction-that is, periodontitis or nonperiodontitis-was not significantly associated with PI.

CONCLUSION

ARP reduces the incidence of periodontitis-related PI at extraction sites. To address the limitations of our study, consistent and prospective randomized controlled trials are warranted.

Augmentation of single tooth extraction socket with deficient buccal walls using bovine xenograft with platelet-rich fibrin membrane

BACKGROUND

Different techniques and materials such as bone grafts and bioactive agents have been used for alveolar ridge augmentation in extraction sockets with a defective wall, there is not a specific material or technique that has resulted in superior outcomes or prevented total bone loss.

OBJECTIVES

This clinical study aims to evaluate radiographically the effectiveness of using bovine xenograft with platelet-rich fibrin (PRF) membrane on vertical and horizontal alveolar ridge dimensional changes following tooth extraction that are complicated by buccal bone loss.

MATERIALS AND METHODS

This study was conducted in Egypt on fourteen patients with a single posterior tooth indicated for extraction. A preoperative cone-beam computed tomography (CBCT) scan confirmed more than 50% loss in buccal bone in each tooth. Extraction sockets were packed with minced PRF clots mixed with a bovine xenograft. Each extraction socket was sealed by PRF membranes. CBCT scans, performed before tooth extraction and after 6 months, were used to assess alveolar ridge changes both vertically and horizontally.

RESULTS

There was a significant gain in the buccal and middle of the extraction socket bone height, recording 86.01% (6.33 mm) and 206.45% (9.6 mm), respectively. There was an insignificant bone loss in the lingual bone height and width, recording - 8.49% (-1.06 mm) and - 13.39% (1.05 mm), respectively. The results also showed a non-significant decrease in alveolar bone density (-14.06%) between pre-operative bone present apical to the extraction socket and newly formed bone inside the socket.

CONCLUSIONS

Ridge preservation/augmentation techniques using a bone graft mixed with PRF and covered by PRF membranes in fresh extraction sockets complicated by the loss of buccal bone result in buccal bone augmentation and a reduction in horizontal and vertical ridge collapse after tooth extraction.

CLINICAL RELEVANCE

The bovine xenograft in conjunction with PRF can be used immediately after extraction for ridge preservation, providing adequate bone width and height for implant placement.

A Socket Seal Technique With the Use of Autologous Dental Roots for Socket Seal: A Case Series

The literature identified variations in socket seal surgery, each with limitations. This case series aimed to observe the outcome of using autologous dental root (ADR) for socket sealing on socket preservation (SP). A total of 9 patients with 15 extraction sockets were documented. After flapless extraction, the xenograft or alloplastic grafts were placed in the sockets. Autologous dental roots were prepared extraorally and applied to seal the socket entrance. All SP sites healed uneventfully. Cone-beam computed tomography (CBCT) scan was performed after 4-6 months of healing to evaluate ridge dimensions. The preserved alveolar ridge profiles were verified on CBCT scans and during implant surgery. Implants were placed successfully with a reduced need for guided bone regeneration. Histological biopsy specimens were examined in 3 cases. The histological examination demonstrated vital bone formation and osseointegration of graft particles. All patients completed the final restorations and were monitored for 15.56 ± 9.08 months after functional loading. The favorable clinical outcomes support the use of ADR for SP procedures. It was not only accepted to patients but also easy to perform with low complication rates. The ADR technique is thus a feasible method for socket seal surgery.

Is alveolar ridge preservation an overtreatment?

The morphology and dimensions of the postextraction alveolar ridge are important for the surgical and restorative phases of implant treatment. Adequate new bone formation and preservation of alveolar ridge dimensions following extraction will facilitate installation of the implant in a restorative position, while preservation of soft tissue contour and volume is essential for an aesthetic and implant-supported restoration with healthy peri-implant tissues. Alveolar ridge preservation (ARP) refers to any procedure that aims to: (i) limit dimensional changes in the alveolar ridge after extraction facilitating implant placement without additional extensive bone and soft tissue augmentation procedures (ii) promote new bone formation in the healing alveolus, and (iii) promote soft tissue healing at the entrance of the alveolus and preserve the alveolar ridge contour. Although ARP is a clinically validated and safe approach, in certain clinical scenarios, the additional clinical benefit of ARP over unassisted socket healing has been debated and it appears that for some clinicians may represent an overtreatment. The aim of this critical review was to discuss the evidence pertaining to the four key objectives of ARP and to determine where ARP can lead to favorable outcomes when compared to unassisted socket healing.

Use of Injectable Platelet-Rich Fibrin Accompanied by Bone Graft in Socket Endurance: A Radiographic and Histological Study

Background Ridge preservation became a crucial dental health issue and strategy to keep away from ridge defacement after post-tooth loss. The recent scientific evolution of platelet-rich fibrin (PRF) comprises a parenteral formulation of PRF. The combined allograft for socket preservation gives benefits. In this study, bone allografts, demineralized freeze-dried bone allografts (DFDBA) and freeze-dried bone allografts (FDBA) are used in a 30:70 ratio alone or in combination with injectable PRF (I-PRF) for socket preservation. Methods This study is a radiographic and histological examination conducted on 60 participants aged between 19-65 years. Participating patients agreed voluntarily that they would not bear any fixed prosthesis for the next nine months and plan for implanted teeth placement, including multi-rooted mandibular molars denticles. Both groups received atraumatic extraction; then, the socket was preserved with bone allograft alone in the control group and bone allograft mixed with I-PRF, forming sticky bone, in the experimental group. Clinical, radiological, and histological assessments were taken at the inception stage, three months, six months, and nine months. A multivariate regression model and a generalized estimating equation (GEE) model were used to analyse the effects of these changes on outcomes. Results In all the parameters, the test group indicated a good amount of bone growth with increasing intervals of time for bone height radiographically with statistically significant difference present (p<0.05) and histologically after nine months when socket site grafted with bone graft in combination with I-PRF. Conclusion This study's results demonstrated that I-PRF possesses the potential to regenerate and heal in the tooth-extracted socket. This study further recommends the implementation of I-PRF in safeguarding and conserving the raised rim of the tooth. Future research should take place on the osteogenic capability of I-PRF in more comprehensive ridge accession surgical procedures and additional expanding and improving capacities in periodontal reconstruction.

Regeneration of Buccal Wall Defects after Tooth Extraction with Biphasic Calcium Phosphate in Injectable Form vs. Bovine Xenograft: A Randomized Controlled Clinical Trial

Bone healing after tooth extraction may be affected by defects of the alveolus buccal wall, such as fenestrations and dehiscences. Therefore, to minimize dimensional changes it is advisable to perform alveolar ridge preservation after tooth extractions. Different biomaterials are used for this purpose. The aim of this study was to investigate the qualitative and quantitative histological changes in human biopsies taken after 6 months of healing of extraction sockets with buccal wall defects. For this purpose, the defects of 36 patients (18 per group) were treated with injectable biphasic calcium phosphate (I-BCP) or bovine xenograft (BX) after extraction. After six months of healing, biopsies were taken and proceeded to the histology laboratory. No evidence of an inflammatory response of the tissue was observed in the biopsies of either group, and the newly formed bone (NB) was in close contact with the remaining biomaterial (BM). The histomorphometric results showed that there was no statistically significant difference between the groups in the mean percentage of NB (p = 0.854), BM (p = 0.129), and soft tissue (p = 0.094). To conclude, both biomaterials exhibited osteoconductivity and biocompatibility and achieved satisfactory bone regeneration of buccal wall defects after tooth extraction.

Extraction Socket Augmentation with Autologous Platelet-Rich Fibrin (PRF): The Rationale for Socket Augmentation

After tooth extraction, the alveolar ridge undergoes a physiological process of remodelling and disuse atrophy. Socket augmentation (SA) has been shown to preserve alveolar bone volume in order to facilitate implant placement and reduce the need for staged grafting at a later date. Although autogenic grafting has been shown to be the gold standard in bone regeneration, it has significant disadvantages. To prevent post-extraction volumetric alterations and alveolar bone resorption occurring, alternative grafting materials, including xenografts, alloplasts, and allografts, have been used successfully in fresh extraction sites. However, these materials act mostly as bio-scaffolds and require a slower integration period of 6-8 months prior to implant placement. Recently, the use of autologous platelet-rich fibrin (PRF) has been advocated alongside socket augmentation as a method of bio-enhancement of healing of soft and hard tissues. PRF contains platelet-derived growth factors, hormones, and bioactive components such as cytokines that have been shown to promote angiogenesis and tissue regeneration during wound healing. The aim of this article is to review the evidence base for the SA technique Clinical benefits of SA will be discussed with a reference to two cases. Therefore, this narrative review will discuss the post-extraction bone changes, the importance of SA, and the bio-enhancement role of PRF in the management of extraction site defects when the alternative technique of immediate implant placement is not possible or contraindicated.

Clinical evaluation of different alveolar ridge preservation techniques after tooth extraction: a randomized clinical trial

OBJECTIVE

The aim of the present randomized controlled trial (RCT) was to evaluate the efficacy of different alveolar ridge preservation (ARP) techniques on dimensional alterations after tooth extraction, based on clinical measurements.

BACKGROUND

Alveolar ridge preservation (ARP) is a common procedure in every day clinical practice, when dental implants are involved in treatment planning. In ARP procedures, a bone grafting material is combined with a socket sealing (SS) material in order to compensate the alveolar ridge dimensional alterations after tooth extraction. Xenograft and allograft are the most frequently used bone grafts in ARP, while free gingival graft (FGG), collagen membrane, and collagen sponge (CS) usually applied as SS materials. The evidence comparing xenograft and allograft directly in ARP procedure is scarce. In addition, FGG is usually combined with xenograft as SS material, while the evidence combing allograft with FGG is absent. Moreover, CS could probably be an alternative choice in ARP as SS material, since it has been used in previous studies but more clinical trials are required to evaluate its effectiveness.

MATERIALS AND METHODS

Forty-one patients were randomly assigned in four treatment groups: (A) freeze-dried bone allograft (FDBA) covered with collagen sponge (CS), (B) FDBA covered with free gingival graft (FGG), (C) demineralized bovine bone mineral xenograft (DBBM) covered with FGG, and (D) FGG alone. Clinical measurements were performed immediately after tooth extraction and 4 months later. The related outcomes pertained to both vertical and horizontal assessment of bone loss.

RESULTS

Overall, groups A, B, and C presented significantly less vertical and horizontal bone resorption compared to group D. No statistically significant difference was observed between allograft and xenograft, except for the vertical bone resorption at the buccal central site, where xenograft showed marginally statistically significantly reduced bone loss compared to allograft (group C vs group B: adjusted β coef: 1.07 mm; 95%CI: 0.01, 2.10; p = 0.05). No significant differences were observed in hard tissue dimensions when CS and FGG were applied over FDBA.

CONCLUSIONS

No differences between FDBA and DBBM could practically be confirmed. In addition, CS and FGG were equally effective socket sealing materials when combined with FDBA, regarding bone resorption. More RCTs are needed to compare the histological differences between FDBA and DBBM and the effect of CS and FGG on soft tissue dimensional changes.

CLINICAL RELEVANCE

Xenograft and allograft were equally efficient in ARP 4 months after tooth extraction in horizontal level. Xenograft maintained the mid-buccal site of the socket marginally better than the allograft, in vertical level. FGG and CS were equally efficient as SS materials regarding the hard tissue dimensional alterations.

TRIAL REGISTRATION

Clinical trial registration Number: NCT04934813 (clinicaltrials.gov).

Alveolar ridge preservation: Complications and cost-effectiveness

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Alveolar ridge preservation in post-extraction sockets using concentrated growth factors: a split-mouth, randomized, controlled clinical trial

Aim

The aim of this clinical trial was to assess the impact of autologous concentrated growth factor (CGF) as a socket-filling material and its ridge preservation properties following the lower third molar extraction.

Materials and methods

A total of 60 sides of 30 participants who had completely symmetrical bilateral impacted lower third molars were enrolled. The primary outcome variables of the study were bone height and width, bone density, and socket surface area in the coronal section. Cone beam computed tomography images were obtained immediately after surgery and three months after surgery as a temporal measure. Follow-up data were compared to the baseline using paired and unpaired t-tests.

Results

CGF sites had higher values in height and width when compared to control sites (Buccal wall 32.9 ± 3.5 vs 29.4 ± 4.3 mm, Lingual wall 25.4 ± 3.5 vs 23.1 ± 4 mm, and Alveolar bone width 21.07 ± 1.55vs19.53 ± 1.90 mm, respectively). Bone density showed significantly higher values in CGF sites than in control sites (Coronal half 200 ± 127.3 vs -84.1 ± 121.3 and Apical half 406.5 ± 103 vs 64.2 ± 158.6, respectively). There was a significant difference between both sites in the reduction of the periodontal pockets.

Conclusion

CGF application following surgical extraction provides an easy, low-cost, and efficient option for alveolar ridge preservation. Thus, the use of CGF by dentists during dental extractions may be encouraged, particularly when alveolar ridge preservation is required.

Clinical trial registration

TCTR identification, TCTR20221028003.

Alveolar ridge preservation: A review of concepts and controversies

The loss of thickness and height of the alveolar process after tooth extraction is a significant impediment to implant placement, which limits the aesthetic results of many restorative treatments. Alveolar ridge preservation can reduce bone resorption. Knowing how beneficial this procedure is can help clinicians decide if it is worth doing. The purpose of this article is to present a contemporary review of the different approaches to preserving the dimensions of the alveolar ridge. We analyze the alveolar healing process, atraumatic extraction techniques, graft materials, and controversies.

Immediate Implant and Customized Healing Abutment for a Periodontally Compromised Socket: 1-Year Follow-Up Retrospective Evaluation

Immediate dental implant placement with or without immediate loading is reported in daily dentistry and implantology, but these procedures are not common in the case of periradicular and periapical lesions around the tooth needed to be replaced. In the following retrospective evaluation, 10 cases with a 1-year follow-up were selected to propose the technique of an immediate provisional non-loading prosthesis being delivered on the same day of the post-extraction implant placement in multiradicular teeth affected by chronic periradicular and periapical lesions. Post-extractive sockets underwent immediate dental implant placement by filling the empty space with sterile, re-absorbable gelatin sponges. The widths of the alveolar ridge were measured on three-dimensional radiographs before and after the operation, 4 and 12 months later. Non-parametric statistics were performed to compare the outcomes over time with a level of significance of 0.05. Comparing the preoperative cross-sectional images of cone beam computerized tomography (CBCT) scans to the postoperative ones, it was noted that changes in the crestal ridge width, ΔCW, (compared to baseline) were negligible and not clinically appreciable. However, while ΔCW at 4 months appeared to be negative (-0.17 ± 045 mm), crestal width at 12 months was at the same level as the baseline (ΔCW = 0.02 ± 0.48 mm), with a significant difference between 4 and 12 months (p-value = 0.0494). Immediate implant placement with an immediate non-loading provisional customized healing abutment of polyether-ether-ketone placed into the post-extractive sockets with asymptomatic and large chronic periapical and periradicular lesions could represent a further treatment strategy for patients' rehabilitation and soft tissue preservation to replace a hopeless tooth.

Primary flap closure in alveolar ridge preservation for periodontally damaged extraction socket: A randomized clinical trial

INTRODUCTION

The effect of primary wound closure (PC) on alveolar ridge preservation (ARP) in periodontally damaged sockets has yet to be fully discovered.

METHODS

Periodontally damaged sockets were allocated to one of the following groups: (1) ARP with PC (group PC), and (2) ARP without PC (group secondary wound closure [SC]). Following tooth extraction and flap elevation, granule-type xenogeneic bone substitute material and a collagen barrier were applied. Ridge change was evaluated using cone-beam computed tomographic (CBCT) scans immediately after ARP and at 4 months. Core biopsy specimens were examined histomorphometrically.

RESULTS

A total of 28 patients were included in the analysis (13 in group PC, 15 in group SC). Histomorphometrically, the percentage of newly formed bone was 26.2 ± 17.7% and 24.6 ± 18.4% in groups PC and SC, respectively (independent t-test, degree of freedom [df] = 25, p > 0.05). Horizontal ridge changes on CBCT were -4.9 ± 3.1 mm and - 4.2 ± 2.5 mm in groups PC and SC at the 1 mm level below the ridge crest, respectively (independent t-test, df = 26, p > 0.05). Approximately half of the sites required additional bone augmentation at implant placement.

CONCLUSIONS

ARP with/without PC yielded similar new bone formation and radiographic ridge change. This clinical trial was not registered prior to participant recruitment and randomization (https://cris.nih.go.kr/cris/search/detailSearch.do/19718).

Bone envelope for implant placement after alveolar ridge preservation: a systematic review and meta-analysis

PURPOSE

To assess the dimensional establishment of a bony envelope after alveolar ridge preservation (ARP) with deproteinized bovine bone mineral (DBBM) in order to estimate the surgical feasibility of standard diameter implants placement without any additional augmentation methods.

METHODS

PubMed, Embase and CENTRAL databases were searched for suitable titles and abstracts using PICO elements. Inclusion criteria were as follows: randomized controlled trials (RCTs) comprising at least ten systemically healthy patients; test groups comprised placement of (collagenated) DBBM w/o membrane and control groups of no grafting, respectively. Selected abstracts were checked regarding their suitability, followed by full-text screening and subsequent statistical data analysis. Probabilities and number needed to treat (NNT) for implant placement without any further need of bone graft were calculated.

RESULTS

The initial database search identified 2583 studies. Finally, nine studies with a total of 177 implants placed after ARP with DBBM and 130 implants after SH were included for the quantitative and qualitative evaluation. A mean difference of 1.13 mm in ridge width in favour of ARP with DBBM could be calculated throughout all included studies (95% CI 0.28-1.98, t2 = 1-1063, I2 = 68.0%, p < 0.01). Probabilities for implant placement with 2 mm surrounding bone requiring theoretically no further bone augmentation ranged from 6 to 19% depending on implant diameter (3.25: 19%, RD = 0.19, C = 0.06-0.32, p < 0.01/4.0: 14%, RD = 0.14, C = 0.05-0.23, p < 0.01/5.0: 6%, RD = 0.06, C = 0.00-0.12, p = 0.06).

CONCLUSION

ARP employing DBBM reduces ridge shrinkage on average by 1.13 mm and improves the possibility to place standard diameter implants with up to 2 mm circumferential bone housing; however, no ARP would have been necessary or additional augmentative bone interventions are still required in 4 out of 5 cases.

Collagen Versus Xenograft Bovine Bone Inserted Into Extraction Sockets: Healing and Pain Management

Background

Different materials can be used in filling the extraction socket to achieve an alveolar ridge preservation. The present study compared the wound healing potential and pain management efficacy of the collagen and the xenograft bovine bone, covered by a cellulose mesh, inserted into the socket of extracted teeth.

Materials and Methods

Thirteen patients were willingly chosen to enter our split-mouth study. It was a clinical trial of crossover design with a minimum of two teeth to be extracted for each patient. Randomly, one of the alveolar sockets was filled with collagen material as Collaplug®, and the second alveolar socket was filled with xenograft bovine bone substitute Bio-Oss® and covered with a cellulose mesh Surgicel®. Post-extraction follow-up was observed at day 3, 7 and 14, and each participant was told to document his/her pain experience in our prepared Numerical Rating Scale (NRS) document for 7 consecutive days.

Results

Clinically, the differential wound closure potential between the two groups was significant in the buccolingual (P = 0.045) but not significant in the mesiodistal (P = 0.204) mouth areas. The pain expressed as rated in the NRS was higher in the case of the Bio-Oss®, but there was no significant difference upon comparing the two procedures for 7 consecutive days (P = 0.397) except on day 5 (P = 0.004).

Conclusions

Collagen appears to support faster wound healing rate, higher potential influence on socket healing and decreased pain perception than xenograft bovine bone.

Structure and Properties of Bioactive Glass-Modified Calcium Phosphate/Calcium Sulfate Biphasic Porous Self-Curing Bone Repair Materials and Preliminary Research on Their Osteogenic Effect

In this study, calcium phosphate (CP)/calcium sulfate biphasic bone repair materials were modified with bioactive-glass (BG) to construct a self-curing bone repair material. Tetracalcium phosphate, calcium hydrogen phosphate dihydrate, and calcium sulfate hemihydrate (CSH) with different BG ratios and phosphate solution were reacted to prepare a porous self-curing bone repair material (CP/CSH/BG). The solidification time was about 12 min, and the material was morphologically stable in 24 h. The porosity was about 50%, with a pore size around 200 μm. The strength of CP/CSH/BG was approaching trabecular bone, and could be gradually degraded in Tris-HCl solution. MC3T3-E1 cells were cultured in the leaching solution of the materials. Cytotoxicity was detected using Cell Counting Kit 8 assays, and the expression of osteogenesis-related biomarkers was detected using quantitative real-time reverse transcription PCR (qRT-PCR). The results showed that all BG groups had increased ALP and ARS staining, implying that the BG groups could promote osteoblast mineralization in vitro. qRT-PCR showed significant upregulation of bone-related gene expression (Osx, Ocn, Runx2, and Col1) in the 20% BG group (p < 0.05). Therefore, the CP/CSH/BG self-curing bone repair materials can promote osteogenesis, and might be applied for bone regeneration, especially for polymorphic bone defect repair.

Clinical applications of concentrated growth factors membrane for sealing the socket in alveolar ridge preservation: a randomized controlled trial

The purpose of this study was to evaluate the efficacy of concentrated growth factor (CGF) membrane for the sealing of alveolar socket in alveolar ridge preservation (ARP). A total of 22 patients with 24 alveolar sockets were recruited and divided randomly into CGF group and Bio-Gide collagen membrane group. The soft tissue wound healing rate was calculated using intraoral scanner at 3, 7, and 14 days after ARP, and the bone resorption volume at 1, 3, and 5 mm below the alveolar ridge was measured by CBCT at 6 months postoperation. The keratinized gingival width was also measured before and 6 months after ridge preservation. In terms of soft tissue healing rate, the CGF group exhibited significant higher than that of Bio-Gide group at both 7 and 14 days after surgery (P < 0.05). However, there was no significantly different in bone resorption rate and the width of keratinized gingival after 6 months (P > 0.05). Therefore, the use of CGFs membranes for wound closure in ARP is a reliable method, but more clinical data are needed to prove it.

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.

Histological and histomorphometric evaluation of alveolar ridge preservation using an allograft and nonresorbable membrane with and without primary closure: A pilot randomized controlled clinical trial

The aim of this article is to assess the formation of new vital bone (VB) using histomorphometric analysis in alveolar ridge preservation (ARP), with and without primary closure. Eight patients needed bilateral tooth extraction and planned for ARP. All patients had a nonresorbable membrane with freeze-dried bone allograft after the extractions. Biopsies were obtained 6 months after ARP and were evaluated using histomorphometric analysis. The study included 6 males and 2 females, with an average age of 54.2 years (standard deviation, 9.7). The teeth requiring extraction included a bilateral canine (1 case), premolars (5 cases), and molars (2 cases). Histomorphometric values of new VB, residual bone (RB) substitute particles, and marrow tissue formation were 71.1 %, 16.2%, and 9.69% for closed flap and 50.9%, 15.3%, and 8.19 for open flap. P values were 0.066, 0.878, and 0.326, respectively. The present findings indicate that leaving the flap without primary closure did not have any effect on new VB, RB particles, and immature bone marrow compared with closed flap. However, the results favored the closed-flap technique.

Collagenase Administration into Periodontal Ligament Reduces the Forces Required for Tooth Extraction in an Ex situ Porcine Jaw Model

Minimally invasive exodontia is among the long-sought-for development aims of safe dental medicine. In this paper, we aim, for the first time, to examine whether the enzymatic disruption of the periodontal ligament fibers reduces the force required for tooth extraction. To this end, recombinantly expressed clostridial collagenase G variant purified from Escherichia coli was injected into the periodontal ligament of mesial and distal roots of the first and second split porcine mandibular premolars. The vehicle solution was injected into the corresponding roots on the contralateral side. Following sixteen hours, the treated mandibles were mounted on a loading machine to measure the extraction force. In addition, the effect of the enzyme on the viability of different cell types was evaluated. An average reduction of 20% in the applied force (albeit with a large variability of 50 to 370 newton) was observed for the enzymatically treated roots, reaching up to 50% reduction in some cases. Importantly, the enzyme showed only a minor and transient effect on cellular viability, without any signs of toxicity. Using an innovative model enabling the analytical measurement of extraction forces, we show, for the first time, that the enzymatic disruption of periodontal ligament fibers substantially reduces the force required for tooth extraction. This novel technique brings us closer to atraumatic exodontia, potentially reducing intra- and post-operative complications and facilitating subsequent implant placement. The development of novel enzymes with enhanced activity may further simplify the tooth extraction process and present additional clinical relevance for the broad range of implications in the oral cavity.

The Effect of Coenzyme Q10/Collagen Hydrogel on Bone Regeneration in Extraction Socket Prior to Implant Placement in Type II Diabetic Patients: A Randomized Controlled Clinical Trial

Background: The healing of an extraction socket leads to alveolar ridge resorption that can hinder future implant placement and further rehabilitation with special concerns in diabetes mellitus. Coenzyme Q10 (CoQ10) has been developed as a new material for alveolar socket augmentation. The aim of this study was to investigate the effect of CoQ10 hydrogel on bone regeneration after extraction of mandibular teeth in Type II diabetic patients. Methods: This trial was registered under the number NCT05122299 and included eighteen patients. The hydrogel was first prepared and characterized. After tooth extraction, the hydrogel was placed in the extraction sockets. Bone formation was evaluated three months after tooth extraction. Results: The bone density was significantly higher in the CoQ10 group than the other two groups measured on cone beam computed tomography (CBCT). The relative gene expression of Runt-related transcription factor 2 (RUNX2) and Osteopontin (OPN) showed significant increase in the presence of CoQ10. Histomorphometry revealed significantly less fibrous tissue in the CoQ10 group in comparison to the control or collagen group. Conclusion: The local application of CoQ10 after tooth extraction provided a simple, inexpensive, yet effective treatment facilitating bone formation and healing in the extraction sockets of diabetic patients.

Histological and dimensional changes of the alveolar ridge following tooth extraction when using collagen matrix and collagen-embedded xenogenic bone substitute: A randomized clinical trial

Aim

To assess the horizontal and vertical dimensional changes of the alveolar ridge when using a collagen matrix in combination with collagen embedded xenogenic bone substitute, in comparison with natural healing after tooth extraction.

Methods

Patients that required extraction in non‐molars areas were included. Test group‐15 sockets were treated with deproteinized bovine bone mineral containing 10% collagen (DBBM‐C), covered by a procaine collagen membrane (CMXs). Control group‐15 sockets left for spontaneous healing. We used a custom‐made acrylic stent as a reference for alveolar ridge measurements. Six‐month postoperative, a single implant was placed in the experimental site. A core biopsy was taken from the site, using a trephine bur. Histomorphometric analysis assessed bone area, connective tissue, bone marrow, and residual bone graft.

Results

Six months later, horizontal ridge width at −3 mm showed a significant (p < 0.05) reduction in both groups albeit smaller in the test group 1.19 ± 1.55 mm, compared with the control 2.27 ± 1.52 (p = 0.087). At −5 mm sub‐crestally, statistically non‐significant reduction was noted in both groups, 1.61 ± 1.53 and 1.96 ± 1.52 mm for the test and control groups, respectively (p = 0.542). Vertical changes were smaller in the test group (0.14 ± 1.84 mm) compared with control (0.98 ± 1.49 mm). Keratinized tissue (KT) width was 7.3 ± 2.13 and 7.5 ± 3.49 mm in the test and control groups, respectively. Newly formed bone occupied 33.79 ± 17.37% and 51.14 ± 23.04% in the test and control groups, respectively, (p = 0.11). Connective tissue volume was 33.74 ± 13.81% and 30.12 ± 18.32% in the test and control groups, respectively (p = 0.65). Bone marrow occupied 19.57 ± 10.26% and 18.74 ± 17.15% in the test and control groups, respectively (p = 0.91). Residual graft occupied 12.9 ± 9.88% in the test group.

Conclusion

Alveolar ridge preservation using DBBM‐C resulted in reductions of the vertical and horizontal dimensions albeit not reaching statistical significance. The larger than anticipated standard deviation and smaller inter‐group differences might account for this phenomenon.

Autologous Dentin Graft after Impacted Mandibular Third Molar Extraction to Prevent Periodontal Pocket Formation-A Split-Mouth Pilot Study

This preliminary study aims to evaluate the efficacy of an autologous dentin graft in preventing periodontal defects after impacted or semi-impacted lower third molars' (M3) surgical extraction. For this purpose, radiographic and periodontal evaluation of post-extractive sockets were performed. Ten patients were enrolled in the study: twenty M3 extraction sockets were treated with a split-mouth modality. After tooth extraction, the experimental sites were filled with autologous dentin graft obtained by the extracted M3, while the control sites were filled with blood clot alone. Flaps were closed by first intention to ensure the stability of the wounds. Post-extractive sites were monitored at days 15, 90 and 180. The healing was not affected by any complications associated with the use of the autologous dentine graft in all cases. The measurements recorded at six months showed a reduction of the probing pocket depth distal to the second lower molar (M2) at both surgical sites, with a greater reduction observed at the experimental sites. Radiographic evaluation also showed a greater amount of bone gain at the grafted sites compared to the control sites. The results of this preliminary study suggest that autologous dentin grafts can be useful in preventing the formation of periodontal defects distal to M2 after M3 surgical extraction.

A Retrospective Digital Analysis of Contour Changing after Tooth Extraction with or without Using Less Traumatic Surgical Procedures

BACKGROUND

The present retrospective analysis aimed to compare two different single tooth extraction surgical approaches in both premolar and molar areas: less traumatic magneto-electrical versus conventional tooth extraction in minimizing the edentulous ridge volume loss.

METHODS

In the present retrospective control trial, 48 patients who underwent one-tooth extraction, were allocated either to control (28 sites treated with conventional tooth extraction procedures) or test group (20 subjects treated with less traumatic tooth extraction procedures by tooth sectioning and magnetoelectric roots subluxation). Intraoperatively (during tooth extraction surgery just after the subsequent filling of the alveolar socket with the sterile fast re-absorbable gelatin sponge), and then four months later, contours of the sockets were acquired through a laser intra-oral scanner. The digitally superimposed models were converted to dicom (Digital Imaging and Communications in Medicine) format first, then volumetric and area evaluations were performed with a DentaScan tool package. Non-parametric tests were applied with a level of significance set at p < 0.01.

RESULTS

significant reductions of anatomical features were observed four months later in all the groups (p-values < 0.001) with volume losses leading to a final alveolar ridge volume of 0.87 ± 0.34 cm³ for atraumatic extractions and 0.66 ± 0.19 cm³ for conventional extractions. No significant differences were registered for outcomes related to the basal surface variables. When just molar tooth were considered, the outcomes relating to volume loss between baseline and four months (ΔV) and its percentage (ΔV%) showed a better behavior in the less traumatic procedure (ΔV = -0.30 ± 0.10 cm³ and ΔV% = -22.3 ± 8.4%) compared to the conventional extractions (ΔV = -0.59 ± 0.10 cm³ and ΔV% = -44.3 ± 5.8%) with p-values < 0.0001.

CONCLUSIONS

at four months, the less traumatic tooth extraction procedures by tooth sectioning and magnetoelectric root subluxation seemed to be able to better preserve the volume of the alveolar crest (reduction close to 22% with less traumatic extraction in molar sites) when compared to subjects treated with the conventional tooth extraction techniques.

Classification Based on Extraction Socket Buccal Bone Morphology and Related Treatment Decision Tree

Background: Alveolar ridge preservation (ARP) can successfully reduce volumetric ridge changes. However, there is still no consensus on what technique is the most advantageous for each specific clinical scenario. Hence, the aim of the present paper was to provide a treatment decision tree to guide the choice of predictable ARP procedures based on extraction socket buccal bone morphology and integrity. Material and Methods: Three socket types (ST) are proposed and discussed based on buccal bone morphology (intact, dehiscence or fenestration). Results: A decision tree for ARP was developed in order to merge ST classification with suitable treatment modalities. In the decision tree, the issue of when to allow unassisted healing or ARP was discussed. Described methods included bone grafting and collagen plug, and absorbable membrane or non-resorbable membrane, with or without flap elevation. Conclusion: A decision tree for ARP procedures was provided to guide clinicians towards the most conservative and predictable treatment approach based on remaining socket anatomical structures after extraction.

Efficacy of Bovine Hydroxyapatite and Collagen Along With Platelet-Rich Fibrin as a Scaffold and Human Chorion as a Membrane for Ridge Preservation: A Case-Control Study

Aim: The present study aims to determine the efficacy of bovine hydroxyapatite and collagen (G-graft) mixed with platelet-rich fibrin (PRF) used as a scaffold and chorion membrane as a barrier in post-extraction sockets with extraction sites alone.

Methods and material: Thirty individuals were randomly assigned into two groups. In the control group, after debridement of the extracted tooth socket, no additional treatment was done. In the test group, after debridement of the extracted tooth socket, the sockets were filled with bovine hydroxyapatite and collagen (G-graft) mixed with PRF. They were covered by a chorion membrane, and a non-absorbable suture material was used to secure the membrane in place. Clinical parameters assessed were plaque index, gingival index, buccolingual width, buccal bone plate height, and lingual bone plate height at baseline and at six months.

Results: Clinically, there was a more significant reduction in the buccolingual width of the control group than the test group after six months. A statistically significant difference between the two groups for vertical ridge height at the mesial and distal socket sites was observed. No statistically significant difference in buccal and lingual bone plate height was observed between the two groups (p>0.05).

Conclusions: Both groups showed a significant reduction in the Buccolingual width, but it was less in the ridge preservation group. Thus, the use of G-graft with PRF and chorion membrane was highly effective in ridge preservation.

Key messages: Natural bovine bone mineral, along with PRF and chorion as a membrane, can be utilized effectively for ridge preservation in extracted tooth sockets due to periodontal disease.

Clinical applications of concentrated growth factors combined with bone substitutes for alveolar ridge preservation in maxillary molar area: a randomized controlled trial

PURPOSE

To evaluate the clinical effects of concentrated growth factors (CGFs) combined with bone substitutes for alveolar ridge preservation (ARP) in the maxillary molar area.

METHODS

Thirty-six patients who underwent extraction of the upper molars were recruited and randomly divided into three groups: 1. Grafted with CGFs combined with deproteinized bovine bone mineral (DBBM) and covered with CGFs membrane (CGFs/DBBM group), 2. Grafted with DBBM alone and covered with collagen membrane (DBBM group), 3. Control group spontaneous healing. The area of the alveolar bone in center (C-), mesial (M-) and distal (D-) section was compared with preoperative in radiography. Bone cores were obtained for histopathology observation and comparison.

RESULTS

In C-, M- and D-section, the alveolar ridge area in all three groups was significantly reduced at 8 months postoperatively compared to the baseline (P < 0.05). The alveolar ridge area declines in the CGFs/DBBM group (C-12.75 ± 2.22 mm2, M-14.69 ± 2.82 mm2, D-16.95 ± 4.17 mm2) and DBBM group (C-14.08 ± 2.51 mm2, M-15.42 ± 3.47 mm2, D-16.09 ± 3.97 mm2) were non-significant differences. They were significantly less than the decline in the control group (C-45.04 ± 8.38 mm2 M-31.98 ± 8.34 mm2, D-31.85 ± 8.52 mm2) (P < 0.05). The percentage of newly formed bone in the CGFs/DBBM group (41.99 ± 12.99%) was significantly greater than that in DBBM group (30.68 ± 10.95%) (P < 0.05). The percentage of residual materials in the CGFs/DBBM group (16.19 ± 6.63%) was significantly less than that in the DBBM group (28.35 ± 11.70%) (P < 0.05).

CONCLUSION

Combined application of CGFs and DBBM effectively reduced the resorption of alveolar ridge and resulted in more newly formed bone than the use of DBBM with collagen membranes.

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.

Synthetic Material for Bone, Periodontal, and Dental Tissue Regeneration: Where Are We Now, and Where Are We Heading Next?

Alloplasts are synthetic, inorganic, biocompatible bone substitutes that function as defect fillers to repair skeletal defects. The acceptance of these substitutes by host tissues is determined by the pore diameter and the porosity and inter-connectivity. This narrative review appraises recent developments, characterization, and biological performance of different synthetic materials for bone, periodontal, and dental tissue regeneration. They include calcium phosphate cements and their variants β-tricalcium phosphate (β-TCP) ceramics and biphasic calcium phosphates (hydroxyapatite (HA) and β-TCP ceramics), calcium sulfate, bioactive glasses and polymer-based bone substitutes which include variants of polycaprolactone. In summary, the search for synthetic bone substitutes remains elusive with calcium compounds providing the best synthetic substitute. The combination of calcium sulphate and β-TCP provides improved handling of the materials, dispensing with the need for a traditional membrane in guided bone regeneration. Evidence is supportive of improved angiogenesis at the recipient sites. One such product, (EthOss^® Regeneration, Silesden, UK) has won numerous awards internationally as a commercial success. Bioglasses and polymers, which have been used as medical devices, are still in the experimental stage for dental application. Polycaprolactone-TCP, one of the products in this category is currently undergoing further randomized clinical trials as a 3D socket preservation filler. These aforementioned products may have vast potential for substituting human/animal-based bone grafts.

Octacalcium Phosphate Bone Substitute (Bontree®): From Basic Research to Clinical Case Study

Bone grafts used in alveolar bone regeneration can be categorized into autografts, allografts, xenografts, and synthetic bones, depending on their origin. The purpose of this study was to evaluate the effect of a commercialized octacalcium phosphate (OCP)-based synthetic bone substitute material (Bontree®) in vitro, in vivo, and in clinical cases. Material characterization of Bontree® granules (0.5 mm and 1.0 mm) using scanning electron microscopy and X-ray diffraction showed that both 0.5 mm and 1.0 mm Bontree® granules were uniformly composed mainly of OCP. The receptor activator of NF-κB ligand (RANKL) and alkaline phosphatase (ALP) activities of MG63 cells were assessed and used to compare Bontree® with a commercial biphasic calcium phosphate ceramic (MBCP+TM). Compared with MBCP+TM, Bontree® suppressed RANKL and increased ALP activity. A rabbit tibia model used to examine the effects of granule size of Bontree® grafts showed that 1.0 mm Bontree® granules had a higher new bone formation ability than 0.5 mm Bontree® granules. Three clinical cases using Bontree® for ridge or sinus augmentation are described. All eight implants in the three patients showed a 100% success rate after 1 year of functional loading. This basic research and clinical application demonstrated the safety and efficacy of Bontree® for bone regeneration.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

Alveolar ridge preservation: an overview of systematic reviews

The aim of this overview was to assess the methodological quality of systematic reviews of randomized clinical trials on alveolar ridge preservation after a tooth extraction. During March 2020, two independent reviewers performed an electronic search of the PubMed (MEDLINE), Scopus, Web of Science, and Cochrane Library databases to identify all relevant systematic reviews including randomized clinical trials on alveolar ridge preservation. A manual search of articles in renowned journals was also conducted. The methodological quality of the included reviews was determined using the AMSTAR-2 tool. From the 53 initially retrieved studies, 11 were finally included: three systematic reviews and eight systematic reviews with meta-analyses. The methodological quality of the included reviews was low or critically low. Higher quality clinical studies should be conducted prior to performing further reviews and these should meet the methodological requirements that are fundamental to this type of research.

Application of hydroxyapatite/collagen composite material for maxillary sinus floor augmentation

The aim of this study was to clarify whether hydroxyapatite/collagen composite material (HAp/Col) could be useful as a graft material for maxillary sinus floor augmentation (MSFA). MSFA and implant placement were performed simultaneously. When the lateral approach was employed, 3 out of 19 implants failed in 3 maxillary sinuses (success rate; 84.2%), and in these cases the alveolar bone heights, cortical bone thicknesses and values of the implant stability quotient were smaller. If alveolar the bone height, cortical bone thickness, and healing period are optimized, HAp/Col can be a useful graft material for MSFA.

The impact of autologous concentrated growth factors on the alveolar ridge preservation after posterior tooth extraction: A prospective, randomized controlled clinical trial

BACKGROUND

Alveolar ridge preservation can effectively decrease alveolar ridge resorption following tooth extraction, but it can be limited by reducing new bone formation and residual bone graft material. Efforts to develop more efficacious approaches are thus an area of active research.

PURPOSE

To assess the impact of autologous concentrated growth factors (CGF) on alveolar ridge absorption and osteogenesis following posterior tooth extraction.

MATERIALS AND METHODS

Fifty patients were randomly assigned to have extraction sockets treated with CGF or no treatment. At 10 days, 1 month, and 3 months postextraction, soft tissue color and texture were examined and evaluated with healing score. Cone-beam computed tomography (CBCT) scans were performed before and 3 months after extraction, while radiographic analyses were used to assess vertical and horizontal bone changes. Bone samples were collected from the extraction sockets during implant placement, and micro-computed tomography (micro-CT) scans and histological analysis were performed to evaluate new bone formation. t-Test or Mann-Whitney U test was used to compare data and the level of statistical significance was set at 0.05 for all analyses.

RESULTS

Forty-six patients completed the trial. Sockets in the experimental group exhibited significantly better healing score on Day 10 postextraction relative to the control group, whereas comparable healing was observed in both groups at 1 and 3 months postextraction. Experimental group exhibited reduced vertical bone changes relative to the control (p < 0.05). Significant reductions were observed in ridge width changes at 1 and 2 mm apical to the crest (p < 0.05), although differences at 3 and 5 mm apical to the crest were not significant. Significant differences of bone mineral density (BMD) and microarchitecture of trabecular bone were observed via micro-CT analyses, and the experimental group had better results.

CONCLUSION

CGF application following posterior tooth extraction may reduce vertical and horizontal bone resorption and promote new bone formation.

Evaluation of alveolar process resorption after tooth extraction using the socket shield technique without immediate installation of implants: a randomised controlled clinical trial

Our aim was to evaluate resorption of the alveolar ridge using the socket shield technique (SST) without immediate placement of dental implants. This randomised controlled clinical trial included 27 patients: 14 maxillary non-molar teeth were partially extracted using the SST (test group) and 13 were extracted using a minimally traumatic extraction approach (control group). Alterations in height and thickness of the alveolar ridge were evaluated by cone beam computed tomograms taken immediately after, and 100 days after, surgery. Minor resorption was observed in the height of the buccal and palatal plates, without intergroup difference (p ≥ 0.10). The test group showed significantly better preservation of the buccal-to-palatal crest dimension (p ≤ 0.05). In the control group, preservation of buccal plate thickness was significantly greater (p ≤ 0.05), but intragroup vertical resorption of the buccal plate and reduction in the buccal-to-palatal crest distance were greater (p ≤ 0.05). The SST without the immediate placement of implants showed greater preservation of the buccal-to-palatal crest dimension and lower preservation of buccal wall thickness compared with minimally traumatic extraction. In addition, it provided superior maintenance of the baseline buccal wall height. The modified SST is a promising approach, but factors that interfere with the results should be investigated.

Facial alveolar bone thickness and modifying factors of anterior maxillary teeth: a systematic review and meta-analysis of cone-beam computed tomography studies

BACKGROUND

Understanding the anatomy of the facial alveolar bone (FAB), provides a prognostic tool for estimating the degree of dimensional ridge alterations after tooth extraction. This systematic review and meta-analysis aims to determine the FAB thickness and modifying factors of anterior maxillary teeth measured by CBCT scans. A secondary objective was to assess the facial distance from the cementoenamel junction (CEJ) to the bone crest.

METHODS

An electronic search was made of Medline, Embase, Web of Science, Cochrane Library and Google Scholar up to December 2019. Studies that analyze and quantitatively compare FAB thickness at maxillary teeth by CBCT scans were included. The methodological quality of the included studies was appraised using the ROBINS-I tool and the overall meta-evidence certainty using the GRADE approach. A single means random-effects meta-analysis was performed to obtain the weighted mean for 95% confidence interval. A meta-regression of covariates and subgroup analysis was conducted. The nullity Qh test and I2 index for heterogeneity was estimated.

RESULTS

2560 potentially relevant articles were recorded from which 29 studies were selected for the qualitative analysis, including 17,321 teeth. Seventeen studies considered the facial bone crest, and 12 the CEJ as a reference point for their measurements. Mean FAB thickness was ≤ 1 mm in maxillary incisors and canines (0.75-1.05 mm) and 1-2 mm in premolars. Patients over 50 years of age, females and thin gingival phenotype was associated with thinner FAB at some apico-coronal locations of maxillary incisors and canines. The geographical setting was an effect modifier that could explain up to 87% of the heterogeneity in FAB thickness, being Asian populations that showed the lowest FAB thickness values. The CEJ-bone crest distance was 2-2.5 mm in all teeth analyzed. Population over 50 years of age exhibited greater CEJ-bone crest distances, and males also showed a trend for greater distance. Evidence certainty has shown moderate quality in most analysis subsets.

CONCLUSIONS

Facial alveolar bone at anterior maxillary teeth is thin, heterogeneous in width along its apico-coronal dimensions, and increases in thickness in maxillary premolars. The CEJ-bone crest distance presented homogeneous and similar values in all teeth analyzed.

Alveolar ridge preservation using autogenous whole-tooth versus demineralized dentin grafts: A randomized controlled clinical trial

OBJECTIVE

The objective of this randomized controlled trial was to evaluate the radiographic changes and histologic healing following alveolar ridge preservation (ARP) using autogenous whole tooth (AWTG), test group, versus autogenous demineralized dentin graft (ADDG), control group.

MATERIAL AND METHODS

Twenty non-molar teeth indicated for extraction were randomized into two groups (n = 10/group). Extracted teeth were prepared into AWTG or ADDG (0.6N HCl; 30 min), inserted into extraction sockets and covered by collagen membranes. Cone-beam computed tomography (CBCT) scans at baseline and six months were compared to assess ridge-dimensional changes. At six months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically.

RESULTS

All sites healed uneventfully. Reduction was 0.85 ± 0.38 mm and 1.02 ± 0.45 mm in ridge width, 0.61 ± 0.20 mm and 0.72 ± 0.27 mm in buccal and 0.66 ± 0.31 mm and 0.56 ± 0.24 mm in lingual ridge height for the AWTG and ADDG group, respectively (p > .05). Histologically, no inflammatory reactions were noticeable and all samples showed new bone formation. Qualitatively, graft-bone amalgamations were more pronounced in ADDG samples. Histomorphometrically, new bone, graft remnants and soft tissue occupied 37.55% ± 8.94%, 17.05% ± 5.58% and 45.4% ± 4.06% of the areas in the AWTG group and 48.4% ± 11.56%, 11.45% ± 4.13% and 40.15% ± 7.73% in the ADDG group of the examined areas, respectively (p > .05).

CONCLUSIONS

AWTG and ADDG are similarly effective in ARP. Yet, histologically ADDG seems to demonstrate better graft remodeling, integration and osteoinductive properties.

Comparison of the Efficacy of Platelet-Rich Fibrin and Bone Allograft for Alveolar Ridge Preservation after Tooth Extraction: A Clinical Trial

Objectives:

Bone remodeling after tooth extraction results in decreased ridge volume and complicates implant placement. Platelet-rich fibrin (PRF) is a rich source of autogenous cytokines and growth factors; it has been proven to effectively improve soft tissue healing and hard tissue regeneration. This study sought to compare the clinical application of freeze-dried bone allografts (FDBA) and PRF for alveolar ridge preservation after tooth extraction.

Materials and Methods:

This clinical trial was conducted on 32 patients presenting for the extraction of hopeless non-molar teeth. The teeth were extracted with minimal trauma, and the samples were randomly divided into two groups (n=16). Tooth sockets were filled with either FDBA or PRF (prepared using 10cc of the patient’s blood). Bone regeneration was assessed by evaluating changes in horizontal and vertical bone dimensions after 12 weeks (the time of implant placement) using an acrylic stent fabricated before tooth extraction and a periodontal probe. The results were compared by repeated-measures analysis of variance (ANOVA; P<0.05).

Results:

Ridge width showed a significant reduction compared to the baseline in both groups (P=0.001); ridge height changes were not significant (P>0.05). The evaluated groups did not show any significant difference in height/width changes (P>0.05).

Conclusion:

The results showed an acceptable efficacy for PRF without graft materials in alveolar ridge preservation. This material is cost-effective and could be easily prepared. PRF application in extraction sockets yielded similar results to FDBA.

The Use of Autogenous Teeth for Alveolar Ridge Preservation: A Literature Review

Alveolar ridge resorption is a natural consequence of teeth extraction, with unpleasant aesthetic and functional consequences that might compromise a future oral rehabilitation. To minimize the biological consequences of alveolar ridge resorption, several surgical procedures have been designed, the so-called alveolar ridge preservation (ARP) techniques. One important characteristic is the concomitant use of biomaterial in ARP. In the past decade, autogenous teeth as a bone graft material in post-extraction sockets have been proposed with very interesting outcomes, yet with different protocols of preparation. Here we summarize the available evidence on autogenous teeth as a biomaterial in ARP, its different protocols and future directions.

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.