Flap versus flapless procedure for ridge preservation in alveolar extraction sockets: a histological evaluation in a randomized clinical trial

Assessment of soft and hard tissue changes following micro crestal flap-Alveolar ridge preservation and augmentation at molar extraction sites in patients with stage III/IV periodontitis: A randomized controlled trial

AIM

This study aimed to assess hard and soft tissue contour changes following micro crestal flap-alveolar ridge preservation (MCF-ARP) and natural healing (NH) in periodontally compromised molar extraction sites and to analyse the feasibility and need for bone augmentation during implant therapy.

MATERIALS AND METHODS

Fifty-six patients with 70 sites were randomized into two groups at the site level (35 sites from 31 patients in the test group and 35 sites from 29 patients in the control group). Among whom, four patients contributed one tooth to the control group and one tooth to the test group. Hard tissue indicators were measured using cone beam computed tomography performed before tooth extraction and 6 months after surgery. Soft tissue contour changes were assessed using intraoral scanning performed before and immediately after surgery and also 2 weeks and 1, 3 and 6 months after surgery.

RESULTS

Six months after surgery, the MCF-ARP group showed less resorption in buccal bone height (p = .032) and greater augmentation in central bone height (p = .001) and ridge width (p = .009). The mean, vertical and horizontal collapse of buccal soft tissue contour in the MCF-ARP group were 0.95 mm (p = .010), 0.61 mm (p = .019) and 0.56 mm (p = .013) less than that in the NH group, respectively. There were significantly (p = .007) fewer sites in the MCF-ARP group than in the NH group (0% vs. 26.7%) for staged bone augmentation and more sites that could be treated with simple implant procedure in the MCF-ARP group than in the NH group (71.9% vs. 56.6%).

CONCLUSIONS

Compared with NH, MCF-ARP reduced bone resorption in periodontally compromised molar extraction sites and maintained the buccal soft tissue contour. MCF-ARP reduces the need for complex bone augmentation procedures in implant therapy.

TRIAL REGISTRATION

Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on 4 February 2022, Version 1.0.

Half- and full-grafting alveolar ridge preservation with different sealing materials: A three-arm randomized clinical trial

OBJECTIVE

The objective of this study is to investigate the effect of different alveolar ridge preservation (ARP) approaches on bone resorption and their potential for facilitating implant placement.

MATERIALS AND METHODS

Patients who underwent one or two tooth extractions with a desire for restoration were included in the study. The participants were randomly assigned to one of three groups for ARP. The groups were as follows: (1) Half grafting of bovine bone mineral (DBBM-C) covered with non-resorbable dense polytetrafluoroethylene (dPTFE) membrane (Test 1 group); (2) Half grafting of bovine bone mineral (DBBM-C) covered with collagen membrane (Test 2 group); and (3) Full grafting with collagen membrane (DBBM-C + Collagen membrane) as the Control group. After 6-month healing period, the evaluation encompassed clinical, radiographic, implant-related outcomes, and the factors contributing to hard and soft tissue alterations.

RESULTS

Enrollment in this study comprised 56 patients. At the 6-month follow-up, radiographic analysis in computed beam computed tomography images was conducted for 18, 19, and 19 patients with 18, 20, and 20 tooth sites in Test 1, Test 2, and Control groups, respectively. Additionally, a total of 15, 17, and 17 patients with 15, 18, and 17 implants were evaluated. Based on radiographic analysis, all groups showed limited ridge resorption at 1 mm from crest horizontally (Test 1: 1.29 ± 1.37; Test 2: 1.07 ± 1.07; Control: 1.54 ± 1.33 mm, p = 0.328), while the Control group showed greater radiographic bone height gain in mid-crestal part vertically (Test 1: 0.11 ± 1.02; Test 2: 0.29 ± 0.83; Control: -0.46 ± 0.95 mm, p = 0.032). There were no significant intergroup differences in terms of keratinized mucosal width, bone density, insertion torque, and the need of additional bone graft. However, the use of a dPTFE membrane resulted in a significantly higher vertical mucosal thickness (Test 1: 2.67 ± 0.90; Test 2: 3.89 ± 1.08; Control: 2.41 ± 0.51 mm, p < 0.001).

CONCLUSIONS

The study showed comparable dimensional preservation with limited vertical shrinkage, while thin buccal bone plate, non-molar sites, and large discrepancy between buccal and palatal/lingual height may contribute to greater shrinkage. Thicker mucosa with dPTFE membrane required further investigation for interpretation.

CLINICAL TRIAL REGISTRATION NUMBER

NCT06049823. This clinical trial was not registered prior to participant recruitment and randomization.

A new hydroxyapatite-alginate-gelatin biocomposite favor bone regeneration in a critical-sized calvarial defect model

This study aimed to evaluate the osteogenic potential of hydroxyapatite (HA), Alginate (Alg), and Gelatine (Gel) composite in a critical-size defect model in rats. Twenty-four male rats were divided into three groups: a negative control with no treatment (Control group), a positive control treated with deproteinized bovine bone mineral (DBBM group), and the experimental group treated with the new HA-Alg-Gel composite (HA-Alg-Gel group). A critical size defect (8.5mm) was made in the rat's calvaria, and the bone formation was evaluated by in vivo microcomputed tomography analysis (µCT) after 1, 15, 45, and 90 days. After 90 days, the animals were euthanized and histological and histomorphometric analyses were performed. A higher proportion of mineralized tissue/biomaterial was observed in the DBBM group when compared to the HA-Alg-Gel and Control groups in the µCT analysis during all analysis periods. However, no differences were observed in the mineralized tissue/biomaterial proportion observed on day 1 (immediate postoperative) in comparison to later periods of analysis in all groups. In the histomorphometric analysis, the HA-Alg-Gel and Control groups showed higher bone formation than the DBBM group. Moreover, in histological analysis, five samples of the HA-Alg-Gal group exhibited formed bone spicules adjacent to the graft granules against only two of eight samples in the DBBM group. Both graft materials ensured the maintenance of defect bone thickness, while a tissue thickness reduction was observed in the control group. In conclusion, this study demonstrated the osteoconductive potential of HA-Alg-Gel bone graft by supporting new bone formation around its particles.

Alveolar Ridge Preservation Using the One-Piece Autologous Tuberosity Graft: A Clinical, Radiological, and Histological Pilot Study

This prospective study investigated clinically and radiologically the effectiveness of the use of a combined hard and soft tissue graft retrieved from the maxillary tuberosity and designed for alveolar ridge preservation following tooth extraction. Seven patients scheduled for a single mono-rooted tooth extraction were included in the study. After atraumatic extraction, sockets were filled with a "one-piece" dual tissue graft harvested from the tuberosity using an adjusted trephine. CBCTs were performed before the extraction and 4 months after ridge preservation, to analyze the vertical and horizontal alterations of the ridge, using ITK-Snap software. Clinical measurements of both soft and hard tissues were also assessed during the extraction and implant placement. All sites healed uneventfully. After 4 months, the 3D super-imposition of both CBCTs showed a mean bone volume resorption of 65 ± 76.7 mm3 (10.2 ± 10%). The mean horizontal reduction at 2, 4, and 6 mm from the top of the crest was respectively 1.5 ± 1.3 mm, 0.47 ± 1.4 mm and 0.57 ± 0.7 mm, while the mean vertical loss was 0.026 mm ± 2 mm. The mean soft tissue horizontal gain was 1.73 ± 1.12 mm. The "one-piece" autologous tuberosity graft was proven to be a safe and effective alveolar ridge preservation technique and may represent a feasible, user-friendly, time saving, low-cost solution for minimizing dimensional loss following tooth extraction.

Ridge preservation in periodontally compromised molar sockets with and without primary wound closure: A comparative controlled clinical trial

OBJECTIVE

This study aimed to compare hard- and soft-tissue changes after ridge preservation in periodontally compromised molar sockets with and without primary wound closure.

MATERIALS AND METHODS

Forty molars with severe periodontitis requiring extraction were included and allocated to two treatment modalities. After tooth extraction, the sockets were filled with deproteinized bovine bone mineral and covered with a bioabsorbable porcine collagen membrane. Primary wound closure was achieved in the control group, whereas the test group underwent minimally invasive open healing. The dimensions of the bone and soft tissue were recorded at baseline and 6 months.

RESULTS

Over 6 months, the control and test groups had similar mean ridge heights at the center of sockets of 8.59 ± 2.47 mm and 8.47 ± 2.51 mm, respectively. The total volume of the control group increased from 1070.17 to 1713.52 mm3 for a mean gain of 643.35 mm3 , whereas that of the test group increased from 992.51 to 1514.05 mm3 for a mean gain of 521.54 mm3 . Compared with the test group, the control group showed a statistically significant decrease in keratinized tissue width of 1.08 ± 1.63 mm.

CONCLUSIONS

Bone dimensional changes following ridge preservation with and without primary wound closure were comparable. ARP without primary wound closure preserves more keratinized tissue than that with (Chinese Clinical Trial Registry: ChiCTR-ONN-16009433).

Biomaterials for Alveolar Ridge Preservation as a Preoperative Procedure for Implant Treatment: History and Current Evidence

In implant treatment, the reduction and structural changes in the alveolar ridge that occur after tooth extraction limit the length, width, and placement position of the implant body, impair esthetics, and, in some cases, make implant placement difficult. To solve these problems, an alveolar ridge preservation (ARP) technique, which is performed simultaneously with tooth extraction, generally aims to promote bone regeneration and prevent alveolar ridge reduction by filling the extraction socket with bone graft material and then covering it with a barrier membrane to protect against the invasion of epithelial tissue. The extraction socket provides a favorable environment for bone regeneration throughout the healing period because the blood supply is abundant, and it effectively retains the bone graft material by using the remaining bone wall of the socket. In recent years, advances in bioengineering technology have led to the development of graft materials with various biological properties, but there is currently no clear consensus regarding the selection of surgical techniques and materials depending on the condition of the alveolar ridge. This review will provide a comprehensive survey of the evidence accumulated to date on ARP, present many cases according to the clinical situation, and discuss various treatment options.

Success of Xenografts in Alveolar Ridge Preservation Based on Histomorphometric Outcomes

Different xenograft approaches in alveolar ridge preservation (ARP) are essential to understand relative to their histomorphometric outcomes. Therefore, the aim of this study involved studying biomaterials of a xenograft nature that are used in ARP procedures, to compare the different approaches and evaluate their efficacy in relation to histomorphometric data. An electronic search was completed using the databases: Ovid (Medline), Google Scholar and Wiley Online Library, including a hand search for relevant articles and grey literature. Only randomised controlled trials, using xenograft biomaterials for alveolar ridge preservation procedures involving human studies, dated from 2010-2022 were included in the review. An initial search yielded 4918 articles, after application of the eligibility criteria, 18 studies were deemed eligible for inclusion in the systematic review. The two main xenograft groups found were of bovine origin and of porcine origin. The main histomorphometric outcomes evaluated included new bone percentage (N.B%) and residual graft percentage (R.G%). The mean N.B% for the bovine and porcine groups were 33.46% and 39.63% respectively and the mean R.G% for the bovine and porcine groups were 19.40% and 18.63% respectively. The current evidence suggests that the two main xenograft biomaterials used in ARP procedures after tooth extraction, which are of bovine and porcine origin, displayed effectiveness in producing new bone.

A Comparative Study of the Flap and Flapless Techniques of Ridge Preservation: A Clinical Double-Blinded Study

Introduction

Extraction of the tooth often leads to crestal bone loss. It is difficult for clinicians to decide on the technique of extraction. Many studies on flap and flapless have led to confusion. Hence it becomes necessary to conduct this study to show the efficient ridge preservation technique.

Materials and Methods

Twenty patients were selected for this study. It was divided into the flap and flapless groups. In group A, the flap was elevated, tooth extraction was undertaken, the socket was cleaned, a graft was placed, a barrier was placed, and a suture was placed. In group B all the procedures were the same but without flap elevation. After surgery, clinical and radiographical parameters were recorded.

Result

Flapless technique showed a better result in bone preservation. There was a low vertical bone loss in the flapless technique.

Conclusion

Both techniques showed bone loss. But the flapless technique gave better results.

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.

Flap versus flapless alveolar ridge preservation: A clinical and histological single-blinded, randomized controlled trial

BACKGROUND

The aim of this randomized clinical trial was to compare a flapless technique of alveolar ridge preservation (ARP) to a flap technique to determine if preserving the periosteal blood supply would limit loss of crestal ridge width and height.

METHODS

Twenty-four patients were randomly assigned to receive ARP using either a flapless or flap technique. Sockets were grafted with demineralized bone matrix and mineralized particulate allograft then covered with a barrier in both groups. Re-entry was performed at 4 months to obtain samples for histological analysis and subsequent implant placement.

RESULTS

Ridge width of the flapless group at the crest decreased from 8.3 ± 1.3 mm to 7.0 ± 1.9 mm for a mean loss of 1.3 ± 0.9 mm (p < 0.05), whereas the flap group decreased from 8.5 ± 1.5 mm to 7.5 ± 1.5 mm for a mean loss of 1.0 ± 1.1 mm (p < 0.05). The mean midbuccal vertical change for the flap group was a loss of 0.9 ± 1.3 mm (p < 0.05) versus 0.5 ± 0.9 mm (p < 0.05) for the flapless group. There was no statistically significant difference between the groups. Histologically, flapless ARP revealed more vital mineralized tissue (44 ± 10%) compared to the flap group (p>0.05). In the flapless group, the occlusal soft tissue was significantly thicker than in the flap group at the 4-month re-entry (p< 0.05).

CONCLUSIONS

Crestal ridge width, height, and percentage of vital mineralized bone following treatment with a flapless ARP technique, was not significantly different from a flap technique.

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).

Therapeutic Efficacy of Bromelain in Alveolar Ridge Preservation

Most of research in regenerative oral surgery describes materials or techniques for increasing volumetric results for implant-supported prosthesis. The use of bio-materials in alveolar ridge preservation after tooth extraction commonly leads to a delayed recovery. Bromelain is an enzyme that belongs to a family of proteolytic enzymes derived from the stem of the pineapple plant (Ananas comosus) with effectiveness in decreasing the inflammation development and swelling. The present paper reports a prospective comparative study performed in order to test the possible use of oral bromelain 40 mg in alveolar ridge preservation. Evaluations were performed at three time points after the surgery: after 2 days (t1), after 7 days (t2) and after 14 days (t3). A statistically significant difference among patients that used bromelain and patients that used placebo resulted among the use of bromelain and lower Visual Analogue Scale (VAS) at t1 (r = -0.75, p = 0.0067), t2 (r = -0.90, p = 0.0001) and t3 (r = -0.8566, p = 0.0008). Bromelain therapy reported a statistically significant difference among patients that used bromelain and patients that used placebo even with regards to the use of bromelain and postoperative swelling at t1 (r = -0.79, p = 0.0034), t2 (r = -0.81, p = 0.0020) but not at t3 (r = -0.34, p = 0.2967). With the result of the present paper, and the poorness of contraindication of the investigated drug, bromelain may be suggested to be used for patients that undergo to alveolar ridge preservation after tooth extraction.

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.

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.

A comparison between anorganic bone and collagen-preserving bone xenografts for alveolar ridge preservation: systematic review and future perspectives

After tooth extraction, dimensional changes affect the alveolar socket, leading to loss in alveolar bone height and width. Histological modifications also occur, with initial formation of a blood clot that is replaced with granulation tissue and subsequently with a provisional connective tissue matrix. Spontaneous healing ends with socket filling with woven bone, which is gradually replaced with lamellar bone and bone marrow. Adequate alveolar ridge dimensions and bone quality are required to assure optimal stability and osseointegration following dental implant placement. When a tooth is extracted, alveolar ridge preservation (ARP) procedures are an effective method to prevent collapse of the post-extraction socket. Heterologous bone is widely chosen by clinicians for ARP, and anorganic bone xenografts (ABXs) made bioinert by heat treatment represents the most used biomaterial in clinical applications. Collagen-preserving bone xenografts (CBXs) made of porcine or equine bone are fabricated by less invasive chemical or enzymatic treatments to remove xenogenic antigens, and these are also effective in preserving post-extraction sites. Clinical differences between anorganic bone substitutes and collagen-preserving materials are not well documented in the literature but understanding these differences could clarify how processing protocols influence biomaterial behavior in situ. This systematic review of the literature compares the dimensional changes and histological features of ABXs versus CBXs in ridge preservation procedures to promote awareness of different bone xenograft efficacies in stimulating the healing of post-extraction sockets.

Ridge preservation in molar sites comparing xenograft versus mineralized freeze-dried bone allograft: a randomized clinical trial."

OBJECTIVES

To compare the dimensional ridge changes and the histological composition after the use of an allograft or xenograft and a resorbable membrane in ridge preservation in molar sites, and to evaluate the influence of bone plate thickness on dimensional changes and the need of lateral sinus augmentation following ridge preservation.

MATERIAL AND METHODS

Twenty-four patients in need of maxillary or mandibular first or second molar extraction and subsequent implant placement were included and randomly assigned to a group; allograft or xenograft, plus a collagen membrane. Cone Beam Computed Tomographies were obtained after molar extraction and after five months. A bone sample was harvested at the time of implant placement and analysed by histomorphometry.

RESULTS

Bone ridge was reduced significantly. Major changes in width occurred at 1 mm from the bone crest (-2.93 ± 2.28 mm) (p = 0.0002), while in height, the greatest reduction occurred at the buccal area (-1.97 ± 2.21 mm) (p = 0.0006). However, differences between groups were not significant. Thicker buccal bone plates exhibited less bone remodelling, while histologically, both biomaterials resulted in similar tissue composition. The resulting available bone height in the implant site measured 7.30 ± 3.53 mm initially and 6.8 ± 3.61 mm after 5 months which allowed implant placement without the need of lateral sinus augmentation in all cases. Still, 55% of the preserved areas needed transcrestal sinus lift.

CONCLUSION

Ridge preservation in molar sites using a mineralized allograft or xenograft provides similar dimensional and histomorphometrically results after five months.

Impact of the periodontal phenotype in premolar and molar sites on bone loss following full thickness mucoperiosteal flap. A 1-year prospective clinical trial

BACKGROUND

Full thickness mucoperiosteal flap (FTF) elevation could potentially affect the periodontium of the involved teeth; it is not clear if the periodontal phenotype of teeth involved in a FTF may influence these changes. The aim of this study was to evaluate the impact of FTF on teeth periodontium, as well as assessing the impact of periodontal phenotype on bone remodeling.

METHODS

In this single arm prospective clinical trial, 26 subjects and a total of 52 adjacent teeth were included. Patients receiving implant surgery in the posterior area, at the time of implant site preparation, an FTF was extended one tooth mesial and distal to the planned site, and the flap was elevated both facially and lingually. Vertical and horizontal bone linear changes were measured on both adjacent teeth, using superimposed cone-beam computerized tomography (CBCT) images taken prior to implant placement (T0) and at 12 months (T1). Baseline digital scans of models and DICOM files were superimposed to assess the periodontal phenotype.

RESULTS

Vertical bone changes from T0 to T1 were statistically significant (p = 0.013), with changes were significantly higher at the mesial (-0.31± 0.30 mm) and facial (p<0.05) sites. Horizontal dimensional changes 5 mm subcrestally were similar among different locations (p = 0.086) and the bone width loss was higher closest to the crest (p = 0.001). No correlation was found between soft tissue thickness and bone changes. However, bone thickness at baseline appears to influence the extent of horizontal bone remodeling. Overall, the magnitude of bone loss either vertically or horizontally was clinically insignificant (≤0.4 mm).

CONCLUSION(S)

Marginal bone changes in maxillary and mandibular posterior teeth following FTF at 12 months are very minimal, and mainly influenced by bone rather than soft tissue thickness. Overall, FTF does not seem to have deleterious effects on adjacent teeth periodontium. This article is protected by copyright. All rights reserved.

A Multidisciplinary Approach to Congenitally Missing Central Incisors: A Case Report

Hypodontia is one of the most common developmental problems of human dentition. The treatment of missing maxillary central incisors is always a challenging task, often requiring a multidisciplinary approach. This case report describes such a multidisciplinary approach for a female patient with congenitally missing maxillary central incisors and class II division 1 occlusion. Significant horizontal overlap was present with class II division 1 occlusion in a patient with a history of cleft palate. Implant therapy was thereby not an option. Orthodontic treatment was provided to decrease the horizontal overlap and reposition the teeth. Esthetic crown lengthening was performed and monolithic lithium disilicate crowns were placed. Critical analysis of the treatment plan through cooperation among specialists is required to obtain the ideal result. Orthodontic treatment may be necessary to close or gain more space, followed by implant placement (if acceptable), and restorative treatment. It is important to create the treatment plan through a multidisciplinary approach involving orthodontists, surgeons, and restorative specialists before initiating treatment.

Open Healing: A Minimally Invasive Protocol with Flapless Ridge Preservation in Implant Patients

Simple Summary

We describe a minimally invasive technique for optimal preservation of post-extraction tooth socket, prior to implant insertion in over 100 patients (n = 104, with 0.55 sex ratio), with a follow-up period of up to five years. This “open healing” concept is a flapless protocol, using a collagen membrane and a bovine bone substitute that yielded an uneventful healing, with sufficient bone formation, checked periodically after one, two, and five years by calibrated computer tomography. Open-healing protocol led to alveolar ridge and height preservation that contributed to a 98.5% implant survival and 94.8% success rate at five-year follow-up.

Abstract

We aimed to validate the safety and efficacy of the minimally invasive “open healing” flapless technique for post-extraction socket and alveolar ridge preservation, while assessing the alveolar bone changes. The study enrolled (n = 104) patients (0.55 sex ratio), with atraumatic extraction of (N = 135) hopeless teeth, followed by either immediate placement of tissue level implants (N₁ = 26), or later stage implant insertion (N₂ = 109). No flap was raised in either situation. Post-extraction sockets were filled with deproteinized bovine bone granules and covered by collagen resorbable membrane—left purposely exposed during healing. This yielded an uneventful healing, with sufficient bone formation, while avoiding soft-tissue problems. The need for additional augmentation was assessed clinically and by calibrated CBCT scans at six months, before either loading (N₁) or implant insertion (N₂). Implant success and survival rate were evaluated at 12-, 24-, and 60-month follow-up control sessions. The inserted implants had a survival rate of 98.5% and a success rate of 94.8% at five-year follow-up. Open healing technique with flapless approach can be favorable for preserving the 3D architecture of the post-extraction socket, as well as the alveolar ridge width and height.

Soft tissue dimensional changes after alveolar ridge preservation using different sealing materials: a systematic review and network meta-analysis

Background

Alveolar ridge preservation (ARP) is a proactive treatment option aiming at attenuating post-extraction hard and soft tissue dimensional changes. A high number of different types of biomaterials have been utilized during ARP to seal the socket, but their effectiveness in terms of soft tissue outcomes has rarely been investigated and compared in the literature.

Objective

To evaluate the efficacy of different types of membranes and graft materials in terms of soft tissue outcomes (keratinized tissue width changes, vertical buccal height, and horizontal changes) after ARP, and to assign relative rankings based on their performance.

Materials and methods

The manuscript represents the proceedings of a consensus conference of the Italian Society of Osseointegration (IAO).

PUBMED (Medline), SCOPUS, Embase, and Cochrane Oral Health’s Information Specialist were utilized to conduct the search up to 06 April 2021. English language restrictions were placed and no limitations were set on publication date. Randomized controlled trials that report ARP procedures using different sealing materials, assessing soft tissue as a primary or secondary outcome, with at least 6-week follow‐up were included.

Network meta-analysis (NMA) was performed using mean, standard deviation, sample size, bias, and follow-up duration for all included studies. Network geometry, contribution plots, inconsistency plots, predictive and confidence interval plots, SUCRA (surface under the cumulative ranking curve) rankings, and multidimensional (MDS) ranking plots were constructed.

Results

A total of 11 studies were included for NMA. Overall, the level of bias for included studies was moderate. Crosslinked collagen membranes (SUCRA rank 81.8%) performed best in vertical buccal height (VBH), autogenous soft tissue grafts (SUCRA rank 89.1%) in horizontal width change (HWch), and control (SUCRA rank 85.8%) in keratinized mucosa thickness (KMT).

Conclusions

NMA confirmed that the use of crosslinked collagen membranes and autogenous soft tissue grafts represented the best choices for sealing sockets during ARP in terms of minimizing post-extraction soft tissue dimensional shrinkage.

Clinical relevance

Grafting materials demonstrated statistically significantly better performances in terms of soft tissue thickness and vertical buccal height changes, when covered with crosslinked collagen membranes. Instead, soft tissue grafts performed better in horizontal width changes. Non-crosslinked membranes and other materials or combinations presented slightly inferior outcomes.

Ridge preservation in maxillary molar extraction sites with severe periodontitis: a prospective observational clinical trial

OBJECTIVES

To assess alveolar bone changes and treatment modality alterations after ridge preservation on maxillary molar extraction sockets with severe periodontitis, compared to natural healing.

MATERIAL AND METHODS

Thirty-six maxillary infected-molar teeth either receiving ridge preservation (RG group) or undergoing natural healing (NT group) were investigated. Cone-beam computed tomography (CBCT) scanning was performed immediately after surgery (the baseline) and repeated 6 months later to measure the linear and volumetric changes of the sockets.

RESULTS

Based on radiographic measurements, alveolar bone width decreased by 1.58 ± 4.61 mm in the NT group but increased by 3.74 ± 4.17 mm in the RG group (p < 0.05). Significant increases in ridge height at the center of both the NT (7.54 ± 4.54 mm) and RG (9.20 ± 3.26 mm) groups were observed. Mean sinus pneumatization was 0.19 ± 0.45 mm in the RG group and 0.59 ± 0.63 mm in the NT group (p < 0.05). The relative increase in total ridge volume was 8.0% and 35.5% in the NT and RG group, respectively (p < 0.05). Implant placement with additional sinus augmentation procedure was performed in 16.7% of the RG group cases, whereas 50% in the NT group cases.

CONCLUSIONS

Ridge preservation in the maxillary molar extraction sockets with severe periodontitis can improve alveolar ridge dimensions and decrease the necessity of advanced regenerative procedures at implant placement compared to natural healing.

CLINICAL RELEVANCE

Ridge preservation on maxillary molar extraction sockets with severe periodontitis maintained the vertical bone height more efficiently and resulted in less need for sinus augmentation procedures at 6 months compared to natural healing.

Comparison Study of the Histomorphometric Results after Socket Preservation with PRF and Allograft Used for Socket Preservation-Randomized Controlled Trials

The aim of the present clinical study was to assess and compare the histomorphometric results and efficacy of freeze-dried bone allograft (FDBA) in combination with platelet-rich fibrin (PRF), and PRF as a sole grafting material for socket preservation. Ninety patients in need of tooth extraction and implant restoration were included in this study. The participants were randomly divided into three groups based on post-extraction clinical protocol: socket preservation procedure with allograft in combination with a PRF membrane (PRFm), PRF as a sole grafting material, and a control group. A total of 90 implants were placed four months post-extraction. During the surgical re-entry a bone biopsy was harvested with a trephine drill. Histological samples were prepared and analyzed for percentage vital bone and connective tissue. One-way ANOVA with Bonferroni post-hoc analysis were used to assess the results. Both test groups revealed a significantly higher percentage of vital bone formation compared to the control group. No statistically significant differences regarding vital bone formation and connective tissue quantity between the tested groups were observed (FDBA + PRFm: 3.29 ± 13.03%; and PRF: 60.79 ± 9.72%). From a clinical and histological point of view, both materials in the test groups are suitable for the filling of post-extraction sockets without bone defects. Both of the tested groups revealed a significantly higher percentage of vital bone formation compared to the control group.

Flapped versus flapless alveolar ridge preservation: a systematic review and meta-analysis

Alveolar ridge preservation (ARP) procedures can limit bone changes following tooth extraction. Flapped and flapless surgical approaches have been used for ARP; however, there is a lack of strong scientific evidence regarding their specific influences on the clinical outcomes of ARP. The aim of this systematic review and meta-analysis was to evaluate the effects of flapped and flapless surgical approaches on the dimensional changes of hard and soft tissues and patient-reported outcomes following ARP. Electronic databases were searched to identify randomized controlled trials (RCTs) that compared flapped ARP by means of a coronally advanced flap to flapless ARP where barrier membranes were left exposed. The risk of bias was assessed using the Cochrane Collaboration Risk of Bias tool. Data were analysed using a statistical software program. A total of 754 studies were identified, of which five studies with 149 extraction sockets in 128 participants were included. Overall, meta-analysis did not show any significant differences in the changes in ridge width or height between flapped and flapless ARP. The use of flapless ARP was associated with significantly less postoperative pain, thicker labial soft tissues, and marginally more favourable changes in width of the keratinized tissues compared to the flapped approach. The short-term hard tissue changes following ARP with a flapped or flapless approach are comparable. Postoperative pain and labial soft tissue changes are more favourable following ARP using a flapless approach. Further evidence from long-term RCTs is still required to substantiate the current findings.

Alveolar ridge preservation with fibroblast growth factor-2 modified acellular dermal matrix membrane and a bovine-derived xenograft: An experimental in vivo study

OBJECTIVE

To investigate the effect of a bone substitute material combined with fibroblast growth factor-2 (FGF-2) loaded barrier membrane on the preservation of alveolar ridge after tooth extraction.

MATERIAL AND METHODS

Four dogs were included. Six extraction sockets of each animal received the 3 treatments and were randomly divided into three groups. Group A: negative control; Group B: bovine xenografts + membrane; and Group C: bovine xenografts + FGF-2-loaded membrane. CBCT and histological analysis were performed to evaluate changes in the width and height of alveolar ridges and extraction socket bone healing 8 weeks post-extraction.

RESULTS

CBCT showed that the alveolar bone in Group A was significantly thinner than that in Group B and Group C at 1 and 3 mm apically from the alveolar crest. The alveolar width at 1 mm in Group C (60.99 ± 15.36%) was significantly thicker than that in Group B (39.75 ± 30.18%). Histomorphmetrical measurements showed that the buccal alveolar width at 1 mm was significantly thicker in Groups B and C than in Group A. Additionally, buccal bone height and lingual bone width at 1 mm in Group C (87.06 ± 10.34%, 89.09 ± 10.56%) were significantly greater than in Group A (53.48 ± 23.94%, 82.72 ± 12.59%).

CONCLUSION

The present findings indicate that application of bovine bone combined with barrier membrane with or without FGF-2 over tooth sockets can effectively reduce ridge absorption, especially in terms of ridge width and FGF-2 modified membrane seems to improve the outcomes obtained with membrane alone.

Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site development

BACKGROUND

Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used. This is an update of the Cochrane Review first published in 2015.

OBJECTIVES

To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 19 March 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2021, Issue 2), MEDLINE Ovid (1946 to 19 March 2021), Embase Ovid (1980 to 19 March 2021), Latin American and Caribbean Health Science Information database (1982 to 19 March 2021), Web of Science Conference Proceedings (1990 to 19 March 2021), Scopus (1966 to 19 March 2021), ProQuest Dissertations and Theses (1861 to 19 March 2021), and OpenGrey (to 19 March 2021). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. A number of journals were also handsearched.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) on the use of ARP techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the extraction site, and complications of future prosthodontic rehabilitation.

DATA COLLECTION AND ANALYSIS

We selected trials, extracted data, and assessed risk of bias in duplicate. Corresponding authors were contacted to obtain missing information. We estimated mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (95% CI). We constructed 'Summary of findings' tables to present the main findings and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 16 RCTs conducted worldwide involving a total of 524 extraction sites in 426 adult participants. We assessed four trials as at overall high risk of bias and the remaining trials at unclear risk of bias. Nine new trials were included in this update with six new trials in the category of comparing ARP to extraction alone and three new trials in the category of comparing different grafting materials. ARP versus extraction: from the seven trials comparing xenografts with extraction alone, there is very low-certainty evidence of a reduction in loss of alveolar ridge width (MD -1.18 mm, 95% CI -1.82 to -0.54; P = 0.0003; 6 studies, 184 participants, 201 extraction sites), and height (MD -1.35 mm, 95% CI -2.00 to -0.70; P < 0.0001; 6 studies, 184 participants, 201 extraction sites) in favour of xenografts, but we found no evidence of a significant difference for the need for additional augmentation (RR 0.68, 95% CI 0.29 to 1.62; P = 0.39; 4 studies, 154 participants, 156 extraction sites; very low-certainty evidence) or in implant failure rate (RR 1.00, 95% CI 0.07 to 14.90; 2 studies, 70 participants/extraction sites; very low-certainty evidence). From the one trial comparing alloplasts versus extraction, there is very low-certainty evidence of a reduction in loss of alveolar ridge height (MD -3.73 mm; 95% CI -4.05 to -3.41; 1 study, 15 participants, 60 extraction sites) in favour of alloplasts. This single trial did not report any other outcomes. Different grafting materials for ARP: three trials (87 participants/extraction sites) compared allograft versus xenograft, two trials (37 participants, 55 extraction sites) compared alloplast versus xenograft, one trial (20 participants/extraction sites) compared alloplast with and without membrane, one trial (18 participants, 36 extraction sites) compared allograft with and without synthetic cell-binding peptide P-15, and one trial (30 participants/extraction sites) compared alloplast with different particle sizes. The evidence was of very low certainty for most comparisons and insufficient to determine whether there are clinically significant differences between different ARP techniques based on changes in alveolar ridge width and height, the need for additional augmentation prior to implant placement, or implant failure. We found no trials which evaluated parameters relating to clinical attachment levels, specific aesthetic or prosthodontic outcomes for any of the comparisons. No serious adverse events were reported with most trials indicating that the procedure was uneventful. Among the complications reported were delayed healing with partial exposure of the buccal plate at suture removal, postoperative pain and swelling, moderate glazing, redness and oedema, membrane exposure and partial loss of grafting material, and fibrous adhesions at the cervical part of previously preserved sockets, for the comparisons xenografts versus extraction, allografts versus xenografts, alloplasts versus xenografts, and alloplasts with and without membrane.

AUTHORS' CONCLUSIONS

ARP techniques may minimise the overall changes in residual ridge height and width six months after extraction but the evidence is very uncertain. There is lack of evidence of any differences in the need for additional augmentation at the time of implant placement, implant failure, aesthetic outcomes, or any other clinical parameters due to lack of information or long-term data. There is no evidence of any clinically significant difference between different grafting materials and barriers used for ARP. Further long-term RCTs that follow CONSORT guidelines (www.consort-statement.org) are necessary.

Biphasic Calcium Phosphate Biomaterials: Stem Cell-Derived Osteoinduction or In Vivo Osteoconduction? Novel Insights in Maxillary Sinus Augmentation by Advanced Imaging

Maxillary sinus augmentation is often necessary prior to implantology procedure, in particular in cases of atrophic posterior maxilla. In this context, bone substitute biomaterials made of biphasic calcium phosphates, produced by three-dimensional additive manufacturing were shown to be highly biocompatible with an efficient osteoconductivity, especially when combined with cell-based tissue engineering. Thus, in the present research, osteoinduction and osteoconduction properties of biphasic calcium-phosphate constructs made by direct rapid prototyping and engineered with ovine-derived amniotic epithelial cells or amniotic fluid cells were evaluated. More in details, this preclinical study was performed using adult sheep targeted to receive scaffold alone (CTR), oAFSMC, or oAEC engineered constructs. The grafted sinuses were explanted at 90 days and a cross-linked experimental approach based on Synchrotron Radiation microCT and histology analysis was performed on the complete set of samples. The study, performed taking into account the distance from native surrounding bone, demonstrated that no significant differences occurred in bone regeneration between oAEC-, oAFMSC-cultured, and Ctr samples and that there was a predominant action of the osteoconduction versus the stem cells osteo-induction. Indeed, it was proven that the newly formed bone amount and distribution decreased from the side of contact scaffold/native bone toward the bulk of the scaffold itself, with almost constant values of morphometric descriptors in volumes more than 1 mm from the border.

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.

Open healing of contained and non-contained extraction sockets covered with a ribose cross-linked collagen membrane: a pilot study

PURPOSE

This study investigated whether the placement of ribose cross-linked collagen (RCLC) membranes without primary soft tissue closure predictably resulted in sufficient alveolar ridge preservation in contained and non-contained extraction sockets.

METHODS

Membranes were positioned across extraction sockets, undermining full-thickness flaps, and the gingival margins were fixed by double-interrupted sutures without crossed horizontal mattress sutures for 1 week. In non-contained sockets, a bone substitute was used to support the membrane within the bony envelope. Radiographs and clinical images obtained 4 months later were analyzed by ImageJ software using non-parametric tests.

RESULTS

In 18 patients, 20 extraction sockets healed uneventfully and all sites received standard-diameter implants (4.1, 4.8, or 5.0 mm) without additional bone augmentation. Soft tissues and the muco-gingival border were well maintained. A retrospective analysis of X-rays and clinical photographs showed non-significant shrinkage in the vertical and horizontal dimensions (P=0.575 and P=0.444, respectively). The new bone contained vital bone cells embedded in mineralized tissues.

CONCLUSIONS

Within the limitations of this pilot study, open healing of RCLC membranes may result in sufficient bone volume for implant placement without additional bone augmentation in contained and non-contained extraction sockets.

Soft Tissue Dimensions Following Tooth Extraction in the Posterior Maxilla: A Randomized Clinical Trial Comparing Alveolar Ridge Preservation to Spontaneous Healing

Background: To assess the soft tissue dimension following tooth extraction and alveolar ridge preservation in the posterior maxilla compared to spontaneous healing. Methods: Thirty-five patients randomly assigned to alveolar ridge preservation (ARP) and spontaneous healing (SH) after maxillary molar extraction. The crestal, buccal, and palatal gingival thickness at 6 months was measured around virtually placed implant fixtures using superimposed cone-beam computed tomography and intraoral scan taken at 6 months. Buccal mucogingival junction (MGJ) level change over 6 months was estimated using intraoral scans obtained at suture-removal and 6 months. Results: The crestal gingiva was significantly thinner in group ARP (−1.16 mm) compared to group SH (p < 0.05). The buccal and palatal gingiva was significantly thinner at the implant shoulder (IS) level in group ARP (buccal: −0.75 mm; palatal: −0.85 mm) compared to group SH (p < 0.05). The thickness at 2 mm below the IS of both sides and the buccal MGJ level change were similar in both groups (p > 0.05). Conclusions: ARP in the posterior maxilla resulted in a thinner soft tissue on top of and at the prospective level of the implant shoulder at 6 months. The buccal MGJ level changed minimal for 6 months in both groups.

Prevention of Bone Resorption by HA/β-TCP + Collagen Composite after Tooth Extraction: A Case Series

After tooth extraction, alveolar ridge loss due to resorption is almost inevitable. Most of this bone loss occurs during the first six months after the extraction procedure. Many studies have indicated that applying socket-filling biomaterials after extraction can effectively reduce the resorption rate of the alveolar ridge. The purpose of this study was to investigate the clinical efficacy of the application of a hydroxyapatite/β-tricalcium plus collagen (HA/β-TCP + collagen) dental bone graft in dental sockets immediately after tooth extraction, so as to prevent socket resorption. The study was conducted on 57 extraction sockets located in the mandible and maxilla posterior regions in 51 patients. HA/β-TCP + collagen was inserted into all of the dental sockets immediately after extraction, and was covered with a flap. Follow-up was performed for three months after extraction, using radiographs and stents for the vertical and horizontal alveolar ridge measurements. A minimal alveolar bone width reduction of 1.03 ± 2.43 mm (p < 0.05) was observed. The height reduction showed a slight decrease to 0.62 ± 1.46 mm (p < 0.05). Radiographically, the bone height was maintained after three months, indicating a good HA/β-TCP + collagen graft performance in preserving alveolar bone. In conclusion, the HA/β-TCP + collagen graft demonstrated adequate safety and efficacy in dental socket preservation following tooth extraction.

Dental Implant Outcomes in Grafted Sockets: a Systematic Review and Meta-Analysis

Objectives

To assess the treatment outcomes of the dental implants placed in the grafted sockets.

Material and Methods

A search protocol was developed to evaluate the treatment outcomes of dental implants placed in the grafted sockets in terms of implant survival rates (primary outcome), marginal-bone-level (MBL) changes, clinical parameters (i.e., bleeding on probing, probing depth), occurrence of peri-implant diseases, and aesthetic outcomes (secondary outcomes). Randomized controlled clinical trials (RCTs), controlled clinical trials, and prospective studies with at least 12 months of follow-up and a minimum of 10 patients having at least one dental implant inserted into the grafted socket were conducted. MEDLINE (PubMed) was searched for relevant articles published until 1st April 2019. A meta-analysis was performed using the random-effects model on the selected qualifying articles.

Results

The present analysis included 7 RCTs. The survival rate of the implants inserted into the grafted sockets ranged from 95 to 100% after 1 to 4 years of follow-up. MBL loss was found to be significantly greater for the implants placed in the non-grafted healed sites than for those placed in the previously grafted sockets (weighted mean difference = -1.961 mm, P < 0.0001). In terms of MBL changes, no difference was detected between immediately inserted implants versus implants placed in previously grafted sockets. None of the included studies reported on the clinical parameters or occurrence of peri-implant diseases

Conclusions

Implants inserted into the previously grafted sockets showed high survival rates and lower marginal-bone-level loss than the implants inserted into the non-grafted sites.

A Comparison between Primary and Secondary Flap Coverage in Ridge Preservation Procedures: A Pilot Randomized Controlled Clinical Trial

Aims

To assess the bone dimensional changes after extraction and alveolar ridge preservation (ARP) using primary coverage (closed flap technique, CFT) or healing by secondary intention (open flap technique, OFT).

Materials and Methods

Ten patients (split mouth design) were planned for extraction and ARP. All sites received ARP with freeze-dried bone allograft (FDBA) and nonresorbable membrane after extraction. Clinical standardized measurements were used to assess the dimensional alterations of the alveolar ridge.

Results

All patients completed the study, and a total of 20 sites were randomized to CFT or OFT group. Center height (mean difference of 8.1 mm, SD =1.9 CFT, and 7.5 mm, SD= 1.8 OFT) and buccal height (mean difference of 0.8 mm, SD =1.0 CFT, and 0.3 mm, SD= 1.1 OFT) were significantly different within the same group. However, there was no statistically significant difference between groups. In the OFT group, the keratinized tissue width was higher and the pain VAS scores at 24 hours were lower compared with the CFT (p = 0.004 and p = 0.006, respectively).

Conclusions

Leaving the flap open did not have any effects on the dimensional changes of bone height or width. However, there was a wider band of keratinized tissue and less pain with the CFT compared with the OFT. The study protocol was registered at ClinicalTrials.gov, Identifier NCT03136913.

Ridge Architecture Preservation Following Minimally Traumatic Exodontia Techniques and Guided Tissue Regeneration

OBJECTIVE

To compare hard-tissue healing after 3 exodontia approaches.

MATERIALS AND METHODS

Premolars of dogs were extracted: (1) flapless, (2) flap, and (3) flap + socket coverage with polytetrafluoroethylene (dPTFE) nonresorbable membrane (flap + dPTFE). Animals were euthanized at 1 and 4 weeks. Amount of bone formation within socket and socket total area were measured.

RESULTS

Amount of bone formation revealed significant difference between 1 and 4 weeks; however, there was no differences among groups. Socket total area decreased after 4 weeks, and the flap + dPTFE group showed significantly higher socket total area. As a function of time and group, flap + dPTFE 4 weeks presented similar socket total area values relative to flap + dPTFE at 1 week, and significantly higher socket total area than flapless and flap. The histological sections revealed almost no bone formation within socket after 1 week, which increased for all groups at 4 weeks.

CONCLUSION

Socket coverage with polytetrafluoroethylene (dPTFE) membrane showed to effectively preserve bone architecture. Bone formation within sockets was not influenced by tooth extraction technique.

Effectiveness of naturally derived bovine hydroxyapatite (Cerabone™) combined with platelet-rich fibrin matrix in socket preservation: A randomized controlled clinical trial

BACKGROUND AND OBJECTIVES

Socket preservation is the procedure which is carried out at the time of extraction to enhance the esthetic predictability of prosthesis and to reduce the number of surgical interventions by minimizing the crestal bone loss. The aim of the present study was to compare the efficacy of natural bovine hydroxyapatite and platelet-rich fibrin (PRF) matrix along with collagen plug to unassisted natural healing in extraction sites.

MATERIALS AND METHODS

A sample of 25 patients of age 17-50 years who require extraction of at least two teeth which were not adjacent to each other were included in the study. One site in each patient was subjected to ridge preservation procedure using Cerabone™ PRF along with collagen plug and the other site was subjected to atraumatic extraction alone. Parameters such as loss of ridge width and loss of ridge height were measured clinically and radiographically at baseline and after 6 months.

RESULTS

The mean loss of width was found to be 2.75 mm (2.75 ± 1.49) at the control site compared to 1.47 mm (1.47 ± 1.44) at the test site. The test site showed 2.31 mm bone fill, (8.7%) compared to the control site.

CONCLUSION

Within the limitations of the study, the results suggest that socket preservation procedure is a reliable method that minimizes the alveolar bone loss.

Alveolar ridge preservation in the esthetic zone

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

Preservation and augmentation of molar extraction sites affected by severe bone defect due to advanced periodontitis: A prospective clinical trial

BACKGROUND

Studies of the extracted infected-molar ridge preservation are limited.

PURPOSE

To compare alterations of hard and soft tissue in infected-molar sockets receiving ridge preservation compared with natural healing.

MATERIALS AND METHODS

Thirty-five infected-molar extraction sites either preserving with Bio-Gide membrane covered the Bio-Oss material or receiving natural healing procedure as controls. The soft tissue profile was evaluated before tooth extraction and after 6-month healing. Cone-beam computed tomography scans were taken immediately and 6 months after extraction. Vertical and horizontal bone changes were assessed radiographically. Data were analyzed with Mann-Whitney U test and α = 0.05.

RESULTS

No significant differences in soft tissue and vertical bone changes in the medium region of the sockets were found (P > .05). Buccal bone changes in the mesial and distal sites in the test group were significantly lower than the control group (P < .05). Ridge width increased from 0.21mm to 5.30mm at 1mm apical from the crest in the test and reduced from 0.12 mm to 1.00 mm in the control groups.

CONCLUSION

Ridge preservation at periodontally compromised molar extraction sites might compensate for ridge width and buccal bone resorption that occurs with natural healing alone.

Alveolar Ridge Preservation Using Allografts and Dense Polytetrafluoroethylene Membranes With Open Membrane Technique in Unhealthy Extraction Socket

We evaluated the effectiveness of the open membrane technique using a high-density polytetrafluoroethylene (dPTFE) membrane with freeze-dried bone allografts in damaged sockets for alveolar ridge preservation (ARP). This retrospective study included 26 sites from 20 patients who had received ARP for the placement of dental implants. ARP was conducted using dPTFE membrane with allografts on the day of extraction without primary closure. When the membrane was removed after 4 weeks, the newly formed reddish tissue at the grafted site was checked (first outcome, clinical evaluation). Four months after membrane removal, a core biopsy was performed from the center of the grafted site before implant placement (second outcome, histomorphometric evaluation). Radiographic measurements of alveolar bone changes between implant prosthesis delivery and the 1-year follow-up were obtained (third outcome, radiographic evaluation). A total of 23 sites from 18 patients had no complications during the follow-up period. Three sites from two patients were excluded because of early membrane removal. Newly formed reddish tissue was found at 15 sites, and partially formed tissue was found at 8 sites. Although we were unable to harvest bone core from all sites, histomorphometric analysis in 11 patients indicated that the mean area of new bone was 28.48% ± 6.60%, that of the remaining graft particle was 27.68% ± 9.18%, and that of fibrous tissue was 43.84% ± 6.98%. The mean loss of marginal bone was 0.13 ± 0.06 mm at the mesial area and 0.15 ± 0.06 mm at the distal area, as assessed using radiographic evaluations. The results of this nonrandomized study suggest that this technique may be an appropriate procedure for ARP. Further studies with a control group and more subjectives can be designed based on this study.

Regenerative properties of collagenated porcine bone grafts in human maxilla: demonstrative study of the kinetics by synchrotron radiation microtomography and light microscopy

OBJECTIVES

Recently, it has been reported that heterologous biomaterials, where the collagen matrix is preserved, seem to facilitate blood clotting and the subsequent invasion of repairing and regenerative cells. This study aimed at evaluating the healing of human extraction sockets grafted with a collagenated cortico-cancellous porcine bone (mp3®, OsteoBiol®, Tecnoss®, Giaveno, Italy) by synchrotron radiation X-ray microtomography (microCT) and histology in order to have a 3D quantitative characterization over time.

MATERIALS AND METHODS

Ridge preservation with porcine bone and collagen membrane was performed on 21 patients using a flapless approach and a secondary soft tissue closure. At the time of implant placement, six bone samples were harvested, two in the 3-month group, two in the 6-month group, one in the 12-month group post-surgery, and one spontaneously healed control, and evaluated by microCT and histology.

RESULTS

MicroCT revealed that in the grafted sites there were a greater number of trabeculae, although they appeared thinner than in the control sites; these trabeculae homogenously filled the defects, suggesting an improved strength of the socket. Histology showed that over time, the amount of biomaterial decreased and the newly formed bone increased, while less dense bone with wider marrow spaces was detected in the control sample, supporting synchrotron findings.

CONCLUSIONS

The morphometric data converge to indicate the suitability of porcine bone for the preservation of post-extraction sockets.

CLINICAL RELEVANCE

The use of mp3 is encouraged to preserve and heal sockets.

Effect of ridge preservation for early implant placement - is there a need to remove the biomaterial?

AIM

To assess (i) bone regeneration around implants placed early in sites with or without ridge preservation and (ii) if the bone substitute material (DBBM-C) has to be removed at implant placement.

MATERIALS AND METHODS

In eight beagle dogs, three sites were randomly assigned to ridge preservation (DBBM-C plus collagen matrix (CMX)) (two sites; RP) or spontaneous healing (1 site; SH). Four weeks later, in one of the RP sites, dental implants were placed without removing the DBBM-C (RP1), whereas in RP2 and SH sites all non-integrated DBBM-C and/or granulation tissue were removed before implant placement and concomitant GBR. Histomorphometric outcomes were assessed at 4 and 12 weeks.

RESULTS

The median buccal fBIC (first bone-to-implant contact) was located more apical in groups RP1: 1.34 mm (0.09; 2.96) and RP2: 1.41 mm (0.54; 2.72) than in group SH: 0.79 mm (0.26; 1.50) (p = 0.452) at 4 weeks. At 12 weeks, median buccal fBIC values were for RP1: 0.88 mm (0.00; 2.33), for RP2: 0.16 mm (0.00; 1.33) and for SH: 0.00 mm (0.00; 0.98) (p = 0.362). BIC values increased over 12 weeks in all groups.

CONCLUSIONS

Ridge preservation followed by early implant placement led to higher BIC values at 12 than at 4 weeks. There is no need to remove the biomaterial at implant placement to ensure osseointegration. No relevant differences were observed between the three groups for any outcome measure.

Randomized clinical trial of ridge preservation using porcine bone/cross-linked collagen vs. bovine bone/non-cross-linked collagen: cone beam computed tomographic analysis

PURPOSE

The aim of this study was to radiographically compare horizontal and vertical alterations of the alveolar ridge after ridge preservation using different combinations of biomaterials.

MATERIALS AND METHODS

The patients were randomly assigned into two groups: (a) the test group, which received collagenated porcine bone plus cross-linked collagen membrane (n = 15), and (b) the control group, which received collagenated bovine bone plus non-cross-linked collagen membrane (n = 15). Cone beam computed tomography (CBCT) was performed immediately after ridge preservation and 4 months thereafter to compare the horizontal and vertical alterations of the ridge. Intention-to-treat (ITT) and per protocol (PP) analyses were performed.

RESULTS

In both analyses, there was no statistically significant difference in the horizontal alteration of the alveolar ridge between the test and control groups: -1.3 ± 0.6 (ITT)/1.2 ± 0.5 (PP) vs. -1.5 ± 0.9 mm at the 1-mm level; -1.2 ± 0.7 (ITT and PP) vs. -1.2 ± 0.7 mm at the 3-mm level; and -0.9 ± 0.7 (ITT)/ -0.9 ± 0.7 (PP) vs. -0.9 ± 0.9 mm at the 5-mm level, whereas the vertical height in the midfacial area was significantly reduced in the test group compared with the control group: --1.1 ± 2.8 (ITT)/1.5 ± 3.0 (PP) vs. -0.7 ± 1.8 mm.

CONCLUSIONS

The horizontal ridge alteration in ridge preservation did not differ significantly between using the test the control groups, but the vertical ridge alteration was more pronounced when using the test group (KCT0001709).

An open randomized controlled clinical trial to evaluate ridge preservation and repair using SocketKAP(™) and SocketKAGE(™) : part 2 - three-dimensional alveolar bone volumetric analysis of CBCT imaging

OBJECTIVES

The aims of this study were (i) to evaluate the efficacy of ridge preservation and repair procedures involving the application of SocketKAP(™) and SocketKAGE(™) devices following tooth removal and (ii) to evaluate alveolar bone volumetric changes at 6 months post-extraction in intact sockets or those with facial wall dehiscence defects using 3-dimensional pre- and postoperative CBCT data.

MATERIALS AND METHODS

Thirty-six patients required 61 teeth extracted. Five cohorts were established: Group A: Intact Socket Negative Control Group B: Intact Socket + SocketKAP(™) Group C: Intact Socket Filled with Anorganic Bovine Bone Mineral (ABBM) + SocketKAP(™) Group D: Facial Dehiscence Socket Negative Control Group E: Facial Dehiscence Socket Filled with ABBM + SocketKAP(™) + SocketKAGE(™) . Preoperative CBCT scans were obtained followed by digital subtraction of the test teeth. At 6 months post-extraction, another CBCT scan was obtained. The pre- and postoperative scans were then superimposed, allowing highly accurate quantitative determination of the 3D volumetric alveolar bone volume changes from baseline through 6 months.

RESULTS

Significant volumetric bone loss occurred in all sockets, localized mainly in the 0-3 mm zone apical to the ridge crest. For intact sockets, SocketKAP(™) + ABBM treatment led to a statistically significant greater percentage of remaining mineralized tissue volume when compared to negative control group. A significant difference favoring SocketKAP(™) + SocketKAGE(™) + ABBM treatment was observed for sockets with facial dehiscence defects compared to the negative control group.

CONCLUSIONS

SocketKAP(™) , with ABBM, appears effective in limiting post-extraction volumetric bone loss in intact sockets, while SocketKAP(™) + SocketKAGE + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects.

Periosteal Transposition Flap for Graft Coverage and Ridge Preservation in the Aesthetic Zone

Implant treatment in esthetic zone has been challenging for a long time. To achieve the best results optimum amounts of alveolar bone and soft tissue especially attached gingiva is needed. We presented the use of inverted periosteal flap which is a periosteal transposition flap in an esthetic zone. This flap may play a significant role in ridge augmentation and socket preservation in the esthetic zone and could be considered as an alternative for other local flaps. This flap provides sufficient-soft tissue coverage and reduces the risk of dehiscence.

Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site development

BACKGROUND

Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used.

OBJECTIVES

To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 22 July 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2014, Issue 6), MEDLINE via OVID (1946 to 22 July 2014), EMBASE via OVID (1980 to 22 July 2014), LILACS via BIREME (1982 to 22 July 2014), the Meta Register of Current Controlled Trials (to 22 July 2014), ClinicalTrials.gov (to 22 July 2014), the World Health Organization International Clinical Trials Registry Platform (to 22 July 2014), Web of Science Conference Proceedings (1990 to 22 July 2014), Scopus (1966 to 22 July 2014), ProQuest Dissertations and Theses (1861 to 22 July 2014) and OpenGrey (to 22 July 2014). A number of journals were also handsearched. Trial authors were contacted to identify unpublished randomised controlled trials. There were no restrictions regarding language and date of publication in the searches of the electronic databases.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) on the use of alveolar ridge preservation techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the extraction site, and complications of future prosthodontic rehabilitation.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently and assessed risk of bias for each included trial. Corresponding authors were contacted to obtain missing information. Results were combined using random-effects models with mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (95% CI). We constructed 'Summary of findings' tables to present the main findings.

MAIN RESULTS

A total of 50 trials were potentially eligible for inclusion, of which 42 trials were excluded. We included eight RCTs with a total of 233 extraction sites in 184 participants. One trial was judged to be at unclear risk of bias and the remaining trials were at high risk of bias. From two trials comparing xenograft with extraction alone (70 participants, moderate quality evidence), there was some evidence of a reduction in loss of alveolar ridge height (MD -2.60 mm; 95% CI -3.43 to -1.76) and width (MD -1.97 mm; 95% CI -2.48 to -1.46). This was also found in one trial comparing allograft with extraction (24 participants, low quality evidence): ridge height (MD -2.20 mm; 95% CI -0.75 to -3.65) and width (MD - 1.40 mm; 95% CI 0.00 to -2.80) and height. From two RCTs comparing alloplast versus xenograft no evidence was found that either ridge preservation technique caused a smaller reduction in loss of ridge height (MD -0.35 mm; 95% CI -0.86 to 0.16) or width (MD -0.44 mm; 95% CI -0.90 to 0.02; two trials (55 participants); moderate quality evidence). There was insufficient evidence to determine whether there are clinically significant differences between different ARP techniques and extraction based on the need for additional augmentation prior to implant placement, complications, implant failure, or changes in peri-implant marginal bone levels and probing depths of neighbouring teeth. We found no trials which evaluated parameters relating to clinical attachment levels, specific aesthetic or prosthodontic outcomes.

AUTHORS' CONCLUSIONS

There is limited evidence that ARP techniques may minimise the overall changes in residual ridge height and width six months after extraction. There is also lack of evidence of any differences in implant failure, aesthetic outcomes or any other clinical parameters due to the lack of information or long-term data. There is no convincing evidence of any clinically significant difference between different grafting materials and barriers used for ARP. Further long term RCTs that follow CONSORT guidelines (www.consort-statement.org) are necessary.

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

STATEMENT OF PROBLEM

Several biomaterials and techniques have been reported for socket grafting and alveolar ridge preservation. However, the evidence for clinical and histologic outcomes for socket grafting with different types of materials in flapless extraction is not clear.

PURPOSE

The purpose of this systematic review was to analyze the outcomes of a socket grafting procedure performed with flapless extraction of teeth in order to determine which graft material results in the least loss of socket dimensions, the maximum amount of vital bone, the least remnant graft material, and the least amount of connective tissue after a minimum of 12 weeks of healing. Secondary outcomes, including the predictability of regenerating deficient buccal bone, necessity of barrier membranes, and coverage with autogenous soft tissue graft, were also evaluated.

MATERIAL AND METHODS

An electronic search for articles in the English-language literature was performed independently by multiple investigators using a systematic search process with the PubMed search engine. After applying predetermined inclusion and exclusion criteria, the final list of randomized controlled clinical trials (RCTs) for flapless extraction and socket grafting was analyzed to derive results for the various objectives of the study.

RESULTS

The initial electronic search resulted in 2898 titles. The systematic application of inclusion and exclusion criteria resulted in 32 RCTs studying 1354 sockets, which addressed the clinical and histologic outcomes of flapless extraction with socket grafting and provided dimensional and histologic information at or beyond the 12-week reentry period. From these RCTs, the mean loss of buccolingual width at the ridge crest was lowest for xenografts (1.3 mm), followed by allografts (1.63 mm), alloplasts (2.13 mm), and sockets without any socket grafting (2.79 mm). Only 3 studies reported on loss of width at 3 mm below the ridge crest. The mean loss of buccal wall height from the ridge crest was lowest for xenografts (0.57 mm) and allografts (0.58 mm), followed by alloplasts (0.77 mm) and sockets without any grafting (1.74 mm). The mean histologic outcomes at or beyond the 12-week reentry period revealed the highest vital bone content for sockets grafted with alloplasts (45.53%), followed by sockets with no graft material (41.07%), xenografts (35.72%), and allografts (29.93%). The amount of remnant graft material was highest for sockets grafted with allografts (21.75%), followed by xenografts (19.3%) and alloplasts (13.67%). The highest connective tissue content at the time of reentry was seen for sockets with no grafting (52.53%), followed by allografts (51.03%), xenografts (44.42%), and alloplast (38.39%). Data for new and emerging biomaterials such as cell therapy and tissue regenerative materials were not amenable to calculations because of biomaterial heterogeneity and small sample sizes.

CONCLUSIONS

After flapless extraction of teeth, and using a minimum healing period of 12 weeks as a temporal measure, xenografts and allografts resulted in the least loss of socket dimensions compared to alloplasts or sockets with no grafting. Histologic outcomes after a minimum of 12 weeks of healing showed that sockets grafted with alloplasts had the maximum amount of vital bone and the least amount of remnant graft material and remnant connective tissue. There is a limited but emerging body of evidence for the predictable regeneration of deficient buccal bone with socket grafting materials, need for barrier membranes, use of tissue engineering, and use of autogenous soft tissue grafts from the palate to cover the socket.

Influence of local administration of pamidronate on extraction socket healing--a histomorphometric proof-of-principle pre-clinical in vivo evaluation

OBJECTIVES

To evaluate the influence of local administration of pamidronate histomorphometrically, adsorbed on a collagenated porcine bone substitute, on extraction socket healing.

MATERIAL AND METHODS

Two American Fox-hound dogs were used within this proof-of-principle study. Following endodontic treatment of the distal root of the three lower premolars, the teeth were hemisected, and the mesial roots were extracted flapless. The sockets were then loosely filled, in a split-mouth fashion, with a collagenated porcine bone substitute (Osteobiol Gen-Os; CPB), rehydrated either with 90 mg/ml pamidronate (Aredia(®) ; test) or with sterile saline (control). Extraction sockets were sealed with connective tissue punches obtained from the palate and secured with sutures. After 4 months of healing, specimens containing the socket sites and remaining roots were retrieved and histomorphometrically examined.

RESULTS

Histological evaluation of the sections revealed substantial differences in healing patterns. Control sites presented with various amounts of newly formed bone and no evidence of CPB inside the socket; in contrast, limited amounts of bone were observed at test sites, which were filled with CPB mainly embedded in connective tissue. Only minor differences were observed between test and control sites regarding vertical bone loss (buccal bone: -1.01 mm vs. -1.15 mm; lingual bone: -0.92 mm vs. -1.15 mm). Horizontal bone loss was nearly three times higher in control sites comparing to sites treated with pamidronate (-2.19 ± 1.81 mm vs. -0.80 ± 0.91 mm) at a level corresponding to 3 mm below the cemento-enamel junction (CEJ).

CONCLUSION

Local administration of pamidronate adsorbed on a collagenated porcine bone substitute in particulate form appeared to delay extraction socket healing, but may also reduce post-extraction dimensional changes in terms of horizontal bone width. Additionally, pamidronate appears to obstruct resorption of the porcine bone substitute.