Determinants of alveolar ridge preservation differ by anatomic location

Postextraction ridge preservation by using dense PTFE membranes: A systematic review and meta-analysis

STATEMENT OF PROBLEM

The use of dense polytetrafluoroethylene (dPTFE) membranes in alveolar ridge preservation may help reduce the risk of bacterial contamination and infection, maintaining the soft-tissue anatomy. However, systematic reviews on their efficacy in postextraction sites are lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to assess the efficacy of alveolar ridge preservation with dPTFE membranes when used alone or in combination with bone grafting materials in postextraction sites.

MATERIAL AND METHODS

An electronic search up to February 2021 was conducted by using PubMed, Embase, and the Cochrane library to detect studies using dPTFE membranes in postextraction sites. An additional manual search was performed in relevant journals. Clinical and radiographic dimensional changes of the alveolar ridge, histomorphometric, microcomputed tomography, implant-related findings, and rate of complications were recorded. One-dimensional meta-analysis was performed to calculate the overall means and 95% confidence intervals (α=.05).

RESULTS

A total of 23 studies, 14 randomized controlled trials, 4 retrospective cohort studies, 3 case series, and 2 prospective nonrandomized clinical trials, met the inclusion criteria. Five studies were included in the quantitative analysis. The meta-analysis revealed that the use of dPTFE membranes resulted in a statistically significant (P=.042) increase in clinical keratinized tissue of 3.49 mm (95% confidence interval [CI]: 0.16, 6.83) when compared with extraction alone. Metaregression showed that the difference of 1.10 mm (95% CI: -0.14, 2.35) in the radiographic horizontal measurements was not significant (P=.082), but the difference of 1.06 mm (95% CI: 0.51, 1.62) in the radiographic vertical dimensional change between dPTFE membranes+allograft and extraction alone was statistically significant (P<.001).

CONCLUSIONS

The use of dPTFE membranes was better than extraction alone in terms of keratinized tissue width and radiographic vertical bone loss.

Distribution and influencing factors on residual pockets of the teeth in patients with periodontitis following non-surgical periodontal treatment: a retrospective observational study

BACKGROUND

Periodontitis is a chronic and multi-factorial infectious disease. A notable difference exists in the prognosis of patients with severe periodontitis after non-surgical periodontal treatment. Thus, a retrospective study was conducted to identify common and specific factors that impact the prognosis of patients with periodontitis stage III-IV following non-surgical periodontal treatment at different tooth sites.

METHODS

A total of 977 teeth were included in the study, comprising 266 patients diagnosed with periodontitis stage III-IV. This sample included 330 anterior teeth, 362 maxillary posterior teeth, and 285 mandibular posterior teeth. Following treatment, the teeth were categorized into two groups based on residual pocket depth [probing depth (PD) ≥ 5 mm] at 3 months post-treatment. The prognosis of periodontitis stage III-IV was assessed through multivariate analysis employing logistic regression to determine the association of various risk factors.

RESULTS

The PD values of each site and the deepest PD values of each tooth significantly decreased at 3 months post-treatment. Residual pockets were predominantly found in the mesio/disto-buccal and mesio/disto-lingual regions. Multivariate analysis revealed that gender, PD, sulcus bleeding index (SBI) and plaque index (PLI) at baseline, and crown-root ratio in anterior teeth had a significant influence on periodontitis stage III-IV (P < 0.05). Smoking, PD, PLI and furcation involvement (FI) at baseline, PLI at 3 months post-treatment, grades of periodontitis, and crown-root ratio were prediction factors for maxillary posterior teeth. Factors such as PD, PLI and FI at baseline, PLI at 3 months post-treatment, and crown-root were significant in mandibular posterior teeth.

CONCLUSIONS

The outcome of non-surgical treatment varies depending on the tooth positions for patients with periodontitis stage III-IV. Dentists must accurately identify the affected teeth that have periodontal pockets of more than 5 mm, taking into consideration the positions of the affected teeth, as well as various local and systemic factors. This comprehensive assessment will enable dentists to develop a customized and effective treatment plan.

Complications following alveolar ridge augmentation procedures

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

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.

Autogenous particulated dentin for alveolar ridge preservation. A systematic review

PURPOSE

This review aimed to investigate the clinical outcomes of autogenous particulated dentin (APD) used for alveolar ridge preservation (ARP), evaluating volume gain, histologic/histomorphometric data, and associated complications.

MATERIAL AND METHODS

The review followed PRISMA guidelines and was registered in the International Prospective Register of Systematic Reviews (PROSPERO). An automated search was made in four databases (Medline/Pubmed, Scopus, Web of Science, and Cochrane Library) supplemented by a manual search for relevant clinical articles published before March 10th, 2022. The review included human studies of at least four patients in which extraction and subsequent ARP were performed in a single surgery. Both comparative studies and studies that assessed ARP with APD exclusively were admitted. The quality of evidence was assessed with the Cochrane bias assessment tool, the Newcastle-Ottawa Quality Assessment Scale, and the Joanna Briggs Institute Critical Appraisal tool.

RESULTS

Eleven studies fulfilled the inclusion criteria and were included for descriptive analysis, with a total of 215 patients, and 337 alveoli preserved by APD, spontaneous healing (blood clot), or other bone substitutes, obtaining comparatively less vertical and horizontal resorption when APD was used.

CONCLUSIONS

After dental extraction, autogenous dentin was effective in terms of volume maintenance, showing promising results in histologic/histomorphometric analysis, and a low complication rate. Nevertheless, few comparative studies with comparable parameters have been published and so more research providing long-term data is needed to confirm these findings.

Characterizations of alveolar repair after mandibular second molar extraction: an experimental study in rats

BACKGROUND

Characterizations of rat mandibular second molar extraction socket with significantly different buccal and lingual alveolar ridge width remain unclear.

OBJECTIVE

To observe alterations in the alveolar ridge after extraction of mandibular second molars, and to examine processes of alveolar socket healing in an experimental model of alveolar ridge absorption and preservation.

METHODOLOGY

Eighteen Wistar rats were included and divided into six groups regarding healing time in the study. Bilateral mandibular second molars were extracted. The rats with tooth extraction sockets took 0, 1.5, 2, 3, 4 and 8 weeks of healing. Histological observation, tartrate-resistant acidic phosphatase (TRAP) staining, Masson's trichrome staining, immunohistochemical staining and micro-computed tomography (micro-CT) were applied to estimate alterations in the alveolar ridge.

RESULTS

Different buccal and lingual alveolar ridge width led to different height loss. Lingual wall height (LH) decreased significantly two weeks after tooth extraction. Buccal wall height rarely reduced its higher ridge width. From two to eight weeks after extraction, bone volume (BV/TV), density (BMD), and trabecular thickness (Tb.Th) progressively increased in the alveolar socket, which gradually decreased in Tb.Sp and Tb.N. LH showed no significant change during the same period. Osteogenic marker OCN and OPN increased during bone repair from two to eight weeks. The reduced height of the lingual wall of the tooth extraction socket was rarely repaired in the later repair stage. Osteoclast activity led to absorption of the alveolar ridge of the alveolar bone wall within two weeks after operation. We observed positive expression of EMMPRIN and MMP-9 in osteoclasts that participated in the absorption of the spire region.

CONCLUSION

Extraction of rat mandibular second molars may help the study of alveolar ridge absorption and preservation. The EMMPRIN-MMP-9 pathway may be a candidate for further study on attenuating bone resorption after tooth extraction.

Alveolar ridge preservation reduces the need for ancillary bone augmentation in the context of implant therapy

Background

There is limited information on the need for bone augmentation in the context of delayed implant placement whether alveolar ridge preservation (ARP) is previously performed or not. The primary aim of this retrospective cohort study was to evaluate the efficacy of ARP therapy after tooth extraction compared with unassisted socket healing (USH) in reducing the need for ancillary bone augmentation before or at the time of implant placement.

Methods

Adult subjects that underwent non‐molar single tooth extraction with or without simultaneous ARP therapy were included in this study. Cone beam computed tomography scans obtained before tooth extraction and after a variable healing period were used to record the baseline facial bone thickness and to virtually plan implant placement according to a standard method. A logistic regression model was used to evaluate the effect of facial alveolar bone thickness upon tooth extraction and baseline therapy (USH or ARP) on the need for additional bone augmentation, adjusting for several covariates (i.e., age, sex, baseline KMW, and tooth type).

Results

One hundred and forty subjects that were equally distributed between both baseline therapy groups constituted the study population. Implant placement was deemed virtually feasible in all study sites. Simultaneous bone augmentation was considered necessary in 60% and 11.4% of the sites in the USH and ARP group, respectively. Most of these sites (64.2% in the USH group and 87.5% in the ARP group) exhibited a thin facial bone phenotype (<1 mm) at baseline. Logistic regression revealed that the odds of not needing ancillary bone augmentation were 17.8 times higher in sites that received ARP therapy. Furthermore, the need for additional bone augmentation was reduced 7.7 times for every 1 mm increase in facial bone thickness, regardless of baseline therapy.

Conclusions

Based on a digital analysis, ARP therapy, compared with USH, and thick facial alveolar bone largely reduce the need for ancillary bone augmentation at the time of implant placement in non‐molar sites.

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.

Evaluation of healing at molar extraction sites with ridge preservation using a non-resorbable dense polytetrafluoroethylene membrane: A four-arm cohort prospective study

Objectives

To examine ridge dimensional changes and histologic parameters of healing when ridge preservation (RP) was performed at molar sites using dense polytetrafluoroethylene (dPTFE) membrane alone, without a bone graft.

Material and Methods

Eighteen patients had molar extraction and RP using dPTFE membrane alone. Ridge dimensions were measured using two standardized cone beam computerized tomography (CBCT) scans taken within 72 h and 3 months following extraction. Following a 3‐month healing period, an implant osteotomy was prepared using a trephine drill and bone cores were collected for histological analysis. Four‐arm analyses were performed using data from three previously published study arms of the same research group.

Results

There was a significant change in the buccal ridge height between the four groups at all aspects of the socket. Alveolar ridge width reduction at 3 mm from crest for all aspects (mesial, midpoint, distal) of the socket showed statistically significant difference for dPTFE alone group compared to the other three groups. Percentage of vital bone formation (62.10%) was significantly greater in dPTFE alone group compared to the other groups.

Conclusions

RP using dPTFE membrane alone in molar sites with intact socket walls showed successful outcomes in maintaining ridge dimensions and in histologic wound healing.

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.

Is ridge preservation effective in the extraction sockets of periodontally compromised teeth? A randomized controlled trial

OBJECTIVE

To verify whether ridge preservation is effective in the reduction of dimensional loss and in bone formation compared to spontaneous healing in extraction sockets of periodontally compromised teeth.

METHODS

Twenty-six subjects requiring tooth extraction for stage III/IV periodontitis were randomly assigned to one of two interventions: alveolar ridge preservation using collagenated bovine bone mineral and a resorbable collagen membrane (test, RP) or spontaneous healing (control, SH). Six months later, postoperative cone-beam computed tomography (CBCT) was performed to measure the linear and volumetric changes of the sockets compared to baseline scans. Biopsies were retrieved at the implant site for histomorphometric calculations. Nonparametric tests were applied for statistical analysis.

RESULTS

Significantly less shrinkage occurred in RP compared to SH, mainly in the crestal zone. The width loss difference between groups was 3.3 mm and 2.2 mm at 1 mm and 3 mm below the crest, respectively (p < .05). RP yielded a gain in socket height of 0.25 mm, whereas a loss of -0.39 mm was observed in SH (p < .05). The percentage of volume loss recorded in RP was also less than that recorded in SH (-26.53% vs -50.34, p < .05). Significantly less bone proportion was detected in biopsies from RP (30.1%) compared with SH (53.9%). A positive association between baseline bone loss and ridge shrinkage was found in SH but not in RP.

CONCLUSION

Ridge preservation in extraction sockets of periodontally compromised teeth was effective in reducing the amount of ridge resorption.

Efficacy of stem cell allograft in maxillary sinus bone regeneration: a randomized controlled clinical and blinded histomorphometric study

Purpose

This study aimed to evaluate the quality and quantity of newly generated bone in the maxillary sinus grafted with stem cell-based allograft material.

Methods

This study was a single site, prospective, blinded, randomized, and controlled clinical trial. Eleven subjects with 18 edentulous posterior maxillary sites requiring sinus augmentation for delayed implant placement using a lateral window approach were enrolled. At the time of sinus augmentation, test sinus was grafted with stem cell-based allograft (Osteocel Plus; NuVasive Therapeutics), while the control sinus was grafted with conventional cortico-cancellous allograft (alloOss; ACE Surgical). Cone beam computer tomography (CBCT) scan was taken before and 14 weeks post-sinus augmentation procedure, i.e., 2 weeks before implant placement. Thirty-six trephined core bone biopsies were harvested from the anterior and posterior grafted lateral-window osteotomy sites at the time of implant placement.

Results

The results showed a statistically significant difference in the vital bone percentage between the test and the control groups at the posterior grafted sites (p = 0.03). There was no significant difference in the percentage of vital bone between the anterior and posterior grafted sites within the test and control groups (p > .05). The CBCT analysis showed that the maxillary sinuses at the posterior grafted sites were statistically wider than those at the anterior grafted sites in both groups (p < .05).

Conclusions

Different allograft bone materials can be used in the maxillary sinus augmentation procedures. Stem cell allograft has more osteogenic potential with a better outcome in the wide posterior sinus.

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.

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

Objectives

The purpose of this systematic review was to assess quantitatively and qualitatively the influence of two different factors: membranes and soft tissue graft influence for the extraction socket preservation.

Material and Methods

A wide-ranging electronic search was performed in six databases up to 30 of November 2018 in order to identify all the clinical and randomized clinical trials performed in humans published with no data restriction. The inclusion criteria were extraction socket preservation with and without membranes or a soft tissue graft in a intact socket with at least six months of follow-up, have more than 12 patients or treat more than 12 sites per group and evaluated at least one of the primary outcomes measures (radiographic measures histological assessment, clinical measures).

Results

From an initial search of 1524 studies only 6 papers fulfil the inclusion and exclusion criterions. All the six selected papers, presented a wide heterogeneity of treatments used, evaluated variables and observation period that made impossible to recommend any specific techniques and/or material to achieve better results. The limited data found suggest that the used of membrane reveals to achieve better results. It wasn’t possible to observe in any clinical trial that compares the used of soft tissue graft.

Conclusions

New trials need to be performed in order to identify what specific techniques and/or materials are better to decrease the reabsorption of the socket after tooth extraction. Clinical trials designed to understand when/how the soft tissues grafts influence at the socket preservation is needed.

Comparison between two bone substitutes for alveolar ridge preservation after tooth extraction: Cone-beam computed tomography results of a non-inferiority randomized controlled trial

AIM

To test the non-inferiority of demineralized bovine bone mineral (DBBM) compared to DBBM with 10% collagen (DBBM-C) for maintenance of bone volume after tooth extraction in the anterior maxilla.

MATERIALS AND METHODS

Sixty-six patients were randomly treated with DBBM or DBBM-C, both of which were covered with a collagen matrix for ridge preservation in the anterior maxilla. Cone-beam computed tomographic analysis was performed immediately and 4 months after treatment. The primary outcome, for which non-inferiority of DBBM was tested, was change in the horizontal ridge width 1 mm below the buccal alveolar crest (HW-1) 4 months after extraction.

RESULTS

Four months after extraction, HW-1 measured -1.60 mm ± 0.82 mm for DBBM-C, while the DBBM group showed a mean loss of -1.37 mm ± 0.84 mm (p = 0.28, 0.23 [95% CI: -0.19; 0.64]). The horizontal ridge width at 3 mm (HW-3) showed -0.98 mm (±0.67 mm) for DBBM-C and -0.84 mm (±0.62 mm) for DBBM (p = 0.40, 0.12 [95% CI: -0.19; 0.45]), and the horizontal ridge width at 5 mm (HW-5) showed -0.67 mm (±0.47 mm) for DBBM-C and -0.56 mm (±0.48 mm) for DBBM (p = 0.36, 0.11 [95% CI: -0.13; 0.34]).

CONCLUSIONS

The present clinical trial demonstrated non-inferiority of DBBM compared to DBBM-C for maintenance of alveolar bone volume 4 months after tooth extraction in the anterior maxilla.

Efficacy of Alveolar Ridge Preservation after Maxillary Molar Extraction in Reducing Crestal Bone Resorption and Sinus Pneumatization: A Multicenter Prospective Case-Control Study

Aim

To evaluate, with three-dimensional analysis, the effectiveness of alveolar ridge preservation (ARP) after maxillary molar extraction in reducing alveolar bone resorption and maxillary sinus pneumatization when compared to unassisted socket healing.

Methods

Patients were included in the study following inclusion criteria and underwent minimally traumatic maxillary molar extraction followed by ARP using synthetic nanohydroxyapatite (Fisiograft Bone, Ghimas, Italy) (test group) or unassisted socket healing (control group). Cone-beam computerized tomographies (CBCT) were performed immediately after tooth extraction (T0) and 6 months postoperatively (T1). CBCTs were superimposed by using a specific software (Amira, Thermo Fisher Scientific, USA) and the following items were analyzed in both groups: (i) postextractive maxillary sinus floor expansion in coronal direction and (ii) postextractive alveolar bone dimensional changes (both vertical and horizontal). All data were tested for normality and equality of variance and subsequently analyzed by independent samples T-test and Mann–Whitney test.

Results

Thirty patients were treated by three centers and twenty-six (test n=13; control n=13) were included in the final analysis. Mean sinus pneumatization at T1 was 0.69±0.48 mm in the test group and 1.04±0.67 mm in the control group (p=0.15). Mean vertical reduction of the alveolar bone at T1 was 1.62±0.49 mm in the test group and 2.01±0.84 mm in the control group (p=0.08). Mean horizontal resorption of crestal bone at T1 was 2.73±1.68 mm in test group and 3.63±2.24 mm in control group (p=0.24).

Conclusions

It could be suggested that ARP performed after maxillary molar extraction may reduce the entity of sinus pneumatization and alveolar bone resorption, compared to unassisted socket healing. This technique could decrease the necessity of advanced regenerative procedures prior to dental implant placement in posterior maxilla.

High Frequency Acceleration: A New Tool for Alveolar Bone Regeneration

INTRODUCTION

A common problem in clinical dentistry is the significant and rapid bone loss that occurs after periodontitis, osteoporosis, tooth extractions, lack of function, or any other pathologic condition that target the alveolar bone. Currently there is no stable solution for the long-term preservation or rehabilitation of alveolar bone. In this article, we review the latest concepts on bone response to mechanical stimulation, and summarize the results of our studies on the effect of high frequency acceleration (HFA) on healthy alveolar bone and on healing alveolar bone after extractions.

METHODS

In both studies, we used adult Sprague Dawley rats to test the response of alveolar bone to different frequencies and accelerations applied to the maxillary molars.

RESULTS

Once we determined which parameters of HFA induced a higher osteogenic response, we tested the effect of this mechanical stimulation during bone healing after molar extraction. Our studies strongly show that HFA can stimulate bone formation in the healthy alveolar bone surrounding the tooth/point of application as well as the distant bone surrounding the neighboring teeth. When HFA was applied to the second molar, after extraction of the third molar, it accelerated bone healing and prevented alveolar bone resorption in and around the extraction socket.

CONCLUSION

HFA is a noninvasive safe treatment that can be used to prevent alveolar bone loss, accelerate bone healing and to improve the quality and quantity of alveolar bone under both physiological and pathological conditions.

Gingival Perfusion and Tissue Biomarkers During Early Healing of Postextraction Regenerative Procedures: A Prospective Case Series

BACKGROUND

Postextraction alveolar bone loss, mostly affecting the buccal plate, occurs despite regenerative procedures. To better understand possible determinants, this prospective case series assesses gingival blood perfusion and tissue molecular responses in relation to postextraction regenerative outcomes.

METHODS

Adults scheduled to receive bone grafting in maxillary, non-molar, single-tooth extraction sites were recruited. Clinical documentation included the following: 1) probing depth (PD); 2) keratinized tissue width (KT); 3) tissue biotype (TB); and 4) plaque level. Wound closure was clinically evaluated. Gingival blood perfusion was measured by laser Doppler flowmetry (LDF). Wound fluid (WF) and gingival biopsies were analyzed for protein levels and gene expression, respectively, of relevant molecular markers. Bone healing outcomes were determined radiographically (cone-beam computed tomography). Healing was followed for 4 months.

RESULTS

Data from 15 patients are reported. Postoperatively, neither complications nor changes in PD, KT, or TB were observed. LDF revealed decreased perfusion followed by hyperemia that persisted for 1 month (P ≤0.05). WF levels of angiopoietin-2, interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α), and vascular endothelial growth factor peaked on day 6 (P ≤0.05) and decreased thereafter. Only IL-8 and TNF-α exhibited increased gene expression. Linear bone changes were negligible. Volumetric bone changes were minimal but statistically significant, with more bone loss when membrane was used (P = 0.05).

CONCLUSIONS

Gingival blood perfusion after postextraction bone regenerative procedures follows an ischemia-reperfusion model. Transient increases in angiogenic factor levels and prolonged hyperemia characterize the soft tissue response. These soft tissue responses do not determine radiographic bone changes.

Comparison of Bio-degradation for Ridge Preservation Using Silk Fibroin-based Grafts and a Collagen Plug

A material for ridge preservation should have dimensional stability to resist bio-degradation. This study was designed to compare bio-degradation of ridge preservation materials. Collagen plug was used as a positive control. Untreated, ethanol-treated, and 4-hexylresorcinol (4HR)-treated silk plugs were used for the experimental group. Each material underwent a scanning electron microscopic exam and a Fourier transform infrared (FT-IR) spectroscopic exam. Bio-degradation was evaluated by analyzing cylindrical bony defects in rabbit tibias. There were no prominent differences in microstructure among the silk plug groups. FT-IR exam demonstrated that the ethanol- and 4HR-treated silk plug groups had enhanced β-sheet structure. All silk plug groups exhibited significantly higher residual graft than the collagen plug group 4 weeks postoperative (p < 0.05). In conclusion, silk fibroin-based ridge preservation material was less bio-degradable than a collagen plug until at least 4 weeks after grafting.

Ridge Preservation Comparing a Nonresorbable PTFE Membrane to a Resorbable Collagen Membrane: A Clinical and Histologic Study in Humans

PURPOSE

The primary aim of this randomized, controlled, blinded clinical trial was to compare the effect of a resorbable collagen membrane (CM group) versus a nonresorbable high-density polytetrafluoroethylene membrane (PTFE group) on the clinical and histologic outcomes of a ridge preservation procedure.

MATERIALS AND METHODS

All 24 sites received an intrasocket cancellous allograft and a buccal overlay bovine derived xenograft.

RESULTS

The change in horizontal crestal ridge width was -1.4 ± 1.2 mm for the CM group, whereas the PTFE group lost -2.2 ± 1.5 mm, which was not statistically significant between groups (P > 0.05). Vertical ridge height change was -1.2 ± 1.5 for the CM group, whereas the PTFE group lost -0.5 ± 1.6, which was not significantly different between groups (P > 0.05). The percent vital bone was similar and not significantly different between groups. Primary closure was not obtained and the exposed membrane portion over the socket opening healed with keratinized tissue.

CONCLUSION

The choice of a resorbable versus a nonresorbable barrier membrane did not affect the clinical or the histologic outcome of ridge preservation treatment.

Conditions and calibration to obtain comparable grey values between different clinical cone beam computed tomography scanners

OBJECTIVES

The objective of the present study was to examine the grey value parameters and their magnitudes produced by CBCT and whether they are influenced by different scanners with various scanning conditions.

METHODS

An ATOM Max dental and diagnostic artificial head was scanned by two CBCT scanners (Planmeca and iCAT). Under full field of view with normal dose and ultralow-dose (ULD) conditions, the Planmeca scanner was examined for three scanning resolutions (200, 400, and 600 micron voxel sizes) and the iCAT scanner was tested for four scanning resolutions (200, 250, 300 and 400 micron voxel sizes). After 9 weeks, the artificial head was scanned again by the Planmeca scanner with the same scanning conditions. In addition, two hydroxyapatite phantoms (1220 and 1540 mg cm^-3) were adhered on the artificial head and scanned using normal and ULD scanning conditions of 400 micron voxel size with both scanners. The grey value histogram of each region, which is proportional to the bone mineral density (BMD) histogram, was utilized to determine grey value distribution parameters and compare scanners (ANOVA, p < 0.05).

RESULTS

The different scanning conditions and the bilateral locations of the artificial head did not have significant effects on measurements of the grey value parameters (p > 0.436) with excellent repeatability. However, the iCAT scanner produced significantly different grey values from the Planmeca scanner (p < 0.001).

CONCLUSIONS

CBCT can assess BMD, while calibration of absolute measures is necessary to obtain comparable values between different scanners that are currently used to assess oral bone quantity and quality.

Microarchitectural study of the augmented bone following ridge preservation with a porcine xenograft and a collagen membrane: preliminary report of a prospective clinical, histological, and micro-computed tomography analysis

Socket preservation using a combination of porcine xenograft and collagen membrane maintains the vertical and horizontal dimensions of the ridge. The aim of this study was to evaluate the microarchitecture of the grafted area by histological analysis and micro-computed tomography. Patients in the test group (group 1; nine patients) underwent socket preservation, while the sockets in the control group (group 2; eight patients) were allowed to heal without preservation. After a 6-month healing period, bone core biopsy samples were obtained and implants were placed in the augmented sites in the test group (12 biopsy samples) and the non-augmented sockets of the control group (12 biopsy samples). Analysis of the biopsy samples obtained from group 1 revealed that particles of the graft were surrounded by newly formed bone in eight cases and by granulation tissue in four cases. Micromorphometric data showed statistically significant differences in several parameters between the microarchitecture of the native bone and the newly formed bone within the augmented sites, which suggests that the xenograft particles interfere with the bony healing of the alveoli.

Evaluation of Healing at Molar Extraction Sites With and Without Ridge Preservation: A Randomized Controlled Clinical Trial

BACKGROUND

To date, limited evidence is available specifically evaluating ridge preservation (RP) and implant placement in molar sites. The primary aim of this study is to radiographically compare alveolar ridge changes with and without RP with cone-beam computed tomography (CBCT).

METHODS

This parallel, two-arm randomized clinical trial included 40 patients evenly distributed between two treatment groups. After molar extraction, sites were allowed to heal naturally or received RP with freeze-dried bone allograft covered by a non-resorbable dense polytetrafluoroethylene membrane. CBCT scans were taken immediately and 3 months postextraction, and then a dental implant was placed. Width and height measurements were made radiographically.

RESULTS

Significantly greater loss in alveolar ridge height was found in molar sites allowed to heal without RP on the buccal aspect of the socket (RP: -1.12 ± 1.60 mm versus no RP: -2.60 ± 2.06 mm, P = 0.01). No significant difference in ridge width loss was found between groups. Two-thirds ridge width reduction was experienced on the buccal aspect in sites without RP, but width loss was evenly distributed between buccal and lingual aspects when RP was performed. Bone grafting at time of placement was required in 25% of implants in the group without RP versus 10% of implants in the RP group.

CONCLUSIONS

In molar extraction sites without RP, significantly more reduction in ridge height occurred, and the majority of ridge width loss was localized to the buccal aspect. When RP was performed, ridge width loss was not significantly decreased, but the loss was evenly distributed between facial and lingual aspects of the extraction site.

Effect of starch on the mechanical and in vitro properties of collagen-hydroxyapatite sponges for applications in dentistry

This study sought to improve the mechanical and blood-absorbing properties of collagen sponges, while keeping them compressible, by incorporating blended hydroxyapatite (HA)-starch. Results were compared with CollaPlug(®) (pure collagen). The elastic modulus increased from 1.5±0.2kPa for CollaPlug(®) to 49±8kPa for sponges with composition 1:4:10 (collagen:HA:starch, by weight). The modified microstructure and surface area provided by the starch granules on the sponges improved cell viability. Sponges with composition 1:4:10 maintained their blood-clotting capability with almost no change from 5 to 15min after contact with blood, while CollaPlug(®) diminished to about half its capacity to absorb blood and form clots. Incorporation of HA-starch into the sponges with composition of 1:4:10, increased the elastic modulus of the collagen-HA sponges, making them more structurally robust. The viability of cells and the blood-clotting capability increased with starch incorporation.

A new method to standardize CBCT for quantitative evaluation of alveolar ridge preservation in the mandible: a case report and review of the literature

Cone-beam computerized tomography (CBCT) is an effective technique for assessment of changes to the alveolar ridge (AR). However, its accuracy and reliability could be improved by standardization of imaging positions to remain unchanged during measurements. In this study, an alveolar ridge preservation procedure was performed on a left third molar (38) socket by filling it with a radiotransparent synthetic bone graft, mineralized collagen (MC). Photographic, X-ray and CBCT images were captured before and 3, 6 and 12 months after surgery. A new method was developed to standardize CBCT for quantitative evaluation. Obtained CBCT images showed good comparability. The post-extraction alveolar width and height were both over 95% of the original values, but some resorption of the lingual bone wall (>50%) and inter-crestal bone (>30%). It is concluded that an effective positional standardization method was developed for CBCT assessment of AR dimensional changes in the posterior mandible. The use of MC in combination with a collagen membrane improved dimensional preservation of the AR.

High-Frequency Acceleration: Therapeutic Tool to Preserve Bone following Tooth Extractions

A common problem in clinical dentistry is the significant and rapid bone loss that occurs after tooth extraction. Currently there is no solution for the long-term preservation of alveolar bone. Previously, we showed that high-frequency acceleration (HFA) has an osteogenic effect on healthy alveolar bone. However, it is not known if HFA can preserve alveolar bone after extraction without negatively affecting wound healing. The purpose of this study was to evaluate the effect of HFA on alveolar bone loss and the rate of bone formation after tooth extraction. Eighty-five adult Sprague-Dawley rats were divided into 3 groups: control, static (static load), and HFA. In all groups, the maxillary right third molar was extracted. The HFA group received HFA for 5 min/d, applied through the second molar. The static group received the same magnitude of static load. The control group did not receive any stimulation. Some animals received fluorescent dyes at 26 and 54 d. Samples were collected on days 0, 7, 14, 28, and 56 for fluorescence microscopy, micro-computed tomography, histology, RNA, and protein analyses. We found that HFA increased bone volume in the extraction site and surrounding alveolar bone by 44% when compared with static, while fully preserving alveolar bone height and width long-term. These effects were accompanied by increased expression of osteogenic markers and intramembranous bone formation and by decreased expression of osteoclastic markers and bone resorption activity, as well as decreased expression of many inflammatory markers. HFA is a noninvasive safe treatment that can be used to prevent alveolar bone loss and/or accelerate bone healing after tooth extraction.

Grafts for Ridge Preservation

Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome.

Does ridge preservation following tooth extraction improve implant treatment outcomes: a systematic review: Group 4: Therapeutic concepts & methods

OBJECTIVE

(1) Primary focused question (Q1): to evaluate the effect of alveolar ridge preservation (ARP) on implant outcomes (implant placement feasibility, need for further augmentation, survival/success rates, marginal bone loss) compared with unassisted socket healing (USH) and (2) secondary focused question (Q2): to estimate the size effects (SE) of these outcomes in three different interventions (GBR, socket filler, socket seal).

MATERIAL AND METHODS

Electronic (MEDLINE, EMBASE, Cochrane Central Register LILACS; Web of Science) and hand search was conducted up to July 2014. Randomised controlled trials (RCT), controlled clinical trials (CCT) and prospective cohort studies with USH as controls were eligible in the analysis for Q1. RCTs, CCTs and prospective case series, with or without USH as control, were eligible for Q2.

RESULTS

Ten (8 RCTs, 2 CCTs) and 30 studies (21 RCTs, 7 CCTs, 2 case series) were included in the analysis for Q1 and Q2, respectively. The risk for bias was unclear or high in most of them. Q1: Implant placement was feasible in ARP-treated and USH sites. These implants presented similar survival/success rates and marginal bone levels. The need for further augmentation decreased when ARP was performed (Relative risk: 0.15, 95% CI: 0.07-0.3). Q2: The SE for implant placement feasibility was 98.5% (95% CI: 96.4-99.6) in GBR and 96.2 (95% CI: 93.1-98.2) in socket filler group. The SE for need for further augmentation was 11.9 (95% CI: 5.6-19.9) for GBR and 13.7% (95% CI: 5.0-25.6) for socket filler groups. GBR and socket filler presented similar SE for survival/success rates and average marginal bone loss. Limited data were available for implant-related outcomes in sites treated with socket seal.

CONCLUSIONS

There is limited evidence to support the clinical benefit of ARP over USH in improving implant-related outcomes despite a decrease in the need for further ridge augmentation during implant placement. Similar implant placement feasibility, survival/success rates and marginal bone loss should be anticipated following ARP or USH. Currently, it is not clear which type of ARP intervention has a superior impact on implant outcomes.

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.

Alveolar ridge preservation using xenogeneic collagen matrix and bone allograft

Alveolar ridge preservation (ARP) has been shown to prevent postextraction bone loss. The aim of this report is to highlight the clinical, radiographic, and histological outcomes following use of a bilayer xenogeneic collagen matrix (XCM) in combination with freeze-dried bone allograft (FDBA) for ARP. Nine patients were treated after extraction of 18 teeth. Following minimal flap elevation and atraumatic extraction, sockets were filled with FDBA. The XCM was adapted to cover the defect and 2-3 mm of adjacent bone and flaps were repositioned. Healing was uneventful in all cases, the XCM remained in place, and any matrix exposure was devoid of further complications. Exposed matrix portions were slowly vascularized and replaced by mature keratinized tissue within 2-3 months. Radiographic and clinical assessment indicated adequate volume of bone for implant placement, with all planned implants placed in acceptable positions. When fixed partial dentures were placed, restorations fulfilled aesthetic demands without requiring further augmentation procedures. Histological and immunohistochemical analysis from 9 sites (4 patients) indicated normal mucosa with complete incorporation of the matrix and absence of inflammatory response. The XCM + FDBA combination resulted in minimal complications and desirable soft and hard tissue therapeutic outcomes, suggesting the feasibility of this approach for ARP.

Can dental cone beam computed tomography assess bone mineral density?

Mineral density distribution of bone tissue is altered by active bone modeling and remodeling due to bone complications including bone disease and implantation surgery. Clinical cone beam computed tomography (CBCT) has been examined whether it can assess oral bone mineral density (BMD) in patient. It has been indicated that CBCT has disadvantages of higher noise and lower contrast than conventional medical computed tomography (CT) systems. On the other hand, it has advantages of a relatively lower cost and radiation dose but higher spatial resolution. However, the reliability of CBCT based mineral density measurement has not yet been fully validated. Thus, the objectives of this review are to discuss 1) why assessment of BMD distribution is important and 2) whether the clinical CBCT can be used as a potential tool to measure the BMD. Brief descriptions of image artefacts associated with assessment of gray value, which has been used to account for mineral density, in CBCT images are provided. Techniques to correct local and conversion errors in obtaining the gray values in CBCT images are also introduced. This review can be used as a quick reference for users who may encounter these errors during analysis of CBCT images.

Atraumatic extraction and immediate implant installation: The importance of maintaining the contour gingival tissues

There is an accelerated resorption in the first six months after the extraction of the dental element, both horizontally and vertically. These clinical changes normally undertake the aesthetic result of prosthetic rehabilitation, and implant installation after the extraction can be a resource to decrease resorption. The clinical case described in this paper demonstrates a sequence of clinical atraumatic extraction, and then the Immediate installation provisionalization. It is concluded that when carefully indicated and planned, this technique can provide an immediate result promising with maintaining the tooth gingival contour. How to cite this article: Tavarez RR, Machado dos Reis WL, Rocha AT, Firoozmand LM, Bandéca MC, Tonetto MR, Malheiros AS. Atraumatic extraction and immediate implant installation: The importance of maintaining the contour gingival tissues. J Int Oral Health 2013; 5(6):113-8 .