Higher odds of periodontitis in systemic lupus erythematosus compared to controls and rheumatoid arthritis: a systematic review, meta-analysis and network meta-analysis.

Introduction: Periodontitis as a comorbidity in systemic lupus erythematosus (SLE) is still not well recognized in the dental and rheumatology communities. A meta-analysis and network meta-analysis were thus performed to compare the (i) prevalence of periodontitis in SLE patients compared to those with rheumatoid arthritis (RA) and (ii) odds of developing periodontitis in controls, RA, and SLE. Methods: Pooled prevalence of and odds ratio (OR) for periodontitis were compared using meta-analysis and network meta-analysis (NMA). Results: Forty-three observational studies involving 7,800 SLE patients, 49,388 RA patients, and 766,323 controls were included in this meta-analysis. The pooled prevalence of periodontitis in SLE patients (67.0%, 95% confidence interval [CI] 57.0-77.0%) was comparable to that of RA (65%, 95% CI 55.0-75.0%) (p>0.05). Compared to controls, patients with SLE (OR=2.64, 95% CI 1.24-5.62, p<0.01) and RA (OR=1.81, 95% CI 1.25-2.64, p<0.01) were more likely to have periodontitis. Indirect comparisons through the NMA demonstrated that the odds of having periodontitis in SLE was 1.49 times higher compared to RA (OR=1.49, 95% CI 1.09-2.05, p<0.05). Discussion: Given that RA is the autoimmune disease classically associated with periodontal disease, the higher odds of having periodontitis in SLE are striking. These results highlight the importance of addressing the dental health needs of patients with SLE. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/ identifier CRD42021272876.

Conventional versus comprehensive dental prophylaxis: comparing the clinical outcomes between rubber cup and air polishing and the importance of plaque disclosure.

Objective: This study aimed to compare the clinical outcomes in dental prophylaxis between rubber cup polishing and an air polishing system using erythritol powder, with or without prior dental plaque disclosure. Method and materials: In this single-blind, randomized, controlled, split-mouth clinical trial, healthy participants with full-mouth plaque score ≥ 60% were recruited. Quadrants in each participant were randomly assigned to four treatment groups: air polishing with prior plaque disclosure; air polishing without plaque disclosure; rubber cup polishing with prior plaque disclosure; or rubber cup polishing without plaque disclosure. Plaque scores and treatment time for each quadrant were recorded. Posttreatment satisfaction questionnaires for both the participants and operators were also completed. Results: In total, 88 participants consisting of 42 men and 46 women (mean age 23.1 ± 2.0 years) were recruited. Air polishing with prior plaque disclosure had significantly lower posttreatment marginal mean plaque score (21.7 ± 17.5%) compared to air polishing (33.5 ± 23.4%) or rubber cup polishing (34.5 ± 19.7%) without prior plaque disclosure (P < .001). Marginal mean treatment time for air polishing (325 seconds; SE = 10 seconds) was significantly shorter compared to rubber cup polishing (407 seconds; SE = 15 seconds) (P < .001). Both the participants and operators preferred air polishing over rubber cup polishing (P < .001). Conclusion: Prior plaque disclosure enhanced the effectiveness of plaque removal. Air polishing exhibited better treatment efficiency than rubber cup polishing and was the patients' and clinicians' preferred treatment modality.

Clinical and histological sequelae of surgical complications in horizontal guided bone regeneration: a systematic review and proposal for management.

It is not uncommon to encounter post-surgical complications after horizontal guided bone regeneration (GBR). The primary aim of this review was to evaluate the incidence and types of complications that occur after horizontal GBR and propose management strategies to deal with these clinical situations. A secondary aim was to conduct a histomorphometric review of the wound healing process at sites that experienced post-surgical complications after GBR. A keyword search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for studies published in English from January 2015 to January 2020 was conducted for the primary aim and 23 studies were selected. A second search addressing the secondary aim was conducted, and five studies were included. Site-level analysis showed that the weighted mean incidence proportion of minor wound dehiscence and minor infections occurring at the augmented site was 9.9% [95% CI 6.4, 13.9, P < 0.01] and 1.5% [95% CI 0.4, 3.1, P = 0.21) respectively. Patient-level analysis showed minor and major complications occurring at a weighted mean incidence proportion of 16.1% [95% CI 11.9, 20.8, P = 0.01] and 1.6% [95% CI 0.0, 4.7, P < 0.01] respectively, while neurosensory alterations at the donor site was 7.0% [95% CI 1.3, 15.5, P < 0.01]. Subgroup analysis also revealed that the use of block grafts increased the incidence proportion of minor post-surgical complications, whereas a staged GBR procedure increased the incidence proportion of both minor and major post-surgical complications. Although exposure of the barrier membrane is often associated with less bone regeneration and graft resorption, the type of membrane used (resorbable or non-resorbable) had no statistically significant influence on any post-surgical complication. Histologically, a layer of fibrous connective tissue instead of bone is commonly observed at the interface between the native bone at the recipient site and the regenerated bone in cases with membrane exposure after GBR procedure. Minor wound dehiscence was the highest incidence proportion of post-surgical complications. Methods ranging from daily application of antiseptics, use of systemic antimicrobials, regular reviews, and total removal of the non-integrated biomaterials are commonly prescribed to manage these post-surgical complications in attempt to minimise the loss of tissue at the surgical site.

Breaking the wave of peri-implantitis.

Peri-implant diseases are prevalent with a weighted mean prevalence rate of 43% across Europe and 22% across South and North America. Although the main etiologic agent is bacterial biofilm, a myriad of factors influence the initiation and progression of the disease. Unfortunately, the treatment of peri-implant diseases is at best favorable in the short term with a high rate of persistent inflammation and recurrence. Therefore, it is sensible to consider and control all potential factors that may predispose an implant to peri-implant tissue inflammation in an attempt to avoid the disease. This paper reviews recent evidence on factors that may predispose implants to peri-implantitis and measures that can be taken to prevent it.

Biotransformation of Piceatannol, a Dietary Resveratrol Derivative: Promises to Human Health.

SCOPE: To evaluate the health-promoting potentials of piceatannol (PIC), a dietary resveratrol derivative, its biotransformation is examined. METHODS AND RESULTS: The biotransformation is tested in human/rat hepatic microsomes and cytosols; its pharmacokinetic profiles are assessed in rats. Although limited phase I metabolism exists in microsomes, PIC is rapidly converted to two pharmacologically active metabolites, namely rhapontigenin (RHA) and isorhapontigenin (ISO) in cytosols. Such biotransformation is completely blocked by entacapone, a well-known catechol-O-methyltransferase (COMT) inhibitor, demonstrating that the O-methylation is mediated by COMT. Moreover, PIC is identified as a substrate inhibitor of COMT, suggesting its potential benefits in Alzheimer's disease. Due to extensive phase II metabolism including glucuronidation, sulfation, and O-methylation, PIC displays rapid clearance and at least 4.02% ± 0.61% and 17.70% ± 0.91% of PIC is converted to RHA and ISO, respectively, in rats after intravenous administration. Similarly, PIC serves as an effective precursor of ISO upon oral administration. CONCLUSION: Since PIC and its metabolites possess pleiotropic health-promoting activities, it has emerged as a promising nutraceutical candidate for further development. This study also reinforces the importance of in vivo testing in nutritional researches as the active metabolite(s) may be absent from the in vitro system.

Mesenchymal stem cell exosomes enhance periodontal ligament cell functions and promote periodontal regeneration.

Mesenchymal stem cells (MSCs) are potential therapeutics for the treatment of periodontal defects. It is increasingly accepted that MSCs mediate tissue repair through secretion of trophic factors, particularly exosomes. Here, we investigated the therapeutic effects of human MSC exosome-loaded collagen sponge for regeneration of surgically created periodontal intrabony defects in an immunocompetent rat model. We observed that relative to control rats, exosome-treated rats repaired the defects more efficiently with regeneration of periodontal tissues including newly-formed bone and periodontal ligament (PDL). We also observed that concomitant with this, there was increased cellular infiltration and proliferation. We therefore postulated that MSC exosomes enhanced regeneration through increased cellular mobilisation and proliferation. Using PDL cell cultures, we demonstrated that MSC exosomes could increase PDL cell migration and proliferation through CD73-mediated adenosine receptor activation of pro-survival AKT and ERK signalling. Inhibition of AKT or ERK phosphorylation suppressed PDL cell migration and proliferation. Our findings demonstrated for the first time that MSC exosomes enhance periodontal regeneration possibly by increasing PDL migration and proliferation. This study suggests that MSC exosome is a viable ready-to-use and cell-free MSC therapeutic for the treatment of periodontal defects. STATEMENT OF SIGNIFICANCE: Mesenchymal stem cell (MSC) therapies have demonstrated regenerative potential for the treatment of periodontal defects. However, translation of cellular therapies is hampered by challenges in maintaining optimal cell vitality and viability from manufacturing and storage to final delivery to patients. Although the use of MSCs for tissue repair was first predicated on their differentiation potential, the therapeutic efficacy of MSCs has increasingly been attributed to its paracrine secretion, particularly exosomes or small extracellular vesicles. In this study, MSC exosome-loaded collagen sponge enhanced periodontal regeneration in an immunocompetent rat periodontal defect model without any obvious adverse effects. These findings provide the basis for future development of MSC exosomes as a cell-free strategy for periodontal regeneration.

Effect of Deproteinized Bovine Bone Mineral at Implant Dehiscence Defects Grafted by the Sandwich Bone Augmentation Technique.

The aim of this study was to compare the amount of radiographic horizontal buccal bone thickness (BBT) at implant dehiscence defects grafted with the sandwich bone augmentation (SBA) and modified sandwich bone augmentation (MSBA) techniques. Compared to the SBA technique, the MSBA approach involved an additional outer layer of deproteinized bovine bone mineral (DBBM) to maintain the space for bone regeneration for longer periods. A total of 19 patients, each with a buccal implant dehiscence defect, were recruited. The control group was treated with SBA technique (n = 10), while the test group was treated with MSBA technique. Cone beam computed tomography (CBCT) scans, taken at three time points (before and immediately after implant surgery, and 6 months post-treatment) were used to assess the BBT at the implant platform (-1.8 mm), the rough-smooth junction (0 mm), and 2, 4, 6, 8, and 10 mm apical to the rough-smooth junction. At 6 months postsurgery, the mean BBT in control and test groups was 1.69 ± 0.38 mm and 2.55 ± 0.21 mm, respectively. Mean BBT was significantly greater in the test group at 2, 4, 6, and 8 mm apical to the rough-smooth junction. There was no statistical difference in the mean BBT at the implant platform, the rough-smooth junction, and 10 mm apical to the rough-smooth junction between the two groups (P > .05). Within the limitations of this study, it was concluded that the additional layer of DBBM enhanced BBT along the implant, except at the smooth collar.

Graft-Free Maxillary Sinus Floor Elevation: A Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis aims to investigate survival rates of dental implants placed simultaneously with graft-free maxillary sinus floor elevation (GFSFE). Factors influencing amount of vertical bone gain (VBG), protruded implant length (PIL) in sinus at follow-up (PILf), and peri-implant marginal bone loss (MBL) are also evaluated. METHODS: Electronic and manual searches for human clinical studies on simultaneous implant placement and GFSFE using the lateral window or transcrestal approach, published in the English language from January 1976 to March 2016, were conducted. The random-effects model and mixed-effect meta-regression were used to analyze weighted mean values of clinical parameters and evaluate factors that influenced amount of VBG. RESULTS: Of 740 studies, 22 clinical studies were included in this systematic review. A total of 864 implants were placed simultaneously with GFSFE at edentulous sites having mean residual bone height of 5.7 ± 1.7 mm. Mean implant survival rate (ISR) was 97.9% ± 0.02% (range: 93.5% to 100%). Weighted mean MBL was 0.91 ± 0.11 mm, and it was significantly associated with the postoperative follow-up period (r = 0.02; R2 = 43.75%). Weighted mean VBG was 3.8 ± 0.34 mm, and this parameter was affected significantly by surgical approach, implant length, and PIL immediately after surgery (PILi) (r = 2.82, 0.57, 0.80; R2 = 19.10%, 39.27%, 83.92%, respectively). Weighted mean PILf was 1.26 ± 0.33 mm (range: 0.3 to 2.1 mm). CONCLUSION: Within limitations of the present systematic review, GFSFE with simultaneous implant placement can achieve satisfactory mean ISR of 97.9% ± 0.02%.

Can Periimplantitis Be Treated?

Over the past few decades, dental implants have been found to have high predictability and survival rates because of improvements in knowledge, clinical expertise, and implant designs. As such, dental implants are frequently integrated in the clinical management of fully or partially edentulous patients. It is prudent to realize that despite the high early survival rates, dental implants do have their fair share of long-term esthetic, biological, and mechanical complications. Therefore, this paper aims to review the current evidence on the management of peri-implant diseases in an attempt to answer the following question: Can periimplantitis be treated?

Surgical Site Assessment for Soft Tissue Management in Ridge Augmentation Procedures.

The success of bone augmentation is usually dependent on primary wound closure. This review provides a literature-based system to assess the predictability of achieving primary wound closure. Seven pertinent factors that determine the risk for wound exposure were identified: (1) the width of keratinized mucosa, (2) flap thickness, (3) flap tension, (4) vestibular depth, (5) type and (6) size of the bony defect, and (7) materials used. Clinical cases are used to demonstrate evaluation of these factors. This evaluation system may aid clinicians in differentiating cases with various risks of wound exposure and making decisions on flap modifications and the most appropriate surgical designs.

The Effect of Vertical Implant Position in Relation to Adjacent Teeth on Marginal Bone Loss in Posterior Arches: A Retrospective Study.

PURPOSE: The aim of this retrospective study was to investigate the possible association between peri-implant marginal bone loss and the apicocoronal (vertical) positioning of dental implants placed adjacent to a tooth. MATERIALS AND METHODS: Dental records at the University of Michigan, School of Dentistry, were screened. To be included in the study, the patient had to have at least one implant in the premolar or molar region, unilaterally or bilaterally, in either arch, with an immediately mesial adjacent tooth. The implant had to have been functionally loaded for at least 3 years after crown insertion, and clear, nondistorted periapical films had to be available. Several landmarks were identified: the cementoenamel junction (CEJ) and crestal bone (CB) of the tooth adjacent to the implant, the implant platform (PL), and the first radiographic implant-bone contact (BL). The following parameters were measured: CEJ-PL, CEJ-CB, CB-PL, horizontal distance between the adjacent tooth and PL (HD), and vertical distance between BL and the first implant thread at the mesial (BL-m) and distal (BL-d) implant surfaces. RESULTS: A total of 139 patients with a mean age of 62.1 ± 9.3 years were included. The mean follow-up period was 4.42 ± 2.5 years. When the implant was placed more than 3 mm apical to the CEJ of the adjacent tooth, significantly greater peri-implant bone loss occurred at the mesial (difference of means = 0.57 mm) and distal (difference of means = 0.83 mm) implant surfaces. CONCLUSION: In this study population, implants placed in the posterior area with a vertical distance greater than 3 mm from the CEJ of the adjacent tooth displayed more peri-implant bone loss. Further investigation is required to determine whether this increased peri-implant bone loss predisposes a site to peri-implantitis.

A randomized clinical trial evaluating the efficacy of the sandwich bone augmentation technique in increasing buccal bone thickness during implant placement. II. Tomographic, histologic, immunohistochemical, and RNA analyses.

OBJECTIVES: This study aimed to evaluate the biologic and structural phenotypes of the bone regenerated via the sandwich bone augmentation (SBA) technique, on buccal implant dehiscence defects. MATERIAL AND METHODS: Twenty-six patients with one buccal implant dehiscence defect each were randomly assigned to two groups. Both groups received a standardized amount of mineralized cancellous and cortical allogenic bone graft. In the test group, a bovine pericardium membrane was placed over the graft, while no membrane was placed in the control group. After 6 months of healing, a bone core biopsy of the regenerated bone was harvested and processed for histologic, immunohistochemical, mRNA, and micro-computed tomography (µCT) analyses. Of the 26 bone core biopsies, only six cores from the test group and six cores from the control group were suitable for the analysis. RESULTS: Bone volume (BV) in the test group was maintained, but tissue maturation appeared to be delayed. In contrast, tissue maturation appeared to be completed in the control group, but BV was compromised. Micro-CT analysis showed that specimens from the control group were more structured and mineralized compared with those from the test group. Histologic analysis showed more residual graft particles scattered in a loose fibrous connective tissue matrix with sparse bone formation in the test group, while the control group showed obvious vital bone formation surrounding the residual graft particles. Positive periostin (POSTN), sclerostin, and runt-related transcription factor-2 (RUNX2) immunoreactivities were detected in both the control and test groups. However, tartrate-resistant acid phosphatase (TRAP) positive was mostly noted in the control group. There were significant differences in POSTN, RUNX2 and VEGF expressions between the test and control groups. CONCLUSION: These findings indicated that the SBA technique was an effective method in preserving adequate structural volume while promoting new vital bone formation. Use of the collagen barrier membrane has successfully maintained the volumetric dimensions of the ridge but might have slowed down the complete maturation of the outermost layer of the grafted site.

Using Cone Beam Computed Tomography Angle for Predicting the Outcome of Horizontal Bone Augmentation.

BACKGROUND: The aim of this study was to assess the influence of ridge morphology on the amount of horizontal bone augmentation achieved with the sandwich bone augmentation (SBA) technique in the reconstruction of buccal dehiscence defects on dental implants. METHODS: Cone beam computed tomography (CBCT) was used to assess bone width changes in 26 patients who participated in a randomized controlled trial conducted in 2008 to 2011. The amount of horizontal bone gain was evaluated at four different levels (3, 6, 9, and 12 mm apical to the alveolar crest) and three different time points (T1: baseline, T2: at time of graft placement, and T3: 6 months later). Different morphological characteristics of the alveolar ridge were also evaluated to determine their influence on horizontal bone augmentation. A total of 78 CBCT scans were assessed. RESULTS: Comparison of the changes in ridge morphology at all measurement locations showed an overall ridge width gain of 2.30 ± 2.20 mm after 6 months. The use of membranes and the angulation of the concavity played a role in influencing the outcomes of the SBA technique. Critical crest angulation (CA) is 150° for bone gain at 9 mm apical to the crest. When CA is smaller than 150°, the horizontal bone gain was 4.3 ± 2.2 mm; if CA is greater than 150°, the gain was significantly lower at 1.3 ± 1.7 mm (p = .001). CONCLUSIONS: SBA is a reliable and predictable technique to gain horizontal ridge width with simultaneous implant placement. Crest ridge angulation can be used as a tool to predict bone gain at 9 mm apical to the bone crest.

Implant survival rate and marginal bone loss of 6-mm short implants: a 2-year clinical report.

PURPOSE: This study aimed to evaluate (1) the association between implant diameter and marginal bone loss (MBL) of short (6 mm) implants and (2) the survival rates of short implants. MATERIALS AND METHODS: Thirty-three 6-mm implants were placed in the mandibles of 16 qualified patients. The selected sites had > 5 mm ridge width and < 9 mm bone height. None of the implant sites required bone augmentation procedures. All implants were uncovered 3 months after placement, and all patients were rehabilitated with 2- or 3-unit implant-supported fixed partial dentures. Standardized periapical films were taken after 24 months of function. Radiographs were digitalized, and MBL was assessed. RESULTS: For all implants, the mean MBL was 0.17 mm at the point of uncovering. At the 2-year follow-up, all implants were immobile and functional. Implants with 4.2-mm diameters had significantly more MBL (1.95 mm) than wider implants (0.47 mm and 0.35 mm for 5.0-mm and 6.0-mm implants, respectively). CONCLUSION: This 2-year study illustrated that short implants are a viable option in selected clinical scenarios. Short implants with wider diameters are preferred because they have less marginal implant bone loss.

A randomized clinical trial evaluating the efficacy of the sandwich bone augmentation technique in increasing buccal bone thickness during implant placement surgery: I. Clinical and radiographic parameters.

OBJECTIVES: Sandwich bone augmentation (SBA) has been proposed to augment the width of edentulous ridges for implant placement. This study aimed to investigate the effect of a membrane on SBA for the regeneration of buccal implant dehiscence defects. MATERIAL AND METHODS: Twenty-six healthy patients, each with a single defect, were randomly assigned into two groups. Both groups received an inner and outer layer of mineralized human cancellous and cortical particulate allograft. In the test group, a bovine pericardium membrane covered the bone grafts, while no membrane was placed in the control group. Cone beam computed tomography (CBCT) scans were taken before and immediately after implant placement and at 6 months post-surgery. RESULTS: All implants placed were successfully osseointegrated at 6 months. Clinical re-entry measurements showed significant buccal bone gain in the test group compared with the control group (P < 0.05). The test group had 1.12, 2.21 and 2.44 mm more buccal bone thickness at 2, 4 and 6 mm below the bone crest. There were no significant differences in the mid-buccal vertical bone height, defect height and width reductions and bone fill between the two groups (P > 0.05). Cone beam computed tomography analysis demonstrated significant buccal bone gain of 1.22 mm in the test group. Radiographic vertical bone loss at 1-year post-surgery showed no significant differences between the groups. CONCLUSION: Sandwich bone augmentation is a predictable technique for regenerating buccal bone on implant dehiscence defects. Addition of a barrier membrane prevented significant horizontal buccal bone resorption as space was maintained more effectively when compared with sites treated without a membrane.

A systematic review on marginal bone loss around short dental implants (<10 mm) for implant-supported fixed prostheses.

PURPOSE: This systematic review aimed to evaluate the effect of implant length on peri-implant marginal bone loss (MBL) and its associated influencing factors. MATERIAL AND METHODS: An electronic search of the PubMed and MEDLINE databases for relevant studies published in English from November 2006 to July 2012 was performed by one examiner (AM). Selected studies were randomized clinical trials, human experimental clinical trials or prospective studies (e.g., cohort as well as case series) with a clear aim of investigating marginal bone loss of short dental implants (<10 mm) supporting fixed prostheses. A random-effect meta-regression model was used to determine the relationship between the effect size mean MBL and the covariate "implant length." Additionally, a subgroup analysis, by means of a random-effect one-way ANOVA model, comparing mean MBL values at different levels of each factor ("type of connection" and "type of prostheses") was also performed. RESULTS: The meta-regression of mean MBL on the moderator "implant length" was found to be insignificant (P = 0.633). Therefore, it could not be concluded that implant length had an effect on peri-implant MBL. In addition, standardized differences in mean MBL on the subgroups short (<10 mm) and standard (≥ 10 mm) implants, as determined by the meta-analysis (random-effect model), were found to be statistically insignificant (P = 0.222). CONCLUSIONS: Within limitations of the present systematic review, it could be concluded that short dental implants (<10 mm) had similar peri-implant MBL as standard implants (≥ 10 mm) for implant-supported fixed prostheses.

Impact of implantoplasty on strength of the implant-abutment complex.

PURPOSE: Implantoplasty, a procedure that is done to smooth contaminated implant surfaces, has been used in the treatment of peri-implantitis. It reduces the implant diameter, which might compromise the implant's strength. This in vitro study was designed to evaluate the effect of implantoplasty on implant strength. MATERIALS AND METHODS: Thirty-two tapered implants were used; half were 3.75 mm in diameter (narrow) and the other half were 4.7 mm in diameter (wide). All implants were connected to 20-degree angled abutments. The apical half of each implant was embedded in acrylic resin. Eight 3.75-mm- and eight 4.7-mm-diameter implants were randomly assigned to receive implantoplasty. The remaining implants did not receive implantoplasty (control group). Implantoplasty was performed with a series of diamond and polishing burs. The specimens were then loaded 30 degrees off-axis in a universal testing machine until fracture failure occurred. Bending and fracture strength values were recorded and analyzed statistically (α = .05). The fractured surfaces were evaluated under a scanning electron microscope. RESULTS: All narrow implants failed by fracture at the implant platform. The mean bending strength of narrow implants was statistically significantly reduced by implantoplasty (511.4 ± 55.9 N versus 613.9 ± 42.8 N). Implantoplasty did not affect the strength of wide implants; fracture failures occurred at the abutment screw. The fracture mode was ductile and the crack growth was oblique in direction, indicating complex stress distribution and concentration under loading. CONCLUSION: Within the limits of this study, implantoplasty appeared to weaken the strength of narrower implants. Therefore, this procedure should be performed with caution on narrower, freestanding implants that are subject to greater occlusal force (eg, posterior regions). Validation of these results is needed for different implant systems.

Ridge width gain with screw spreaders: a cadaver study.

BACKGROUND: The aim of this cadaver study was to evaluate the amount of ridge expansion with screw spreaders. METHODS: Eleven edentulous maxillae providing 20 eligible sites were used. Ridges with initial width of 3 to 6 mm were expanded using a set of 6 screw spreaders, and implants (ø3.7 × 10 mm) were subsequently placed. Ridge width at 2 mm apical to the crest was measured at the baseline, after expansion, and implant placement. Buccal plate thickness and incidence of buccal dehiscence after implant placement were measured. RESULTS: The mean initial ridge width was 3.97 ± 0.82 mm. After the expansion, the mean ridge width increased to 4.76 ± 0.77 mm (Δ = 0.79 mm). Majority of sites (7/9 sites) with an initial ridge width of <4 mm had a buccal dehiscence after implant placement. A buccal plate thickness of ≥1 mm was consistently present in cases with an initial ridge width of ≥4.5 mm after implant placement. CONCLUSIONS: The screw spreaders had a modest effect on ridge expansion. Their use might be limited because additional bone augmentation might be required to prevent or correct the bony dehiscence encountered in ridges <4.5 mm wide. Therefore, using this particular instrument kit for horizontal ridge augmentation is only indicated in specific cases.

Alterations in bone quality after socket preservation with grafting materials: a systematic review.

PURPOSE: While the ability of various grafting materials to preserve extraction socket morphology has been adequately reviewed, the quality of the grafted bone in the socket is not as well understood. This systematic review aimed to compare the proportion of vital bone and connective tissue between grafted and naturally healed sockets. MATERIALS AND METHODS: An electronic search of five databases (from 1965 to November 2011) and a hand search of peer-reviewed journals for relevant articles were performed. Human clinical trials that compared histologic components of soft and hard tissues in augmented sockets and naturally healed sites, with at least five samples per group, were included. RESULTS: Eight studies (five randomized controlled trials and three controlled clinical trials) were included. The mean percentages of vital bone and connective tissue in natural healing sockets were 38.5% ± 13.4% and 58.3% ± 10.6%, respectively. Limited evidence (one to two articles for each material) implied that vital bone fraction was not different with demineralized allografts and autografts and increased by 6.2% to 23.5% with alloplasts in comparison to nongrafted sites. Four studies investigating the effect of xenografts were available, with equivocal results. The difference in the mean percentage of vital bone ranged from -22.2% (decrease) to 9.8% (increase). Connective tissue content decreased with the use of the aforementioned bone substitutes. Considerable residual hydroxyapatite and xenograft particles (15% to 36%) remained at a mean of 5.6 months after socket augmentation procedures. CONCLUSIONS: Based on a limited number of prospective comparative studies, the use of grafting materials for socket augmentation might change the proportion of vital bone in comparison to sockets allowed to heal without grafting. Whether these changes in bone quality will influence implant success and peri-implant tissue stability remains unknown.

Reliability of volumetric imaging software for cone-beam computed tomogram scans in the anterior maxilla.

PURPOSE: This study aimed to compare buccal bone thickness in the maxillary anterior region provided by cone-beam computed tomography scans of cadaveric specimens using 2 different volumetric imaging software. METHODS: Cone-beam computed tomography scans of the maxilla of 15 cadaver heads were obtained from a database at the School of Dentistry, University of Michigan. Buccal bone thickness of the right and left maxillary canines and lateral and central incisors was measured at 2.0 mm below the crestal bone margin using 2 different volumetric software. RESULTS: A tooth-by-tooth comparison revealed strong correlation between measurements from the 2 software for the right canine (r = 0.859), lateral incisor (r = 0.817), and left lateral incisor (r = 0.933). When comparing tooth groups, there was a moderate correlation for central incisors (r = 0.635) and a strong correlation for canines (r = 0.820) and lateral incisors (r = 0.863). Measurements from both software were strongly correlated (r = 0.807) with 95.56% of the measurements in agreement. CONCLUSIONS: Measurements from 2 different volumetric imaging software were in agreement and either software can be used in analyzing soft and hard tissue volumes.