Clinical Outcomes of Metal-Ceramic versus Metal-Acrylic Resin Implant-Supported Fixed Complete Dental Prostheses: A Systematic Review and Meta-analysis.

PURPOSE: To compare the clinical outcomes of metal-ceramic vs metal-acrylic resin implant-supported fixed complete denture prostheses (IFCDPs). MATERIALS AND METHODS: An electronic literature database search was conducted in the CINAHL, EMBASE, PubMed, and Web of Science databases. Additionally, a manual search of the literature was performed. Studies conducted in edentulous human subjects comparing clinical outcomes of metal-acrylic resin IFCDPs to those of metal-ceramic IFCDPs were included if quantitative outcomes for the following variables were reported: implant failure, prosthetic failure, incidence of peri-implantitis, incidence of peri-implant mucositis, incidence of peri-implant mucosal recession, prosthetic complications, and any patient-centered outcomes. Data from included studies were pooled to estimate effect size. RESULTS: Five studies met the inclusion criteria. A quantitative analysis was possible for risk of implant failure, prosthesis failure, and incidence of peri-implantitis. Meta-analysis showed no statistically significant differences in the risk of implant or prosthesis failure between the two groups. However, meta-analysis showed a significantly greater risk of developing peri-implantitis at the implant level in the metal-acrylic group when compared to the metal-ceramic group (risk difference = 0.069; 95% CI = 0.028 to 0.06; P = .001; fixed-effects model). Furthermore, descriptive analysis of the literature indicated a higher incidence of other biologic complications such as peri-implant mucositis and peri-implant mucosal recession, as well as prosthetic complications such as abrasion and veneer fracture, in metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs. CONCLUSION: The available evidence suggests that a higher incidence of biologic and prosthetic complications, including a higher risk of peri-implantitis, are present with metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs.

Peri-Implantitis and Peri-Implant Mucositis Case Definitions in Dental Research: A Systematic Assessment.

The aim of this review was to determine the most common peri-implant mucositis and peri-implantitis case definitions used worldwide in the implant dentistry literature. A systematic assessment of peri-implant disease classification was conducted using all publications in MEDLINE, EMBASE, SCOPUS, and Google Scholar between 1994 and November 2017. Screening of eligible studies and data extraction were conducted in duplicate and independently by 2 reviewers. The search protocol identified 3049 unique articles, of which 2784 were excluded based on title and abstract. In total, 265 full texts were screened, 106 of which met the eligibility criteria. Of these, 41 defined peri-implant mucositis. Eight (19.6%) used bleeding on probing (BOP) only; 8 (19.6.7%) used a combination of probing depth (PD), BOP, and radiograph; and 5 (12.3%) used PD and BOP. Cases with crestal bone loss of ≤2 mm in the first year and ≤0.2 mm in each subsequent year were considered as peri-implant mucositis. Ninety-three articles defined peri-implantitis; 28 (30.1%) used a combination of PD with suppuration, BOP, and radiograph, followed by 25 (26.9%) using a combination of PD, BOP, and radiograph. The main criteria in most of the studies were considered to be BOP, PD, and radiograph. Cases of crestal bone loss of ≥2 mm and PD ≥3 mm are considered peri-implantitis. Different peri-implant disease case definitions may affect disease prevalence and treatment strategies. We need to standardize case definitions to avoid discrepancies in case diagnosis and prognosis.

Enhanced Lateral Bone Augmentation With a Perforated Resorbable Barrier Membrane.

INTRODUCTION: To the best of the authors' knowledge, this is the first case report to describe the use of a perforated resorbable barrier membrane (PRBM) to enhance lateral bone augmentation for implant site development. CASE PRESENTATION: A 41-year-old female presented to the Advanced Specialty Education Program in Periodontics at Stony Brook University, Stony Brook, New York, for implant consultation regarding a missing maxillary right lateral incisor. The tooth had been lost as a result of trauma 10 years prior to presentation. Clinical examination and radiographs showed significant horizontal ridge deficiency (<5 mm) that supported a staged intervention. Horizontal bone augmentation was performed following guided bone regeneration principles using a mineralized mixed corticocancellous (70:30) allograft followed by a PRBM. A cone beam computed tomography scan was obtained before surgery and 8 months after treatment, from which volumetric width changes were quantified. A bone biopsy was obtained at the time of implant placement to measure new vital bone (NVB) formation, residual graft (RG) particles, and connective tissue (CT) formation. Dimensional width changes were assessed during reentry for implant placement. The lateral bone gain was 5.0 mm, clinically and radiographically. Histologically, the amount of NVB formation, RG particles, and CT infiltration was 38.1%, 38.9%, and 23.1%, respectively. Implant placement was uneventful, with no further need for bone augmentation. CONCLUSIONS: Previous studies using similar techniques and regenerative materials have shown an average of 3.5 mm of horizontal bone augmentation. The use of a PRBM appeared to significantly enhance lateral bone augmentation. An ongoing clinical trial is underway to confirm these results.

A Novel Treatment Decision Tree and Literature Review of Retrograde Peri-Implantitis.

BACKGROUND: Although retrograde peri-implantitis (RPI) is not a common sequela of dental implant surgery, its prevalence has been reported in the literature to be 0.26%. Incidence of RPI is reported to increase to 7.8% when teeth adjacent to the implant site have a previous history of root canal therapy, and it is correlated with distance between implant and adjacent tooth and/or with time from endodontic treatment of adjacent tooth to implant placement. Minimum 2 mm space between implant and adjacent tooth is needed to decrease incidence of apical RPI, with minimum 4 weeks between completion of endodontic treatment and actual implant placement. The purpose of this study is to compile all available treatment modalities and to provide a decision tree as a general guide for clinicians to aid in diagnosis and treatment of RPI. METHODS: Literature search was performed for articles published in English on the topic of RPI. Articles selected were case reports with study populations ranging from 1 to 32 patients. Any case report or clinical trial that attempted to treat or rescue an implant diagnosed with RPI was included. RESULTS: Predominant diagnostic presentation of a lesion was presence of sinus tract at buccal or facial abscess of apical portion of implant, and subsequent periapical radiographs taken demonstrated a radiolucent lesion. On the basis of case reports analyzed, RPI was diagnosed between 1 week and 4 years after implant placement. Twelve of 20 studies reported that RPI lesions were diagnosed within 6 months after implant placement. A step-by-step decision tree is provided to allow clinicians to triage and properly manage cases of RPI on the basis of recommendations and successful treatments provided in analyzed case reports. It is divided between symptomatic and asymptomatic implants and adjacent teeth with vital and necrotic pulps. CONCLUSIONS: Most common etiology of apical RPI is endodontic infection from neighboring teeth, which was diagnosed within 6 months after implant placement. Most common findings, radiographically and clinically, are lesions around implant apex and sinus tract. A small number of implants did not improve with treatment. Decision tree provides a path to diagnose and treat lesions to facilitate their management. Further studies are needed to focus on histologic data around periapical microbiota to establish specific etiology and differential diagnoses compared with marginal peri-implantitis and other implant-related conditions.

Retrieval of Displaced Implant Attributable to an Ill-Fitting Denture From the Maxillary Sinus Six Months After Transcrestal Sinus Floor Augmentation and Implant Placement.

INTRODUCTION: Asymptomatic displacement of dental implants into the maxillary sinus after a transcrestal sinus augmentation is a rare complication that can occur when there is poor bone quality and minimal residual bone height. Patient compliance with postoperative appointments and failure to comply with denture-wearing instructions are critical contributing factors. To the best of the authors' knowledge, no cases of implant dislodgement attributable to a removable prosthesis have been reported in the literature, although some studies have suggested that improper occlusal forces can cause a long-standing implant to develop peri-implantitis and subsequent displacement of an implant into the sinus cavity. CASE PRESENTATION: A 71-year-old female presented 6 months after undergoing transcrestal sinus lift and implant surgery that involved a modified Summers technique using mineralized solvent-dehydrated cancellous bone allograft and placement of six maxillary implants. A displaced dental implant was retrieved from the right maxillary sinus, which had an intact Schneiderian membrane. The patient was asymptomatic and infection free. The displaced implant was accessed and retrieved via a lateral window sinus technique. No clinical signs of sinus infection were evident, and there were no additional complications during the 2-year follow-up period. CONCLUSION: This case report demonstrates a technique for the retrieval of implants that have been dislodged and migrated into the maxillary sinus cavity caused by an ill-fitting denture and improper masticatory forces.

Gingival crevicular fluid bone morphogenetic protein-2 release profile following the use of modified perforated membrane barriers in localized intrabony defects: a randomized clinical trial.

BACKGROUND: In guided tissue regenerative surgery, membrane perforations may serve as a mechanism for the passage of cells and biologic mediators from the periosteum and overlying gingival connective tissue into the periodontal defects. To test this assumption, this study was designed to evaluate levels of bone morphogenetic protein-2 (BMP-2) in gingival crevicular fluid (GCF) during the early stages of healing for sites treated with modified perforated membranes (MPMs) as compared with occlusive membranes (OMs). METHODS: Fifteen non-smoking patients with severe chronic periodontitis participated in this prospective, randomized and single-blinded clinical trial. Each patient contributed two interproximal contralateral defects that were randomly assigned to either an experimental modified perforated membrane group (15 sites) or a control occlusive membrane group (15 sites). Plaque index, gingival index, probing depth(PD), clinical attachment level (CAL) and the relative intrabony depth of the defect (rIBD) were measured at baseline and reassessed at three, six and nine months after therapy. Gingival crevicular fluid samples were collected on day 1 and 3, 7, 14, 21, and 30 days after therapy. RESULTS: The MPM-treated group showed a statistically significant improvement in PD reduction and clinical attachment gain compared to the OM control group. Similarly, rIBD was significantly reduced in MPM-treated sites as compared with those of the OM group. BMP-2 concentrations peaked in the MPM samples obtained during the early postoperative period (days 1, 3 and 7) with a statistically significant difference compared with OM-treated groups. BMP-2 levels decreased sharply in the samples obtained at days 14, 21 and 30 with non-significant higher levels in MPM samples as compared with those of OM sites. CONCLUSION: Within the limits of the present study, one can conclude that MPM coverage of periodontal defects is associated with a significant initial increase in GCF levels of BMP-2, a factor that could improve the clinical outcomes of guided tissue regenerative surgery.

Mixed nano/micro-sized calcium phosphate composite and EDTA root surface etching improve availability of graft material in intrabony defects: an in vivo scanning electron microscopy evaluation.

BACKGROUND: The use of nanoparticles of graft materials may lead to breakthrough applications for periodontal regeneration. However, due to their small particle size, nanoparticles may be eliminated from periodontal defects by phagocytosis. In an attempt to improve nanoparticle retention in periodontal defects, the present in vivo study uses scanning electron microscopy (SEM) to evaluate the potential of micrograft particles of ß-tricalcium phosphate (ß-TCP) to enhance the binding and retention of nanoparticles of hydroxyapatite (nHA) on EDTA-treated and non-treated root surfaces in periodontal defects after 14 days of healing. METHODS: Sixty patients having at least two hopeless periodontally affected teeth designated for extraction were randomly divided into four treatment groups (15 patients per group). Patients in group 1 had selected periodontal intrabony defects grafted with nHA of particle size 10 to 100 nm. Patients in group 2 were treated in a similar manner but had the affected roots etched for 2 minutes with a neutral 24% EDTA gel before grafting of the associated vertical defects with nHA. Patients in group 3 had the selected intrabony defects grafted with a composite graft consisting of equal volumes of nHA and ß-TCP (particle size 63 to 150 nm). Patients in group 4 were treated as in group 3 but the affected roots were etched with neutral 24% EDTA as in group 2. For each of the four groups, one tooth was extracted immediately, and the second tooth was extracted after 14 days of healing for SEM evaluation. RESULTS: Fourteen days after surgery, all group 1 samples were devoid of any nanoparticles adherent to the root surfaces. Group 2 showed root surface areas 44.7% covered by a single layer of clot-blended grafted particles 14 days following graft application. After 14 days, group 3 samples appeared to retain fibrin strands devoid of grafted particles. Immediately extracted root samples of group 4 had adherent graft particles that covered a considerable area of the root surfaces (88.6%). Grafted particles appeared to cover all samples in a multilayered pattern. After 14 days, the group 4 extracted samples showed multilayered fibrin-covered nano/micro-sized graft particles adherent to the root surfaces (78.5%). CONCLUSION: The use of a composite graft consisting of nHA and microsized ß-TCP after root surface treatment with 24% EDTA may be a suitable method to improve nHA retention in periodontal defects with subsequent graft bioreactivity.

Enhancing guided tissue regeneration of periodontal defects by using a novel perforated barrier membrane.

BACKGROUND: The present study was designed to determine whether exclusion of the gingival connective tissue (CT) and periosteum with contained stem cells has a positive or negative effect on periodontal regeneration by comparing the use of a novel modified perforated collagen membrane with a traditional cell occlusive barrier membrane. METHODS: Twenty non-smoking patients with severe chronic periodontitis were included in the study. Single deep intrabony defects from each of the patients were randomly divided into two groups, as follows: occlusive bovine collagen membranes (OM control group, 10 sites) and modified perforated bovine collagen membranes (MPM test group, 10 sites). Plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), defect base level (DBL), and crestal bone level (CBL) were measured at baseline and were reassessed at 6 and 9 months after therapy to evaluate the quantitative changes in the defect. RESULTS: At 6- and 9-month observation periods, the MPM-treated sites showed a statistically significant improvement in PD reduction and CAL gain compared with the OM control group. DBL was significantly reduced with no significant difference between the two groups at 6- and 9-month observation periods. CBL was significantly higher in the MPM group when compared with that of the OM group at both observation periods. The postoperative differences between the two groups were 2 and 1.7 mm at 6 and 9 months, respectively, in favor of the MPM-treated sites. CONCLUSIONS: The present study demonstrated enhanced clinical outcomes when using novel MPMs compared to OMs in guided tissue regeneration procedures. These results may be affected by the penetration of gingival CT contained stem cells and periosteal cells and their differentiation into components of the attachment apparatus.

Bisphosphonates: case report of nonsurgical periodontal therapy and osteochemonecrosis.

The risk of developing osteochemonecrosis is increased in patients who are taking bisphosphonate drugs and must undergo extractions or other dental surgery. Because of the difficulty in predicting and preventing osteochemonecrosis and in managing patients after it has occurred, avoidance of surgery has been advised. This paper reports on the development of this complication in a patient who received nonsurgical periodontal treatment. Although it is believed that the risk of developing this severely debilitating complication is low when treating patients nonsurgically, practitioners must be able to recognize and understand the presentation and difficulties in managing osteochemonecrosis, even when only nonsurgical therapy is performed.

Effects of enamel matrix derivative on Porphyromonas gingivalis.

BACKGROUND: Enamel matrix derivative (EMD) is used during periodontal surgery for the regeneration of periodontal tissue. It consists of the amelogenin fraction of porcine enamel matrix (AMEL) suspended in a vehicle of propylene glycol alginate (PGA). EMD-treated sites appear to heal with less inflammation. It has been suggested that antimicrobial properties of EMD might account for improved healing in vivo. The objectives of this study were: 1) to determine the antibacterial effects of EMD on the periodontal pathogen Porphyromonas gingivalis and 2) to establish the component(s) of EMD that are responsible for this effect. METHODS: The antimicrobial effects were determined in vitro using the broth dilution assay. P. gingivalis at a starting inoculum of 10(9) colony forming units/ml was treated with EMD, AMEL, and PGA in Hank's balanced salt solution (HBSS) for 1, 3, and 24 hours. The CFU/ml of P. gingivalis recovered on enriched Brucella blood agar was determined at 6 and 10 days. RESULTS: EMD (containing AMEL and PGA) or PGA alone eliminated recoverable CFUs of P. gingivalis. Interestingly, AMEL in HBSS increased recoverable CFUs from 8.62 log CFU/ml to 8.93 log CFU/ml. Further analysis of the dose response at concentrations of 0.3, 3, and 30 mg/ml of AMEL in HBSS revealed that only 30 mg/ml (clinical concentration) increased CFUs of P. gingivalis relative to baseline (from 8.8 log CFU/ml to 9.2 log CFU/ml in 3 hours). Additionally, AMEL was compared to a protein control bovine serum albumin (BSA) to determine whether this effect was unique to AMEL. A marked increase in recoverable CFUs occurred with the AMEL (increasing from 8.8 log CFU/ml to 9.47 log CFU/ml), but not with BSA. CONCLUSIONS: EMD possesses antimicrobial properties that can be attributed to the propylene glycol alginate vehicle. The amelogenin fraction of porcine enamel matrix in enamel matrix derivative (i.e., AMEL) is not antibacterial for P. gingivalis and was shown to increase recoverable CFUs.