International Journal of Periodontics & Restorative Dentistry, 05/2011

The aims of this article were to perform a detailed evaluation of the healing of extraction sockets covered with a resorbable collagen membrane 12 weeks following exodontia and to determine if this device had ossifying properties. Ten consecutive subjects in need of extraction of maxillary premolars were recruited. Each subject had a hopeless maxillary premolar extracted with minimal trauma. Sockets were then covered with a collagen barrier membrane alone. At 12 weeks, reentry surgery was performed, clinical measurements were repeated, and bone core biopsies were obtained prior to dental implant placement for histologic and microcomputed tomography (micro-CT) analysis. Study sites showed mean bone regeneration horizontally of 7.7 mm (buccopalatally) and 4.6 mm (mesiodistally). Vertical bone repair showed a mean gain of 10.9 mm. Subtraction radiography showed a mean apical shift of the crestal bone at the center of the socket of 2.1 mm (range, 0.7 to 4.3 mm). Micro-CT and histology revealed formation of well-mineralized tissue at 12 weeks, with a mean percentage of vital bone of 45.87% ± 12.35%. No signs of membrane ossification were observed. A detailed analysis of tissue neogenesis in extraction sites protected by this barrier membrane has demonstrated that adequate bone formation for implant placement occurs as early as 12 weeks following exodontia, with minimal changes in alveolar ridge dimensions. No evidence of membrane ossification was observed.

Comparing tooth loss for populations comprising subjects with periodontal disease has been limited by broad and different definitions of disease severity. Numeric scores for periodontal disease severity and risk were used to enhance the precision of comparing tooth loss for two populations. Both populations received routine dental care, but only one received comprehensive periodontal treatment. The analysis provides evidence that adding periodontal treatment to routine dental care is associated with less tooth loss and more patients who do not lose any teeth. Furthermore, it may be possible to nearly eliminate tooth loss associated with periodontal disease.

The objective of this study was to assess the osseous healing of buccal plate extraction socket defects. There were four cohorts: group A (mineral collagen bone substitute [MCBS] scaffold alone), group B (MCBS with recombinant human platelet-derived growth factor BB [rhPDGF-BB; 0.3 mg/mL]), group C (MCBS with enamel matrix derivative [EMD]), and group D (combination of EMD with bone ceramic). The primary outcome of bone quality was evaluated using light microscopy, backscatter scanning electron microscopy, and histomorphometrics. Reentry surgery provided an opportunity for clinical observation of the healed ridge morphology. Sixteen patients with buccal wall extraction socket defects were randomized into four treatment groups of equal size. Grafting was provided at the time of extraction with advancement of the buccal flap for primary closure. A trephine core biopsy of the implant site preparation was performed after 5 months for implant placement. Histologic examination identified new bone healing around the biomaterial scaffolds. Statistically significant differences in new bone formation were not observed among the treatment groups. There was a histomorphometric trend toward more new bone for the rhPDGF-BB-treated group (group B). This group had the most favorable ridge morphology for optimal implant placement.

Crown width/length ratios have been considered an important aspect in the esthetic zone. Because previous investigations focused on Caucasian populations, limited information is available on other ethnic groups to propose a comprehensive approach to anterior maxillary teeth. The purpose of this study was to analyze the dimensions of anatomical crowns of maxillary anterior tooth groups with respect to width, length, and width/length ratios among an Asian population. The tooth dimensions presented in this investigation may serve as guidelines for treatment planning in restorative dentistry and periodontal surgery for this particular ethnic group.

One of the crucial factors in the success of guided bone regeneration procedures is the correct management of the soft tissues. This allows for stable primary wound closure without tension, which can result in premature exposure of the augmentation area, jeopardizing the final outcome. The use of vertical and periosteal incisions to passivate buccal and lingual flaps in the posterior mandible is often limited by anatomical factors. This paper reports on a series of 69 consecutive cases introducing a novel surgical technique to release and advance the lingual flap coronally in a safe and predictable manner.

The aim of this research was to verify clinically and histologically whether an excessively large horizontal and vertical gap distance of an implant placed into an immediate extraction socket would osseointegrate coronally at the implantsocket interface without primary flap closure, a bone graft, or a barrier membrane. An immediate implant and straight-profile healing abutment were placed at the palatal aspect of the extraction socket replacing a nonrestorable maxillary left canine. The residual horizontal defect measured 4.2 mm buccolingually and was allowed to heal by secondary intention. The implant was loaded after 5 months and biopsied after 10 months of placement, using the coronal portion of the buccal bone. The histologic section of the coronal aspect of the implant interface revealed intimate bone contact to the first thread. There was reestablishment of the implant biologic width coronal to the bone contact with connective tissue and junctional epithelium. This case report provides clinical and histologic proof that the immediate placement of implants into extraction sockets with an intact buccal wall allows healing and osseointegration despite a large gap distance and without primary flap closure, a bone graft, or a barrier membrane.

Research shows that practitioners tend to underestimate the amount of tooth structure that must be exposed during a crown lengthening procedure. In the anterior portion of the mouth, this can lead to biologic width problems and subsequent cosmetic issues. This paper presents a biologically based, stepby- step approach to periodontal esthetic crown lengthening. Using a series of innovative measuring gauges, the ideal clinical crown length of a tooth as well as the proper occlusogingival placement of the interproximal papilla will be determined based on established, documented tooth proportion relationships. The biologic crown length of the tooth, defined as the distance from the incisal edge to the bone crest, will subsequently be determined as a function of the clinical crown length, with the ultimate goals being adequate tooth structure for the placement of a restorative margin, establishment of a healthy dentogingival complex, and the placement of an esthetically pleasing definitive restoration.

The aims of the present study were to clinically and histologically evaluate human fresh frozen bone (FFB) grafts used to treat severe maxillary horizontal defects prior to dental implant placement. Ten patients were treated with FFB onlay grafts. Measurements using computed tomography scans were recorded preoperatively and at 5 months. Six core biopsies were retrieved and processed for light microscopy. At baseline, thickness of the maxillary alveolar ridge measured 2.3 ± 0.4 mm; it measured 6.8 ± 0.5 mm after reconstruction. All implants were successful after 24 months. Histologic results showed that FFB blocks and new bone were integrated perfectly. Histomorphometry revealed a mean percentage of bone of 57.5% ± 24.7%.

The purposes of this prospective, randomized, controlled clinical investigation were to evaluate the performance of motorized ridge expanders (MREs) and to compare their results with those achieved using lateral ridge augmentation (LRA). Eight subjects with bilateral ridge deformities were selected. One technique was used on the right side and the other on the left. Implants were placed 6 months after bone augmentation procedures. All measurements were recorded at 2 and 5 mm from the most coronal aspect of the crest. The augmentation achieved with both techniques was statistically significant: 1.2 mm for LRA and 1.5 mm for MRE 2 mm from the crest and 1.5 mm for LRA and 1.6 mm for MRE at 5 mm from the crest. The differences between the two techniques were statistically insignificant. The amount of expansion achieved in the MRE sites appeared to be negatively correlated with the thickness of the cancellous bone (P .05), and it was not affected by the thickness of the cortical plate. The MRE technique appears to be as effective as the LRA technique in augmenting the thickness of atrophic ridges. Defects treated with MREs showed less bone width contraction during the first 6 months of healing.

This report presents a new clinical protocol that facilitates the diagnostic, surgical, and prosthetic phases of immediately loaded implant rehabilitations. The proposed technique aims to simplify recording of the centric relation, which is usually done immediately after surgery, during the surgical impression phase. This shortens operative time while meeting requirements for an accurate impression and is thus simple and cost effective. The case report of a maxillary full-arch immediately loaded implant rehabilitation in a 45-year-old patient illustrates the clinical steps in the proposed procedure and confirms its repeatability.

The aim of this study was to histologically evaluate the viability of mechanically expanded subepithelial connective tissue grafts. Sixteen samples of palatal connective tissue were collected from eight beagle dogs. Half of the samples were subjected to the expansion procedure and used as subepithelial grafts in the canine region, and the samples not subjected to expansion were grafted at the contralateral side. After 60 days, biopsies were collected and examined histologically by light and confocal laser microscopy and immunohistochemically with anti-CD31 antibody for endothelial cells. There were no significant differences between the control and test groups. It was concluded that this new method to expand the area of connective tissue grafts was not only viable biologically, but also decreased surgical risks without increasing processing time.

This article introduces a surgical technique developed to achieve soft tissue augmentation of the interproximal space. The technique was designed to minimize surgical trauma and blockage of blood supply to the existing papilla by accessing the papillary area through vertical incisions and by elevating a single full-thickness flap without disrupting the papillary bridge. A free connective tissue graft was placed beneath the undermined papilla and secured with sutures. Advantages and variations of the technique are discussed.

Air polishing increases the surface roughness of dental restorations, enhancing bacterial adhesion. This in vitro study was the first, to the authors' knowledge, to evaluate the effect of sodium bicarbonate and glycine powders, at different application distances (2 and 7 mm) and times (5, 10, and 30 seconds), on the surface roughness of a nanocomposite material used in restorations. Untreated slides were used as controls. Surface roughness was measured using atomic force microscopy. Air polishing with glycine powder for 5 seconds, at both application distances, determined the lowest surface damage. Even with all the limitations of any in vitro analysis, this study further supports the safety of this method of air polishing.

This article describes the treatment of gingival recession associated with noncarious cervical lesions by a connective tissue graft in combination with a resin-modified glass-ionomer restoration (CTG + R). Eleven patients showing the association of recession and lesions were selected and treated by CTG + R. Bleeding on probing, probing depth, relative gingival recession, clinical attachment level, noncarious cervical lesion height, and dentin sensitivity were measured. The treatment provided statistically significant gains in clinical attachment level and shallow probing depths. The percentage of cervical lesion height covered was 74.0% ± 22.90%. It can be concluded that the presence of resin-modified glass-ionomer filling did not interfere with coverage achieved by the connective tissue graft.

This study investigated the effect of surface treatments on the retentive strength of zirconia posts and cores to root canals. Maxillary central incisors (n = 40) were treated endodontically, obturated, and post spaces were prepared. Zirconia posts and cores (n = 40) were obtained and assigned randomly to four groups (n = 10 per group; control, sandblasting, tribochemical silica coating, and tribochemical silica coating + silanization). Posts were cemented adhesively, and tensile force was applied. All treatment methods increased the tensile strength of zirconia posts and cores compared to the control group (P = .034). No significant difference was found between treatment methods. Failure types varied depending on the surface treatment method.

Treatment planning in the esthetic zone has classically presented some of the greatest challenges to the practitioner. The purpose of this article is to describe a staged, multidisciplinary approach and follow-up to a case of aggressive periodontitis. Microbial sampling for suspected periodontopathogens was taken before and after treatment. Qualitative polymerase chain reaction analysis was done to detect the presence of cytomegalovirus and Epstein-Barr virus type 1 6 years after active periodontal therapy. A control computed tomography scan taken 5.5 years postaugmentation showed stable bone levels and excellent volume maintenance of the transplanted block graft.