Histologic wound healing in studies using different ridge preservation protocols: A review.

BACKGROUND: Alveolar ridge preservation (ARP) procedures are designed to lessen dimensional changes in the alveolar ridge after tooth extraction. Wound healing after ridge preservation involves the formation of new vital bone in the former socket, and this vital bone is important in the osseointegration of dental implants. METHODS: A series of ARP studies have been performed to help clinicians better understand the wound-healing events that occur following tooth extraction and ridge preservation. Different protocols have been examined using various materials and periods of healing time prior to implant placement. The primary aim of these studies was to ascertain the relative percentage of vital bone formation, residual graft material, and connective tissue (CT)/other at the healing site using histomorphometric examination of bone core biopsies obtained during osteotomy preparation. RESULTS: For allografts, the use of demineralized bone alone or in combination with mineralized is associated with more vital bone formation than the use of mineralized allograft alone. For mineralized allografts, the use of cortical versus cancellous bone has only minimal impact on new bone formation. Xenografts from bovine and porcine sources appear to have similar vital bone formation. Longer healing times prior to implant placement are associated with increased vital bone formation and decreased residual graft material. The most stable component in most studies is the percentage of CT/other. CONCLUSIONS: The percentage of vital bone and residual graft at ARP sites is dependent on the materials used and the length of healing time prior to obtaining core biopsies. KEY POINTS: What factors may affect the amount of new bone at the ARP site? At a time point about 4 months after ARP, the type of graft material used for ARP plays a large role in new bone formation. Studies focus on means and standard deviations, but patients often do not "follow the mean." Even if a single ARP protocol is used for all patients, there is great interindividual variability in new bone formation, and there is often variability between sites within a single patient. How long after ARP with an allograft should I wait to place an implant? Longer healing times such as 4-5 months generally provide higher amounts of vital bone formation than shorter healing times like 2-3 months. Differences in vital bone formation between ARP protocols tend to decrease with longer healing time. FDBA that contains demineralized bone, either alone or combined with mineralized FDBA, often provides higher amounts of new bone formation than 100% mineralized allograft, especially at shorter healing periods. Even a year after ARP with an allograft, residual graft material is often still present at the ARP site.

Accuracy of dental calculus detection using digital radiography and image manipulation.

BACKGROUND: The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs. METHODS: Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners. RESULTS: None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05). CONCLUSIONS: Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

Comparative evaluation of the stability of two different dental implant designs and surgical protocols-a pilot study.

BACKGROUND: The purpose of this study was to compare a parallel wall design implant to a tapered apex design implant when placed in the posterior maxilla using two different surgical protocols. METHODS: Twenty-seven patients (30 implants) were divided into three groups. All implants were 4 mm wide in diameter and 8 mm long. Group A received 10 tapered implants (OSPTX) (Astra Tech OsseoSpeed TX™) using the soft bone surgical protocol (TXSoft). Group B received 10 tapered implants (OSPTX) (AstraTech OsseoSpeedTX™) using the standard surgical protocol (TXStd). Group C received 10 parallel wall implants (OSP) (AstraTech OsseoSpeed™) using the standard surgical protocol (OStd). All implants were placed in the posterior maxilla in areas with a minimum of 8-mm crestal bone height. Resonance frequency measurements (implant stability quotient (ISQ)) and torque values were recorded to determine initial implant stability. All implants were uncovered 6 weeks after placement and restored with a functionally loaded resin provisional screw-retained crown. Resonance frequency measurements were recorded at the time of implant placement, at 6 weeks and 6 and 12 months. Twelve months after implant placement, the stability of the implants was recorded and the final restorations were placed using custom CAD/CAM fabricated abutments and cement-retained PFM DSIGN porcelain crowns. After implant restoration, bone levels were measured at 6 and 12 months with standardized radiographs. RESULTS: Radiographic mean bone loss was less than 0.5 mm in all groups, with no statistically significant differences between the groups. Implant survival rate at 1 year was 93.3%, with 2/30 implants failing to integrate prior to functional loading at 6 weeks. No statistically significant difference was found between ISQ measurements between the three groups at all time intervals measured. Strong positive correlations were found between overall bone loss at 6 months and insertion torque at time of placement. A very weak correlation was found between insertion torque and ISQ values at time of implant placement. CONCLUSIONS: Survival and stability of OSPTX and OSP implants is comparable. Osteotomy preparation by either standard or soft bone surgical protocol presented no significant effect on implant survival and stability for the specific implant designs.

Histologic Evaluation of Acellular Dermal Matrix Allografts in Humans.

INTRODUCTION: Acellular dermal matrix (ADM) is a cell-free dermal matrix comprised of a structurally integrated basement membrane complex and extracellular matrix in which collagen bundles and elastic fibers are the main components. There are several commercially available ADM allografts that have different processing methods. This case series reports the histologic presentation of two of the most widely used ADM allografts, referred to as ADM-A and ADM-B, in patients that had specific situations involving reentry. CASE SERIES: Two patients referred to the Louisiana State University Department of Periodontics, New Orleans, Louisiana, with 1- to 3-mm recession of at least two non-contiguous sites needing soft tissue augmentation, were treated with appropriate mucogingival procedures using ADM-A or ADM-B. After ≈6 to 8 months of healing, and due to clinical findings that necessitated further periodontal procedures, small tissue biopsies were obtained and examined microscopically. CONCLUSIONS: All samples of ADM (A and B) analyzed after staining with hematoxylin and eosin had a generally similar appearance under light microscopic examination, which suggests they are both well incorporated into native tissues after 6 to 8 months of healing. When stained with Verhoeff-Van Gieson, all samples showed elastin fibers, a finding consistent with previously published light microscopic observations of ADM. There appeared to be a more densely packed elastin pattern in the deep base of ADM-A compared with ADM-B. This might be an indication these two materials have a different healing pathway when used to augment the oral mucosa.

Peripheral giant cell granulomas: a series of 279 cases.

OBJECTIVE: This study investigated the demographic, clinicopathologic, and histopathologic findings of lesions diagnosed as peripheral giant cell granuloma (PGCG) by the Louisiana State University Oral Pathology Biopsy Service from 1974 to 2011. STUDY DESIGN: Clinical, demographic, and histopathologic evaluation was completed for 279 cases. A follow-up questionnaire was mailed to all surgeons who performed these biopsies from 1990 to 2011. RESULTS: Of the 279 lesions, 58% occurred in the mandible, 44% occurred in the anterior portion of the arches, 83% were adjacent to teeth, 14% occurred in edentulous areas, and 2% were adjacent to implants. Average duration was 10.5 months, and the average size was 12.7 mm. The recurrence rate was 17.5%. Histopathologically, 78% of lesions extended to the base of the specimen, 50% exhibited ulceration, 41% contained calcifications, and 6% exhibited features overlapping with another pathologic entity. CONCLUSIONS: PGCG is a well-defined pathologic entity among reactive gingival lesions. Recurrent lesions were more likely to contain calcifications.