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.

Bur Choice When Removing Zirconia Restorations.

PURPOSE: Removal of zirconia restorations can be challenging and time consuming, requiring dental burs with optimal cutting efficiency to minimize iatrogenic complications. Yet, there are very few burs marketed for this purpose and little evidence of their comparative benefit. This study evaluated one specialized bur and compared its cutting efficiency with three general-purpose burs (one single use and two multiple uses). MATERIALS AND METHODS: This study was designed to assess the cutting efficiency of 4 burs on a high-strength zirconia substrate. One of these burs is a multiple-use bur marketed for high-strength ceramics (Komet 4ZR), another is a single-use general-purpose bur (Piranha 837.012 coarse), and two are multiple-use general-purpose burs (Brassler 6837.31.012C coarse and Komet 6837.314.012 coarse). The cutting efficiency of each bur was determined by measuring the time taken to perform serial 2 mm cuts into a block of zirconia. Ten burs in each group were tested with repeated cuts until the time taken for a 2 mm cut was twice that of the first 2 mm cut (50% loss of efficiency). This study was performed under reproducible conditions using a custom-designed and fabricated rig assembly. RESULTS: The results demonstrated a statistically significant difference in the cutting efficiency between bur types. The single-use general-purpose bur (Piranha 837.012) was the most efficient for all cut numbers p <2.2 × 10-16 . The performance of all burs decreased with each cut, with cutting efficiency dependent on time point/cut number (p = 0.02). The rate of deterioration varied between burs, but this difference was not sufficient to be statistically significant. CONCLUSIONS: This study demonstrated that a single-use bur is more efficient than 3 multiple-use burs. The cutting efficiency of a single-use general-purpose bur (Piranha 837.012 coarse) on Cerec Zirconia Mono L was statistically superior to that of multiple patient use burs in this study, including one marketed for use on high-strength ceramics. Because single-use burs are comparatively inexpensive and require no sterilization, they should be strongly considered for the removal of zirconia restorations.

Autologous blood products: Usage and preparation protocols.

FOCUSED CLINICAL QUESTION: What are the appropriate preparation protocols for autologous blood products to support their clinical utilization? SUMMARY: Autologous blood products provide a unique clinical benefit. Their popularity among the professions is growing. However, as this is a rapidly evolving field, multiple modalities are presented within the literature. Frequently there is no demonstrated superiority to previous iterations. This brief review attempts to offer a concise chronology on their evolution, preparation, and where possible, evidence to support their clinical utilization. CONCLUSIONS: The field of autologous blood products is expanding rapidly. These products appear to yield variable clinical benefits in specific indications. However, evidence supporting their universal application is scant, and the superiority of one formulation versus another is yet to be demonstrated.