Digital subtraction arthrography and arthrofluoroscopic dynamic observations on TMJ dysfunction syndrome

Digital subtraction arthrography and arthrofluoroscopic dynamic observation were performed for seventy cases with TMJ dysfunction syndrome. A comparative study between the findings of digital subtraction arthrography and the operative findings was carried out for eleven cases who underwent surgery. It has been found that digital subtraction arthrography can overcome the disadvantages of conventional arthrography and has important diagnostic value for TMJ dysfunction syndrome, especially for disc perforation. In addition. The procedure of digital subtraction arthrography, the normal and abnormal manifestations of digital subtraction arthrograms were described in the present study.     

The influence of bone mechanical properties and implant fixation upon bone loading around oral implants.

Finite element models were created to study the stress and strain distribution around a solitary BAnemark implant. The influence of a number of clinically relevant parameters was examined: bone-implant interface (fixed bond versus frictionless free contact), bone elastic properties, unicortical versus bicortical implant fixation and the presence of a lamina dura. Bone loading patterns in the vicinity of the implant seem to be very sensitive to these parameters. Hence they should be integrated correctly in numerical models of in vivo behaviour of oral implants. This necessitates the creation of patient-dependent finite element models.     

Immunoglobulins in milk from cows immunized with oral strains of Actinomyces, Prevotella, Porphyromonas, and Fusobacterium.

Immunization of pregnant cows with bacteria leads to the presence of high concentrations of specific antibodies in colostrum and milk. A total of 14 cows was immunized with single strains of heat-killed oral bacteria or pools of strains of Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Two cows were treated with adjuvant alone. The mean percentages of IgG1, IgG2, IgM, and IgA in all of the milks were 83.8, 3.8, 9.3, and 3.1, respectively. ELISA and whole cell agglutination assays demonstrated high titers in the milks from the cows immunized with either individual strains or the bacterial pools. The highest titers determined by ELISA belonged to the IgG1 isotype and in several milks were 64-fold greater than titers in milk from cows treated with adjuvant alone. The concentrations of all antibodies and the titers determined by ELISA and whole cell agglutination assays markedly decreased from the first to the sixth milkings. The functional specificity of the antibodies was demonstrated by agglutination tests against a wide range of bacteria including members of Actinomyces, Fusobacterium, Porphyromonas, Prevotella, Streptococcus, Eubacterium, Propionibacterium, Peptostreptococcus, Bacteroides, Actinobacillus, Haemophilus, Capnocytophaga, and Wolinella. Minimal cross-reactions with bacteria in other genera were observed with all of the milks. High-titer milk preparations have been obtained from immunized cows, and the capacity of the bovine antibodies to agglutinate target bacteria indicates their potential usefulness in oral passive immunization studies.     

Clinical evaluation of freeze-dried block allografts for alveolar ridge augmentation: a case series

Various grafting materials have been used in guided bone regeneration procedures to augment alveolar ridges deficient in horizontal or vertical dimensions or both. Autogenous block grafts from intraoral and extraoral sites have been used for ridge augmentation with encouraging results. However, the risk of vascular and neurologic injury at the donor site as well as postoperative patient morbidity have been reported following these surgical procedures. The use of a cancellous block allograft could be one alternative to avoid potential donor site complications. Five deficient alveolar ridges in three patients were each grafted with a freeze-dried cancellous block allograft and a resorbable barrier membrane. Ridge measurements taken at baseline, graft placement, and a 6-month reentry surgery demonstrated an increase in alveolar ridge width from 2 to 4 mm. These gains in ridge width compare favorably with other guided bone regeneration studies, suggesting that a freeze-dried cancellous block allograft in conjunction with a resorbable membrane may be an acceptable alternative to the autogenous block graft in the treatment of compromised alveolar ridge deficiencies.     

Prosthodontic rehabilitation of a patient with partial anodontia: a clinical report

This clinical report describes the prosthodontic rehabilitation of a 22-year-old female patient diagnosed with partial anodontia. A combined dental therapy approach was used and included endodontic therapy and a post-and-core buildup on the mandibular left canine, fabrication of a mandibular removable denture, and fabrication of maxillary fixed restorations. Canine-protected occlusion was developed in the final restorations to decrease lateral forces on the posterior dentition. Protrusive guidance was evenly distributed across the maxillary and mandibular incisors. Functional and esthetic results were achieved.     

Thermal analysis of commercial Gutta-percha using differential scanning calorimeter and dynamic mechanical thermal analysis.

Gutta-percha is the most widespread root canal filling material and knowledge of its chemical and thermomechanical properties is of a great interest to its use in clinical dentistry. In the present investigation, the results from differential scanning calorimeter were compared with those obtained by dynamic mechanical thermal analysis. A significant correlation was established between these results and the chemical composition of six different commercial samples of gutta-percha.     

Human periodontal ligament cell responses to recombinant human bone morphogenetic protein-2 with and without bone allografts

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been found to promote the osteoblastic differentiation of human periodontal ligament cells. Its effect depends on the delivery system used. In this study we examined the effect of rhBMP-2 on the proliferation and osteoblastic differentiation of human periodontal ligament cells cultured alone or with 3 different bone allografts. METHODS: The rhBMP-2 effect on cell proliferation and osteoblastic differentiation was examined by measuring [3H] thymidine incorporation and ALPase activity, respectively, on human periodontal ligament (hPDL) cells. Two human demineralized freeze-dried allografts of cortical (DFDBAco) and cancellous (DFBDAca) bone origin and 1 non-demineralized freeze-dried allograft (FDBA) of cancellous bone origin, derived from different tissue banks, were used to evaluate the rhBMP-2 effect on cell osteoblastic differentiation. The measurements were taken on various days. RESULTS: rhBMP-2 decreased hPDL cell proliferation. rhBMP-2 acted on the third day of the process of cell differentiation, had a specific time of action, achieved its peak effect on the fourth and fifth days, and then did not provoke any further effects. The 3 bone allografts were efficiently combined with rhBMP-2. The combination of rhBMP-2 and DFDBAco showed the effect with the longest duration. rhBMP-2, on day 4, made the inactive bone allograft more active while, on the other days, its effect was dependent on the allograft alone. CONCLUSIONS: rhBMP-2 promotes the osteoblastic differentiation of human periodontal ligament cells and decreases cell proliferation. In this study rhBMP-2 in the presence of the bone allografts tested resulted in hPDL cell differentiation.