Surface finishing of dental porcelain

A technique is presented to polish a porcelain surface whose natural glaze has been broken by grinding. The technique involves the use of a hard rubber wheel, fine wet pumice, and wet tin oxide. A comparison of the polished and naturally glazed porcelain surfaces of vacuum-fired porcelain appear similar both clinically and under an SEM.     

Mechanical properties of resin-based cements with different dispensing and mixing methods

Statement of problem

Resin-based cements are frequently used in clinical practice. To reduce time and technique sensitivity, manufacturers have introduced the same brand of cement with different dispensing methods. The effect of this change on properties of the cement is unknown.

Subanesthetic doses of ketamine,diazepam, and nitrous oxide for adult outpatient sedation

The use of ketamine in adults has been complicated by untoward hallucinatory emergence reactions. The addition of nitrous oxide and diazepam to subanesthetic doses of ketamine may be effective in decreasing these reactions. Adult patients were sedated for outpatient oral and maxillofacial surgery procedures using nitrous oxide, diazepam, and either fentanyl or ketamine. Postoperative questionnaires were used to evaluate hallucinatory reactions, amnesia, and patient acceptance. Comparison of the results of patients receiving ketamine and those receiving fentanyl revealed no statistical differences in hallucinatory reactions or patient acceptance. Amnesia was more complete in the ketamine than the fentanyl group.     

Intraoperative complications of sagittal osteotomy of the mandibular ramus: incidence and management

The intraoperative complications occurring with 256 sagittal osteotomies operated by two different osteotomy designs are presented. Intraoperative complications occurred in 8.2% of the cases. Aside from operator experience and skill, complications appeared to be related to the osteotomy design and attention to detail during the operation.     

Radiographic appearance and population distribution of the pneumatized articular eminence of the temporal bone

The pneumatized articular eminence of the temporal bone (PAT) is a cavity similar to that seen in the mastoid process that occurs in the zygomatic process of the temporal bone. Panoramic radiographs of 1061 dental school patients were reviewed to determine the radiographic appearance and population characteristics of this finding; PAT was found in 28 patients (2.6%). The mean age of the patients was 32.5 years; there was no sex predilection and four patients showed this defect bilaterally. Two radiographic types of PAT were identified, unilocular and multilocular. Panoramic radiography appears to be an efficacious method to display the articular eminence for visualization of PAT. Due to the relatively common occurrence of PAT and the increasing amount of surgery of the temporomandibular joint, visualization of this defect becomes important for the clinician planning surgical manipulation of the articular eminence.     

Effect of brushing and thermocycling on the shade and surface roughness of CAD-CAM ceramic restorations

Statement of problem

The effects of toothbrushing (B) and thermocycling (TC) on the surface texture of different materials with various fabrication processes have been investigated. However, studies of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramic restorations are limited.

Autoradiography of protein turnover in subcrestal versus supracrestal fibre tracts of the developing mouse periodontium

Eighteen-day-old C57B1 mice were injected with 5 μCi/g body weight [³H]-proline and killed at intervals of 4 h to 7 wk later. Grain counts in three fibre tracts revealed that (1) half-lives of labelled protein in the developing periodontium were much shorter than those found previously for the mature periodontium, and (2) the half-life of labelled protein in the dento-gingival region was longer than the half-lives in the trans-septal and dento-alveolar fibre tracts (half-lives: DENTO-ALVEOLAR = 2.5 days, TRANS-SEPTAL = 3.8 days; DENTO-GINGIVAL = 7.9 days). Eight mice were given injections of [³H]-proline on days 11, 13, 15 and 17, which encompasses the formation of the three fibre tracts, and killed 4 h, 2.5, 5 and 8 wk after the last injection. All label incorporated during the formation of the peridontium had been lost by 5 wk post-injection, shewing that a stable core fibre (i.e. one which is not metabolized) was not present.