Effects of surface conditioning on the retentiveness of titanium crowns over short implant abutments.

PURPOSE: The integrity and retention of cemented restorations over implant abutments is difficult to achieve when the axial wall height of the abutment is short. PURPOSE: : To compare the effect of different surface conditions on the retentiveness of titanium crowns cemented over short (3 mm) ITI solid abutments using 2 types of cement. Surface pretreatment included sandblasting, silicoating, and application of alloy primer. METHODS AND MATERIALS: Forty-eight ITI implants and solid abutments 5.5 mm in height were divided into six groups. The axial height of abutments in group I was unaltered to serve as a control. The remaining abutments in (groups II-VI) were reduced to a 3-mm height. Groups I and II were luted with ZnPO4 cement without any surface pretreatment. In groups III and IV, the fit surface of the castings and solid abutments were sandblasted, before luting, with ZnPO4 or Panavia 21, respectively. In group V castings and abutments were sandblasted, pretreated with Siloc Bond, and luted with Panavia 21. In group VI castings and abutments were sandblasted, pretreated with alloy primer, and luted with Panavia 21. Crown retention was measured using a universal testing machine after 1 week of storage in water at 37 degrees C. RESULTS: Analysis of variance revealed a highly significant difference among the groups. Sandblasted castings and abutments pretreated with alloy primer or Siloc Bond before luting with Paravia 21 resin cement exhibited the greatest retentive strength (P < 0.05). Castings luted with zinc phosphate over short ITI solid abutment exhibited the lowest retention (P < 0.05). CONCLUSION: The retention of titanium castings luted over ITI solid abutments was influenced by axial height, surface texture, surface pretreatment, and type of cement. Phosphoric alloy primer is more effective and less technique sensitive than the Siloc Bond with regard to retention enhancement of titanium castings over short ITI solid abutment.

Arthroscopy versus arthrocentesis. A retrospective study of disc displacement management without reduction.

OBJECTIVE: To compare the outcome of arthroscopic surgery and arthrocentesis of internal derangement (disc displacement without reduction) of the temporomandibular joint (TMJ). METHODS: The charts of 48 patients with TMJ derangement and treated with arthroscopy or arthrocentesis were included in this study carried out in a specialized private clinic in Beirut, Lebanon, between January 2001 and July 2005. Inclusion criteria included patients with a history of clicking followed by a sudden onset of limited mouth opening without clicking, a complaint of TMJ pain with mouth opening or chewing difficulty, or both, or a positive magnetic resonance imaging diagnosis of TMJ disc displacement without reduction. Patients with limited mouth opening caused by only muscle spasm, prior TMJ surgery, bilateral joint involvement, or serious systemic diseases were excluded from the study. Twenty-eight patients underwent arthroscopy (group one) and 20 patients were treated with arthrocentesis (group 2). RESULTS: Both methods showed a significant reduction in pain and an increase in maximal mouth opening on follow up (p<0.01). There was no statistical difference between the methods. CONCLUSION: Further research should be conducted before one can definitely determine if real benefits are achieved through surgery in TMJ articular disorders. Within the limits of this study, less invasive procedures are highly recommended.

Special technique for attachment incorporation with an implant overdenture.

The Hader bar system is a popular bar and clip concept because of its 20-degree clip rotation, simplicity, and versatility. Two procedures may be used to incorporate the Hader nylon clip into a denture base. The direct technique consists of attaching the clip to the denture base as a clinical procedure. With the indirect technique, the clip is attached during laboratory processing. An alternative method of attaching the clip with a metal superstructure is presented. This procedure combines the advantages of the direct and indirect techniques for incorporation of the nylon clip of the Hader bar into the denture base.

Removable partial denture design: a study of a selected population in Saudi Arabia.

Determination of the incidence of various classes of removable partial dentures (RPDs) including their designs and their comparison with previous studies provide clinically useful information for dental training and continuing education. The purpose of this study is to determine the pattern of partial edentulism, the major connector, clasping, and design of 740 cobalt chromium RPD frameworks constructed for a selected population in Saudi Arabia. RPD framework design information and patient personal data were obtained from the work authorization form and the dental records respectively. The relationship among age, sex, nationality, and various Kennedy classes of the RPDs was determined by chi-square statistical analysis. Results indicate that Kennedy Class III removable partial dentures were the most frequently constructed. Although gender had no significant relationship, age and nationality had statistically significant relationship with the distribution of various Kennedy classes of removable partial dentures. Lingual bars and anterior posterior palatal straps were the most commonly used mandibular and maxillary major connectors. Lingual and palatal plates, however, were more frequently used than any major connectors for distal extension RPDs. Comparison with previous findings confirms the established variation in designing RPDs. The distribution of partially edentulousness revealed the influence of the general pattern of tooth loss, which could be modified by patient's demands and socio-economic status. Practitioners need to avail themselves fully of basic RPD design principles concerning the most commonly encountered classes of RPDs.