Comparative study of abutment screw loosening with or without adhesive material

PURPOSE: The purpose of this study was to achieve more retention and stability and to delay or prevent screw loosening. MATERIALS AND METHODS: Twenty implants (Implantium 3.4 mm, Dentium, Seoul, Korea) were divided into 2 groups (n = 20). In the first group, an adhesive material was applied around the screw of the abutments (test group). In the second group, the screws are soaked in saliva (control group). All the screws were torqued under 30 N/cm, Then, the samples were gone through a cyclic fatigue loading process. After cyclic loading, we detorqued screws and calculated detorque value. RESULTS: In comparison with the control group, all the implant screws in the test group were smeared with the adhesive material, showing significant higher detorque value. CONCLUSION: There are significantly higher detorque values in the group with adhesive. It is recommended to make biocompatible adhesive to reduce screw loosening.

[Accuracy of different abutment level impression techniques in all-on-4 dental implants]

Passive fit of prosthetic frameworks is a major concern in implant dentistry. Impression technique is one of the several variables that may affect the outcome of dental implants. The purpose of this study was to compare the three dimensional accuracy of direct and indirect abutment level implant impressions of ALL-ON-4 treatment plan. A reference acrylic resin model with four Branemark fixtures was made according to All-On-4 treatment plan. Multiunit abutments were screwed into the fixtures and two special trays were made for direct and indirect impression techniques. Ten direct and ten indirect impression techniques with respective impression transfers were made. Impressions were poured with stone and the positional accuracy of the abutment analogues in each dimension of x, y, and z axes and also angular displacement [delta theta] were evaluated using a Coordinate Measuring Machine [CMM]. Data were analyzed using T- test. The results showed that direct impression technique was significantly more accurate than indirect technique [P<0.001]. The results showed that the accuracy of direct impression technique was significantly more than that of indirect technique in Delta theta and delta r coordinate and also delta x, delta y, delta z.

Repair of large lip vermilion defects with mutual cross lip musculomucosal flaps

Vermilion irregularities are common secondary deformities after cleft lip repair, regressed or resected hemangiomas, trauma and tumor surgeries. Vermilion deficiency attracts considerable attention and detracts from an otherwise excellent lip repair. Minor and moderate vermilion defects can be corrected with upper lip advancement, rotation flaps, tongue flaps or grafts. Major defects defy correction with local flaps. A technique is described for correction of large absolute tissue defects of the vermilion using Mutual Cross-Lip Musculomucosal Flaps [MCLMF] Or Ahmad-Ali's flaps. This technique was applied in eight patients with major vermilion defects secondary to hemangioma regression, neoplasia, and trauma. Reconstruction with MCLMF led to create a balanced donor and recipient lips appearance and function. There were no postoperative complications. Surgical results were satisfactory in all patients, and sufficient lip mobility with adequate bulk was maintained. One patient demonstrated minimal transient lip tightening. Use of Ahmad-Ali's flaps in selected patients resulted in successful reconstruction of severe vermilion defects