Modified measuring compass as an intraoral paralleling device.

This article describes a simple technique of useful modification of measuring compass, procured from a school compass box, to make an intraoral paralleling device. This device is useful in examining parallelism of tooth or implant abutment preparations for a common path of placement in fixed dental prostheses. It can be used to examine the parallelism of guiding planes in removable partial denture patients as well.

The comparative study of thermal inductive effect between internal connection and external connection implant in abutment preparation / 대한치과보철학회지

STATEMENT OF PROBLEM: The cement-type abutment would be needed for the reduction of its body in order to correct the axis and to assure occlusal clearance. In the case of intraoral preparation, there is a potential risk that generated heat could be transmitted into the bone-implant interface, where it can cause deterioration of tissues around the implant and failed osseointegration. PURPOSE: The purpose of this study was to assess the difference of the heat transmitting effect on external and internal connection implant types under various conditions. MATERIAL AND METHOD: For evaluating the effects of alternating temperature, the thermocoupling wires were attached on 3 areas of the implant fixture surface corresponding to the cervical, middle, and apex. The abutments were removed 1mm in depth horizontally with diamond burs and were polished for 30 seconds at low speed with silicone points using pressure as applied in routine clinical practice. Obtained data were analyzed using Mann-Whitney rank-sum test and Wilcoxon / Kruskal-Wallis Tests. PESULT: Increased temperature on bone-implant interface was evident without air-water spray coolant both at high speed reduction and low speed polishing (p<.05). But, the difference between connection types was not shown. CONCLUSION: The reduction procedure of abutment without using proper coolant leads to serious damage of oral tissues around the implant irrespective of external and internal connection type.