PURPOSE: This study evaluated the effect of different screw tightening sequences and methods on detorque values in a well-fitting implant superstructure. MATERIAL AND METHODS: A fully edentulous mandibular master model and a metal framework directly connected to four parallel implants (Astra Tech) with a passive fit to each other were fabricated. Six stone casts were made with a splinted impression technique to represent a 'well-fitting' situation with the metal framework. Detorque values were measured twice after screw tightening using 20 Ncm. Detorque values and minimum detorque values for three screw tightening sequences (1-2-3-4, 2-4-3-1, and 2-3-1-4) and for two tightening methods (two-step and one-step) were analyzed using multi-way analysis of variance and two-way analysis of variance, respectively, at a .05 level of significance. RESULTS: The mean detorque values for screw tightening sequences ranged from 12.8 Ncm (2-4-3-1) to 13.1 Ncm (2-3-1-4), and for screw tightening methods were 13.1 Ncm (two-step) and 11.8 Ncm (one-step). The mean of mimimum detorque values for screw tightening sequences were 11.1 Ncm (1-2-3-4) and 11.2 Ncm (2-4-3-1 and 2-3-1-4), and for screw tightening methods were 11.2 Ncm (two-step) and 9.9 Ncm (one-step). No statistically significant differences among three screw tightening sequences were found for detorque values and for mimimum detorque values. But, statistically significant differences between two screw tightening methods were found for two values. Two-step screw tightening method showed higher detorque value (P = .0003) and higher minimum detorque value (P = .0035) than one-step method. CONCLUSION: Within the limitations of this study, the screw tightening sequence was not a critical factor for the detorque values in a well-fitting implant superstructure by the splinted impression technique. But, two-step screw tightening method showed greater detorque values than one-step method.
Splints

No abstract available.
Splints

As the inaccuracy which was made in implant impression prevented passive fit,it needed to solder the sectioned framework at several locations to correct the inaccuracy. Many clinicians have suggested impression techniques which could make passive fit between implant and superstructure. The purpose of this research was to measure and compare the accuracy of three methods of taking impression with the strain amplifier. The experimental groups were classified as follows : Group I; splinted the two parts with Futar D Occlusion. Group II; splinted the two parts with DuraLay. Group III; didn't splint the two parts. The results were as follows ; 1.The values of strain in the vertical and horizontal surfaces were increased in the order of groupI,group II and group III. 2.Group I showed higher accuracy of the duplicated casts in the vertical and horizontal surfaces than group IIand group III(p<0.05). 3.There were no significant differences in the accuracy of the duplicated casts between group IIand groupIII. From the above results,it is considered that the splinting method of impression copings could make an influence on the accuracy of the master casts.To improve the accuracy of the master casts, splinting the squared impression copings with the additional silicone occlusion materials is recommendable.
Silicones ; Splints

INTRODUCTION: The restoration of function after surgery with mandibular reconstruction is of utmost importance. Mastication and deglutition are compromised if pre-operative dental occlusion is not reestablished. For this purpose, occlusal splints are fabricated pre-operatively. Various methods of occlusal splint fabrication are at hand. DESIGN: Surgical Instrumentation SETTING: Tertiary Academic Hospital OBJECTIVE: This paper presents a simple, quick and inexpensive way of fabricating an occlusal splint with the use of dental modeling compound. MATERIALS AND METHODS: The dental modeling compound is used pre-operatively to make an occlusal appliance. Occlusal splint fabricated with this method was used in 6 patients who underwent segmental mandibular resection with reconstruction for various pathologies. Post-operatively, patients were assessed in terms of occlusion, type of diet and pain on mastication. RESULTS: Out of the 6 patients, only 5 patients were available for evaluation. One patient suffered a myocardial infarction 3 days post-operation and subsequently died. The five patients had good mandibular-maxillary relation post-surgery. They were able to tolerate regular diet with no pain on mastication. CONCLUSION: In conclusion, we have discussed a simple, quick and cost-effective way of fabricating an occlusal splint for use in mandibular reconstruction. (Author)
OCCLUSAL SPLINTS

The purpose of this study was to evaluate the reliability of 6-axis model surgery simulator (6AMSS) for orthognathic surgery. A rectangular parallelepiped plastic block was assembled to model-mounting plate of 6AMSS. Left-right (X), anterior-posterior (Y), up-down (Z) translation and pitching (empty set X), rolling (empty set Y) and yawing (empty set Z) rotation was planned and performed using 6AMSS. The actual translation and rotation were measured with dial gauge and precisional protractor, respectively. Comparison between the planned and actual movements of plastic block for each variable were made using paired t- test. Statistical analysis for X, Y, Z, empty set X, empty set Y and empty set Z movement have shown no significant differences between planned and actual movement (P > 0.05). This indicate that model surgery performed with the aid of the 6AMSS is accurate in 3D translation and rotation. The 6AMSS is practically useful for accurate fabrication of surgical splint for orthognathic surgery.
Orthognathic Surgery ; Plastics ; Splints

No abstract available.
Occlusal Splints* ; Temporomandibular Joint*

Statement of problem: Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression technique in internal connection implant system. Purpose: This study evaluated the accuracy of splinted fixture-level impression technique using clinical methods and the effect of internal hex on fit of superstructure in internal connection implant system (Astra Tech). Material and method: Two metal master frameworks made from two abutments (Cast-to Abutment ST) each for parallel and divergent conditions and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts were made with vinyl polysiloxane impressions from the master cast by acrylic resin splinted fixture-level impression technique. To evaluate the accuracy of impression technique, the fit of master frameworks for test models was evaluated using screw resistance test (SRT) and onescrew test. The results of SRT were recorded as SRT values from grade 1 to grade 5 by 1/4 turn. And to evaluate the effect of hex on fit of superstructure, the same tests were performed after removing hexes of master frameworks. Results: 1. There was only one case (2.5%) showing SRT value of test model below grade 2 in total before and after removing hexes of master frameworks. And, by removing hexes, SRT values decreased in only one test model (5%) and did not change in 17 test models (85%). 2. SRT values of the 1st screws were grade 2 in 80% of cases before, and grade 1 in 80% of cases after removing hexes. And, by removing hexes, SRT values decreased in 72.5% of cases. 3. SRT values of the 2nd screws were grade 3 in 85% of cases before, and grade 3 in 95% of cases after removing hexes. And, by removing hexes, SRT values did not change in 85% of cases. 4. There were only 2 cases regarded as acceptable fit by one-screw test, and SRT values of 2nd screws of both cases were grade 2. Conclusion: Within the limitations of this study, fixture-level impression of internal connection implant system is considered to obtain inaccurate working cast, even using acrylic resin splinted impression technique. And, it is considered to be unable to improve the fit to remove the hexes of implant restoration.
Prostheses and Implants ; Siloxanes ; Splints

STATEMENT OF PROBLEM: Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression techniques in internal connection implant systems. PURPOSE: The purpose of this study was to compare the accuracy of two fixture-level impression techniques in two conditions (parallel and divergent) and to assess the effect of tightening sequences and forces on stresses generated on superstructures in internal connection implant system (Astra Tech). MATERIAL AND METHODS: Two metal master frameworks made from two abutments (Cast-to Abutment ST) each and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts for each impression techniques (direct unsplinted and splinted technique) were made with vinyl polysiloxane impressions from the master cast. Strain gauges for each framework were fixed midway between abutments to measure the degree of framework deformation on each stone cast. Pairs of strain gauges placed opposite each other constituted one channel (half Wheatstone bridge) to read deformation in four directions (superior, inferior, anterior, and posterior). Deformation data were analyzed using one-way ANOVA and the Tukey test at the .01 level of significance. And the effect of tightening sequences (right-to-left and left-to-right) and forces (10 Ncm and 20 Ncm) were assessed with ten stone casts made from parallel condition by the splinted technique. Deformation data were analyzed using paired t-test at the .01 level of significance. CONCLUSIONS: Within the limitations of this study, the following conclusions could be drawn. 1. Frameworks bent toward the inferior side on all casts made by both direct unsplinted and splinted impression techniques in both parallel and divergent conditions. 2. There was no statistically significant difference of accuracy between the direct unsplinted and splinted impression techniques in both parallel and divergent conditions (P>.01). 3. There was no statistically significant difference of stress according to screw tightening sequences in casts made by the splinted impression technique in parallel condition (P>.01). 4. Greater tightening force resulted in greater stress in casts made by the splinted impression technique in parallel condition (P<.01).
Prostheses and Implants ; Siloxanes ; Splints*

No abstract available.
Splints* ; Sterilization, Tubal*

No abstract available.
Root Planing* ; Splints*