RESUMO
Background@#Different genioplasty techniques are applied for the adjustment of chin area deformities such as chin deviation. @*Results@#Thirty patients with simple facial asymmetry due to chin deviation underwent computer-assisted horizontal translational osseous genioplasty. In this technique, a surgical guide was used to cut a bone strip from the side where the chin should be transferred to; then, the same bone strip was used for the filling of the gap that was formed on the opposite side. @*Conclusion@#According to the experience gained from this study, the authors believe that computer-assisted horizontal translational osseous genioplasty is a simple and reliable technique for patients with facial asymmetry due to chin deviation.
RESUMO
Background@#Different genioplasty techniques are applied for the adjustment of chin area deformities such as chin deviation. @*Results@#Thirty patients with simple facial asymmetry due to chin deviation underwent computer-assisted horizontal translational osseous genioplasty. In this technique, a surgical guide was used to cut a bone strip from the side where the chin should be transferred to; then, the same bone strip was used for the filling of the gap that was formed on the opposite side. @*Conclusion@#According to the experience gained from this study, the authors believe that computer-assisted horizontal translational osseous genioplasty is a simple and reliable technique for patients with facial asymmetry due to chin deviation.
RESUMO
Endodontically treated teeth are prone to fracture because they loose a large amount of their structure. The treatment plan of those teeth is completed when they are rehabilitated with a strong and functional restoration. The purpose of this study was to evaluate the fracture resistance of endodontically treated teeth restored with amalgam cuspal coverage in comparison with other restorative techniques. 40 human healthy maxillary premolars were divided into 4 groups: group1 [S]: sound teeth, group 2[Co]: endodontically treated teeth with MOD cavity restored with bonding and composite, group 3[Am-B]: endodontically treated teeth with MOD cavity restored with bonding and amalgam and group 4 [Am-CC]: endodontically treated teeth with MOD cavity restored with amalgam cuspal coverage. Then the restorations were stored in water and room temperature for 100 days at then thermocycled for 500 cycles between water baths at [5.5 +/- 1] and [55 +/- 1][degree]C. The fracture resistance was evaluated by Universal Testing Machine [Instron, 1195 UK] with the compressive force of about 2000 N in 0.5 mm/min. The fracture modes were evaluated in four groups by a stereomicroscope. Statistical analysis [Scheffe test] was done for all groups [P<0.05 was considered as the level of meaningfulness]. The highest fracture resistance was found in group 4 [Am-CC] [976 +/- 23.27 N] that had no significant difference with sound tooth [P>0.05]. The lowest fracture resistance was found in group 2 [Co] [384 +/- 137.4 N] that had no significant difference with group 3 [Am-B] [P>0.05]. The fracture resistance in group 4 was significantly higher than group 2 [Co] and 3 [Am-B]. The fracture mode in group 1 was cohesive within tooth and in group 2 [Co] and 3 [Am-B] was mixed cohesive and adhesive, and in group 4 was cohesive within restorative material. The highest fracture resistance was obtained in teeth that received amalgam cuspal coverage.
Assuntos
Humanos , Fraturas dos Dentes , Endodontia , Amálgama Dentário , Dente Pré-Molar , Dente CaninoRESUMO
The marginal integrity of fixed restorations always is a major matter of concern for dental clinicians. Any cause of distortion, including veneering processes, in the marginal integrity is supposed to be detrimental for long-term success of fixed dental prostheses. The aim of this in vitro study was to compare the marginal adaptation of two different full ceramic restoration systems [Zirkouzahu and Cercon] and possible changes in marginal integrity following the multiple veneering process. Twelve all-ceramic crowns in the form of coping were fabricated on a pre-made standard metal die with finish line of shoulder preparation from two commercial systems: Cercon_ and Zirkonzahn_. The specimens were not cemented. The Crown/Die discrepancy were measured by means of a precise stereo microscope [accuracy +/- 0.1 microm], at various points [n=12] selected along circumferential margin of the restorations. Same procedure was accomplished after applying the veneering porcelain. The mean gap dimensions were calculated and data were analyzed by multivariate [b] test. Mean marginal gap dimensions before and after veneering porcelain firing cycles, for Cercon_ were [59.67 +/- 13.46 microm] and [63.75 +/- 14.16 microm] and for Zirkonzahn_ were [65.81 +/- 24.37 microm] and [64.74 +/- 21.94 microm], respectively. Hotelling trace Multivariate[b] test method showed that the rate ofmismatching marginal integrity in two groups [Cercon_ and Zirkonzahn_] had no significant difference before and after porcelain firing [P>0.05]. Within the limitation of this study, the marginal integrity of both systems were seems to be within the clinically acceptable standard dimension, i.e. 120microm.The marginal gap of both all-ceramic systems were not affected by veneering porcelain firing cycles