Bone height measurement of maxillary and mandibular bones in panoramic radiographs of edentulous patients

Objectives. The purpose of this in vitro study were to determine variation in maxillary and mandibular vertical measurements and to assess vertical bone loss made from panoramic radiographs in edentulous measurements. Study Design. In this descriptive study, a total of 600 panoramic radiograph’s of edentulous patient were examined. The mean ages of edentulous patients were 31 and 87 years respectively. Measurements were made from reference lines drawn from anatomic landmarks on standardized panoramic rediographs. All radiographs were made using a standardized manner by the same technician. Twelve sites were measured on every panoramic radiograph whenever possible, five sites in the maxilla and seven sites in the mandible. Results. In the maxilla all vertical measurements distance were significantly greater in the edentulous men than in the edentulous women (p<0,05). In the mandible all vertical measurements distance were significantly greater in the edentulous men than in the edentulous women (p<0,05). Conclusion. The results of this study may guide clinicians to make primer decision of implant insertion area for implant supported prosthesis in edentulous patient

Effect of Femtosecond Laser Treatment on the Shear Bond Strength of a Metal Bracket to Prepared Porcelain Surface

Objective: The aim of this study was to investigate the effects of femtosecond laser treatment (Group FS) on the shear bond strength (SBS) of a metal bracket to prepared porcelain surface, and to compare it with other surface treatment techniques [50 mu m Al2O3 sandblasting (Group SB), 9.6% hydrofluoric acid gel (Group HF), and neodymium-doped yttrium aluminium garnet (Nd:YAG laser) (Group NY)]. Background data: Because of the increasing number of adult patients in current orthodontic practice, achieving sufficient bond strength of composite resin to porcelain restorations without bond failure during the treatment is a challenge for orthodontists. Methods: In total, 80 glazed feldspathic porcelain samples were prepared and randomly assigned to four groups of 20. Treated surfaces were treated with a silane agent. Brackets were bonded to porcelain samples. The specimens were stored in distilled water for 24 h and then thermocycled for 500 cycles between 5 degrees and 55 degrees C. The SBS of the brackets was tested with a universal testing machine at a crosshead speed of 1 mm/min, until bonding failure occurred. The data were analyzed statistically using analysis of variance (ANOVA) and Tamhane multiple comparisons tests. The results of ANOVA indicated that the SBS values varied according to the surface treatment method (p<0.001). Results: Results of the Tamhane post-hoc tests indicated that the bond strength in Group NY (5.11 +/- 1.53) was significantly lower than the other groups (p<0.05). There were no statistically significant differences among Groups SB (9.07 +/- 3.76), HF (9.09 +/- 3.51), and FS (11.58 +/- 4.16) (p=0.28). Conclusions: The results of this study showed that FS treatment produced high SBS of the processes assessed; therefore, it appears to be an effective method for bonding orthodontic metal brackets to prepared porcelain surfaces

Effect of femtosecond laser and sllica-coating on zirconia framework-veneering ceramic bonding, surface chemistry and crystallographic changes

The aim of this study was the assessment of various surface conditioning methods upon zirconia framework veneering ceramic bonding, crystallographic changes, and surface chemistry. 91 prepared zirconia specimens were randomly assigned to 4 groups (n = 18) according to conditioning method: Group SB: Air-borne-particle abrasion with 50 µm Al2O3; Group R: Tribochemical silica coating; Group FL: Femtosecond-laser application; Group Si25: argon/oxygen plasma (8:1 in flux) film deposition on the zirconia surface for 25 min and Group Si49: as in Si25 but only 49 min. The veneering ceramic was fired upon the zirconia surface and the interface of the framework-veneer assemblies were subjected to shear force using a Universal Testing Machine (1 mm/min). Three specimens from every group were analyzed with profilometry and SEM. Data were statistically analyzed using a One-way ANOVA and Tukey’s test for multiple comparisons (α = 0.05). Failure modes were obtained and SEM-EDX was used to identify tetragonal to monoclinic transformation phase change. Group Si49 (32 ± 3) presented the highest mean bond strength values (MPa) followed by Group Si25 (28 ± 6) being not significant from one another (p > 0.05). Groups SB (15 ± 5) and R (16 ± 5) did not show significant difference (p > 0.05), being significantly less than that of Group FL (22 ± 6) (p < 0.05). All groups presented predominantly mixed failures. Silica-based coating was most effective in terms of bond strength, minimal flaws and transformation in the zirconia tested