Color changes of ceramic veneers following glazing with respect to their composition

PURPOSE: The purpose of this study was to compare the translucency and color changes of ceramic laminate veneers of different composition following glazing process. MATERIALS AND METHODS: 10 mm × 10 mm square specimens of 0.6 mm and 1.0 mm thicknesses were fabricated with IPS e.max Press (EM) and IPS e.max ZirPress (ZP) (n=10 per group). The color coordinates (CIE L* a* b*) of the specimens were recorded with a colorimeter before and after glazing. The color changes and translucency parameter (TP) were calculated. For the comparisons with the composition and thicknesses between the ‘not glazed’ and ‘glazed’ groups, statistical analyses were done through paired T-test, independent two-sample T-test, and multiple regression analysis using SPSS 18.0 (P < .05). RESULTS: The TP of 0.6 mm EM was higher than that of 0.6 mm ZP. Total color difference (ΔE*) between bare and glazed specimens of 1.0 mm EM was greater than that of 1.0 mm ZP with statistical significance. Following glazing, specimens from all groups showed statistically significant amount of decrease in L* and a*, and statistically significant increase in b*. The result of multiple regression analysis of EM and ZP showed that ΔL* improved ΔE*. CONCLUSION: Within the limitations of present study, we conclude that translucency and color of ceramic laminate veneers change significantly after glazing process, and the nature and amount of changes vary with different compositions.

Tonsillectomy as prevention and treatment of sleep-disordered breathing: a report of 23 cases / 대한악안면성형재건외과학회지

BACKGROUND: The paradigm of tonsillectomy has shifted from a treatment of recurrent throat infection to one of multi-discipline management modalities of sleep-disordered breathing (SDB). While tonsillectomy as a treatment for throat problems has been performed almost exclusively by otorhinolaryngologists, tonsillectomy as a part of the armamentarium for the multifactorial, multidisciplinary therapy of sleep-disordered breathing needs a new introduction to those involved in treating SDB patients. This study has its purpose in sharing a series of tonsillectomies performed at the Seoul National University Dental Hospital for the treatment and prevention of SDB in adult patients. METHODS: Total of 78 patients underwent tonsillectomy at the Seoul National University Dental Hospital from 1996 to 2015, and 23 of them who were operated by a single surgeon (Prof. Jin-Young Choi) were included in the study. Through retrospective chart review, the purpose of tonsillectomy, concomitant procedures, grade of tonsillar hypertrophy, surgical outcome, and complications were evaluated. RESULTS: Twenty-one patients diagnosed with SDB received multiple surgical procedures (uvulopalatal flap, uvulopalatopharyngoplasty, genioglossus advancement genioplasty, tongue base reduction, etc.) along with tonsillectomy. Two patients received mandibular setback orthognathic surgery with concomitant tonsillectomy in anticipation of postoperative airway compromise. All patients showed improvement in symptoms such as snoring and apneic events during sleep. CONCLUSIONS: When only throat infections were considered, tonsillectomy was a procedure rather unfamiliar to oral and maxillofacial surgeons. With a shift of primary indication from recurrent throat infections to SDB and emerging technological and procedural breakthroughs, simpler and safer tonsillectomy has become a major tool in the multidisciplinary treatment modality for SDB.