PURPOSE: . This study evaluated the fracture resistance of premolar screwretained implant-supported hybrid abutment crowns (HACs) fabricated from different monolithic restorative materials following artificial aging. MATERIALS AND METHODS: . Forty-four titanium implant analogs were restored with HACs fabricated from four materials: 5 mol% yttria-partially stabilized monolithic zirconia (ST), strength-gradient multilayered zirconia (YM), lithium disilicate ceramic (LD), and resin composite containing dispersed nanoparticles (CM) (n = 11 per group). All specimens were subjected to thermocycling (10,000 cycles) and mechanical loading (1.2 million cycles) to simulate 5 years of clinical service.Fracture resistance was evaluated under compressive loading, and failure modes were analyzed using optical microscopy and scanning electron microscopy.Statistical analysis was performed using the Kruskal-Wallis and Steel-Dwass tests (α = 0.05). RESULTS: . Significant differences were found among all groups (P = 0.00033-0.0022). The YM group exhibited the highest median fracture resistance (2.06 kN, IQR: 2.00 – 2.60 kN), followed by ST (1.74 kN, IQR: 1.69 – 1.80 kN), LD (1.29 kN, IQR: 1.14 – 1.41 kN), and CM (0.87 kN, IQR: 0.79 – 0.92 kN). All specimens survived the artificial aging protocols. Distinct fracture patterns were observed depending on the restorative material, with zirconia-based groups showing more favorable resistance than resin composite. CONCLUSION . All tested HACs exhibited fracture resistance values exceeding maximum bite forces, supporting their clinical applicability. Strength-gradient multilayered zirconia demonstrated superior reliability after simulated 5-year aging, emphasizing its structural advantage and broader safety margin compared with other restorative materials.

OBJECTIVE: In cervical intraepithelial neoplasia (CIN), p16INK4a immunohistochemistry has been reported to be a useful diagnostic biomarker. However, limited information is available about the association between the p16INK4a immunohistochemistry and the outcomes of CIN. Here, we report p16INK4a immunohistochemistry as an effective biomarker to predict the outcomes of CIN. METHODS: p16INK4a immunohistochemistry was performed in patients with CIN from January 2000 to August 2009. Among these patients, we have performed a retrospective analysis of the medical records to evaluate the outcome of CIN 1-2 and performed statistical analysis to determine the correlation between p16INK4a expression and the outcomes. We also performed HPV genotyping and analyzed the relation between the infecting human papillomavirus (HPV) genotype and the outcomes. RESULTS: A total of 244 patients, including 82 with CIN 1, 60 with CIN 2, and 102 with CIN 3, were examined. The rate of p16INK4a overexpression increased with increasing CIN grade, 20.7% for CIN 1, 80.0% for CIN 2, and 89.2% for CIN 3, with significant differences between CIN 1 and CIN 2-3 group. In the 131 CIN 1-2 patients, the progression rate was significantly higher for the patients showing p16INK4a overexpression than for those not showing p16INK4a overexpression (p=0.005); the regression rate was also found to be significantly lower for the patients showing p16INK4a overexpression (p=0.003). High-risk HPV genotypes were detected in 73 patients (73.7%). Both progression and regression rates were not significantly different between the high-risk HPV-positive and HPV-negative groups (p=0.401 and p=0.381, respectively). CONCLUSION: p16INK4a overexpression was correlated with the outcome of CIN 1-2, and p16INK4a is considered to be a superior biomarker for predicting the outcome of CIN 1-2 compared with HPV genotyping.
Cervical Intraepithelial Neoplasia ; Genotype ; Humans ; Immunohistochemistry ; Medical Records ; Retrospective Studies

OBJECTIVE: The aim of this study was to investigate the risk and recurrence of early invasive adenocarcinoma of the cervix, and to determine whether non-radical methods of management could be performed. METHODS: The medical and histopathological records of 50 patients with early invasive adenocarcinoma of the cervix treated at Keio University Hospital between 1993 and 2005 were reviewed, and compared with the literature. RESULTS: The median follow-up period was 64.3 months. The depth of stromal invasion was < or =3 mm in 33 cases and >3 mm, but < or =5 mm in 17 cases. The horizontal spread was < or =7 mm in 25 cases and >7 mm in 25 cases. One of the 33 cases that had tumor volumes of < or =500 mm3, and three of the 17 cases with tumor volumes of >500 mm3 were positive for lymph node metastasis. When our data were combined with previously reported results, statistically significant differences were observed between the tumor volume and the frequency of pelvic lymph node metastasis/the rate of recurrence (p<0.0001). The frequency of pelvic lymph node metastases was significantly higher in the lymphovascular space invasion (LVSI)-positive group than in the LVSI-negative group (p=0.02). No adnexal metastasis or parametrial involvement was noted. CONCLUSION: Assessment of the depth of stromal invasion, tumor volume, and LVSI is critical for selecting an appropriate therapeutic modality. Non-radical methods of management are considered suitable for patients with LVSI-negative adenocarcinoma of the cervix exhibiting a stromal invasion depth of < or =5 mm and a tumor volume of < or =500 mm3.
Adenocarcinoma ; Cervix Uteri ; Conization ; Female ; Follow-Up Studies ; Humans ; Lymph Nodes ; Neoplasm Metastasis ; Recurrence ; Tumor Burden ; Uterine Cervical Neoplasms