STATEMENT OF PROBLEM: Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. PURPOSE: This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. MATERIAL AND METHODS: Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. RESULTS: The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile bonding strength to Silfix-Imprint II at all drying periods. CONCLUSION: Significant increase in tensile bonding strength with Silfix-Aquasil and VPS Tray adhesive-Imprint II combination until 10 and 15 minutes respectively. Tray adhesive-impression material combination from the same company presented higher tensile bonding strength at all drying time intervals than when using tray adhesive-impression material of different manufactures.
Adhesives ; Collodion ; Dental Impression Materials ; Elastomers ; Head ; Polymers ; Polymethyl Methacrylate ; Polyvinyls ; Siloxanes

BACKGROUND: A single-arm phase II study of neoadjuvant chemotherapy plus durvalumab and tremelimumab in the treatment of advanced-stage ovarian cancer has begun in Korea. We hypothesized that adding durvalumab (anti-programmed death-ligand 1 antibody) and tremelimumab (anti-cytotoxic T-lymphocyte-associated protein 4 antibody) to chemotherapy in treating this cancer can increase progression-free survival (PFS) with minimal effects on safety. METHODS: During treatment, serial biopsies will be performed on pre-treatment, at interval debulking surgery and progression to identify immune biomarkers and changes in the tumor microenvironment. Patients with histologically confirmed stage IIIC/IV epithelial ovarian cancer are offered durvalumab, tremelimumab plus chemotherapy for neoadjuvant chemotherapy and durvalumab plus chemotherapy for adjuvant chemotherapy. Twenty-four patients will be included from four Korean institutions within 1 year. The primary endpoint is a 12-month PFS rate. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03899610
Biomarkers ; Biopsy ; Chemotherapy, Adjuvant ; Disease-Free Survival ; Drug Therapy ; Humans ; Immunotherapy ; Korea ; Ovarian Neoplasms ; Tumor Microenvironment