Engineering Interfacial Integrity with Hydrolytic-Resistant, Self-Reinforcing Dentin Adhesive.

The leading cause of composite restoration failure is secondary caries, and although caries is a multifactorial problem, weak, damage-prone adhesives play a pivotal role in the high susceptibility of composite restorations to secondary caries. Our group has developed synthetic resins that capitalize on free-radical polymerization and sol-gel reactions to provide dental adhesives with enhanced properties. The resins contain γ-methacryloxypropyltrimethoxysilane (MPS) as the Si-based compound. This study investigated the properties of methacrylate-based resins containing methacryloxymethyltrimethoxysilane (MMeS) as a short-chain alternative. The degree of conversion (DC), polymerization kinetics, water sorption, mechanical properties, and leachates of MMeS- and MPS-resins with 55 and 30 wt% BisGMA-crosslinker were determined. The formulations were used as model adhesives, and the adhesive/dentin (a/d) interfaces were analyzed using chemometrics-assisted micro-Raman spectroscopy. The properties of the 55 wt% formulations were comparable. In the 30 wt% BisGMA formulations, the MMeS-resin exhibited faster polymerization, lower DC, reduced leachates, and increased storage and loss moduli, glass transition (Tg), crosslink density, and heterogeneity. The spectroscopic results indicated a comparable spatial distribution of resin, mineralized, and demineralized dentin across the a/d interfaces. The hydrolytically stable experimental short-chain-silane-monomer dental adhesive provides enhanced mechanical properties through autonomous strengthening and offers a promising strategy for the development of restorative dental materials with extended service life.

Digital evaluation of the muscle functions of the lower extremities among inguinal hernia patients treated using three different surgical techniques: a prospective randomized study.

PURPOSE: An inguinal hernia is a common pathology that can be treated using several different surgical procedures. Although there have been many studies comparing the clinical results of these techniques, there has so far been no digital analysis of the alterations developing secondary to pain with regard to the muscle functions of the lower extremities. This prospective randomized trial was designed to compare this aspect for subjects treated using the laparoscopic techniques and those treated using the conventional method. METHODS: A total of 75 patients, 25 of whom who had undergone hernia repair using the total extraperitoneal technique, 25 of whom who had undergone repair using the transabdominal preperitoneal technique, and 25 who had undergone repair using the Prolene mesh graft technique, were evaluated preoperatively and on the third postoperative day by isometric and isokinetic measurements, the visual analog score (VAS), the necessity of postoperative analgesia, complications, and the time that had elapsed before returning to work, and these results were recorded. RESULTS: Hernia repair using the conventional method led to an average of 3 times more muscle function loss compared with the laparoscopic techniques, and this difference was shown to be statistically significant. The VAS, postoperative complications, and time elapsed before returning to work were lower for laparoscopic surgeries and also were compatible with the findings described in the previous literature. CONCLUSIONS: Use of a digital environment with numerical parameters and measurements recorded using a dynamometer demonstrated that in the early postoperative period and on the third postoperative day, open surgery causes more functional loss in the lower extremities than laparoscopic methods. Therefore, surgeons should use laparoscopic methods whenever possible to reduce both pain and loss of muscle function.

Application of inverse gas chromatography in the surface characterization of diethanol amine modified polystyrene based polymer.

In the present work, diethanol amine modified polystyrene based polymer (PVBC-Diethanol amine) was synthesized and characterized, then surface properties of the polymer were examined by inverse gas chromatography method at infinite dilution. The retention diagrams obtained based on the interaction of polar and nonpolar probes with the polymer were drawn over a temperature range from 30 to 55 °C. Through the diagrams, the dispersive component of the surface free energy, g S D of the polymer surface, and the specific enthalpy of adsorption, DH A S , of probes on the polymer were also calculated. Lewis acid, K A , and Lewis base, K D , parameters of PVBC-Diethanol amine surface were determined. The values of K A and K D indicated that PVBC-Diethanol amine surface exhibited a basic behavior.