Computational Study of the Formation Reaction of Polyacid Precursors of Glass-Ionomer Materials

The formation of polyacids in a glass-ionomer cement was computationally modeled. The polyacid modelled is an oligomer made up of three molecules: acrylic acid, itaconic acid and an additional molecule that acts as a spacer group between the previous two. Acryloyl and meta-acryloyl derivatives of some amino acids and related molecules such as N-vinyl pyrrolidone and N-vinyl caprolactam were used as spacer groups. Some of these molecules have been previously used experimentally as spacer groups. In this work the spacer behaviour of 15 different molecules was investigated. To our knowledge, this is the first computational attempt to model some promising molecules to be incorporated into glass-ionomer dental cements. The results revealed the best structural arrangement for the investigated molecules.

The presence and outcome of biliary sphincter disorders in liver-transplant recipients according to the Rome IV classification

Background Biliary sphincter disorders after liver transplantation(LT)are poorly described.We aim to describe the presence and outcome of patients with papillary stenosis(PS)and functional biliary sphincter disorders(FBSDs)after LT according to the updated Rome IV criteria.Methods We reviewed all endoscopic retrograde cholangiopancreatographies(ERCPs)performed in LT recipients between January 2003 and December 2019.Information on clinical and endoscopic findings was obtained from electronic health records and endoscopy databases.Laboratory and clinical findings were collected at the time of ERCP and 1 month after ERCP.Results Among the 1,307 LT recipients,336 underwent 849 ERCPs.Thirteen(1.0%)patients met the updated Rome IV criteria for PS[former sphincter of Oddi dysfunction(SOD)type I]and 14 patients(1.0%)met the Rome IV criteria for FBSD(former SOD type II).Biliary sphincterotomy was performed in 13 PS and 10 FBSD cases.One month after sphincterotomy,bilirubin,gamma-glutamyl transferase and alkaline phosphatase levels decreased in 85%,61%,and 92%of those in the PS group(P¼0.019,0.087,and 0.003,respectively)and in 50%,70%,and 80%of those in the FBSD group(P¼0.721,0.013,and 0.093,respectively).All the 14 patients initially suspected of having a FBSD turned out to have a different diagnosis during the follow-up.Conclusions PS after LT is uncommon and occurs in only 1%of LT recipients.Our data do not support the presence of an FBSD after LT.Sphincterotomy is a safe and effective procedure in LT recipients with PS.