Essentials of Standard Chinese Phonetics for Prosthetic Dentistry

Speech adaptation after oral rehabilitation is based on a complex interaction of articulatory and myofunctional factors. The knowledge of basic phonetic principles may help clinicians identify phonetic problems associated with prosthodontic treatment. The purpose of this article is to illustrate basic phonetic terminology, standard Chinese (Putonghua) phonetics, and the anatomic structures relevant for dentistry. In cooperation with a Chinese linguistic specialist, Chinese articulators were selected and are described and compared with English phonetics. Established test words and sentences aid the identification of mispronounced articulators and their related dental structures. The pronunciation of most consonants and vowels in standard Chinese is similar to English, but some of them, such as the retropalatals (/zh/ [t?], /ch/ [th?], /sh/ [?]), have notable differences. Palatal consonants (/j/ [t?], /q/ [t?h], /x/ [?]) are unique to the Chinese phonetic system and are not found in English phonetics. The comprehension of the basic anatomic regions involved in Chinese phonetics may help prosthodontists treat patients whose native language is standard Chinese.     

Analysis of six heavy metals in Ortho mineral trioxide aggregate and ProRoot mineral trioxide aggregate by inductively coupled plasma–optical emission spectrometry

Ortho mineral trioxide aggregate (MTA) is a mineral aggregate newly developed for perforation repair, root end filling and pulp capping. The aim of this study was to investigate the levels of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) in Ortho MTA and ProRoot MTA. A total of 0.2 g of each MTA was digested using a mixture of hydrochloric and nitric acids and filtered. Six heavy metals in the resulting filtrates were analyzed by inductively coupled plasma–optical emission spectrometry (n = 5). The results were statistically analyzed using the Mann–Whitney U‐test. The concentrations of Cd, Cu, Fe, Mn, Ni and Zn in Ortho MTA were 0.10, 7.73, 49.51, 2.58, 0.82 and 10.09 p.p.m., respectively. The concentrations of Cd, Cu, Fe, Mn, Ni and Zn in ProRoot MTA were 0.16, 9.38, 1438.11, 74.51, 18.98 and 4.05 p.p.m., respectively. In conclusion, Ortho MTA had lower levels of Cd, Cu, Fe, Mn and Ni than ProRoot MTA.     

Salivary bacteria and oral health status in medicated and non-medicated children and adolescents with attention deficit hyperactivity disorder (ADHD)

Objectives

Attention deficit hyperactivity disorder (ADHD) is a childhood neurological disorder. Studies have shown that children with ADHD are more prone to caries than those without. The study investigated children diagnosed with ADHD, both with and without pharmacological intervention, and the following: DMFT\dmft, plaque index (PI), mutans streptococci (MS) levels, lactobacilli (LB) levels, salivary flow, salivary buffer capacity, oral hygiene, and diet.

Study design

DMFT/dmft index, PI, MS and LB levels, salivary flow, and salivary buffer capacity were examined in three groups of children: ADHD1—diagnosed with ADHD with no pharmacological intervention (N?=?31), ADHD2—treated with medications for ADHD (N?=?30), and a healthy control group (N?=?30). Diet and oral health habits were assessed through questionnaires completed by parents.

Results

There were no differences in the DMFT/dmft index, MS and LB counts, salivary buffer capacity, and parent reported diet and oral health behavior between the three groups. Children with ADHD demonstrated a higher plaque index.

Conclusions

Although children with ADHD did not report different diet and oral health behavior from children without ADHD, this group had significantly higher levels of plaque than the control group, which combined with hyposalivation may be a risk factor for caries at an older age.

Clinical relevance

Medicated and non-medicated ADHD children were similar to control children in their caries rate, MS and LB counts, salivary buffer capacity, and diet and oral health behavior. They differed in the amount of plaque found on their teeth. As a group, ADHD children demonstrated hyposalivation compared with the control.     

Dentin Adhesion and MMPs: A Comprehensive Review

This review examines the fundamental processes responsible for the aging mechanisms involved in the degradation of resin‐bonded interfaces, as well as some potential approaches to prevent and counteract this degradation. Current research in several research centers aims at increasing the resin–dentin bond durability. The hydrophilic and acidic characteristics of current dentin adhesives have made hybrid layers highly prone to water sorption. This, in turn, causes polymer degradation and results in decreased resin–dentin bond strength over time. These unstable polymers inside the hybrid layer may result in denuded collagen fibers, which become vulnerable to mechanical and hydrolytical fatigue, as well as degradation by host‐derived proteases with collagenolytic activity. These enzymes, such as matrix metalloproteinases and cysteine cathepsins, have a crucial role in the degradation of type I collagen, the organic component of the hybrid layer. This review will also describe several methods that have been recently advocated to silent the activity of these endogenous proteases.