More lingual surface attrition of the maxillary anterior teeth in American Indians: prehistoric Panamanians

Lingual surface attrition of the maxillary anterior teeth (LSA-MAT) has been found in additional prehistoric Latin American Indian skeletons. LSAMAT was first observed in crania from an Archaic Brazilian site. This second finding occurs in teeth from Venado Beach, a late prehistoric site in Panama. LSAMAT is also present in some fragmentary specimens from the Archaic Cerro Mangote site in Panama. LSAMAT at Venado Beach is present in 57% of 28 adult crania. As in the Brazilian study, LSAMAT is associated with a high caries rate (82% of 50 adults; 11.7% of 852 permanent teeth). As first suggested, eating and processing of some type of abrasive carbohydrate food, such as manioc, is the possible cause of LSAMAT. However, other possible causes relating to habitation on or near marine coasts cannot be totally ruled out.     

Characteristics of M-Gtfi,A New Inhibitor of Streptococcus Mutans Glucosyltransferase

Abstract

M-GTFI, originally screened as an inhibitor of Streptococcus mutans glucosyltransferase, strongly inhibited α-glucosidase, in a non-competitive manner especially when the synthetic substrate p-nitrophenyl-α-D-glucopyranoside was used. It also inhibited β-glucosidase, β-amylase and, to a lesser extent, β-glu-curonidase.

The inhibitor was stable in neutral and alkaline pH ranges and dependency of the inhibition on pH and temperature was not observed. Some proteinases and polysaccharides-hydrolyzing enzymes as well as human saliva did not inactivate the inhibitor.

There was a correlation between the release of sulfate anions from the inhibitor molecule on incubation with HCI (0.2 N) at 100°c and loss of inhibitory properties of the molecule. It is suggested that the presence of sulfate ester linkages in the inhibitor molecule play an important role in the inhibition process.     

Epidemiology of root caries

Many epidemiological studies have been conducted on a variety of populations. Unfortunately, comparison of the prevalence data, and to a lesser degree of the incidence data, between the various studies is of little use due to the lack of standardised diagnostic criteria, reporting methods and population diversity. In the few incidence studies which have been conducted around 30–40% of people developed root caries, although many adults in the population appear to have been affected by root caries. Many risk factors associated with the occurrence of root caries have been identified and these include oral, medical, mental, behavioural and psychosocial conditions.     

Interobserver reliability of methods for paleopathological diagnosis of dental caries

There is disagreement as to whether clinical methods of caries diagnosis will produce reliable results in skeletal material, and studies vary greatly in the extent to which such methods are employed. The purpose of this study is, therefore, to evaluate the interobserver reliability of visual, tactile, and radiographic methods of scoring dental caries in ancient populations. Thirty-three individuals from a Mogollon skeletal sample were scored on three occasions by pairs of examiners. The first exam employed visual criteria alone. In the second exam, visual methods were supplemented with the dental explorer. For the third exam, mesial and distal surfaces were scored from “intraoral” radiographs. Examiners worked independently, but did calibrate on material from clinical populations prior to the second and third exams. Exams were conducted on a “blind” basis, and analysis was delayed until all exams were completed. Caries scores were expressed as a percentage of total surfaces present per individual. Repeat-measures ANOVA and intraclass correlation coefficients (ICC) were used to estimate interobserver reliabilities. For visual scores, ICC = 0.97, and there is no significant difference between examiners (P = 0.897). For visual plus explorer scores, ICC drops to 0.90, and there is a significant difference between examiners (P = 0.003). For the radiographs, ICC = 0.86, and there is no significant difference between observers (P = 0.117). These results suggest that clinical methods are less reliable in skeletal populations. Probable sources of error include postmortem dehydration of carious dentin, confusing radiolucencies engendered by worn or fractured enamel, and inadequate radiologic standards for root caries. These problems can be avoided through reliance on visual criteria.     

Log-linear analysis of dental caries occurrence in four skeletal series.

Four skeletal series (Corinth, Greece; Gran Quivira, New Mexico; Semna South, Sudanese Nubia, and a large group from scattered sites in England) were coded for sex, jaw, tooth group, dental attrition, dental caries, site and time period. Through thec concepts of a basal level of caries and a cariosity gradient, a single model was found which best described the occurrence of this disease in these samples. All factors were found to contribute significantly to the model. Within the possible subsamples the general characteristics are that the profiles of males, of the mandibulae and of those with light attrition are more likely to have lower overall dental caries levels and to be relatively more carious in the back of the mouth than the front when compared to the pooled sample of all teeth and caries. The opposite is also found to be generally true; the teeth of females, maxillae and heavy attrition are associated with more caries, especially toward the front of the mouth. These results imply that samples appearing otherwise homogeneous display much variation. They also reveal distinct regularities in the reactions of diverse human groups to dental caries.     

A graphene/zinc oxide nanocomposite film protects dental implant surfaces against cariogenic Streptococcus mutans

Oral biofilms play a crucial role in the development of dental caries and other periodontal diseases. Streptococcus mutans is one of the primary etiological agents in dental caries. Implant systems are regularly employed to replace missing teeth. Oral biofilms accumulate on these implants and are the chief cause of dental implant failure. In the present study, the potential of graphene/zinc oxide nanocomposite (GZNC) against the cariogenic properties of Streptococcus mutans was explored and the anti-biofilm behaviour of artificial acrylic teeth surfaces coated with GZNC was examined. Acrylic teeth are a good choice for implants as they are low cost, have low density and can resist fracture. Microscopic studies and anti-biofilm assays showed a significant reduction in biofilm in the presence GZNC. GZNC was also found to be nontoxic against HEK-293 (human embryonic kidney cell line). The results indicate the potential of GZNC as an effective coating agent for dental implants by efficiently inhibiting S. mutans biofilms.