In this study, the effect of beverages (Coke TM, Sprite™, Ribena™, Chrysanthemum tea and mineral water) on the demineralisation of the enamel surface was investigated. Demineralisation was determined by the rate of calcium released from the enamel surface on exposure to the beverages. Calcium was determined using the EDTA titration method. The pH of these beverages was measured using a pH meter and found to be in the acidic range (2.43 to 5.79) while mineral water which served as a control has a pH of 7.00. Ii was found that the rate of calcium released from Coke™(0.76 J..lg/min) showed a significant mean difference from Sprite™ (0.38 J..lg/min), Chrysanthemum tea (0.10 J..lg/min) and mineral water (0.00 J..lg/min)at p< .05, but was however not significantly different from Ribena™. Likewise, Chrysanthemum tea and mineral water also showed statistically no significant mean difference in the released of calcium during the study period. The results obtained in this study indicated that beverages with low pH may pose detrimental effect on the enamel surface which could have clinical implication, especially in people with salivary gland dysfunction or low salivary flow.
Chlorhexidine gluconate and hexitidine have been used in many oral health care products as antiplaque and antigingivitis agents. Based on the clinical observations and the plaque and gingivitis scores, chlorhexidine gluconate has been reported to be a better agent. In this study, the anti-adherence properties of chlorhexidine gluconate and hexitidine on individual bacteria strains isolated from a 3-hour plaque (Streptococcus sanguis, Streptococcus mitis 1 and Actinomyces sp.) and on a whole 6-hour plaque culture were determined and compared. The study showed that chlorhexidine gluconate inhibited almost 100 % the adherence of the individual bacteria strains and 87.7 % the adherence of a whole 6-hour plaque culture to the saliva-coated glass surface. Hexitidine appeared to be more selective in its effect. It was shown to inhibit the adherence of S. sanguis and Actinomyces sp. to saliva-coated glass surface by 86.5 % and 51.4 % respectively. Its effect on the S. mitis 1 strains is comparable to that of a whole 6-hour plaque culture where inhibition to adherence were less than 4 % for both.
The tooth provides a non-shedding surface ideal for microbial and plaque accumulation. Despite being exposed to regular environmental perturbations, the microbial composition and proportions in the plaque often remains in homeostasis and is relatively stable over time. Supragingival plaque sampled from various sites on the tooth surface was pooled and conventionally analyzed for its microbial constituent. Classification of microbial isolates was made based on the characteristics exhibited by the growth colonies, Gram-stained cells, as well as biochemical reactions using the API Identification System kit. Observation was also made of the colony forming units on both non-selective and selective agar culture plates. A variety of bacteria, both of the facultative and anaerobic types, were isolated from the supragingival plaque of the Malaysian population. Among those found to predominate the supragingival plaque include the Gram positive and Gram negative cocci and rods from the genera Streptococcus, Staphylococcus, Actinomyces, Fusobacterium, Corynebacterium, Clostridium, Bacteroides, Veilonella and Lactobacillus. In addition, yeast within the genus Candida was also isolated from the plaque samples.
Water delivered through dental unit waterline system
(DUWS) is often reported contaminated with microbes
dislodged from biofilm that forms within the tubing
of a dental chair unit (DCU). ADM: The study aimed
at evaluating the sanitary level of DCU water from
a teaching dental clinic. Materials: The presence of
pathogenic bacteria which include total coliforms, faecal
coliforms, E. coli, faecal streptococci and P. aeruginosa
were determined using conventional microbiological
methods while PCR technique was used to identify other
microbial contaminants. Result: pH of DCU water was
found slightly acidic at pH 5.4-5.5 and the temperature
was 23°C. Pathogenic contaminants were absent but
the DCU water was highly loaded with Sphingomonas
rhizogenes (17.9%), Sphingomonas dokdonesis
(79.5%), Sphingomonas mucosissima (1.1%) and
Methylobacterium radiotolerans (1.5%). The high load of
microbes that exceeded 200 cfu/ml was of great concern
as it failed to meet recommendation set by the American
Dental Association.