Protective effect of the in situ formed short-term salivary pellicle.
ABSTRACT Salivary pellicle, as previously investigated, protects the enamel surface after certain processes of maturation against the influence of acidic agents. The aim of the present study was to investigate the protective effect of the short-term salivary pellicle formed in situ over periods of 3, 60 and 120 min. Six human volunteers used intraoral acrylic splints with bovine enamel samples fixed at the buccal and palatal sites of the maxillary first molars and second premolars. Enamel specimens (n = 252) with and without pellicle were immersed for 60 s in 1.0% citric acid solution under agitation. Knoop surface hardness (KHN) of uneroded polished enamel was measured as a baseline and estimated immediately after erosive treatment reflecting the microhardness loss (DeltaKHN). The amounts of calcium dissolved from the eroded enamel surface were analysed by atomic absorption spectroscopy and scored in mg/l per 10 mm2 of enamel surface area. In addition, the scanning electron microscope was used for the micromorphological examination of the erosive alterations of the enamel surface. The average microhardness loss values after erosion of the enamel samples with buccally/palatally formed pellicle layers were measured as 139.1/144.9 DeltaKHN for 3 min pellicle, 145.9/146.9 DeltaKHN for 60 min pellicle and 141.7/138.6 DeltaKHN for 120 min pellicle. Calcium release values from the specimens with buccal/palatal pellicles were amounted to 15.0/14.9, 16.5/15.9 and 15.3/17.4 mg/l per 10 mm2 for 3, 60 and 120 min-old pellicles, respectively. No significant differences were related to the pellicle formation time and intraoral site (buccal or palatal) in all tested series (ANOVA, P < 0.05). However, significant protection of the enamel surface provided by the pellicle layer was observed on all pellicle-covered surfaces if compared to the non-covered enamel samples (calcium release: 25.6 mg/l per 10 mm2; microhardness loss 187.0 DeltaKHN). These data were in accordance with the morphologic alterations caused by citric acid on the pellicle-covered and pellicle non-covered specimens. It could be concluded that salivary pellicle formed in situ within a period of 3 min offers protection of enamel against citric acid. However, pellicle does not completely inhibit the erosive action of citric acid under the conditions of the present study.
Article: Effect of Psidium cattleianum leaf extract on enamel demineralisation and dental biofilm composition in situ.[show abstract] [hide abstract]
ABSTRACT: Previous evaluations of Psidium cattleianum leaf extract were not done in conditions similar to the oral environment. The aim of this study was to evaluate the effect of P. cattleianum leaf extract on enamel demineralisation, extracellular polysaccharide formation, and the microbial composition of dental biofilms formed in situ. Ten volunteers took part in this crossover study. They wore palatal appliances containing 4 enamel blocks for 14 days. Each volunteer dripped 20% sucrose 8 times per day on the enamel blocks. Twice a day, deionised water (negative control), extract, or a commercial mouthwash (active control) was dripped after sucrose application. On the 12th and 13th days of the experiment, plaque acidogenicity was measured with a microelectrode, and the pH drop was calculated. On the 14th day, biofilms were harvested and total anaerobic microorganisms (TM), total streptococci (TS), mutans streptococci (MS), and extracellular polysaccharides (EPS) were evaluated. Enamel demineralisation was evaluated by the percentage change of surface microhardness (%ΔSMH) and integrated loss of subsurface hardness (ΔKHN). The researcher was blinded to the treatments during data collection. The extract group showed lower TM, TS, MS, EPS, %ΔSMH, and ΔKHN values than the negative control group. There were no differences between the active and negative control groups regarding MS and EPS levels. There were no differences in pH drop between the extract and active control groups, although they were significantly different from the negative control group. For all other parameters, the extract differed from the active control group. Psidium cattleianum leaf extract exhibits a potential anticariogenic effect.Archives of oral biology 03/2012; 57(8):1034-40. · 1.65 Impact Factor
Article: Dental erosion as oral disease. Insights in etiological factors and pathomechanisms, and current strategies for prevention and therapy.[show abstract] [hide abstract]
ABSTRACT: Dental erosion is induced by the exposure to acids, and together with physical impacts, contributes to the wear and tear of the dentition throughout a lifetime. It is a multifactorial condition, and so far several etiological and protecting factors have been identified. Based on a thorough diagnosis and identification of the acid sources, current preventive and therapeutic strategies focus on causal strategies bringing the acid exposure to a safe level, and/or strengthening the tooth surface against demineralization. There is increasing knowledge about the erosion inhibiting potential of fluorides particularly of compounds with polyvalent metal cations. The paper critically reviews the current literature providing a brief overview on what is known about diagnosis, prevalence, etiology and risk factors with the main focus on preventive and therapeutic strategies.American journal of dentistry 12/2012; 25(6):351-64. · 0.76 Impact Factor
Article: A new optical detection method to assess the erosion inhibition by in vitro salivary pellicle layer.[show abstract] [hide abstract]
ABSTRACT: OBJECTIVES: Application of the recently developed optical method based on the monitoring of the specular reflection intensity to study the protective potential of the salivary pellicle layer against early enamel erosion. METHODS: The erosion progression was compared between two treatment groups: enamel samples coated by the 15h-in vitro-formed salivary pellicle layer (group P, n=90) and the non-coated enamel surfaces (control group C, n=90). Different severity of the erosive impact was modelled by the enamel incubation in 1% citric acid (pH=3.6) for 2, 4, 8, 10 or 15min. Erosion quantification was performed by the optical method as well as by the microhardness and calcium release analyses. RESULTS: Optical assessment of the erosion progression showed erosion inhibition by the in vitro salivary pellicle in short term acidic treatments (≤4min) which was also confirmed by microhardness measurements proving significantly less (p<0.05) enamel softening in the group P at 2 and 4min of erosion compared to the group C. SEM images demonstrated less etched enamel interfaces in the group P at short erosion durations as well. CONCLUSIONS: Monitoring of the specular reflection intensity can be successfully applied to quantify early erosion progression in comparative studies. In vitro salivary pellicle (2h) provides erosion inhibition but only in short term acidic exposures. CLINICAL SIGNIFICANCE: The proposed optical technique is a promising tool for the fast and non-invasive erosion quantification in clinical studies.Journal of dentistry 02/2013; · 2.00 Impact Factor