Comparison of three strip-type tests and two laboratory methods for salivary buffering analysis

This study evaluated the correlation between three strip-type, colorimetric tests and two laboratory methods with respect to the analysis of salivary buffering. The strip-type tests were saliva-check buffer, Dentobuff strip and CRT® Buffer test. The laboratory methods included Ericsson's laboratory method and a monotone acid/base titration to create a reference scale for the salivary titratable acidity. Additionally, defined buffer solutions were prepared and tested to simulate the carbonate, phosphate and protein buffer systems of saliva. The correlation between the methods was analysed by the Spearman's rank test. Disagreement was detected between buffering capacity values obtained with three strip-type tests that was more pronounced in case of saliva samples with medium and low buffering capacities. All strip-type tests were able to assign the hydrogencarbonate, di-hydrogenphosphate and 0.1% protein buffer solutions to the correct buffer categories. However, at 0.6% total protein concentrations, none of the test systems worked accurately. Improvements are necessary for strip-type tests because of certain disagreement with the Ericsson's laboratory method and dependence on the protein content of saliv

The effect of a tin-containing fluoride mouth rinse on the bond between resin composite and erosively demineralised dentin

Objectives: To evaluate the effect of a tin-containing fluoride (Sn/F) mouth rinse on microtensile bond strength (μTBS) between resin composite and erosively demineralised dentin. Materials and methods: Dentin of 120 human molars was erosively demineralised using a 10-day cyclic de- and remineralisation model. For 40 molars, the model comprised erosive demineralisation only; for another 40, the model included treatment with a NaF solution; and for yet another 40, the model included treatment with a Sn/F mouth rinse. In half of these molars (n = 20), the demineralised organic matrix was continuously removed by collagenase. Silicon carbide paper-ground, non-erosively demineralised molars served as control (n = 20). Subsequently, μTBS of Clearfil SE/Filtek Z250 to the dentin was measured, and failure mode was determined. Additionally, surfaces were evaluated using SEM and EDX. Results: Compared to the non-erosively demineralised control, erosive demineralisation resulted in significantly lower μTBS regardless of the removal of demineralised organic matrix. Treatment with NaF increased μTBS, but the level of μTBS obtained by the non-erosively demineralised control was only reached when the demineralised organic matrix had been removed. The Sn/F mouth rinse together with removal of demineralised organic matrix led to significantly higher µTBS than did the non-erosively demineralised control. The Sn/F mouth rinse yielded higher μTBS than did the NaF solution. Conclusions: Treatment of erosively demineralised dentin with a NaF solution or a Sn/F mouth rinse increased the bond strength of resin composite. Clinical relevance: Bond strength of resin composite to eroded dentin was not negatively influenced by treatment with a tin-containing fluoride mouth rins

Clinical Study Monitoring the pH on Tooth Surfaces in Patients with and without Erosion

The aim of this study was to compare tooth surface pH after drinking orange juice or water in 39 patients with dental erosion and in 17 controls. The following investigations were carried out: measurement of pH values on selected tooth surfaces after ingestion of orange juice followed by ingestion of water (acid clearance), measurement of salivary flow rate and buffering capacity. Compared with the controls, patients with erosion showed significantly greater decreases in pH after drinking orange juice, and the pH stayed lower for a longer period of time (p < 0.05). Saliva parameters showed no significant differences between the two patient groups except for a lower buffering capacity at pH 5.5 in the erosion group

Effect of tin-chloride pretreatment on bond strength of two adhesive systems to dentin

Objectives: To determine the effect on resin composite-to-dentin bond strength of incorporation of an acidic tin-chloride pretreatment in two adhesive systems. Materials and methods: Human molars were ground to expose mid-coronal dentin. For microtensile bond strength (μTBS) testing, dentin was treated with Optibond FL or Clearfil SE according to one of six protocols (n = 22/group). Group 1: Phosphoric acid etching, Optibond FL Prime, Optibond FL Adhesive (manufacturer's instructions; control); Group 2: Tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 3: Phosphoric acid etching, tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 4: Clearfil SE Primer, Clearfil SE Bond (manufacturer's instructions; control); Group 5: Phosphoric acid etching, Clearfil SE Primer, Clearfil SE Bond; and Group 6: Tin-chloride pretreatment, Clearfil SE Primer, Clearfil SE Bond. The molars were then built up with resin composite (Clearfil Majesty Esthetic). After storage (1week, 100% humidity, 37°C) the μTBS was measured and failure mode was determined. Additionally, pretreated dentin surfaces were evaluated using SEM and EDX. The μTBS results were analyzed statistically by a Welch Two Sample t-test and a Kruskal-Wallis test followed by exact Wilcoxon rank sum tests with Bonferroni-Holm adjustment for multiple testing (α = 0.05). Results: When Optibond FL was used, partial or total replacement of phosphoric acid with tin-chloride decreased μTBS significantly. In contrast, when Clearfil SE was used, inclusion of a tin-chloride pretreatment in the adhesive procedure increased μTBS significantly. Conclusions: Tin-chloride pretreatment had a beneficial influence on the bond promoting capacity of the MDP-containing adhesive system Clearfil SE

Current erosion indices—flawed or valid? Summary

The problem of erosive tooth wear appears increasingly to be encountered by clinicians and researchers. An adequate way of defining and recording erosive tooth wear is essential in order to assess the extent of this clinical phenomenon, both on an individual level and in the population, and for the adequate provision of preventive and therapeutic measures. Well-established erosion indices have been used in most of these studies, although in many cases modifications have been made to suit the different research aims. This use of different indices is one reason why it still cannot be claimed that there is enough current knowledge on this clinical phenomenon. This article summarises the proceedings of a workshop to discuss the topic of dental erosion indices. The result of the workshop is the proposal for a new scoring system (Basic Erosive Wear Examination, BEWE) designed for use both within the research field and for dental clinicians, with the aims of standardising assessment of erosion for international comparisons, raising awareness and providing guidelines for treatment of erosive tooth wear in dental practice

Toothbrushing Systematics Index (TSI): A new tool for quantifying systematics in toothbrushing behaviour

Systematics is considered important for effective toothbrushing. A theoretical concept of systematics in toothbrushing and a validated index to quantify it using observational data is suggested. The index consists of three components: completeness (all areas of the dentition reached), isochronicity (all areas brushed equally long) and consistency (avoiding frequent alternations between areas). Toothbrushing should take a sufficient length of time; therefore, this parameter is part of the index value calculation. Quantitative data from video observations were used including the number of changes between areas, number of areas reached, absolute brushing time and brushing time per area. These data were fed into two algorithms that converted the behaviour into two index values (each with values between 0 and 1) and were summed as the Toothbrushing Systematics Index (TSI) value; 0 indicates completely unsystematic and 2 indicates perfectly systematic brushing. The index was developed using theoretical data. The data matrices revealed the highest values when all areas are reached and brushed equally long. Few changes occurred between the areas when the brushing duration was 90 s; the lowest values occurred under opposite conditions. Clinical applicability was tested with data from re-analysed videos from an earlier intervention study aiming to establish a pre-defined toothbrushing sequence. Subjects who fully adopted this sequence had a baseline TSI of 1.30±0.26, which increased to 1.74±0.09 after the intervention (p 0.001). When the participants who only partially adopted the sequence were included, the respective values were 1.25±0.27 and 1.69±0.14 (p 0.001). The suggested new TS-index can cover a variety of clinically meaningful variations of systematic brushing, validly quantifies the changes in toothbrushing systematics and has discriminative power

Is diagnosing exposed dentine a suitable tool for grading erosive loss?

Quantifying tooth wear in general and erosion in particular mostly is made by distinguishing between lesions restricted to enamel and lesions reaching the underlying dentine. Various scores for grading have been used, but in all systems, higher scores are given in cases of exposed dentine, thus, indicating a more severe stage of the condition. Clinical diagnosis of exposed dentine is made by assessing changes in colour or optical properties of the hard tissues. This paper aims to review the literature and discuss critically problems arising form this approach. It appears that classifying the severity of erosion by the area or depth of exposed dentine is difficult and poorly reproducible, and taking into account the variation of enamel thickness, the amount of tissue lost often is not related simply to the area of exposed dentine. There has still been very little longitudinal investigation of the significance of exposed dentine as a prognostic indicator. Further work and discussion is needed to reevaluate the explanative power of current grading procedures

Effect of TiF4, ZrF4, HfF4 and AmF on erosion and erosion/abrasion of enamel and dentin in situ

OBJECTIVE: This in situ study aimed to analyse the impact of different tetrafluorides (TiF(4), ZrF(4) and HfF(4)) and AmF on erosion and erosion plus abrasion of enamel and dentin. DESIGN: Ten volunteers took part in this crossover and double-blind study performed in 8 phases of each 3 days. In each phase, 2 bovine enamel and 2 dentin specimens were fixed in intraoral appliances. One enamel and one dentin sample were pretreated once with TiF(4), ZrF(4), HfF(4) or AmF (all 0.5M F) for 60s, while the other samples remained unfluoridated and served as control. Then, all samples were subjected to either erosion only (4 times/day, 90 s) or to erosion and abrasion (2 times/day, 30 s/sample). Toothbrushing abrasion was performed 90 min after the first and last erosion with an electrical toothbrush and fluoridated toothpaste at 1.2N. After 3 days, enamel and dentin loss was assessed by profilometry (microm) and analysed by repeated measures ANOVA and paired t-test (p<0.05). RESULTS: All fluoride solutions reduced enamel and dentin loss significantly compared to the controls. Generally, eroded samples showed less wear than eroded and abraded samples. The protective potential of the fluorides was not significantly different and was only slightly, but mostly not significantly, decreased by abrasion. The protective effect of the fluoride solutions was similar in enamel and dentin. CONCLUSION: Tetrafluorides and AmF are able to reduce erosion and erosion plus abrasion in situ and are almost equally effective

How valid are current diagnostic criteria for dental erosion?

In principle, there is agreement about the clinical diagnostic criteria for dental erosion, basically defined as cupping and grooving of the occlusal/incisal surfaces, shallow defects on smooth surfaces located coronal from the enamel–cementum junction with an intact cervical enamel rim and restorations rising above the adjacent tooth surface. This lesion characteristic was established from clinical experience and from observations in a small group of subjects with known exposure to acids rather than from systematic research. Their prevalence is higher in risk groups for dental erosion compared to subjects not particularly exposed to acids, but analytical epidemiological studies on random or cluster samples often fail to find a relation between occurrence or severity of lesions and any aetiological factor. Besides other aspects, this finding might be due to lack of validity with respect to diagnostic criteria. In particular, cupping and grooving might be an effect of abrasion as well as of erosion and their value for the specific diagnosis of erosion must be doubted. Knowledge about the validity of current diagnostic criteria of different forms of tooth wear is incomplete, therefore further research is needed