Analysis of the Cariogenic Potential of Various Almond Milk Beverages using a Streptococcus mutans Biofilm Model in vitro.

To evaluate the cariogenic properties of almond milk beverages, 6 almond milks, along with soy and whole bovine milk, were analyzed for their abilities to support Streptococcus mutans biofilm formation and acid production, and their capacity to buffer changes in pH. Biofilm formation by S. mutans was analyzed using an in vitro 96-well plate model and measured by crystal violet staining. Acid production by S. mutans was evaluated by a colorimetric L-lactate assay and pH measurement of bacterial cultures. Buffering capacity was assessed by a pH titration assay. Soy milk supported the most biofilm growth, while the least was observed with unsweetened almond milk (both p < 0.001). Among almond milks, sucrose-sweetened milk led to the highest level of biofilm formation (p < 0.001), while the least was observed with unsweetened milk (p < 0.05). Sucrose-sweetened almond milk yielded the lowest pH (4.56 ± 0.66), followed by soy milk and bovine milk; the highest pH was with unsweetened almond milk (6.48 ± 0.5). When analyzed by pH titration, the unsweetened almond milk displayed the weakest buffering capacity while bovine milk showed the highest (p < 0.001). These results suggest that the almond milk beverages, except those that are sweetened with sucrose, possess limited cariogenic properties, while soy milk exhibits the most cariogenic potential. As milk alternatives become increasingly popular, dentists must counsel their patients that almond milks, especially sucrose-sweetened varieties, have cariogenic potential. For patients who are lactose-intolerant or suffer from milk allergy, almond milks may be a better alternative than soy-based products.

Bacterial factors of cariogenicity (literature review).

OBJECTIVE: Introduction: According to the 2003 WHO report, dental caries affects from 60% to 90% of school-age children and adults that makes it one of the most common diseases worldwide. The aim was to systematize data about the modern conception of plaque formation and role of microorganisms in its development. PATIENTS AND METHODS: Materials and methods: Biblosemantic, 50 medical literature sources were systematically reviewed as the material for the research. RESULTS: Review: According to Miller's theory, oral microorganisms can decompose dietary carbohydrates into acids, which in turn dissolve the calcium phosphates found in the enamel, causing it demineralisation Along with Streptococcus mutans, nowadays some other bacteria as Streptococcus sorbinus, Lactobacillus spp. and Actinomyces spp. have been well studied as caries contributors. However, the disease is related to plaque-mediated, because a much larger number of normal oral microflora representatives are involved in creating favourable preconditions for its development. There are a lot of original research papers about a role of bacteria in caries decay but compositions and characters of oral microflora are changing nowadays. Therefore, authors show the main cariogenic bacteria and their factors of pathogenicity which create special conditions for caries lesions. Modern concepts of dental plaque formation and pathogenesis of plaque-assosiative diseases are presented according to the new actual dental research. A lot of attention is paid to the biochemical properties of cariogenic bacteria and chemical process in biofilm. Role of acid and alkali production by oral bacteria in caries decay are shown in this article. Moreover, mechanisms of bacterial acid-fast and acid-tolerance are presented. CONCLUSION: Conclusions: Analysis of literature demonstrates a lot of bacterial pathogenicity factors which play key role in caries development.

Cariogenic Potential of the commonly Prescribed Pediatric Liquid Medicaments in Kingdom of Saudi Arabia: An in vitro Study.

AIM: The aim of this study was to assess the cariogenic potential of the commonly prescribed pediatric liquid medicaments (PLMs) for dental disease in Jazan region, Kingdom of Saudi Arabia. MATERIALS AND METHODS: Seven most commonly prescribed PLMs were selected by prior questioning the pediatric dentists as well as general dentists in Jazan region. The endogenous pH and sucrose concentrations of the liquid medicaments were assessed. The endogenous pH was assessed by Hanna pH meter instrument. The sucrose concentration was assessed by anthrone reagent method. RESULTS: All the PLM were acidic. The pH of the PLM ranged from 4.22 to 6.10. All the PLM contained sucrose and its concentration ranged from 5.38 to 11.41 gm% in the samples. CONCLUSION: In this study, all the PLM were acidic and contained sucrose. Hence, they have cariogenic potential. CLINICAL SIGNIFICANCE: Parents and dentists are unaware of the hidden sugars and cariogenicity of these medications. Strict oral hygiene instructions are mandatory for the children taking these medications. The use of PLM should also be minimized and parents should seek early dental treatment to restore child's oral health.

Effects of Cola-Flavored Beverages and Caffeine on Streptococcus mutans Biofilm Formation and Metabolic Activity.

OBJECTIVE: To examine the effects of cola-flavored beverages and caffeine on growth and metabolism of Streptococcus mutans biofilm. This study was designed to determine if carbonated beverages or caffeine can increase S. mutans growth and biofilm formation and metabolic activity in vitro, potentially leading to increased S. mutans-associated cariogenicity in children that consume them. STUDY DESIGN: Six different cola-flavored products, plus pure caffeine, and pure high fructose corn syrup (HFCS), at different concentrations similar to those in the beverages were tested. A 16-hour culture of S. mutans was treated with different dilutions in bacteriological media. To test for the effect on biofilm formation, the biofilm was stained with crystal violet. The absorbance was determined to evaluate biofilm growth. Biofilm metabolic activity was measured based on biofilm having the ability to reduce XTT to a water-soluble orange compound. RESULTS: The inclusion of HFCS in the beverages, as well as pure HFCS, significantly enhanced bacterial biofilm formation and metabolic activity. Pure caffeine and the presence of caffeine in beverages did not significantly increase biofilm formation, but pure caffeine significantly increased metabolism, and Diet Coke had significantly greater metabolic activity than Caffeine-Free Diet Coke. CONCLUSIONS: HFCS increases both the biofilm formation and metabolism of S. mutans, and caffeine in some cases increases metabolism of S. mutans.

Association between Type, Amount, and Pattern of Carbohydrate Consumption with Dental Caries in 12-Year-Olds in Puerto Rico.

OBJECTIVE: To identify the types, food sources, and pattern of carbohydrates that significantly contribute to dental caries in Puerto Rican children. METHODS: As part of an island-wide cross-sectional oral health study in 1,587 twelve-year-olds, diet intake was assessed in a representative subset (n = 801) with a 24-hour dietary recall. Carbohydrate intake was quantified using a computer-based diet analysis program. Caries was assessed using the National Institute of Dental and Craniofacial Research diagnostic criteria. Odds ratios were used to associate carbohydrate intake quartiles with caries, after controlling for important confounders. RESULTS: A total of 723 subjects had complete data. Most were females (54%) and attended public schools (77%). The caries prevalence was 33%. The highest quartile intake for the following sugars significantly increased the odds of caries compared to the lowest quartile: total carbohydrates (OR = 1.93, 95% CI = 1.08-3.46), total sugars (OR = 1.88, 95% CI = 1.01-351), sucrose (OR = 2.05, 95% CI = 1.13-3.70), fructose (OR = 1.95, 95% CI = 1.05-3.62), and inositol (OR = 2.52, 95% CI = 1.38-4.63). The main food sources of these sugars were juices, including natural juices with no added sugars, and sweetened beverages. The odds of caries also increased significantly in children whose 10% of total energy intake was from total sugars (OR = 3.76, 95% CI = 1.03-13.7). CONCLUSION: After adjusting for important caries risk factors, total carbohydrates, total sugars, ≥10% kilocaloric energy from total sugars, and sucrose, fructose, and inositol intake significantly increased caries risk. Our findings can help raise awareness about the potential caries risk from the main sources of these sugars, natural fruit juices and sweetened beverages, which are consumed in great quantities in many societies.

Effectiveness of a Toothpaste with Low Fluoride Content Combined with Trimetaphosphate on Dental Biofilm and Enamel Demineralization in situ.

OBJECTIVE: The aim of the present study was to evaluate in situ whether a toothpaste with low fluoride associated with sodium trimetaphosphate (TMP) would provide similar effect to that of a 1,100 ppm F toothpaste. DESIGN: This crossover double-blind study consisted of 4 phases (14 days each), during which 10 volunteers wore oral appliances containing 4 enamel bovine blocks. The cariogenic challenge was performed by the application of a 20% sucrose solution (6×/day). The toothpaste treatments (2×/day) were: placebo, 500 ppm F, 500 ppm F plus 1% TMP, and 1,100 ppm F. At the end, enamel mineral loss and biofilm composition were analyzed. RESULTS: The toothpaste with 500 ppm F plus 1% TMP showed the lowest mineral loss (p < 0.05). Regarding the fluoride and calcium concentrations in the enamel and in the biofilm, there were no significant differences between 500 ppm F plus 1% TMP, and 1,100 ppm F toothpastes (p > 0.569), but they were significantly different when compared to toothpaste with 500 ppm F (p < 0.050). CONCLUSION: The addition of 1% TMP to a low-fluoride toothpaste reduces enamel demineralization in situ similar to a 1,100 ppm F toothpaste.

Evaluating the cariogenic potential of flavored milk: an experimental study using rat model.

OBJECTIVE: The purpose of this study was to evaluate and to compare the cariogenic potential of different commonly consumed favored milk on caries development in rat's molar teeth. MATERIALS AND METHODS: Sixty Sprague-Dawley rats infected with an active growing culture of Streptococcus mutans were offered chocolate favored milk, strawberry favored milk, banana favored milk, plain milk, sweetened plain milk with 5% sucrose, and 10% sucrose ad libitum. RESULTS: Rats consuming favored milk developed significantly lower sulcal and smooth surface caries scores than rats consuming 10% sucrose. However, rats consuming plain milk developed significantly lower sulcal and smooth surface caries scores than animals consuming favored or sweetened plain milk except for chocolate favored milk. CONCLUSION: It was concluded that favored milk containing 5% sucrose showed a moderate cariogenic potential. CLINICAL SIGNIFICANCE: Although the overall results suggest that the cariogenic potential of favored milk is moderate and despite their nutritional value, occasional consumption of favored milk as a beverage might be accepted with caution. Parents, dental practitioners and other healthcare professionals should be aware of the cariogenicity of favored milk. They should keenly encourage the use of plain milk and discourage the use of any cariogenic drink which has a deleterious effect on teeth.

[Stevia in the fight against dental caries]. / Stevia in de strijd tegen cariës.

Stevia is a natural, non-caloric sweetener of plant origin. The sweetening power of stevia is several hundred times larger than that of table sugar (sucrose). On the basis of available research, the European Food Safety Authority concluded that stevia is safe for human consumption. Since then, stevia has been approved as a sweetener for the European market. As a substitute for sucrose, stevia can contribute to a reduced caloric intake and can play a role in the prevention and/or treatment of metabolic disorders. In addition, stevia is non-cariogenic and is, moreover, affordable. Promoting the consumption of stevia can therefore be a preventive means of fighting dental caries.

Effectiveness of fluorescence-based methods to detect in situ demineralization and remineralization on smooth surfaces.

This study aimed to evaluate the effectiveness of fluorescence-based methods (DIAGNOdent, LF; DIAGNOdent pen, LFpen, and VistaProof fluorescence camera, FC) in detecting demineralization and remineralization on smooth surfaces in situ. Ten volunteers wore acrylic palatal appliances, each containing 6 enamel blocks that were demineralized for 14 days by exposure to a 20% sucrose solution and 3 of them were remineralized for 7 days with fluoride dentifrice. Sixty enamel blocks were evaluated at baseline, after demineralization and 30 blocks after remineralization by two examiners using LF, LFpen and FC. They were submitted to surface microhardness (SMH) and cross-sectional microhardness analysis. The integrated loss of surface hardness (ΔKHN) was calculated. The intraclass correlation coefficient for interexaminer reproducibility ranged from 0.21 (FC) to 0.86 (LFpen). SMH, LF and LFpen values presented significant differences among the three phases. However, FC fluorescence values showed no significant differences between the demineralization and remineralization phases. Fluorescence values for baseline, demineralized and remineralized enamel were, respectively, 5.4 ± 1.0, 9.2 ± 2.2 and 7.0 ± 1.5 for LF; 10.5 ± 2.0, 15.0 ± 3.2 and 12.5 ± 2.9 for LFpen, and 1.0 ± 0.0, 1.0 ± 0.1 and 1.0 ± 0.1 for FC. SMH and ΔKHN showed significant differences between demineralization and remineralization phases. There was a negative and significant correlation between SMH and LF and LFpen in the remineralization phase. In conclusion, LF and LFpen devices were effective in detecting demineralization and remineralization on smooth surfaces provoked in situ.

Influence of the number of adhesive layers on adhesive interface properties under cariogenic challenge using streptococcus mutans.

PURPOSE: To test the hypothesis that the number of adhesive layers influences the adhesive interface properties under cariogenic challenge conditions using a Streptococcus mutans model. MATERIALS AND METHODS: Bovine teeth (n = 90) were sectioned into blocks of 5 mm and divided into two groups for microleakage testing (n = 60) and tensile bond strength testing (n = 30). In each group, the samples were subdivided into subgroups according to the number of adhesive layers applied on the dentin: one (SB1), two (SB2), and three adhesive layers (SB3). The samples of the control groups were placed in BHI broth medium supplemented with 2% sucrose without microorganisms, and the experimental groups were submitted to Streptococcus mutans American Type Culture Collection (ATCC) for 5 days. For the tensile strength test, samples were sectioned into 1-mm-thick slices and submitted to a constant load of 0.5 mm/min in a universal testing machine. Fractured surfaces were analyzed and characterized as adhesive, cohesive, or mixed. The microleakage test was performed with silver nitrate solution. RESULTS: In experimental groups, the tensile test revealed a statistically significant difference between the one- (18.59 ± 5.3) and three-layer (11.28 ± 5.0) groups (p < 0.001; ANOVA and Tukey's test). The adhesive failure mode was slightly more frequent in the one- (60%) and three-layer (80%) adhesive application groups. On the other hand, the microleakage levels of all experimental groups were statistically similar (Kruskal-Wallis; p > 0.05). CONCLUSION: The experimental conditions influenced tensile properties and failure modes of different adhesive interfaces; however, they did not influence microleakage.

Parental views on delivering preventive advice to children referred for treatment of dental caries under general anaesthesia: a qualitative investigation.

OBJECTIVES: To: 1, Explore opinions of parents of children undergoing caries treatment under general anaesthesia (GA) regarding delivery of oral health advice; 2, Discover current oral health practices and beliefs; 3, Inform further research and action. METHODS: Qualitative study using semi-structured interviews and thematic data analysis, sampling parents of children aged 3-10 years undergoing GA tooth extraction due to dental caries. RESULTS: Twenty nine parents were interviewed (mean age 38.9 years, range 28-50, sd 6.4). The mean age of their children was seven years (range 3-10, sd 2.1). All children required deciduous tooth extractions (5.1 teeth on average). Those that also required permanent tooth extractions had on average 2.1 permanent teeth extracted. Many parents knew the importance of oral hygiene and sugar limitation, describing it as 'general knowledge' and 'common sense'. However, few understood that fruit juice is potentially cariogenic. Parenting challenges seemed to restrict their ability to control the child's diet and establish oral hygiene. Many reported not previously receiving oral health advice and reported never having fluoride varnish applied. There were requests for more caries prevention information and advice via the internet, schools or video games. CONCLUSION: Parental oral health knowledge, parenting skills, and previous advice received seem to all be issues related to the oral health of those children. Providing advice, especially in respect to fruit juice cariogenicity and the benefits of fluoride application through a child-friendly website, including a video game, as well as the use of school programmes might be an acceptable approach.

Role of fluoridated dentifrices in root caries formation in vitro.

PURPOSE: To evaluate in vitro root caries formation in human permanent teeth and to determine the effects of commercially available dentifrices containing different amounts of fluoride, while employing a well-tested artificial caries system using an acidified gel. METHODS: Root surfaces from caries-free human permanent teeth (n = 10) underwent debridement and fluoride-free prophylaxis. The tooth roots were sectioned into six portions, and acid-resistant varnish was placed with two sound root surface windows exposed on each tooth portion. Each portion from a single tooth was assigned to a treatment group: (1) No treatment control; (2) Denticious 5000 dentifrice (5,000 ppm F + xylitol); (3) PreviDent 5000 (5,000 ppm F); (4) AIM dentifrice (1,500 ppm F); (5) Listerine dentifrice (1,300 ppm F); and (6) Crest Regular Paste (1,500 ppm F). Tooth portions were treated with fresh dentifrice twice daily for 180 seconds, followed by fresh synthetic saliva rinsing over a 7-day period. Controls were exposed twice daily to fresh synthetic saliva rinsing over a 7-day period. In vitro root caries were created using an acidified gel (pH 4.25, 21 days). Longitudinal sections (three sections/tooth portion, 30 sections/group; 60 lesions/group) were evaluated for mean lesion depths (water imbibition, polarized light). Statistical analyses were performed using ANOVA and Duncan's Multiple Range test. RESULTS: Mean lesion depths were 389 +/- 43 microm for No treatment - control, 223 +/- 33 microm for Denticious 5000 dentifrice, 242 +/- 42 microm for Prevident 5000, 337 +/- 29 microm for AIM dentifrice, 297 +/- 37 microm for Listerine dentifrice, and 282 +/- 34 microm for Crest Regular Paste dentifrice. All treatment groups had mean depths significantly less than the No treatment - control group (P < 0.05). Denticious 5000 and PreviDent 5000 had significantly reduced mean depth compared with the other dentifrice treatment groups (P < 0.05).

Association between knowledge of caries preventive practices, preventive oral health habits of parents and children and caries experience in children resident in sub-urban Nigeria.

BACKGROUND: The objectives of this study were to assess the association between children and parents' knowledge of caries preventive practices, the parents' caries preventive oral health behaviours and children's caries preventive oral health behaviour and caries experience. METHOD: Three hundred and twenty four participants aged 8-12 years, 308 fathers and 318 mothers were recruited through a household survey conducted in Suburban Nigeria. A questionnaire was administered to generate information on fathers, mothers and children's knowledge of caries prevention measures and their oral health behaviour. Clinical examination was conducted on the children to determine their dmft/DMFT. Analysis was conducted to determine the predictors of the children's good oral health behaviour. RESULT: The mothers' oral health behaviours were significant predictors of the children's oral health behaviours. Children who had good knowledge of caries prevention measures had significant increased odds of brushing their teeth twice daily or more. The children's caries prevalence was 13.9%, the mean dmft was 0.2 and the mean DMFT was 0.09. None of the dependent variables could predict the presence of caries in children. CONCLUSION: The study highlights the effect of maternal oral health behaviour on the oral health behaviour of children aged 8 years to 12 years in suburban Nigeria. A pilot study is needed to evaluate how enhanced maternal preventive oral health practices can improve the oral health preventive practices of children.

Comparative evaluation of cariogenic and erosive potential of commonly prescribed pediatric liquid medicaments: an in vitro study.

INTRODUCTION: Liquid oral medicines being the most accepted form of medication in children are frequently prescribed. The harmful effects of these liquid medicaments on a child's dental health are not known to many. The present study aimed to evaluate and compare the cariogenic and erosive potential of 5 most commonly prescribed pediatric liquid medicaments (PLM) in Pimpri Chinchwad and Pune city, Pune district. MATERIALS AND METHODS: Most commonly prescribed PLM in Pune district were selected as opined by 50 pediatricians. The selected medicaments were Syr. Augmentin® Duo, Syr. Valparin®, Syr. Combiflam®, Syr. Visyneral and Syr. Orofer®. An estimation of pH, percentage of sucrose concentration and calcium dissolving capacity of these preparations was carried out. The results as obtained were subjected to statistical analysis using SPSS v 17.0 for windows. The statistical test as undertaken was Pearson's correlation coeffcient(r). RESULTS: Sucrose was seen to be present in Syr. Combiflam® (35.75% ± 0.25%) and Syr. Visyneral (18.48% ± 0.43%). Acidic pH was observed for Syr. Visyneral (mean pH 3.63 ± 0.04), Syr. Combiflam®(mean pH 5.03 ± 0.02) and Syr. Augmentin® (mean pH 6.22 ± 0.02). Highest calcium dissolution was seen with Syr. Combiflam®(295.86 mg/ml) and the least with Syr. Orofer® (25.51 mg/ml). No statistical significant correlation was observed with calcium dissolution potential of PLM in comparison with their respective pH. CONCLUSION: Syr. Combiflam® can be regarded as the highest cariogenic and erosive potential medicament among the compared and tested PLM. CLINICAL SIGNIFICANCE: Considering syrups with high cariogenic and erosive potential should always follow with proper oral hygiene practices or search for an alternative drugs void of such detrimental effects.

Primary school-based behavioural interventions for preventing caries.

BACKGROUND: Dental caries is one of the most common global childhood diseases and is, for the most part, entirely preventable. Good oral health is dependent on the establishment of the key behaviours of toothbrushing with fluoride toothpaste and controlling sugar snacking. Primary schools provide a potential setting in which these behavioural interventions can support children to develop independent and habitual healthy behaviours. OBJECTIVES: To assess the clinical effects of school-based interventions aimed at changing behaviour related to toothbrushing habits and the frequency of consumption of cariogenic food and drink in children (4 to 12 year olds) for caries prevention. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 18 October 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 4), MEDLINE via OVID (1948 to 18 October 2012), EMBASE via OVID (1980 to 18 October 2012), CINAHL via EBSCO (1981 to 18 October 2012) and PsycINFO via OVID (1950 to 18 October 2012). Ongoing trials were searched for using Current Controlled Trials (to 18 October 2012) and ClinicalTrials.gov (to 18 October 2012). Conference proceedings were searched for using ZETOC (1993 to 18 October 2012) and Web of Science (1990 to 18 October 2012). We searched for thesis abstracts using the Proquest Dissertations and Theses database (1950 to 18 October 2012). There were no restrictions regarding language or date of publication. Non-English language papers were included and translated in full by native speakers. SELECTION CRITERIA: Randomised controlled trials of behavioural interventions in primary schools (children aged 4 to 12 years at baseline) were selected. Included studies had to include behavioural interventions addressing both toothbrushing and consumption of cariogenic foods or drinks and have a primary school as a focus for delivery of the intervention. DATA COLLECTION AND ANALYSIS: Two pairs of review authors independently extracted data related to methods, participants, intervention design including behaviour change techniques (BCTs) utilised, outcome measures and risk of bias. Relevant statistical information was assessed by a statistician subsequently. All included studies contact authors were emailed for copies of intervention materials. Additionally, three attempts were made to contact study authors to clarify missing information. MAIN RESULTS: We included four studies involving 2302 children. One study was at unclear risk of bias and three were at high risk of bias. Included studies reported heterogeneity in both the intervention design and outcome measures used; this made statistical comparison difficult. Additionally this review is limited by poor reporting of intervention procedure and design. Several BCTs were identified in the trials: these included information around the consequences of twice daily brushing and controlling sugar snacking; information on consequences of adverse behaviour and instruction and demonstration regarding skill development of relevant oral health behaviours.Only one included study reported the primary outcome of development of caries. This small study at unclear risk of bias showed a prevented fraction of 0.65 (95% confidence interval (CI) 0.12 to 1.18) in the intervention group. However, as this is based on a single study, this finding should be interpreted with caution.Although no meta-analysis was performed with respect to plaque outcomes (due to differences in plaque reporting between studies), the three studies which reported plaque outcomes all found a statistically significant reduction in plaque in the intervention groups with respect to plaque outcomes. Two of these trials involved an 'active' home component where parents were given tasks relating to the school oral health programme (games and homework) to complete with their children. Secondary outcome measures from one study reported that the intervention had a positive impact upon children's oral health knowledge. AUTHORS' CONCLUSIONS: Currently, there is insufficient evidence for the efficacy of primary school-based behavioural interventions for reducing caries. There is limited evidence for the effectiveness of these interventions on plaque outcomes and on children's oral health knowledge acquisition. None of the included interventions were reported as being based on or derived from behavioural theory. There is a need for further high quality research to utilise theory in the design and evaluation of interventions for changing oral health related behaviours in children and their parents.

Characterizing and identifying incipient carious lesions in dental enamel using micro-Raman spectroscopy.

Early detection of dental caries is vital if improved patient outcomes are to be achieved by reversal of the demineralization process. Current techniques used by dentists for identifying carious lesions are effective in identifying more advanced lesions, but do not have sufficient sensitivity and specificity to detect them at the earliest stages. This study focused on characterizing the growth of incipient carious lesions in vitro using micro-Raman spectroscopy. The incipient carious lesions were grown on the buccal faces of human molars by controlled exposure to lactic acid. Lesions were cross-sectioned to expose the subsurface body of the lesion and then examined using micro-Raman spectroscopy. The intensity of the phosphate peaks in the Raman spectra was found to differ significantly between healthy enamel and the demineralized region of the lesions. The sensitivity of the phosphate peaks to the degree of demineralization was observed by taking a series of spectra over the cross section of the lesions. This revealed that the body of the lesion is highly demineralized, but in a narrow surface region (up to 10 µm) there is little demineralization. All the phosphate peaks were found to be sensitive to the degree of demineralization; however, changes in the intensity of the pronounced phosphate peak at 961 cm(-1) offer the most promise for identifying lesions. The results indicate that micro-Raman spectroscopy has both the sensitivity and selectivity to identify incipient carious lesions, but the presence of a surface layer with a relatively high mineral content could complicate the analysis.

Staining of dentin from amalgam corrosion is induced by demineralization.

PURPOSE: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. METHODS: Sound human molars (n = 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n = 24). Non-demineralized teeth served as controls (n = the 10). A dispersive high-Cu amalgam or conventional low-Cu amalgam was condensed onto dentin surfaces of all groups. After 10 weeks storage in saline, amalgam was removed and teeth were cut into three slices. Surfaces were inspected under optical microscopy and photographed. RESULTS: Penetration of black pigments was observed in dentin underneath both high-Cu and low-Cu amalgams in demineralized specimens. Black deposits were unevenly distributed and observed predominantly in dentin near to pulp horns. Discoloration was not limited to outer demineralized dentin but extended beyond this zone. Evenly distributed bluish-green discoloration was observed underneath all high-Cu amalgam specimens independent of demineralization.

An in vitro study on the secondary caries-prevention properties of three restorative materials.

STATEMENT OF PROBLEM: Secondary caries is considered to be the most important and common reason for the replacement of all types of restorations. PURPOSE: The purpose of the study was to evaluate in vitro both the anticaries efficacy and marginal integrity of amalgam, glass ionomer cement, and composite resin restorations in a cariogenic condition. MATERIAL AND METHODS: Class II cavities were prepared on 60 extracted teeth, which were assigned to 3 groups and restored either with amalgam, glass ionomer, or composite resin. After thermal cycling and sterilization, the teeth were set in an artificial carious environment for 10 days. The bacteria from the margin of the restorations were then collected, and microleakage was evaluated by means of dyeing. According to the locations, the demineralization of tooth tissue around the restoration was divided into 3 parts: artificial outer lesion, artificial enamel wall lesion, and artificial dentin wall lesion. The depths of the artificial outer lesion and the areas of the artificial enamel and dentin wall lesions were investigated with a confocal laser scanning microscope after all the specimens had been stained with 0.1 mM Rhodamine B. Statistical analyses consisted of 1-way ANOVA and Kruskal-Wallis tests (α=.05). RESULTS: No significant difference was noted in terms of the number of bacteria around the restorations for the 3 materials; the microleakage of amalgam was the least among the 3 types of restorations; the outer enamel lesion depth around the glass ionomer cement was the lowest, and the wall lesion area around the amalgam was the smallest. CONCLUSIONS: No definite inhibitory effect of fluoride releasing restorative materials (glass ionomer) was apparent on Lactobacillus acidophilus in this study. The amalgam restorations showed the best marginal integrity and the smallest artificial wall lesion among the 3 types of restorations.

Roles of dentists and dental hygienists in two major earthquakes.

BACKGROUND: In recent years, disasters that overwhelm the capacity of humans have been frequent. However, international cooperation has been swift as a result of advances in transportation, enabling the more prompt administration of First Aid. METHODS: We have had two opportunities to observe outcomes in oral hygiene immediately after and 10 months after two different major disasters. RESULTS: The types of food provided to survivors altered their sense of taste and resulted in the occurrence of dental caries several months after an earthquake. In addition, it is difficult to practise good oral hygiene in the aftermath of a disaster. CONCLUSIONS: We observed the occurrence of previously undocumented problems related to dental issues, such as changes in children's sense of taste caused by unfamiliar types of food provided in relief shelters. Dentists and dental hygienists who are involved in the relief of survivors in the immediate aftermath of a natural disaster should focus on maintaining good oral health in order to prevent the occurrence of dental caries.

Effect of bamboo salt-NaF dentifrice on enamel remineralization.

PURPOSE: To evaluate the laboratory remineralization effects of a dentifrice with bamboo salt and NaF on artificial caries-like enamel lesions, at both the surface and deep areas. METHODS: Early dental caries lesions were formed by treating bovine enamel samples for 48 hours at 37 degrees C with a demineralization solution (pH 5.0) containing 0.1 M lactic acid, 0.2% Carbopol 907, and 50% saturated calcium phosphate tribasic. pH cycling was then performed by immersing the samples in dentifrice slurry for 2 minutes every 8 hours per day, and in demineralization solution for 4 hours and mixed saliva for the remaining time period. The mixed saliva consisted of 50% human saliva and 50% artificial saliva. The surface hardness and the level of mineral surface alterations were analyzed using a hardness tester and transversal microradiography, among negative control (fluoride free), positive control (sodium fluoride 1100 ppm, Crest Cavity Protection), and test dentifrice (3.0% bamboo salt with sodium fluoride 1,000 ppm) groups. RESULTS: Test and positive control groups significantly increased the level of the surface hardness and decreased mineral loss of the artificial caries-like enamel lesions compared to the negative control (P<0.05). The test dentifrice also significantly decreased the lesion depth compared to the other two groups (P<0.05).