In vitro assessment of 3 dentifrices containing fluoride in preventing demineralization of overdenture abutments and root surfaces.

STATEMENT OF PROBLEM: Caries development under overdentures has been a continuing problem and requires the daily use of fluoride to prevent demineralization. PURPOSE: The purpose of this in vitro study was to compare the effectiveness of dentifrices containing tricalcium phosphate or calcium phosphosilicate in combination with fluoride to prevent the demineralization of overdenture abutments and root surfaces. MATERIAL AND METHODS: A total of 56 caries-free extracted teeth were prepared as overdenture abutments. The teeth were painted with acid-resistant varnish, leaving one 1×4-mm window on occlusal and root surfaces. The teeth were randomly divided into 4 groups: a control group treated with distilled/deionized water only, a group treated with ClinPro 5000, a group treated with ReNew, and a group treated with Prevident 5000 gel. Each tooth was subjected to a demineralizing/remineralizing cycling protocol for 12 days with the appropriate treatment products. The teeth were sectioned longitudinally through both windows. Photomicrographs were made of 3 representative sections from each tooth. A representative section was defined as one that included both windows and was cut from the part of the tooth that had the flattest surface to reduce the edge effect. The depths of the lesions were measured on representative sections from each group. A 1-way MANOVA and a 1-way ANOVA with the post hoc Tukey-Kramer test were used to evaluate the treatment effects on the criterion variables (α=.05). RESULTS: The total lesion depths of the control teeth on the occlusal surface were not statistically significantly deeper than for the 3 dentifrices (P=.7705). However, all 3 dentifrices had narrower cavitation depths than the control (mean cavitation band depth, 43.59 [ReNew] versus 37.99 [Prevident 5000 gel] versus 36.70 [ClinPro 5000] versus 246.86 [control]) (P<.001). The mean remineralization band depth for ClinPro 5000 was significantly greater than for the other 2 treatment groups (118.03 [ClinPro 5000] versus 107.80 [ReNew] versus 102.28 [Prevident 5000 gel]) (P<.001). On root surfaces, the total lesion depth for the control group was statistically significantly deeper than for the 3 dentifrices (mean total lesion depth, 150.31 [control] versus 82.05 [ReNew] versus 68.10 [ClinPro 5000] versus 56.97 [Prevident 5000 gel]) (P<.001). The data indicated that teeth treated with Prevident 5000 gel had the shallowest total lesion depth and were statistically significantly different from those treated with ReNew and ClinPro 5000. Moreover, teeth treated with ReNew were found to have the largest remineralization band depth, which was statistically significantly different compared with ClinPro 5000 and Prevident 5000 gel (mean remineralization band depth, 49.66 [ReNew] versus 36.14 [ClinPro 5000] versus 23.27 [Prevident 5000 gel]) (P<.001), but no difference was found in cavitation depth of the root lesions between the 3 dentifrices. CONCLUSIONS: The addition of tricalcium phosphate or calcium phosphosilicate to fluoride-containing dentifrices (5000 ppm) does not significantly improve their ability to prevent demineralization of the cut dentin surface of overdenture abutments. However, on root surfaces, ReNew, which contains calcium phosphosilicate, was found to improve remineralization of the lesions compared with Prevident 5000 gel or ClinPro 5000.

Erosive potentials of brewed teas.

PURPOSE: To measure the pH, titratable acidity, fluoride concentration and erosive potential of brewed teas. METHODS: Bag teas were purchased to represent black, green, citrus, fruity, and floral tea flavors from Tulsi, Bigelow, HyVee, Tazo, and Yogi brands and brewed (1 bag/240 ml) in boiling water for 3 minutes. The pH, titratable acidity, and fluoride concentrations were measured. Following these measurements, a representative tea from each flavor was selected for investigation of erosion potential. Six extracted human molars were randomly assigned to each tea. Teeth were painted with fingernail polish to expose a 1 x 4 mm window and then soaked in tea for a total of 25 hours with teas refreshed every 5 hours. Teeth were then sectioned using a microtome and photographed using a polarized light microscope. Lesion depths (i.e., eroded surfaces) were measured using Image Pro Plus software. Differences in physiochemical properties and lesion depths between beverages were investigated using one-way ANOVA with post-hoc Tukey's HSD test. Relationships among lesion depths and physiochemical properties were evaluated using the Pearson correlation test. RESULTS: pH, titratable acidity and fluoride concentrations differed between tea flavors (P < 0.05) and between brands (P < 0.05). Lesion depths produced by the citrus tea (83.1 +/- 10.3 microm) were greater than those produced by the fruity tea (56.5 +/- 6.1 microm); both teas produced greater depths than black (30.1 +/- 7.4 microm), floral (25.0 +/- 3.2 microm) or green (22.3 +/- 6.3 microm) teas (P < 0.05). pH (r = -0.96; P = 0.009) was inversely and titratable acidity (r = 0.97; P = 0.006) was positively associated with lesion depths.

The inhibitory effect of MI paste, fluoride and a combination of both on the progression of artificial caries-like lesions in enamel.

This in-vitro study evaluated the inhibition of demineralization in enamel sections produced by MI paste, fluoride and a combination of both, compared to artificial saliva and NaF 5000 ppm in a caries progression pH-cycling model. Twenty-one teeth were demineralized to create subsurface enamel lesions (approximately 200 microns in depth). The teeth were sectioned and characterized using polarized-light-microscopy (PLM). A single section from each lesion was assigned to a treatment group: Artificial saliva, NaF 5000 ppm (Prevident, Colgate), MI paste (Recaldent, GC America Inc), NaF 1100 ppm (Crest, Procter & Gamble) and NaF 1100 ppm plus MI paste. The sections were covered with varnish except for an exposed window on the external surface of the lesion and placed in a six-day pH-cycling model with two daily treatment applications of two minutes each. The sections were characterized by PLM, and the lesion areas were measured using a digital image analysis system. Based on a paired-sample t-test, significant differences (p < .05) in percentage of change in lesion size were found between the high fluoride group and all the other groups. No significant difference was found between the artificial saliva and MI paste group, neither was there any significant difference between the NaF 1100 ppm, the combined application group or the MI paste group alone. In conclusion, the higher concentration of NaF (5000 ppm) reduced lesion progression to the greatest extent. The MI paste group did not show any effect on the inhibition of lesion progression. Further studies on the preventive effect and longer treatment applications are recommended.

In vitro protection against dental erosion afforded by commercially available, calcium-fortified 100 percent juices.

BACKGROUND: Calcium in acidic beverages can decrease a person's risk of experiencing dental erosion. The authors compared the pHs and titratable acidities of commercially available calcium-fortified and unfortified 100 percent juices, and enamel and root surface lesion depths after they were exposed to different juices. METHODS: The authors measured the pH and titratable acidity of calcium-fortified and unfortified 100 percent juices. They exposed enamel and root surfaces to different 100 percent juices for 25 hours and measured lesion depths. They used the Spearman rank correlation test and the two-sample t test to identify associations between the juices' properties and lesion depths and to compare lesion depths between fortified and unfortified juices. RESULTS: The authors found that fortifying apple, orange and grapefruit juices with calcium prevented enamel erosion and decreased root surface erosion (P < .01). They also found that fortifying white grape juice with calcium decreased enamel erosion (P < .001) but not root surface erosion. They observed that mean lesion depths were greater in root surfaces than in enamel surfaces after exposure to unfortified orange juice and all fortified juices (P < .001). CONCLUSIONS: Calcium concentrations in commercially available, calcium-fortified 100 percent juices are sufficient to decrease and prevent erosion associated with extended exposure to a beverage. CLINICAL IMPLICATIONS: People at risk of experiencing erosion could decrease their erosion risk by consuming calcium-fortified juices.

Timing of fluoride intake in relation to development of fluorosis on maxillary central incisors.

OBJECTIVES: Several studies have focused on the timing of fluoride intake relative to the development of dental fluorosis. This study reports the relationships of fluoride intake during the first 48 months of life with fluorosis on early-erupting permanent teeth. METHODS: Subjects were followed from birth to 48 months with questionnaires every 3-4 months. Questionnaires gathered data on intakes from water, diet, supplements, and dentifrice to estimate total fluoride intake. Early-erupting permanent teeth of 579 subjects were assessed for fluorosis using the Fluorosis Risk Index (FRI) at approximately age 9. Fluorosis cases were defined as having FRI definitive or severe fluorosis on both maxillary central incisors. Individuals with FRI questionable fluorosis were excluded. The importance of fluoride intake during different time periods was assessed using t-tests and logistic regression. RESULTS: One hundred and thirty-nine (24%) subjects had fluorosis on both maxillary central incisors. Mean fluoride intake per unit body weight (bw) ranged from 0.040 to 0.057 mg/kg bw, with higher intake during earlier time periods and relative stability after 16 months. In bivariate analyses, fluoride intakes during each of the first 4 years were individually significantly related to fluorosis on maxillary central incisors, with the first year most important (P < 0.01), followed by the second (P < 0.01), third (P < 0.01), and fourth year (P = 0.03). Multivariable logistic regression analyses showed that, after controlling only for the first year, the later years individually were still statistically significant. When all four time periods were in the model, the first (P < 0.01) and second years (P = 0.04) were still significant, but the third (P = 0.32) and fourth (P = 0.82) were not. CONCLUSIONS: The first two years of life were most important to fluorosis development in permanent maxillary central incisors; however, this study also suggests the importance of other individual years.

Prevention of demineralization by CO2 and Er,Cr:YSGG laser irradiation of overdenture abutments.

PURPOSE: To assess the effects of Er,Cr:YSGG and CO2 laser irradiation on the prevention of demineralization of overdenture abutments. METHODS: 32 human canines, premolars, and molars were acquired, cleaned, and scaled. They were randomly divided into two groups. Each tooth had two windows on the occlusal cut dentin. One window on each tooth was irradiated by either Er,Cr:YSGG or CO2 laser, while the other window served as a control. After pH cycling at pH 5.5 for 18 days and pH 4.7 for 16 days, the teeth were sectioned and analyzed using polarized light microscopy with water as the imbibing medium. RESULTS: The Er,Cr:YSGG irradiated dentin had a mean lesion depth of 207 +/- 27 microm while its control had a mean lesion depth of 209 +/- 34 microm. The CO2 laser irradiated dentin had a mean lesion depth of 185 +/- 24 microm while its control had a mean lesion depth of 205 +/- 22 microm. Based on paired t-tests Er,Cr:YSGG laser irradiation of dentin did not reduce demineralization when compared to the controls (P= 0.81), while CO2 laser irradiation of dentin showed that it helped reduce demineralization when compared to the controls (P= 0.025).

Fluoride assay methodology for carbonated beverages.

PURPOSE: The purpose of this paper was to review different methodological techniques used for the assessment of fluoride in carbonated beverages, and compare results using a fluoride ion electrode direct read method with and without a prior decarbonation treatment. METHODS: The carbonated beverages in this study were either purchased locally at grocery stores in Iowa City, Iowa, or purchased as part of a national representative sampling approach included in the National Fluoride Database and Intake Assessment Study (NFDIAS). The samples were compared with and without a decarbonating process. Soda pop and beer samples were analyzed by removing a 1-ml sample and adding a 1-ml buffer solution. The fluoride concentration of the sample and buffer combination was then determined using a fluoride ion specific electrode. RESULTS: There was no significant difference in the fluoride concentration of the samples with or without prior decarbonation. The mean absolute difference between the soda pop group with and without decarbonation was 0.01 ppm F, while results from the beer samples showed variation of 0.00 to 0.02 parts per million fluoride (ppm F). These differences were not statistically significant for the soda pop or beer groups (P=.50 and P=.74, respectively). CONCLUSION: Whether or not decarbonation was conducted prior to analysis, the fluoride assay results were the same. Therefore, decarbonation of soda pop and beer was deemed unnecessary prior to fluoride analysis.

Association of amoxicillin use during early childhood with developmental tooth enamel defects.

BACKGROUND: It has been speculated that amoxicillin use could be associated with dental enamel defects. OBJECTIVE: To assess the association between dental fluorosis, one of the most common developmental tooth enamel defects, and amoxicillin use during early childhood. DESIGN, SETTING, AND PARTICIPANTS: As participants in the Iowa Fluoride Study, subjects were followed up from birth to 32 months using questionnaires every 3 to 4 months to gather information on fluoride intake and amoxicillin use. METHODS: Early-erupting permanent teeth of 579 subjects were assessed for fluorosis using the Fluorosis Risk Index at approximately the age of 9 years. Relationships between fluorosis and amoxicillin use were assessed using relative risk (RR), Mantel-Haenszel stratified analyses, and multivariable logistic regression. RESULTS: Amoxicillin use was reported by 75% of subjects by 12 months and 91% by 32 months. Overall, 24% had fluorosis on both maxillary central incisors. Amoxicillin use from 3 to 6 months significantly increased the risk of fluorosis on the maxillary central incisors (RR = 2.04; 95% confidence interval [CI], 1.49-2.78). After adjusting for fluoride intake and otitis media, the risk of fluorosis on the maxillary central incisors from amoxicillin use during 3 to 6 months (Mantel-Haenszel RR = 1.85; 95% CI, 1.20-2.78) was still statistically significant. Multivariable logistic regression analyses confirmed the increased risk of fluorosis from amoxicillin use during 3 to 6 months (odds ratio = 2.50; 95% CI, 1.21-5.15); fluoride intake was also statistically significant. CONCLUSION: The findings from this study suggest a link between amoxicillin use during infancy and developmental enamel defects of permanent teeth; however, further research is needed.

Interfacial fracture toughness between resin-modified glass ionomer and dentin using three different surface treatments.

OBJECTIVES: To identify the long-term dentin-resin modified glass ionomer cement (RMGIC) interfacial fracture toughness (FT) using three different dentin surface treatments prior to RMGIC placement. Fuji II LC (GC America) was bonded to dentin using cavity conditioner (CC), Scotchbond Multipurpose (3M ESPE) complete system (SS), or Scotchbond etching and priming without adhesive (SP). Twenty-four teeth were used for each of the three groups. METHODS: Two samples were obtained from each tooth and they were stored in artificial saliva (AS) or oil for 1- or 24-weeks before determining interfacial FT. The results were fit to Weibull distributions with log-rank and Wilcoxon tests for comparison of failure curves over time for each experimental condition. Statistical analysis was performed at a 0.05 level of significance. RESULTS: FT values in artificial saliva were as follows: 1 week SS=SP>CC, 6 months SS>SP=CC; in oil SS=SP=CC for both storage times. A significant decline in FT occurred between 1- and 24-week storage for SS and SP. Storage in oil, on the other hand tended to increase FT values for all groups. SIGNIFICANCE: These observations support findings of hydrolytic degradation in adhesive resin-based surface treatments.

Effect of topical fluoride and fluoride varnish on in vitro root surface lesions.

PURPOSE: To evaluate the effect of a fluoride varnish on demineralization and remineralization of root surfaces in vitro. METHODS: 80 caries-free teeth were selected from a large pool of extracted anterior and premolar teeth from elderly patients. Acid resistant nail varnish was painted on all surfaces except for a window (l x 4 mm) on the buccal or lingual root surfaces. Teeth were randomly divided into four treatment groups: CONTROL: washed with deionized/distilled water; Daily gel: treated with Karigel-N (5,000 ppm) for 4 minutes daily; Weekly gel: treated with Karigel-N for 4 minutes weekly; and Weekly varnish: treated with Duraflor (22,600 ppm) weekly (the varnish was removed 24 hours after each application). Teeth were then placed in a cycle of demineralization (6 hours at pH 4.3) and remineralization (17 hours at pH 7.0) for 21 days. Half the specimens of each group were brushed with no dentifrice for 10 seconds twice daily. Specimens were evaluated under polarized light microscopy and contact microradiography. The depth of each lesion and width of the remineralization bands were measured. An ANOVA model was used to assess the effect of different treatments. RESULTS: The control group had the deepest lesions and the daily gel group had the shallowest lesions. The weekly varnish group was found to have significantly shallower lesions than the weekly gel group. The varnish brushing subgroup had significantly deeper lesions than varnish non-brushing subgroup (P = 0.01). Remineralization bands were detectable in most lesions. There was no significant difference in band width between different groups (F = 0.634, P = 0.594). However, a significant difference was found when remineralization bands were calculated as percentage of lesion depth between different groups (F = 4.24, P = 0.001). The varnish non-brushing subgroup had significantly higher percentage than the control group, but daily gel non-brushing had the highest percentage. Brushing was a significant factor in the varnish group. Lesions were significantly shallower in the non-brushing varnish subgroup.

In vitro model for evaluating the effect of child formula toothpastes on artificial caries in primary dentition enamel.

PURPOSE: To determine if the in vitro 10-day pH-cycling model used for permanent teeth could be utilized to evaluate de/remineralization effects, on the enamel of primary teeth, of child formula toothpastes. METHODS: Sound extracted primary anterior teeth were coated with nail varnish, leaving a 1 mm-wide window prior to being placed in a demineralizing solution to produce artificial carious lesions in enamel. The teeth were subsequently cut longitudinally into 100 microm thick sections. The 72 specimens were randomly assigned to six groups. In Set 1 contained the specimens in Group a, which were treated with a pea-sized (0.32 g) quantity of non-fluoride toothpaste (First Teeth), and Groups b and c which were treated with half and pea-sized (0.16 g) quantities of fluoridated toothpaste (Colgate), and cycled for 10 days. The specimens in Set 2 (Groups A, B and C) were similarly treated but subjected to 7-day pH-cycling. RESULTS: After Day 8 the lesions in Set 1 extended into dentin and so could not be evaluated. Polarized light microscopy and microradiography were used to evaluate the lesions subjected to 7-day pH-cycling. Lesions in Groups A and B increased in depth and area by approximately 50%, while those in Group C increased in depth and area by 20%; however, no statistically significant differences occurred between the groups. If this model pH cycling is to be used for primary teeth, a reduction from 10 to 7 days in length should be considered.

Effect of 2% plain and fluoridated milk on root surface caries in vitro.

The caries-protective effect of milk and fluoridated milk on enamel has been reported; however, few data are available concerning the role of milk and/or fluoridated milk on root surfaces. The aim of this study was to compare the effect of plain and fluoridated milk on root surface caries. Artificial root surface lesions were created, sectioned and analyzed using polarized light microscopy (PLM) and microradiography (MRG). The sections were covered except for the original surface and assigned to a treatment group. The samples were immersed in 2% plain milk or fluoridated milk for 40 hours and re-evaluated. Changes were measured and mean differences were compared with an unpaired t-test. Both techniques revealed a reduction in lesion depth for each milk group; however, a significantly greater reduction (p<0.05) was observed with the fluoridated milk. These results suggest that fluoridated milk may have a beneficial effect on the remineralization of root surface caries.

Primary tooth fluorosis and fluoride intake during the first year of life.

OBJECTIVES: Few studies in North America have assessed dental fluorosis of the primary dentition and few, if any, anywhere have assessed the relative importance in fluorosis etiology of fluoride intake during different time periods or from multiple sources. The purpose of this paper is to report on analyses relating estimated prenatal fluoride intake and fluoride intake during different parts of the first year of life to primary tooth fluorosis. METHODS: As part of The Iowa Fluoride Study, subjects were recruited at birth and studied longitudinally. Trained examiners assessed dental fluorosis for children aged 4-7 years using the Tooth Surface Index of Fluorosis (TSIF) adapted for the primary dentition. Detailed parent questionnaires at childbirth were used to estimate prenatal fluoride intake and questionnaires sent at 6 weeks and 3, 6, 9, and 12 months were used to estimate fluoride intake during the first year of life (combined fluoride intake from water, food and beverage, supplements, and dentifrice). There were 504 children with prenatal and at least four of the five postnatal responses with complete data. RESULTS: Fluorosis prevalence was 12.1%, occurring primarily on the second primary molars. Receiver operating characteristic (ROC) curves and logistic regression were used to assess the importance of different time periods' fluoride intake. In bivariate analyses, fluoride intake during each time interval was individually significantly related to fluorosis occurrence. For multivariate analyses, the period from 6 to 9 months was most important individually (P = 0.0001), and no other period was jointly statistically significant. CONCLUSIONS: Results suggest that the middle of the first year of life is most important in fluorosis etiology for the primary dentition in this setting.

Effects of CO2 laser on fluoride uptake in enamel.

OBJECTIVES: The objective of this study was to investigate the effects of CO(2) laser on fluoride uptake in the loosely- and firmly-bound forms in enamel. METHODS: Five human molars were cut into halves before being treated with 2.0% NaF topical gel. Each half had three windows on the enamel surface, including one control and two experimental windows irradiated by two laser therapies. One half of each tooth was treated with 1 M KOH solution to remove the loosely-bound fluoride (calcium fluoride). A tooth section was obtained from each window and the relative fluorine concentration was analyzed with Secondary Ion Mass Spectrometry (SIMS). The morphology of the enamel surfaces in the windows was examined using an Environmental Scanning Electron Microscope (ESEM). RESULTS: Significant laser-induced increases in the uptake of fluoride were revealed in both loosely-bound and firmly-bound apatitic fluoride, with both laser treatments (all p<0.001). Calcium fluoride-like deposits on the enamel surfaces receiving the combined laser-fluoride treatment were revealed by ESEM. CONCLUSIONS: The finding of this study substantiated the laser effect in increasing the fluoride uptake into enamel.

Primary tooth fluorosis and amoxicillin use during infancy.

OBJECTIVE: It has been speculated that amoxicillin use could be associated with enamel defects, but there have been few studies of this possible relationship. This study assessed the association between amoxicillin use during the first year of life and primary tooth fluorosis. METHODS: Subjects (n = 490) were recruited at birth and followed prospectively with a series of questionnaires to gather information on fluoride intake and amoxicillin use. Primary tooth fluorosis was assessed by calibrated examiners at approximately 5 years of age. RESULTS: Amoxicillin use for 6 weeks to 3 months and 3 months to 6 months significantly increased the risk for fluorosis of primary second molars in bivariate analyses. However, after controlling for fluoride intake, the adjusted risks of fluorosis were not significant for amoxicillin use. No other antibiotics were significantly associated with fluorosis in the bivariate analyses. In multivariate analyses with logistic regressions, only fluoride intake was statistically significantly related to fluorosis. CONCLUSION: Fluoride exposure was the sole predictor of primary tooth fluorosis in a multivariate model. However, bivariate results suggest that amoxicillin could play a contributing role in the development of primary tooth fluorosis, especially for children exposed to lower levels of fluoride. An investigation of the relationship between amoxicillin intake and fluorosis of permanent teeth is warranted.

Single-step, self-etch adhesives behave as permeable membranes after polymerization. Part III. Evidence from fluid conductance and artificial caries inhibition.

PURPOSE: To test the hypothesis that formation of inhibition zones by bonded restorations in artificially-induced carious dentin lesions is related to the permeability of the self-etch adhesives. METHODS: Fluid conductance of four single-step self-etch adhesives (Prompt L-Pop, Etch&Prime 3.0, One-Up Bond F and Reactmer Bond), and a control two-step self-etch adhesive (UniFil Bond) were measured after sound dentin surfaces were:(1) acid-etched; (2) polished to produce smear layers; (3) bonded with the adhesive; each at 20 cm hydrostatic pressure (hp). Osmotic fluid conductance was also determined for the bonded dentin after immersion in 4.8 M CaCl2 at 0 cm hp. For artificial caries inhibition, a non-fluoride releasing (NFR) two-step self-etch adhesive (UniFil Bond) and a fluoride-releasing (FR) single-step adhesive (Reactmer Bond) were used in combination with a NFR composite (Metafil CX) or a FR restorative material (Reactmer Paste). Artificial caries were induced in these restorations, from which 120 +/- 10 microm thick sections and the effect of caries inhibition were quantitatively assessed with polarizing light microscopy and image analysis. RESULTS: Fluid conductance after bonding with the single-step adhesives Prompt L-Pop and Etch&Prime 3.0 were not significantly different from those recorded from smear layer-covered dentin. Although better seals were achieved with One-Up Bond F and Reactmer Bond, fluid conductance at 20 cm hp was significantly higher than the two-step self-etch adhesive UniFil Bond. Osmotic conductance at 0 cm hp were not significantly different from normal fluid conductance at 20 cm hp. The sizes of artificial carious lesions in UniFil Bond were significantly higher irrespective of whether a FR or NFR composite was used. Significant reduction in lesion size occurred in Reactmer Bond with the use of a NFR composite, and even more so with the use of a FR composite.

Practical fluoride and remineralization protocols for adult patients.

There is a wealth of information on preventive measures and procedures that can be used to care for paediatric and adolescent patients. However, few studies have been conducted in adult or geriatric populations, and an understanding of preventive and non-surgical treatment regimens for these patients is lacking. Traditionally, caries incidence is high among risk groups of low income, low dental IQ and certain ethnic subgroups, but we are now witnessing a high incidence of caries among middle-income and healthy adult patients with an imbalance of protective factors and cariogenic factors. We will direct our attention to the adult population and attempt to address some of the most common questions.

Explorer probing of root caries lesions: an in vitro study.

Probing with a dental explorer is the preferred method of root caries diagnoses. However, studies suggest that use of a dental explorer in coronal caries detection may damage tooth structure. This pilot study investigated the effect of probing on remineralization of root surface lesions in vitro. Root-surface lesions were created on 10 extracted teeth by exposing them to a demineralizing solution for 21 days. One side of each lesion was then randomly selected and probed with an explorer, while the other side was not probed. The teeth then were placed in a remineralizing solution containing 10 parts per million (ppm) fluoride for 21 days. Of the 9 teeth with usable sections, all showed frank evidence of defects on the probed halves. Sites of remineralization were seen in the non-probed halves and adjacent to the probed defects, but not within or at the base of these defects. These results suggest that probing of root surfaces may create defects that do not fully remineralize.

Comparison of in vitro erosion potentials between beverages available in the United Kingdom and the United States.

OBJECTIVE: Our objective was to compare the physiochemical properties and erosion potentials between beverages available in the UK and the US. METHODS: The physiochemical properties (pH, titratable acidity and fluoride concentration) and erosion potential on enamel surfaces of beverages available in the UK were compared to similar beverages from the US. Enamel windows were exposed to beverages for 25h. Teeth were sectioned through the windows, and lesion depths were defined as the average distance between the original tooth structure and the base of demineralization. RESULTS: The pH was lower in UK apple juice, orange juice, Diet Pepsi and Sprite Zero (p<0.05), and higher in UK orange soda and diet orange soda than in similar US beverages (p<0.05). Titratable acidities were higher in UK apple juice, orange juice, orange soda, diet orange soda and Sprite (p<0.01), and lower in UK Sunny D than in the US counterpart (p<0.001). Fluoride concentrations were lower in UK apple juice, orange juice, Coke, and Diet Coke, Sprite and Sprite Zero (p<0.001), and higher in UK orange soda, diet orange soda, Pepsi and Diet Pepsi than in their US counterparts (p<0.001). Lesion depths were higher in UK apple juice, orange juice, Diet Coke, Sprite and Sprite Zero than in their US counterparts (p<0.05). Lesion depths were associated with pH (p=0.010) and country of origin (p=0.002). CONCLUSIONS: Under similar laboratory conditions, the physiochemical properties and erosion potentials on enamel surfaces differed between some, but not all, beverages available in the UK and the US.

In vitro enamel erosion associated with commercially available original-flavor and sour versions of candies.

BACKGROUND: Exposure to acidic foods and beverages is thought to increase the risk of developing dental erosion. The authors hypothesized that the erosion potential of sour candies was greater than the erosion potential of original-flavor versions of the candies. METHODS: The authors measured the pH and titratable acidity of candies dissolved in artificial saliva or water. They then measured the lesion depths of enamel surfaces exposed to candy slurries for 25 hours. Statistical analyses included two-sample t tests and Wilcoxon rank-sum tests to identify differences between original-flavor and sour candies, as well as correlations to identify relationships between lesion depths, pH and titratable acidity. RESULTS: The study results show that lesion depths generally were greater after exposure of enamel to sour candies than they were after exposure of enamel to original-flavor candies, as well as for candies dissolved in water compared with those dissolved in artificial saliva. Lesion depths were negatively associated with the initial slurry pH and positively associated with titratable acidity. CONCLUSIONS: Both original-flavor and sour versions of candies are potentially erosive, with sour candies being of greater concern. Although saliva might protect against the erosive effects of original-flavor candies, it is much less likely to protect against the erosive effects of sour candies. CLINICAL IMPLICATIONS: People at risk of developing candy-associated erosion, particularly those with a high intake of candy, pocketing behaviors or decreased salivary flow, should receive preventive guidance regarding candy-consuming habits.