Investigação do potencial erosivo de gomas de mascar não convencionais / Investigation the erosive potential of unconventional chewing gums

Objetivo: mensurar o potencial erosivo de gomas de mascar não convencionais disponíveis no mercado brasileiro. Material e método: estudo experimental (in vitro) de caráter quantitativo. Foram adquiridos oito sabores de gomas de mascar: Poosh® (pinta língua); Plutonita® (abraço congelante, dentada ardente, baba de bruxa e língua ácida); e TNT® (sangue, lava e tumba). Para análise da acidez, foram realizadas leituras em triplicata do pH e acidez titulável (AT), utilizando um potenciômetro e eletrodo combinado de vidro em soluções obtidas após a maceração das gomas de mascar em água duplamente deionizada. Nas soluções com valores de pH inferiores a 5,5, foi mensurada a AT adicionando-se alíquotas de 100 µLNaOH 0,1 M, até alcançar pH 5,5. Os resultados foram submetidos à Análise de Variância (ANOVA). As comparações das médias de pH e acidez titulável foram realizadas pelo teste de Tukey, com um nível de 5% de significância (p<0,05). Resultados: os valores de pH variaram entre 2,4 (abraço congelante) e 3,5 (baba de bruxa), diferin-do significantemente do controle (água mineral/pH=6,2). Os valores de acidez titulável variaram entre 628µL de NaOH 0,1 M (sangue) e 10700µL de NaOH 0,1 M (abraço congelante). A goma de mascar sabor abraço congelante apresentou o pH mais baixo e a mais elevada acidez titulável, diferindo significantemente dos demais sabores. Conclusões: as gomas de mascar avaliadas são ácidas, mas diferem quanto ao seu potencial erosivo. Seu consumo abusivo pode constituir um fator de risco para erosão dental.(AU)

Objective: to measure the erosive potential of non- -conventional chewing gums available in the Brazilian market. Material and methods: this is an in vitro study using the following flavors of chewing gums from the Brazilian market: Poosh® (tongue cleaner); Plutonita® (freezing hug, burning bite, witch slime and acid tongue); TNT® (blood, lava and tomb). For acidity analysis, pH and titratable acidity (TA) readings were performed in triplicate using a potentiometer and combined glass electrode in solutions obtained after maceration of the chewing gums in double deionized water. In solutions with pH values below 5.5, the TA was measured by adding aliquots of 100 µL 0.1 M NaOH, until pH 5.5 was reached. The results were submitted to Analysis of Variance (ANOVA). Comparisons of pH and titratable acidity means were performed by Tukey test at a 5% significance level (p<0.05). Results: the pH values that ranged from 2.4 (freezing hug) to 3.5 (witch's slime) differed significantly from the control (mineral water/ pH=6.2). Titratable acidity values ranged from 628µL of 0.1 M NaOH (blood) to 10700µL of 0.1 M NaOH (freezing hug). The freezing hug flavor chewing gum had the lowest pH and the highest titratable acidity differing significantly from the other flavors. Conclusions: the evaluated chewing gums are acidic, but differ in their erosive potential. Their abusive consumption may constitute a risk factor for dental erosion.(AU)

The role of human milk and sucrose on cariogenicity of microcosm biofilms.

This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

The role of human milk and sucrose on cariogenicity of microcosm biofilms

Abstract This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

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.

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.

Effect of open-sandwich vs. adhesive restorative techniques on enamel and dentine demineralization: an in situ study.

OBJECTIVES: To assess in situ the effect of different restorative techniques used with fluoride-releasing materials on enamel and dentine demineralization in the presence of a cariogenic challenge. METHODS: Thirty human molars were prepared for 60 Class V cavities, with enamel and dentine margins. The teeth were divided into four groups (n=15): L1 - open sandwich technique with a conventional glass ionomer cement (GIC), L2 - open sandwich technique with a resin-modified GIC, A1 - total-etch bonding with a fluoride-containing adhesive, A2 - total-etch bonding with a nonfluoride-containing adhesive. All the cavities were restored with a nanofilled composite. Fifteen volunteers used appliances containing one specimen from each group. The cariogenic challenge was carried out with a 20% sucrose solution 8×/day for 7 days. The specimens were sectioned for microhardness test and EDS analysis at different depths below the enamel and dentine margins (25, 50 and 100µm) and distances from the tooth-restoration interfaces (25 and 75µm). The data were analyzed by ANOVA and Games-Howell test (α=5%). RESULTS: Both GICs produced higher hardness in enamel at all depth-and-distance combinations, but only L1 produced higher hardness in dentine (p<0.05). L2 and A1 exhibited similar dentine hardness at 25µm distance for all depths (p>0.05). L1 demonstrated significantly higher amounts of calcium in dentine than the other groups, but had similar amounts in enamel to L2 and A1. CONCLUSIONS: The open sandwich technique using conventional GIC proved more effective in reducing enamel and dentine demineralization at depths of up to 100µm under a cariogenic challenge. CLINICAL SIGNIFICANCE: Conventional GICs should be considered the materials of choice for lining of cavities not having all margins in enamel, particularly using the open sandwich technique.

Effect of ammonium hexafluorosilicate application for arresting caries treatment on demineralized primary tooth enamel.

Ammonium hexafluorosilicate (AHF) has been applied to arrest caries without discoloration. The purpose of this study was to observe structural and elemental changes of demineralized and AHF applied primary tooth enamel. Enamel from the labial surface of 20 primary canines was divided into an unground side and ground side at the center of the tooth, and demineralized with 35% phosphoric acid for 6 min. The teeth were divided into 4 groups according to a 3-min application of AHF and 1 week of soaking in artificial saliva, as follows: group A (neither AHF nor saliva), group B (only saliva), group C (only AHF), and group D (AHF and saliva), and then subdivided according to whether the enamel was ground or unground. Specimens were analyzed with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The data were statistically analyzed using ANOVA and Fisher's PLSD test at α = 0.05. In groups A and B, prism structures were seen, however, in groups C and D, enamel surfaces were covered with spherical particles. Ca/P ratio was significantly higher in groups C and D than in groups A and B. There was no significant difference between ground and unground enamel in the content of any element. The values for F, Na, Mg and Si persents and Ca/P ratio were significantly higher for the enamel surface than for points 10-30 µm beneath the surface. Results of this study suggest the possibility that AHF treatment arrests caries, although further study will be required to confirm this result.

Fluoride plus CO2 laser against the progression of caries in root dentin.

PURPOSE: To evaluate the effect of a 1.23% acidulated phosphate fluoride (APF) gel combined with CO2 laser in protecting carious root dentin against further cariogenic challenges. METHODS: After a 7-day lead-in period, 12 volunteers wore an intraoral palatal device containing four carious root dentin slabs, treated with APF and APF+CO2 or placebo and placebo+CO2. After a 14-day wash-out period, volunteers were crossed-over to the other treatment arm. During both intraoral phases, specimens were submitted to cariogenic challenges and then evaluated for cross-sectional Knoop microhardness. RESULTS: Two-way ANOVA demonstrated that there was significant effect for both main factors: CO2 laser irradiation (P < 0.0001) and gel treatment (P < 0.0001), and that there was no interaction between them (P = 0.4706). Protection of carious root dentin against further cariogenic challenges may be provided by APF fluoride gel and CO2 laser, but no additive benefit was found by combining such strategies.

Dietary considerations for patients with dry mouth.

Dental caries is seen frequently in patients diagnosed with dry mouth. Nutritional counseling is important for the effective management of dry mouth and to arrest dental caries. With early intervention and proper individualized care, patients with dry mouth should be able to lead full, comfortable lives.

In vitro evaluation of the effects of a fluoride-releasing composite on enamel demineralization around brackets.

OBJECTIVES: The aim of this in vitro study was to evaluate the effectiveness of a fluoride-releasing bonding agent in inhibiting enamel demineralization around orthodontic brackets after the exposure to a demineralizing solution. MATERIALS AND METHODS: Twenty-six extracted upper molars were bonded with two different composites: Transbond XT (TXT) and Transbond Plus (TPlus), fluoride-releasing (both 3M Unitek, Monrovia, CA, USA). The samples were exposed to an acid lactic solution for three days and then subjected to Metallographic Optical Microscope (MOM) and Scanning Electron Microscope/Energy Dispersive X-Ray (SEM/EDX) analyses. Enamel surface was examined in different areas: un-treated, etched and primer-painted, un-treated area with no acid exposure, central area with bracket bonded. The maximum demineralization depths and the fluoride content at 100, 200 and 300 µm depth were evaluated. RESULTS: MOM analysis showed statistically significant (p<0.001) differences in demineralization depth for TPlus group compared to TXT group with lower values for the first one. EDX analysis confirmed the presence of fluoride in TPlus group. CONCLUSIONS: The fluoride content of TPlus appeared able to weakly reduce the enamel demineralization.

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).

Traditional and emerging oral health practices in parts of Nigeria.

OBJECTIVE: The purpose of this study was to document the beliefs and perceptions and emerging oral health care practices in parts of Nigeria. METHODS: A descriptive study, based in four different locations that were selected to reflect urban-rural and geographical spread, was conducted. Focus group discussions and in-depth interviews were conducted among representative groups and significant gatekeepers in the study areas. The discussions focused on oral health problems frequently encountered in the communities, their dietary and snacking habits as well as the dental remedies commonly employed by the people for prophylactic and therapeutic purposes. RESULTS: It was revealed that in both rural and urban low- to- middle socio-economic classes, periodontitis was the commonest dental problem in adults, while dental caries in children appeared to be also a cause for concern especially in northern Nigeria and the urban south. Most adults ate the local staple carbohydrate diets, however large quantities of cariogenic snacks were reported to be consumed. Chewing sticks and locally prepared toothpastes ranked prominent among the tooth cleaning implements, but many in the cities used toothbrushes. Various dental care remedies were employed ranging from warm saline wash to herbal preparations, antibiotics and battery water. In communities studied, the belief in ill defined "worms" as causative agents of all oral health problems was very firm. Consultation with traditional oral healthcare practitioners was a practice commonly observed in all study sites. CONCLUSION: This study has highlighted specific areas for intervention in disease prevention and oral health promotion in Nigeria.

Anti-cariogenic effect of a cetylpyridinium chloride-containing nanoemulsion.

OBJECTIVES: The aim of this pilot study was to investigate the anticaries activity of a nanoemulsion composed of soybean oil, water, Triton X-100 and cetylpyridinium chloride. METHODS: Tooth blocks (3 mm length x 3 mm width x 2 mm thickness) were cut from smooth surfaces of selected molar teeth using a water-cooled diamond wire saw. The blocks were randomly assigned to three experimental groups: (A) nanoemulsion, (B) 0.12% chlorhexidine gluconate, and (C) no treatment. The formation of dental caries in human tooth enamel was tested using a continuous flow dual-organism (Streptococcus mutans and Lactobacillus casei), biofilm model, which acts as an artificial mouth and simulates the biological and physiological activities observed within the oral environment. Experimental groups A and B were treated with their respective solutions once daily for 30 s on each occasion, while group C received no treatment. 10% sucrose was supplied every 6 h for 6 min to simulate meals and pH cycling. The experiment lasted for 5 days, and the tooth blocks were harvested and processed for demineralization assessment using transverse microradiography (TMR). RESULTS: For both lesion depth and mineral loss, statistical analysis indicated that Emulsion was significantly lower than Control and Chlorhexidine, and Chlorhexidine was significantly lower than Control. CONCLUSIONS: We conclude that cetylpyridinium-containing nanoemulsions appear to present a feasible means of preventing the occurrence of early caries.

TiF(4) and NaF at pH 1.2 but not at pH 3.5 are able to reduce dentin erosion.

OBJECTIVE: This study aimed to analyse and compare the protective effect of buffered (pH 3.5) and native (pH 1.2) TiF(4) in comparison to NaF solutions of same pH on dentin erosion. DESIGN: Bovine samples were pretreated with 1.50% TiF(4) or 2.02% NaF (both 0.48M F) solutions, each with a pH of 1.2 and 3.5. The control group received no fluoride pretreatment. Ten samples in each group were eroded with HCl (pH 2.6) for 10x60s. Erosion was analysed by determination of calcium release into the acid. Additionally, the surface and the elemental surface composition were examined by scanning electron microscopy (two samples in each group) and X-ray energy-dispersive spectroscopy in fluoridated but not eroded samples (six samples in each group). Cumulative calcium release (nmol/mm(2)) was statistically analysed by repeated measures ANOVA and one-way ANOVA at t=10min. RESULTS: TiF(4) and NaF at pH 1.2 decreased calcium release significantly, while TiF(4) and NaF at pH 3.5 were not effective. Samples treated with TiF(4) at pH 1.2 showed a significant increase of Ti, while NaF pretreatment increased F concentration significantly. TiF(4) at pH 1.2 led to the formation of globular precipitates occluding dentinal tubules, which could not be observed on samples treated with TiF(4) at pH 3.5. NaF at pH 1.2 but not at pH 3.5 induced the formation of surface precipitates covering dentinal tubules. CONCLUSION: Dentin erosion can be significantly reduced by TiF(4) and NaF at pH 1.2, but not at pH 3.5.

Ca, Pi, and F in the fluid of biofilm formed under sucrose.

Calcium (Ca), inorganic phosphorus (P(i)), and fluoride (F) concentrations are low in the whole plaque biofilm formed under exposure to sucrose. It was hypothesized that this would be reflected in the biofilm fluid, where these low values should greatly influence the de/remineralization process. Dental biofilms were formed in situ over enamel blocks mounted in palatal appliances and exposed 8 times/day to distilled water, glucose+fructose, or sucrose solutions for 14 days. While Ca, P(i), and F concentrations in the whole biofilms were significantly lower in the glucose+fructose and sucrose groups, no effect on biofilm fluid was observed, even after a cariogenic challenge. An increase in whole biofilm mineral ions was observed 24 hrs after the carbohydrate treatments were suspended, but this effect was also not observed in the fluid. These results suggest that there is a homeostatic mechanism that maintains biofilm fluid mineral ion concentration, regardless of its total concentration in the whole biofilm.

The effect of fluorine and homeopathic medicines in rats fed cariogenic diet.

Although some sectors of dentistry have benefited from technological advances, dental caries is still a major problem. Prevention and treatment of dental caries by fluorine is considered a major advance in public health. Nevertheless fluorosis, caused by ingestion of excessive amounts of fluorine during the period of teeth formation, is of great concern. In accordance with the homeopathic doctrine, minimum doses of fluorine and other substances could prevent and/or treat caries. In this experiment, we compared the preventive action of fluorine and evaluated the effect of homeopathic medicines on the teeth of rats fed a cariogenic diet. None of the groups included in this study developed caries. However, microscopy revealed the presence of precipitate and/or deposit in the groups treated with homeopathic medicines. This phenomenon might be due to deposit in the dental surface or precipitation of bacterial plaque or calcium salts. It was not possible to identify the composition of the deposit/precipitate due for technical reasons. In one of the groups treated with homeopathic medicines fur loss was observed in 40% of animals. These reactions might be caused due to the action of the homeopathic medicines.

In situ effect of frequent sucrose exposure on enamel demineralization and on plaque composition after APF application and F dentifrice use.

Since the effect of the combination of methods of fluoride use on enamel demineralization and on plaque composition is not clearly established, this study examined the effect of the combination of acidulated phosphate fluoride (APF) application and F dentifrice on enamel demineralization and on plaque composition. In this crossover study, 16 volunteers, wearing a palatal appliance containing bovine enamel blocks, were subjected to 4 treatment groups: non-fluoridated dentifrice (PD), FD, APF+PD, and APF+FD. The APF was applied to the enamel before the 14-day experimental period. During the experimental period, test dentifrices were applied 3x/day, and a 20% sucrose solution was applied 4x and 8x/day by being dripped on the blocks. Although APF application was able either to increase F concentration in plaque or to reduce the % of mutans streptococci, its combination with F dentifrice use neither reduced enamel mineral loss nor changed any other measured plaque variable with respect to the FD group alone.

Effect of in situ plaque mineral supplementation on the state of saturation of plaque fluid during sugar-induced acidogenesis.

Dental plaque fluid is normally supersaturated with respect to enamel mineral but this may change to a state of undersaturation when plaque pH falls following sugar exposure, placing the adjacent enamel at risk of caries. We have determined the saturation status of the fluid in both resting and fermenting plaque following mineral supplementation. Eleven subjects abstained from oral hygiene and rinsed their mouth 3 times/d for 3 d with a placebo solution or with test solutions designed to enrich plaque with hydroxyapatite or fluorhydroxyapatite. On the morning of day 4, plaque samples were collected before and after exposure to 10% sucrose. Compared to the placebo, use of the test rinses resulted in significantly higher concentrations of Ca, P and F in plaque residue. In plaque fluid, higher post-sucrose Ca2+ free concentrations and saturation levels with respect to enamel mineral and fluorapatite were found after use of the hydroxyapatite rinse compared to the placebo, effects that probably resulted from the release of cell-bound Ca2+ as well as from the dissolution of apatite. Thus, some evidence was obtained that the test mouthrinses can counteract the fall in saturation level found when plaque is exposed briefly to sucrose. Potential long-term benefits of the test mouthrinses deserve further study.

Effects of honey consumption on enamel microhardness in normal versus xerostomic patients.

The aim was to investigate the effect of honey on the microhardness of enamel in normal and xerostomic patients. Normal subjects and patients who were xerostomic after neck irradiation, wearing prosthetic appliances with slabs of human enamel inserted, were asked to consume a single teaspoonful of pure honey, pH 3.9. Measurements of the saliva pH were taken before, during and after a 5 min exposure to the honey. The pH of the honey-saliva mixtures decreased significantly from about 6 to 4 in both groups, returning to the baseline pH after the mixture was swallowed. The initial microhardness of the surface of the enamel slabs decreased significantly after consumption of a teaspoonful of the honey in the subjects with a regular saliva flow, whereas in the irradiated dry-mouth patients, no enamel microhardness decrease occurred. The supposed solubility-reducing factor present in honey which, according to the literature remains active in the absence of saliva, but will be inactivated by salivary enzymes, gives some support to the hypothesis that honey is less cariogenic in dry-mouth subjects. The absence of adequate controls in the present study prevents the investigation of how specific this effect is to honey.