Protein Profiles of Individuals with Erosive Tooth Wear

Abstract Objective: To determine if protein profiles identified in saliva could be used to determine risk and severity of erosive tooth wear. Material and Methods: Three types of saliva sampling were performed to obtain saliva from 34 18-year old individuals that received regular dental check-ups, along with clinical status of the dentition and risk factor related to erosive tooth wear using the VEDE scale. Protein profiles in saliva were determined using electrophoresis and the calculation of the percentage of a specific band at a specific molecular weight in relationship to the total protein in that sample (% of total) using molecular weight standards. This quantification was repeated for each protein band across a range of molecular weights for each sample to test for association with erosive tooth wear status. Results: There were no differences in the number of detectable proteins sourced from the parotid gland, nor the unstimulated and stimulated whole saliva. Five out of the 34 individuals had no signs of erosive tooth wear despite an acidic diet and were more likely to have proteins with molecular weight smaller than 1 KDa (p=0.03). Conclusion: There is potential for the use of protein profiling to determine risks for erosive tooth wear.

The Post-Amalgam Era: Norwegian Dentists' Experiences with Composite Resins and Repair of Defective Amalgam Restorations.

Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists' satisfaction with alternative restorative materials and to explore dentists' treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam. Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p < 0.01), employees in the Public Dental Service (PDS) (p < 0.01) and dentists working in counties with low dentist density (p = 0.03). There was a tendency towards choosing minimally invasive treatment among dentists who also avoided operative treatment of early approximal lesions (p < 0.01). Norwegian dentists showed positive attitudes towards composite as a restorative material. Most dentists chose minimally- or medium invasive approaches when restoring fractured amalgam restorations.

Posterior composites and new caries on adjacent surfaces - any association? Longitudinal study with a split-mouth design.

BACKGROUND: The aim of this longitudinal study was to compare caries incidence in sound approximal surfaces adjacent to newly placed composite restorations with the caries incidence in corresponding surfaces in contralateral teeth without any restorations in contact; and to assess risk factors for dentine caries development on adjacent and control surfaces. METHODS: Data from a practice-based study, where 4030 posterior approximal restorations placed in permanent teeth by clinicians working in a Public Dental Health Service in Norway, were used. The study was approved by the Regional Committee for Medical Research Ethics. The present study is based on a subsample of patients with a sound surface adjacent to a newly placed composite posterior approximal restoration. All individuals who had intact corresponding contralateral pairs of teeth in the same jaw, were included. At the end of the follow-up period, the study restorations and their adjacent surfaces were evaluated clinically and radiographically. Status of the contralateral tooth pair at baseline and end point was based on recordings from routine dental examinations, retrospectively extracted from the electronic dental records. RESULTS: One hundred and ninety three patients (mean age 15.0 years, SD = 3.4) met the inclusion criteria. The surfaces were followed on average for 4.8 years. Follow-up observations revealed that 41 % of adjacent surfaces remained sound, compared with 67 % of the control surfaces (p < 0.001). Restorations were placed in 17 % of adjacent surfaces, compared with 3 % of the control surfaces (p < 0.001). In multivariate logistic regression analysis adjacent surfaces in maxillary teeth had increased risk for dentine caries development (OR 3.1, CI 1.3-7.3). CONCLUSIONS: Caries incidence in intact approximal surfaces adjacent to newly placed composite posterior approximal restorations was significantly higher compared with the contralateral control surface without a restoration in contact. Adjacent surfaces in maxillary teeth had increased risk for dentine caries development.

Risk factors for caries development on tooth surfaces adjacent to newly placed class II composites--a pragmatic, practice based study.

OBJECTIVES: To assess risk factors for caries development on approximal surfaces in contact with newly placed Class II composite restorations. METHODS: 750 surfaces, either sound or with caries confined to enamel, in contact with newly placed Class II composite restorations, placed by PDS dentists in Norway were evaluated by clinicians, using standardized clinical and radiographic criteria. RESULTS: After the observation period (mean 4.9 year, SD 0.67), 38.8% of the initially sound contact surfaces (n=417) remained sound, 34.0% developed caries confined to enamel and 27.2% developed caries into dentine. Of surfaces with caries confined to enamel present at baseline (n=333), 57.3% remained in enamel, while 42.7% progressed into dentine. Risk factors for dentine caries development were assessed by logistic regression analyses. The risk of developing caries on surfaces that were initially sound at baseline was higher in patients with poor or medium oral hygiene (OR 1.53; CI 1.10-3.68), higher DMFT at baseline (OR 1.12; Cl 1.04-1.20). Maxillary teeth (OR 2.01; Cl 1.14-3.56) and surfaces on the right side of the mouth (OR 1.65; Cl 1.01-2.72) were also risk factors. For surfaces with enamel caries present at baseline, the risk of dentine caries was higher in patients with higher DMFT (OR 1.06; CI 1.00-1.13). In both analyses the treating dentists had a significant impact on the caries development. CONCLUSIONS: Both patient- and dentist related variables are risk factors for caries development on approximal surfaces in contact with newly placed Class II composite restorations. CLINICAL SIGNIFICANCE: All clinicians should be aware of a notable risk of caries development on the adjacent tooth surface, especially when placing approximal restorations in high caries risk patients, and should consider greater use of preventive strategies or non-operative treatment that should be evaluated and repeated at every recall.

May caries-preventive fluoride regimes have an effect on dental erosive wear? An in situ study.

OBJECTIVE: High and low concentration NaF regimes have shown caries protective properties, but the preventive effect against erosive/abrasive wear is unclear. AIM. To measure the inhibiting effect on enamel wear of low and highly concentrated sodium fluoride (NaF) toothpastes and a stannous (SnF2) fluoride gel in a single-blind, randomized in situ study, using a White Light Interferometer. MATERIALS AND METHODS: Sixteen human molars were each divided into four specimens, mounted on acrylic mouth appliances and worn by eight volunteers for 9 days. Experimental procedures were performed in the laboratory. The enamel specimens were brushed every day with fluoride-free toothpaste. Treatments; group 1: no fluoride treatment (control), group 2: SnF2 gel 2500 ppm F (5 min) every third day, group 3: NaF toothpaste 5000 ppm F 5 min every third day and 2 min the other days, group 4: NaF toothpaste 1450 ppm F (2 min) every day. In order to mimic gastric reflux/vomiting, the specimens were etched with 0.01 M HCl for 2 min twice a day. RESULTS: The mean step height (µm) for the control specimens was -32.9 (SD = 6.8). The mean values for the other groups were -22.2 (SD = 8.4) (group 2), -30.8 (SD = 7.8) (group 3) and -31.4 (SD = 7.7) (group 4). Compared with the control, the SnF2 treated specimens showed significantly lower wear. The NaF toothpastes gave no significant protective effect. CONCLUSIONS: Application of SnF2 gel every third day gave protection against erosive-abrasive challenges. Daily application of both low concentration and high concentration NaF toothpaste provided no protection.

The effect of single-application fluoride treatment on simulated gastric erosion and erosion-abrasion of enamel in vitro.

PURPOSE: To compare single-application fluoride formulations on enamel erosion and erosion-abrasion in vitro. MATERIALS AND METHODS: Enamel specimens were pretreated with either sodium, tin, titanium, or sodium/calcium fluoride and subjected to either an erosion model or an erosion-abrasion model, after which optical profilometry was used to measure enamel step height loss. RESULTS: For erosion, the titanium fluoride (P < .001) reduced enamel loss, whereas the calcium, tin, and sodium treatments showed no significant effects (P > .05). For erosion-abrasion, the titanium fluoride increased enamel loss in comparison to control (P < .001). CONCLUSIONS: Titanium fluoride has differing effects on enamel loss from erosion and erosion-abrasion models.

Self-induced vomiting and dental erosion--a clinical study.

BACKGROUND: In individuals suffering from eating disorders (ED) characterized by vomiting (e.g. bulimia nervosa), the gastric juice regularly reaches the oral cavity, causing a possible risk of dental erosion. This study aimed to assess the occurrence, distribution and severity of dental erosions in a group of Norwegian patients experiencing self-induced vomiting (SIV). METHODS: The individuals included in the study were all undergoing treatment at clinics for eating disorders and were referred to a university dental clinic for examinations. One calibrated clinician registered erosions using the Visual Erosion Dental Examination (VEDE) system. RESULTS: Of 72 referred patients, 66 (63 females and three males, mean age 27.7 years) were or had been experiencing SIV (mean duration 10.6 years; range: 3 - 32 years), and were therefore included in the study. Dental erosions were found in 46 individuals (69.7%), 19 had enamel lesions only, while 27 had both enamel and dentine lesions. Ten or more teeth were affected in 26.1% of those with erosions, and 9% had ≥10 teeth with dentine lesions. Of the erosions, 41.6% were found on palatal/lingual surfaces, 36.6% on occlusal surfaces and 21.8% on buccal surfaces. Dentine lesions were most often found on lower first molars, while upper central incisors showed enamel lesions most frequently. The majority of the erosive lesions (48.6%) were found in those with the longest illness period, and 71.7% of the lesions extending into dentine were also found in this group. However, despite suffering from SIV for up to 32 years, 30.3% of the individuals showed no lesions. CONCLUSIONS: Dental erosion commonly affects individuals with ED experiencing SIV, and is more often found on the palatal/lingual surfaces than on the buccal in these individuals, confirming a common clinical assumption.

Prevalence of erosive tooth wear in risk groups.

Individuals have different risks for developing erosive lesions depending on background, behavioural, dietary and medical variables. It is anticipated that people with regular impact of gastric juice, i.e. patients with eating disorders and gastroesophageal reflux disease (GERD) have a specially high risk of developing dental erosions; the same could be true for those with special diets, regular consumption of acidic beverages, medicine and drug intake and occupational exposure to acids. Eating disorders are associated with an increased occurrence, severity and risk for dental erosion, even though not all bulimic patients show a pathological level of tooth wear. There seems also to be a tendency that in the case of GERD, erosion is more common and more severe than in healthy controls. Regarding exogenous causes, many studies, though not all, document a positive association between the consumption of acidic beverages and dental erosions and there seems to be a dose-response relationship; however, further studies are necessary for a final statement. The same applies for the association between drug or medication intake or special diet and erosion prevalence. Though only few studies exist, there seems to be a tendency for an increase of erosion prevalence amongst persons abusively consuming alcohol. Some studies show an increased risk for dental erosion for employees testing wine or working in acid processing factories. Even though some associations between acid impact and erosion prevalence appear clear, the number of studies is small. There is a lack of controlled prevalence studies, making it difficult to give final statements for all risk groups.

Dental erosion: a widespread condition nowadays? A cross-sectional study among a group of adolescents in Norway.

OBJECTIVE: This study aimed to investigate the prevalence, distribution and severity of erosive wear in a group of 16-18-year-olds in the western part of Norway. A second aim was to describe possible associations between caries experience, socioeconomic background and origin of birth. MATERIALS AND METHODS: Adolescents (n = 795) attending recall examinations at Public Dental Service (PDS) clinics were also examined for dental erosive wear on index surfaces, using the Visual Erosion Dental Examination scoring system (VEDE). RESULTS: In total, 795 individuals were examined. Dental erosive wear was diagnosed in 59% of the population (44% erosive wear in enamel only, 14% combination of enamel and dentine lesions, 1% erosive wear in dentine only). The palatal surfaces of upper central incisors and occlusal surfaces of first lower molars were affected the most (33% and 48% of all surfaces, respectively). Cuppings on molars were registered in 66% of the individuals with erosive wear. Erosive wear was significantly more prevalent among men (63%) than women (55%) (p = 0.018). CONCLUSIONS: There were no significant associations between dental erosive wear and caries experience, socioeconomic background or origin of birth.

Prevalence and severity of dental erosive wear among a group of Norwegian 18-year-olds.

OBJECTIVE: The aim was to study prevalence, distribution and severity of erosive wear in a group of 18-year-olds. MATERIALS AND METHODS: A total of 1456 adolescents were screened for erosive wear as part of their regular visit at the Public Dental Health Service (PDHS) clinics in Oslo. Of 554 (38%) registered with erosive wear, 267 accepted a second examination to record lesion distribution and severity, performed by one previously calibrated clinician. A tested erosive wear system (VEDE) was used. Occlusal surfaces of the first and second molars in both jaws and the labial and palatal surfaces of the upper incisors and canines were selected as index surfaces. RESULTS: Of the 267 individuals with erosive wear, 13.5% were without lesions, 54.3% had erosive wear in enamel only, whereas 32.2% had at least one lesion extending into dentine. The upper central incisors (46%) and first lower molars (44%) were the most affected teeth with the highest presence on the palatal surfaces. Cuppings were registered in 62% of the individuals, usually in addition to erosive lesions on other surfaces. Eighty-five per cent of the cuppings were on first molars and 34% on the mesio-buccal cusp. Males had significantly more lesions into dentine compared with females (p = 0.03). There was a significant association between presence of erosive lesions and DMFT (p < 0.01), but no association between lesions and socio-economic or national background. CONCLUSIONS: A high proportion of adolescents had erosive wear. Cuppings were a common finding.

Enamel erosion depths measured on impressions by a white light interferometer.

OBJECTIVE: To investigate if measurements of the step heights on an impression of eroded enamel surfaces may give reliable values of the etching depths measured directly on the enamel. MATERIALS AND METHODS: Twelve human enamel specimens, with one circular amalgam reference surface in each, were mounted on an epoxy block and ground flat. Baseline images were taken by a White Light Interferometer (WLI) followed by 12 min etch by 0.01 M HCl, pH 2.2. The mean etch depth on each specimen was calculated from three repeated measurements, both on the specimen surfaces and on the silicone polymer impressions of the surfaces. Paired samples t-test was used when comparing the precision of measurements on enamel vs on impression. RESULTS: The mean lesion depths after 12 min etch measured on the 12 enamel surfaces and impressions were 9.9 µm and 10.6 µm, respectively. The direct and indirect measurements correlated well (r(2) = 0.95), with 7% higher mean etch depth measured on the impressions (p < 0.05). The reliability of three repeated measurements on enamel and impressions expressed by Intra Class Correlation (ICC) were 0.98 and 0.99, respectively. The average relative precisions of three repeated measurements on the 12 tooth and impression surfaces were (0.5 ± 0.1)% and (0.1 ± 0.02)%, respectively (p < 0.05). The accuracies were 0.4% and 7%, respectively. CONCLUSION: WLI gave reliable but slightly higher etch depth measurements on impressions compared to enamel surfaces.

Longevity of posterior dental restorations and reasons for failure.

Tooth-coloured restorative materials are being used increasingly more often in Class II preparations in permanent teeth. Using a practice-based study design, we aimed to assess the survival time of Class II restorations and to identify factors relevant to their longevity. Class II restorations (n = 4,030), consisting of resin composites (81.5%), compomers (12.7%), amalgams (4.6%), and glass-ionomer cement restorations (1.2%), were placed in 1,873 patients with a median age of 15 yr. In total, 92.7% of restorations were placed due to primary caries and 5.8% were replacements. After an average follow-up period of 4.6 yr, 61.6% of the restorations were successful, 11.2% had failed, and 27.2% were not available for evaluation (owing to patient drop-out). The mean annual failure rate was 2.9% for resin-composite restorations and 1.6% for amalgams. For resin-composite restorations, secondary caries was the most common reason for replacement (73.9%), followed by loss (8.0%), fracture (5.3%), and marginal defects (2.4%). Multilevel Cox-regression analyses identified young age of the patient, high previous caries experience, deep cavities, and saucer-shaped preparation technique as predisposing to shorter longevity of resin-composite restorations. One brand of resin composite had a shorter survival time than the others.

Opinions on Dental Erosive Lesions, Knowledge of Diagnosis, and Treatment Strategies among Norwegian Dentists: A Questionnaire Survey.

This study aimed to investigate dentists' general experience, knowledge about diagnosis, and treatment of dental erosive wear in young adults. A questionnaire was sent to 1262 Norwegian public dental health-employed dentists. The response rate was 60%. Results indicated that most dentists recorded erosive wear, half of them used a specific scoring system, and half registered lesions at the tooth surface level. Lesions were reported most often on palatal surfaces of upper anterior teeth (79% of dentists), on occlusal surfaces of lower 1st molars (74%), and on upper 1st molars (32%). Half the dentists used clinical photographs for documentation and 60% made study models. While 40% reported more erosive lesions in males, 36% reported no gender differences. High intake of carbonated beverages and acidic juices were reported as the most common cause by 97% and 72% of the dentists, respectively. Only 21% of dentists recorded the patient's dietary history, and 73% never measured saliva secretion. The majority (78%) of the dentists treated patients with erosive wear themselves. In general, the survey suggests that the dentists are relatively up to date regarding the clinical recording, diagnosis, and treatment of dental erosive wear. However, dietary and salivary analyses were not given priority, and early, preventive treatment was lacking.

Dental erosive wear and salivary flow rate in physically active young adults.

BACKGROUND: Little attention has been directed towards identifying the relationship between physical exercise, dental erosive wear and salivary secretion. The study aimed i) to describe the prevalence and severity of dental erosive wear among a group of physically active young adults, ii) to describe the patterns of dietary consumption and lifestyle among these individuals and iii) to study possible effect of exercise on salivary flow rate. METHODS: Young members (age range 18-32 years) of a fitness-centre were invited to participate in the study. Inclusion criteria were healthy young adults training hard at least twice a week. A non-exercising comparison group was selected from an ongoing study among 18-year-olds. Two hundred and twenty participants accepted an intraoral examination and completed a questionnaire. Seventy of the exercising participants provided saliva samples. The examination was performed at the fitness-centre or at a dental clinic (comparison group), using tested erosive wear system (VEDE). Saliva sampling (unstimulated and stimulated) was performed before and after exercise. Occlusal surfaces of the first molars in both jaws and the labial and palatal surfaces of the upper incisors and canines were selected as index teeth. RESULTS: Dental erosive wear was registered in 64% of the exercising participants, more often in the older age group, and in 20% of the comparison group. Enamel lesions were most observed in the upper central incisors (33%); dentine lesions in lower first molar (27%). One fourth of the participants had erosive wear into dentine, significantly more in males than in females (p = 0.047). More participants with erosive wear had decreased salivary flow during exercise compared with the non-erosion group (p < 0.01). The stimulated salivary flow rate was in the lower rage (≤ 1 ml/min) among more than one third of the participants, and more erosive lesions were registered than in subjects with higher flow rates (p < 0.01). CONCLUSION: The study showed that a high proportion of physically active young adults have erosive lesions and indicate that hard exercise and decreased stimulated salivary flow rate may be associated with such wear.

Dental erosive wear among Norwegian wine tasters.

OBJECTIVE: To assess the prevalence and severity of dental erosive wear among a group of professional wine tasters. MATERIAL AND METHODS: Eighteen wine tasters currently employed at AS Vinmonopolet, Norway (3 women, 15 men; mean age 39 years) and 30 comparison participants (9 women, 21 men; mean age 39 years) were included in the study. The wine tasters were examined by four calibrated clinicians using the Visual Erosion Dental Examination system. Data concerning medical and dietary history, oral hygiene habits and occupational background were obtained from a self-completed questionnaire. Data were analyzed using Fisher's exact test, and examiner agreement was determined by means of linear-weighted kappa and the intra-class correlation coefficient. RESULTS: Nine (50%) of the wine tasters and six (20%) of the comparison group showed clinical signs of dental erosion. Among the wine tasters, 39% had dentine involvement, compared to just 7% of the comparison group. The erosive lesions were mainly found on the occlusal surfaces of mandibular first molars in the wine tasters, whereas for the controls, the palatal surfaces of upper centrals were most often affected. CONCLUSIONS: There was a significant difference in the prevalence of dental erosive wear between the two groups, the wine tasters having a higher prevalence and more severely affected surfaces than the comparison group. Half of the wine tasters had no erosive wear and, for the other half, there was no relationship between the duration of their professional life and the extent of erosive wear.

Factors influencing dentists' choice of amalgam and tooth-colored restorative materials for Class II preparations in younger patients.

OBJECTIVE: To identify factors associated with dentists' decisions on choice of restorative material in children and adolescents. MATERIAL AND METHODS: In the period 2001-2004, 27 dentists in the Public Dental Health Service in Norway placed 4030 Class II restorations in 1912 patients. The reason for placement, previous caries experience (DMFT), oral hygiene, and characteristics of the cavity were recorded. RESULTS: The most frequently used material was resin composite (81.5%), followed by compomer (12.7%), amalgam (4.6%), and glass ionomer cement (1.2%). Tooth-colored restorations were more frequently placed than amalgam in younger patients (p=0.017). Female patients received fewer amalgam restorations than male patients (p=0.006). Amalgam was more often used in patients with high DMFT (p<0.001) and more commonly in treatment of deeper dentine caries than caries near the dentino-enamel border (p=0.021). Amalgam was more frequently placed in molars than in premolars (p<0.001). In a logistic regression model, gender, DMFT, caries severity, and tooth type were significantly related to choice of material. CONCLUSION: Dentists' choices of restorative material indicate that the majority prefer amalgam in more challenging restorations with respect to caries activity, lesion depth, and tooth type. The findings indicate that in a period when the use of amalgam was phasing out, resin composite was the predominant material of choice for Class II restorations in children and adolescents.

The erosion-inhibiting effect of TiF4, SnF2, and NaF solutions on pellicle-covered enamel in vitro.

OBJECTIVE: The aim of this study was to compare the protective effect of TiF(4), SnF(2), and NaF treatment on the development of erosion-like lesions in pellicle-covered human enamel. MATERIAL AND METHODS: Twelve human molars were each divided into 5 specimens, 4 of which were immersed in saliva for 2 h. Three pellicle-covered specimens from each tooth were treated with a TiF(4), SnF(2), or NaF solution (all 0.5 M F) for 2 min. Control specimens, one with and one without pellicle, were included. Immersion in acid (0.01 M HCl) was carried out stepwise (2+2+2+2 min). The etching depths (in microm) were measured using white light interferometry. RESULTS: Compared with the control with pellicle, TiF(4) reduced enamel loss by 100% after 2 min and by 24% after 8 min of acid exposure. The corresponding values for SnF(2) were 45% and 14%. NaF provided no significant protection of the surface. The pellicle-covered specimens showed reduced lesion depths after 6 and 8 min compared to the controls without pellicle. CONCLUSIONS: TiF(4) gave the best protection against acid attack. SnF(2) provided significant protection only after 2 min of acid exposure, while NaF had no significant protective effect.

Identification of organic eluates from four polymer-based dental filling materials.

Elution from polymer-based dental filling materials may have a potential impact on the biocompatibility of the materials. Since information from the manufacturers about ingredients in the materials often is incomplete, analyses of eluates from the materials are necessary for a better knowledge about possible harmful compounds. The aim of this study was to identify organic eluates from polymerized samples of two composites, one compomer and one resin-reinforced glass ionomer cement. Samples were immersed in ethanol or Ringer's solution. Organic leachables were analyzed by gas chromatography-mass spectrometry. Identification was confirmed with reference substances, if available. Among components detected were monomers, co-monomers, initiators, stabilizers, decomposition products and contaminants. Thirty-two substances were identified and 17 were confirmed with reference substances. From elution in Ringer's we identified 13 eluates from Tetric Ceram, 10 from Z250, 21 from Dyract and six from Fuji II LC; HEMA, HC and CQ were found in all samples. From elution in ethanol 12 eluates from Tetric Ceram, 18 eluates from Z250, 19 from Dyract and 10 from Fuji II LC were identified. The diversity of eluates from the four materials under study is demonstrated. Owing to variation between the materials, the biocompatibility including the allergenic potential may be different.

Dental health behavior, gastroesophageal disorders and dietary habits among Norwegian recruits in 1990 and 1999.

A questionnaire was given to representative samples of Norwegian recruits in 1990 and 1999 to explore dental health habits, history of gastroesophageal disorders and diet with possible relations to dental erosion. The samples were 792 (mean age 20.9 years) and 676 (mean age 21.6 years), respectively, and the corresponding responses were 62% and 100%. Minor differences in self-reported dental health habits and gastroesophageal disorders were found. The respondents' dentists had provided information about dental erosion for 8.2% of the respondents in 1990 versus 14.5% in 1999. There was an increase in the reported frequency of daily intake of juice from 17% to 24% (P = 0.006) and carbonated soft drink from 54% to 61% (P = 0.025) in the period 1990-99. The frequency of training activity showed minor changes, but in 1999 it was more common to drink during exercise (94% versus 74% in 1990, P < 0.001), and the majority drank water. Sixteen percent of recruits ate oranges daily in 1990; in 1999 this had dropped to 11% (P = 0.012). The corresponding proportion that ate apples daily had dropped from 17% to 8% in the period (P < 0.001). It is likely that lifestyle factors related to diet among young men have changed in the period 1990-99 in a direction that may increase the prevalence of dental erosions.