Finding the person behind caries disease: The dental caregivers' experiences of empowering patients to implement beneficial behavioral changes.

OBJECTIVES: This study aimed to elucidate dental professionals' experiences of how to empower patients at risk of developing new or additional caries to promote caries-related preventive behavioral changes. METHODS: Semi-structured in-depth interviews were conducted, audio-recorded, transcribed verbatim, and subjected to qualitative content analysis. To provide credibility and high-quality data, participant recruitment followed strategic sampling. The 10 participants included nine women and one man; six participants were dentists, and four were dental hygienists. In the data analysis, five descriptive and five strategic themes emerged that formed an overarching theme: Finding the person behind caries disease. RESULTS: The results indicated that by initially getting to know the person behind the patient, trusting relationships and knowledge can be generated to successfully influence patients' behaviors related to caries. The five descriptive themes included: Building a treatment alliance, Understanding habitual patterns, Motivating for changes, Implementing new behaviors, and Preserving behavioral improvements. The descriptive themes each revealed a strategy theme containing several strategy proposals for initiating and supporting caries-preventing behavioral changes. CONCLUSIONS: This study highlights the importance of establishing a treatment alliance to improve the patient's skills, knowledge, and motivation. It underscores the significance of recognizing the individual behind the patient, to facilitate optimal behavior change at the lowest possible level of treatment. CLINICAL SIGNIFICANCE: Our findings could assist in strengthening caries-related health promotion, caries prevention, and understanding of oral health literacy techniques.

Caries prevalence and other dental pathological conditions in Vikings from Varnhem, Sweden.

In a late Swedish Viking Age population dating from around 10th-12th century AD, the prevalence, distribution and location of dental caries were studied. Tooth wear, other dental pathology and anatomical variations were identified and recorded clinically and radiographically. A total of 3293 teeth were analyzed from 171 individuals with complete and partial dentitions, of which 133 were permanent and 38 deciduous/mixed dentition. The dentitions were studied clinically, using a dental probe under a strong light source, and radiographs were taken for 18 of the individuals to verify and complement the clinical caries registration. Almost half the population, 83 of 171 individuals (49%), had at least one carious lesion. All individuals with deciduous or mixed dentitions were caries-free. The number of teeth affected by caries among adults was 424 (13%) and the surface most susceptible to caries was the root surface. The tooth most commonly affected by caries was the first mandibular molar. Other findings included apical infections, which were detected clinically in 4% of the teeth, and one case of filed front teeth. The findings gave a unique understanding of life and death in this early Christian Viking community and indicated that it was common to suffer from dental caries, tooth loss, infections of dental origin and tooth pain. These Vikings also manipulated their teeth through filing, tooth picking and other occupational behaviors.

Antimicrobial efficacy of chlorine agents against selected oral pathogens.

OBJECTIVES: Method-dependent comparison of antimicrobial agents' efficacy against oral pathogens. MATERIALS AND METHODS: Several sodium hypochlorite solutions (NaOCl)-Perisolv®, Carisolv® and Dakin's solution-were equated with chlorhexidine (CHX) and hydrogen peroxide (H2O2) against ten oral micro-organisms related to caries and periodontitis using different minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) techniques. Agents were adjusted to the final 70 mmol/L concentration of active chlorine molecule. RESULTS: Apart from H2O2 and the amino acids of Perisolv®, all the agents revealed an antimicrobial effect. Agar diffusion test ranked CHX (p < 0.05) as the most effective against all ten specimens, followed by the NaOCl of Perisolv® and Dakin's solution. Correspondingly, in broth microdilution on agar, CHX was the most effective in eradicating micro-organisms at 0.03 mmol/L compared with 2.2 mmol/L of Dakin's solution. In contrast, the bactericidal concentration of Dakin's solution was the most effective at 0.2 mmol/L, (p < 0.001), followed by Perisolv® (2.14 mmol/L), CHX (2.38 mmol/L) and Carisolv® (3.33 mmol/L) after 5 and 10 min in broth dilution test. In live/dead analysis, 60-min exposure to a 2-fold concentration of agents resulted in two-log Aggregatibacter actinomycetemcomitans inhibition by CHX (35 mmol/L) whilst Streptococcus mutans was more susceptible, in 0.8 and 8.8 mmol/L, after 10 min to CHX and Dakin's respectively. CONCLUSION: Replacement of CHX with tested hypochlorite agents showed evident potential and promoted rapid antimicrobial effect. CLINICAL RELEVANCE: Effective antimicrobial agents are crucial in controlling pathogen-induced oral infections increasing clinical possibilities to combat oral biofilms. Additionally, CHX substitution with hypochlorite agents could eliminate CHX's adverse effects.

Impact of Medical and Surgical Obesity Treatment on Dental Caries: A 2-Year Prospective Cohort Study.

The objective was to study the long-term effects on oral health of bariatric surgery compared with medical treatment of obesity. Swedish females with morbid obesity (n = 66; 18-35 years at baseline) were followed prospectively from before obesity treatment until 2 years after treatment. The main response variable was dental caries registered according to the ICDAS-II system. Possible confounding factors, such as sociodemographic characteristics, general health, oral health habits, and oral hygiene, were controlled for. The statistical methods included χ2 tests, Student's t tests, one-way ANOVA, Wilcoxon's nonparametric tests, and linear regression models. In the surgically treated patients (n = 40), a significant increase over time in enamel caries (mean increase 4.13 tooth surfaces ICDAS1-2), dentine caries (mean increase 2.18 tooth surfaces ICDAS3-6), and total caries (mean increase 6.30 tooth surfaces ICDAS1-6) was registered (all p < 0.001), which was not seen in the medically treated patients (n = 26). However, the difference between the treatment groups (surgical or medical) was only statistically significant for enamel caries (crude ß 4.89, p = 0.003) and total caries (crude ß 6.53, p < 0.001). The relationships were stable and independent of differences in confounders as socioeconomy, general health, and oral health behaviors. In conclusion, 2 years after obesity treatment, a significant increase in dental caries was registered in the surgically treated but not in the medically treated women. The dental service should intensify its preventive efforts in individuals undergoing obesity treatment.

Inhibition of tooth demineralization caused by Streptococcus mutans biofilm via antimicrobial treatment using hydrogen peroxide photolysis.

OBJECTIVES: An antimicrobial technique utilizing hydroxyl radicals generated by the photolysis of 3% H2O2 has been developed recently. The present study aimed to evaluate the effect of H2O2 photolysis treatment on tooth demineralization caused by Streptococcus mutans biofilm. MATERIALS AND METHODS: To induce tooth demineralization, S. mutans biofilm was allowed to form on the maxillary first molars collected from Wistar rats via 24-h culturing. The samples were immersed in 3% H2O2 and irradiated with 365-nm LED (H2O2 photolysis treatment). Viable bacterial counts in the biofilm were evaluated immediately after treatment and after an additional 30-h culturing by colony counting. The acidogenicity of the biofilm, re-established 30 h after treatment, was assessed by measuring the pH. The effect of H2O2 photolysis treatment on tooth demineralization was assessed by measuring the depth of the radiolucent layer in micro-CT images. RESULTS: H2O2 photolysis significantly reduced viable bacterial counts in the biofilm to 3.7 log colony forming units (CFU)/sample, while the untreated group had 7.9 log CFU/sample. The pH of the biofilm re-established after treatment (6.6) was higher than that of the untreated group (5.3). In line with the pH measurement, the treatment group had a significantly lower depth of radiolucent layer in dentin than the untreated group. CONCLUSIONS: H2O2 photolysis treatment was effective not only in killing the biofilm-forming S. mutans but also in lowering the acidogenicity of the biofilm. Thus, this technique could inhibit tooth demineralization. CLINICAL RELEVANCE: H2O2 photolysis can be applicable as a new dental caries treatment.

"Difficult" dental patients: a grounded theory study of dental staff's experiences.

INTRODUCTION: The "difficult" patient is a well-known and potentially negative character in various care contexts. OBJECTIVES: This study aimed to generate a conceptual framework explaining the main concerns about "difficult" dental patients, and obtain a deeper understanding of their characteristics, how they affect the dental staff and how the staff think and act in order to manage these patients. METHODS: Ten interviews were conducted with professional dental caregivers, including dentists, dental hygienists, and dental nurses. The audio-recorded interviews were transcribed and analyzed in accordance with the principles of grounded theory. RESULTS: The main concern regarding "difficult" dental patients generated a framework of seven descriptive interrelated lower-level categories grounded in the data, subsumed in the core category "balancing subjective difficulties". The informants perceived the possession of "showing interaction difficulties" and "having bio-psycho-social complexity", as characteristic features of "difficult" patients, who could further adversely affect the dental staff by "evoking negative emotions and behaviors", "hampering self-esteem and job satisfaction", and "impairing life and health in general". To manage the dental care of these patients, the staff used strategies aimed at "activating internal and external resources" and "creating adaptive treatment relations" with patients. CONCLUSIONS: The dental staff's meaning of the phenomenon of "difficult" dental patients points to specific characteristics, effects, and handling strategies. The core category captures the contradictory dynamics of characteristics and affects as these concepts seem interrelated to the caregivers' handling capacity. The dental staff's possibility of handling the main concern through balancing subjective difficulties depends on contextual conditions regarding time, to bring the patient and/or oneself at the center of attention. This indicates a need for further research regarding dental interactions and studies generalizing the outlook on "difficult" dental patients.

The effect of a non-tobacco-based nicotine pouch on mucosal lesions caused by Swedish smokeless tobacco (snus).

Oral mucosal lesions are commonly found in Swedish smokeless tobacco (snus) users where the pouch is placed. These lesions are reversible, that is, clinical and histological tissue changes return to normal following cessation. However, the exact mechanisms behind these changes are unknown. The main aim of this study was to investigate how snus-like non-tobacco-based nicotine pouches affect the oral mucosa and the severity of pre-existing lesions. Sixty regular users of Swedish smokeless tobacco were encouraged to substitute their snus with non-tobacco-based nicotine pouch products during a 6-week period. Meanwhile, oral mucosal lesions were assessed using a four-degree scale. Over time, a reduction of pre-existing mucosal lesions was observed between baseline and the final visit. In a second part, the effect of exposure to regular snus on the production of 48 different cytokines in peripheral blood mononuclear cells was compared in vitro with that resulting from exposure to the non-tobacco-based nicotine products. Results showed significantly increased production of proinflammatory cytokines in cells exposed to regular snus compared to untreated or cells exposed to the non-tobacco-based nicotine products. This may be related to the improved clinical appearance of the oral mucosa in the participants that used the non-tobacco-based nicotine test pouches.

Oral health by obesity classification in young obese women - a cross-sectional study.

OBJECTIVE: To explore oral health by increasing degree of obesity and the influence of modifying factors. MATERIALS AND METHODS: A cross-sectional design was used. Swedish females (n = 118; 18-35 years) with morbid obesity were recruited from the BAriatric SUbstitution and Nutrition study (BASUN). Body mass index (BMI) was used as continuous and categorized into 35-39.9 kg/m2/40-44.9 kg/m2/≥45 kg/m2. Oral examinations assessed dental caries using the ICDAS system, periodontal status and saliva characteristics. Information on sociodemographics, oral health behaviour and symptoms was collected via a questionnaire. RESULTS: Mean BMI was 42.2 kg/m3 (SD 4.0; range 35.0-63.7). Significantly higher frequencies of dentine caries (p = .001) and total caries (p = .046) were found with higher BMI with an increase in total caries by 0.59 tooth surface (p = .025) for each increasing BMI degree. There were consistent associations between obesity and dentine caries for the group with the highest BMI (≥45), adjusted RR 2.08 (95% CI 1.20-3.61), and all stages of caries, adjusted RR 1.41 (95% CI 1.02-1.96). High scores were found for dental plaque (50.2%) and gingivitis (34.5%). CONCLUSION: Young obese women exhibited poor oral health with higher caries levels by higher BMI. Dental care should adapt the prevention efforts for obese individuals. Trial Registration: The trial was prospectively registered on March 03; 2015; NCT03152617.

Effect of a mouth rinse and a high-fluoride toothpaste on caries incidence in orthodontic patients: A randomized controlled trial.

INTRODUCTION: The objective was to evaluate the effect of a fluoride mouth rinse and a high-fluoride toothpaste on caries incidence in patients undergoing orthodontic treatment with fixed appliances. METHODS: In this 3-armed, parallel-group, randomized controlled trial, patients referred to the Specialist Clinic of Orthodontics, Mölndal, Sweden, were randomly allocated to 1 of the 3 groups. (1) Fluoride mouth rinse (FMR) group: 0.2 % sodium fluoride (NaF) mouth rinse plus 1450 ppm fluoride (F) toothpaste; (2) High-fluoride tootpaste (HFT) group: 5000 ppm F toothpaste; and (3) Control (CTR) group: 1450 ppm F toothpaste. The generation of a randomization sequence was performed in blocks of 30. Inclusion criteria included patients scheduled for treatment with fixed appliances in the maxillary and mandibular arch aged 12-20 years. The primary outcome variable was the change in Decayed Initial Filled Surfaces (ΔDiFS) based on radiographs taken before and after the treatment. For statistical comparisons between groups, the Kruskal-Wallis test were used for continuous variables, whereas the Mann-Whitney U-test was used for pairwise group comparisons. Furthermore, the risk ratio (RR) and 95% confidence interval (CI) based on clinically relevant cutoffs (DiFS ≥2) were calculated to compare the increase of caries during orthodontic treatment between 2 groups. The Cochran-Mantel-Haenszel method was used to adjust RR for baseline values. Blinding was employed during the caries registration and the data analysis. RESULTS: In total, 270 participants were randomized, with 15 patients dropping out, such that 255 patients were included in the statistical analyses. Recruitment was from October 2010 to December 2012. An increase in DiFS (≥1 DiFS) during treatment was observed in 48.3% of the FMR group, 42.0% of the HFT group, and 35.6% of the CTR group. There was no significant difference between the groups regarding increased DiFS (P = 0.17). The risk of increase in DiFS ≥2 during orthodontic treatment was 31.0% in the FMR group, 25.9% in the HFT group, and 18.4% in the CTR group. The RR for an increase of ≥2 DiFS during orthodontic treatment was 1.38 (95% CI, 0.81-2.34; P = 0.23) for FMR vs CTR, 1.21 (95% CI, 0.70-2.10; P = 0.51) for HFT vs CTR, and 0.93 (95% CI, 0.57-1.49; P = 0.76) for HFT vs FMR. CONCLUSIONS: In patients who demonstrate a low prevalence of caries and are undergoing orthodontic treatment, daily use of high-fluoride toothpaste or fluoride mouth rinse in combination with regular toothpaste does not appear to significantly alter the caries incidence compared with the use of regular toothpaste. TRIAL REGISTRATION: The trial was registered in the FoU i Sverige research database (http://www.fou.nu/is/sverige), with registration no. 236251. PROTOCOL: The protocol was not published before trial commencement. FUNDING: Local Research and Development Board for Gothenburg and South Bohuslän (grant no. 768531); and The Swedish Patent Revenue Fund (grant number EKF-780/19).

Prevalence of Dental Caries in Past European Populations: A Systematic Review.

OBJECTIVE: Within the fields of anthropology and osteoarcheology, human teeth have long been studied to understand the diet, habits, and diseases of past civilizations. However, no complete review has been published to collect and analyze the extensive available data on caries prevalence in European man (Homo sapiens) over time. METHOD: In this current study, the two databases, Scopus and Art, Design, and Architecture Collection, were searched using predefined search terms. The literature was systematically reviewed and assessed by two of the authors. RESULTS: The findings include a significant nonlinear correlation with increasing caries prevalence in European populations from 9000 BC to 1850 AD, for both the number of carious teeth and the number of affected individuals. CONCLUSION: Despite the well-established collective belief that caries rates fluctuate between different locations and time and the general view that caries rates have increased from prehistoric times and onwards, this is to our knowledge the first time this relationship has been proven based on published data.

Effect of drops containing Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) on plaque acidogenicity and other caries-related variables in orthodontic patients.

BACKGROUND: The purpose of the study was to investigate the effect of probiotics on biofilm acidogenicity and on the number of salivary Streptococcus mutans and lactobacilli in orthodontic patients. METHODS: This RCT was conducted on 28 young adults who were undergoing orthodontic treatment. The short-term prospective clinical trial lasted for three weeks. The test group rinsed daily with drops containing two Lactobacillus reuteri strains diluted in water, while the placebo group used drops without probiotics. The subjects were enrolled eight months since the beginning of orthodontic treatment. Plaque-pH, saliva and dental biofilm samples were obtained at baseline, one week and three weeks post intervention. RESULTS: Twenty-seven subjects successfully completed the trial period, only one drop out in the test group. No side effects were reported. A statistically significant increase in plaque pH at three weeks post-intervention was found for the test group (p < 0.05), while insignificant changes in the pH value were found for the placebo group in comparison to baseline (p > 0.05). In addition, the AUC7.0 showed a significant difference at three weeks between the test and placebo (p = 0.00002). The three-week samples of stimulated whole saliva showed a statistically insignificant difference in the number of S. mutans and lactobacilli between the two groups (p > 0.05). The qPCR analysis showed the ability of the two strains to get colonized in the dental biofilm without a significant effect on the microbial counts. CONCLUSION/CLINICAL IMPLICATIONS: A mixture of Lactobacillus reuteri has the ability to reduce the pH fall at the three-week follow-up. However, the short-term use of probiotics does not appear to have an effect on the number of salivary Streptococcus mutans and lactobacilli in saliva and on the dental biofilm. TRIAL REGISTRATION: Clinicaltrial.gov (Identifier: NCT04593017 / (19/10/2020)).

Dental markers of biocultural sex differences in an early modern population from Gothenburg, Sweden: caries and other oral pathologies.

BACKGROUND: With the aim to study dental pathological lesions in an early Swedish modern population, with special reference to sex variances of dental caries, the prevalence and distribution of dental caries and tooth wear were determined in complete and partial human dentitions from an early modern-time city graveyard (1500-1620) excavated in Gamlestaden, Gothenburg, Sweden. METHODS: Partial and complete dentitions were examined through visual inspection and using a dental probe. Pathologies were studied, evaluated and presented by teeth and alveoli. RESULTS: The study population consisted of 308 individuals. A total of 4,951 teeth in adults and 1,660 teeth in children were examined. Caries prevalence in the studied population was 55% and the highest prevalence of caries was found among the adults, where 68% of the individuals had at least one carious lesion. Caries experience (DMT > 0) in the entire population was 60%, and among adults caries experience was 76%. Women had significantly higher caries experience than men (p < 0.05). Caries was most prevalent in the molar teeth and least prevalent in the incisors and canines. Significant age-related increases in tooth wear were found, and a positive correlation between wear in molars and incisors (p < 0.001). Other clinical findings were signs of apical lesions, crowding of teeth, aplasia, non-erupted canines and calculus. CONCLUSIONS: Findings show that dental pathological lesions affected a majority of the studied population, and indicate that women were more predisposed to dental disease than their male counterparts. Results are discussed from a multi-factorial explanation model including dietary, physiological and cultural etiological factors.

Oral health profile of postbariatric surgery individuals: A case series.

OBJECTIVES: To describe the oral health profile of individuals who had undergone gastric bypass surgery (GBP) or sleeve gastrectomy (SG) to generate hypotheses for further studies. MATERIAL AND METHODS: Fourteen individuals treated with GBP or SG surgery ≥ 2 years ago and with observed and/or perceived oral problems were recruited to a case series. The documentation included clinical and radiographic examinations, biomedical sampling, and self-reported diet and questionnaires. The results are presented descriptively. RESULTS: The age range was 31 to 66 years and all had a BMI > 25 (range 25.4-44.7). Only four participants were fully dentate. Eleven out of 14 individuals exhibited severe decay. A majority had poor oral hygiene and high bacterial counts. The flow rates of unstimulated saliva were extremely low and hyposalivation was present in ten of the fourteen cases. Most perceived several oral health problems, such as chewing difficulty and tooth hypersensitivity. CONCLUSIONS: Individuals who had undergone GBP or SG surgery had poor clinically diagnosed oral health and perceived oral health problems. Longitudinal studies are needed to monitor the patients' oral health, from before bariatric surgery to long-term postoperatively.

Opportunities for caries prevention using an ion-releasing coating material: a randomised clinical study.

Ion-releasing materials (containing fluoride and boron, for example) have shown caries-preventive effects in vitro. The purpose of the present study was to investigate the impact of multi-ion-releasing coating material on pH stabilisation, plaque accumulation and the bacterial composition of dental plaque during a time period of 90 days. The null hypothesis tested here was that the evaluated material would not show any differences in pH stabilisation, plaque accumulation or bacterial composition compared with control material.The study was carried out as a double-blind, split-mouth, randomised, controlled clinical trial in 28 volunteers. Over the evaluation period (days 4, 30, 60 and 90), pH measurements, plaque index and plaque sampling for bacterial analyses were conducted in a calibrated, standardized manner. The study received ethical permission and was carried out in accordance with the Helsinki Declaration.A significant difference was observed, with less plaque accumulation over time in the subjects in whom the ion-releasing material was applied in comparison to the non-active group. No significant difference was evident in terms of either pH stabilisation or plaque levels of mutans streptococci.The null hypothesis relating to plaque accumulation was rejected, with a lower plaque index shown for the test group up to 60-90 days. No adverse effects during the observation period were observed. Since the studied cohort was healthy from a caries perspective, more clinical studies are needed to further evaluate the caries-prevention potential of the ion-releasing material in other patient groups.

Effect of Lactobacillus brevis CD2 containing lozenges and plaque pH and cariogenic bacteria in diabetic children: a randomised clinical trial.

OBJECTIVE: The short-term effect (60 days) of Lactobacillus brevis CD2 lozenges vs placebo on variables related to caries and gingivitis in type 1 diabetic children was evaluated. MATERIAL AND METHODS: Eight diabetics (4-14 years old) were assigned to two groups (n = 34 subjects each), probiotic lozenges and placebo. Stimulated saliva for microbiological analysis and plaque pH were assessed at baseline (t0), 30 days (t1), 60 days (t2) and in the follow-up period (90 days from baseline, t3). Gingival status was assessed at t0, t2 and t3. Two-way ANOVA assessed differences between groups. RESULTS: In the probiotic group, Streptococcus mutans bacterial density mean scores dropped from 3.11 ± 1.13 at baseline to 1.82 ± 0.72 (t2) and to 2.06 ± 0.56 (t3), while in the placebo group, the scores were 3.09 ± 0.8 (t0), 2.82 ± 0.47 (t2) and 3.11 ± 0.43 (t3) (p < 0.01). Lowest and maximum pH fall increased in the probiotic group, from 5.37 ± 0.41 at baseline to 5.49 ± 0.24 at t3 (p < 0.01) and from 1.20 ± 0.46 to 0.98 ± 0.29 (p = 0.02). Bleeding score decreased significantly in both groups, showing a statistically significant lower bleeding score at t2 in the probiotic group (25.6%, 95% CI 21.5-32.7 vs 29.5%, 95% CI 25.2-34.9, p = 0.02). CONCLUSIONS: Lactobacillus brevis CD2 has shown to improve caries-related risk factors and gingival health in diabetic children. CLINICAL RELEVANCE: Lactobacillus brevis CD2 might contribute to improved oral health in type 1 diabetic children.

Oral Colonisation after the Administration of Drops Containing Lactobacillus reuteri.

PURPOSE: To investigate the oral colonisation potential after four weeks' administration of Lactobacillus reuteri and to examine the short-term effect of probiotics on salivary Streptococcus mutans and lactobacilli. MATERIALS AND METHODS: The study group comprised 13 young adults who volunteered after receiving verbal and written information. The short-term prospective clinical trial lasted 9 weeks, consisting of a 4-week intervention period with administration twice daily and a 5-week post-administration follow-up period with no probiotic consumption. Saliva and dental biofilm samples were obtained immediately before probiotic administration, after 2 weeks and after 4 weeks of L. reuteri administration. Follow-up samples were collected once every week on a regular basis after administration was terminated. The numbers of salivary S. mutans and lactobacilli were assessed by regular plating, while the presence of the two L. reuteri strains in saliva and dental biofilm was evaluated using quantitative polymerase chain reaction (qPCR). RESULTS: The occurrence of L. reuteri in the oral cavity increased gradually during the intervention period and reached the maximum level after four weeks of probiotic administration (p < 0.0001). The 4-week samples of stimulated whole saliva showed a statistically significant decrease in the number of S. mutans and a statistically significant increase in the salivary lactobacilli level in comparison to baseline. qPCR showed that the DSM 17938 strain has better colonisation for both saliva and dental biofilm than the ATCC PTA 5289 strain at the nine-week follow-up. CONCLUSION: Probiotics have the ability to colonise the oral cavity during usage, but it gradually disappears after the completion of intake. It also has ability to decrease the number of salivary S. mutans.

Reactions of dental pulp to hydrogen peroxide photolysis-based antimicrobial chemotherapy under ultraviolet-A irradiation in rats.

Hydrogen peroxide photolysis-based antimicrobial chemotherapy that utilizes ultraviolet-A irradiation (UVA-H2O2 photolysis) has been previously proposed as a method of treatment of cariogenic biofilm. Therefore, in the present study, we aimed to assess time-dependent reactions in the dental pulp of rats after UVA-H2O2 photolysis. Maxillary first molars were treated. UVA irradiation (wavelength: 365 nm) with 3 wt% H2O2 was performed for 90 s at a radiant emittance of 500-2000 mW/cm2 on the rats for 3 consecutive days or only 1 day. The animals were sacrificed at Days 1, 3, 7, and 21 after the treatment for the histological evaluation of inflammatory cells and immunohistochemistry of heat shock protein (HSP)-25, a marker of odontoblasts. Tertiary dentin formation was evaluated at Day 21 by histomorphometry and micro-CT analysis. UVA-H2O2 photolysis elicited little infiltration of inflammatory cells, but disturbances in the odontoblast layer and/or presence of localized degenerative tissue were observed on Day 3. This condition was followed by a healing process that was characterized by the reappearance of HSP-25 positive odontoblast-like cells at Day 7 and tertiary dentin formation at Day 21. The amount of tertiary dentin formed was dependent on the intensity of treatment; repeated UVA irradiations of H2O2 at 2000 mW/cm2 resulted in the largest amount of tertiary dentin formation at the pulp horn regions. Our findings suggest that UVA-H2O2 photolysis treatment can be used to treat dental caries clinically because the post-treatment inflammatory reaction was minimal and tertiary dentin formation was substantial, which may prove effective in protecting dental pulp from external irritants. As a cautionary consideration, the radiant emittance of the UVA irradiation should be carefully optimized before clinical application.

Effect of Different Toothbrushing Routines on Interproximal Fluoride Concentration.

This study aimed to evaluate the effect of different toothbrushing routines and different kinds of toothpaste on the interproximal fluoride concentration after toothbrushing and its clinical relevance to the recommendations given to patients regarding the process of toothbrushing. Eight adults participated a total of 8 times in order to test different toothbrushing routines with different amounts of toothpaste (1 or 2 cm), durations (1 or 2 min) and amounts of water after toothbrushing (10 or 20 mL). An additional 8 adults participated 6 times in total to test different forms of toothpaste administration (paste, gel and foam) with different amounts of water after toothbrushing (no rinsing or 10 mL). Interdental saliva samples were collected from proximal sites 25/26 and 46/45 using small paper points, before and up to 60 min after toothbrushing. The fluoride concentration was measured by an ion-specific electrode. The area under the curve, saliva fluoride concentration versus time, was calculated. Differences between the groups were tested by ANOVA with Tukey's multiple comparisons test. An increase in fluoride concentration of 47.2% was observed when the amount of toothpaste increased from 1 to 2 cm (p < 0.01), 26.8% when increasing the duration from 1 to 2 min (p < 0.01) and 41.2% when reducing the amount of water rinsing from 20 to 10 mL (p < 0.01). The paste and gel resulted in higher fluoride concentration (p < 0.01) compared with foam. These findings suggest that the amount of toothpaste, the duration and the amount of water have a significant effect on fluoride concentration after toothbrushing. Furthermore, despite the lower amount of fluoride, the gel gives almost the same fluoride concentration after toothbrushing as the toothpaste. The results confirm the importance of giving clear advice to patients regarding the process of toothbrushing.

Dose-Response Effect of Fluoride Dentifrices on De-/Remineralization of Root Dentine in situ.

The present study aimed to evaluate the effect of fluoride (F) dentifrice with different F concentrations on root dentine de-/remineralization. Ten healthy volunteers took part in this randomized, double-blinded, cross-over, and split-mouth in situ experimental study. During 4 phases of 7 days, they wore a palatal appliance containing 4 bovine dentine blocks (2 sound and 2 with caries) of 4 × 4 × 2 mm. Treatments were performed with silica-based dentifrices containing 0, 700, 1,300, and 5,000 µg F/g (F as NaF). To provide a cariogenic challenge, a 20% sucrose solution was dripped 3 and 8 times daily on the carious-like and sound blocks, respectively. After each experimental phase, the percentage of surface hardness loss (%SHL) or recovery (%SHR) was calculated and the fluoride concentration in the biofilm was determined. The statistical analysis was performed using ANOVA and the Tukey post hoc test with p at 5%. The relationship between variables was analyzed by linear regression. The results showed a lower %SHL when 5,000 µg F/g dentifrice was used but without a statistically significant difference from the conventional one (1,300 µg F/g). Regarding remineralization and F in biofilms, the high-fluoride dentifrice was expressively superior in mineral replacement on the surface and in the F concentration in the biofilms, respectively, compared to the other 3 products (p < 0.05). Also, a significant linear fit between mineral loss/gain, F in biofilms, and fluoride concentration in the dentifrices could be observed. In conclusion, a dose-response F effect was observed, and the high-fluoride dentifrice was effective in enhancing root dentine remineralization in this short-term in situ study.

Corrigendum: A Hydrogel Drink With High Fructose Content Generates Higher Exogenous Carbohydrate Oxidation and a Reduced Drop in Dental Biofilm pH Compared to Two Other, Commercially Available, Carbohydrate Sports Drinks.

[This corrects the article on p. 88 in vol. 7, PMID: 32596251.].