Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy.

OBJECTIVES: Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily. MATERIALS AND METHODS: Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase. RESULTS: 45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2. CONCLUSIONS: This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC. CLINICAL RELEVANCE: This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.

Clinical characteristics and caries risk assessment of tobacco heating systems smokers, cigarette smokers and non-smokers: a cross-sectional study.

OBJECTIVES: The study compared clinical characteristics and caries risk assessments between tobacco heating system (THS) smokers, cigarette smokers and non-smokers. MATERIALS AND METHODS: General data, data regarding fluoridation, smoking and dietary habits was obtained through a questionnaire. Caries experience was assessed by the DMFT index; the amount of biofilm by the Full mouth plaque score index; the amount of salivation by the quantum of stimulated salivation test; salivary pH with pH indicator strips and salivary number of S.mutans and Lactobacilli by cultivation on agar plates. The Cariogram method was used to assess caries risk. RESULTS: No differences between the groups was detected regarding education level, average daily number of meals, fluoridation programs, systemic diseases, and caries experience. The groups significantly differed in the amount of salivary S.mutans and Lactobacilli (p < 0.001), accumulated biofilm (p = 0.034), salivation quantum (p < 0.001), and saliva pH (p = 0.009). Exposure to tobacco smoke and heated tobacco aerosol increased the accumulation of biofilm and decreased salivary pH. Smoking increased S. mutans, while THS consumption decreased salivation and Lactobacilli the most. The Cariogram analysis found no differences in chances of avoiding new caries lesions between the groups, but a significant difference in developing caries lesions due to dietary habits was detected (p < 0.001) with non-smokers having higher risk than smokers, but not than THS consumers. CONCLUSIONS: THS and cigarette smoking were related to clinical characteristics that affect caries activity even though the caries risk assessment revealed no significant difference in the chances of avoiding new caries lesions between the groups. CLINICAL RELEVANCE: THS and cigarette smokers could have higher caries activity than non-smokers. The clinical study protocol has been registered on ClinicalTrials.gov under the ID number: NCT06314100.

Effectiveness of nanosilver fluoride and silver diamine fluoride in arresting early childhood caries: a randomized controlled clinical trial.

BACKGROUND: One of the most prevalent health problems affecting children worldwide is untreated caries in primary teeth. Agents to arrest caries are used to manage untreated decay in children in disadvantaged communities. Nano Silver Fluoride (NSF) overcomes the staining problems of Silver Diamine Fluoride (SDF). This study compared the clinical cariostatic effect of NSF to 38% SDF for arresting caries lesions. METHODS: The study included 360 children younger than 4 years, with at least one active lesion, ICDAS score ≥ 3, recruited from nurseries in a rural area in Alexandria, Egypt, in 2022. They were randomly assigned to receive a single application of NSF at baseline, or two applications of SDF at baseline and after 6 months. The arrest of active carious lesions was assessed after 6 and 12 months using ICDAS criteria, and parents' satisfaction with child appearance was also assessed. Chi-Square test was used to compare the groups and multi-level multiple logistic regression was used to assess the effect of the intervention on caries arrest at lesion level and binary logistic regression was used to assess the effect at patient level. RESULTS: 1853 active lesions were included in children whose mean (SD) age was 42.3 (8.2) months. The arrest rate was significantly higher in the NSF than the SDF group at lesion level (78.4% and 65.0% at 6 months and 71.3% and 56.3% at 12 months, p < 0.001). In regression analysis, NSF had significantly higher odds of caries arrest than SDF at lesion level (at 6 months, AOR = 2.57, 95% CI: 1.55, 4.26 and at 12 month, AOR = 3.27, 95% CI: 1.89, 5.67). Parents of children receiving NSF had significantly greater satisfaction with their children's dental appearance than those receiving SDF: (97.2% and 76.1%, respectively, p < 0.001). CONCLUSION: NSF demonstrated greater effectiveness in arresting caries in preschool children without inducing black staining of teeth and with greater parental satisfaction than SDF. NSF can be an alternative to SDF in arresting caries especially in underprivileged communities. TRIAL REGISTRATION: The trial was registered in the clinicaltrials.gov registry (#NCT05255913)-16/02/2022.

The Influence of Vitamin D Levels on Dental Caries: A Retrospective Study of the United States Population.

(1) Background: This study examines vitamin D's impact on dental caries to inform prevention strategies, given its critical role in bone and calcium regulation, vital for dental health. (2) Methods: Data from 18,683 participants of the National Health and Nutrition Examination Survey (NHANES) 2011-2016 were analyzed. NHANES collects U.S. population data through interviews, physical exams, and tests, including vitamin D levels and dental health assessed using both the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured according to serum 25(OH)D concentrations, and the analyses adjusted for confounders such as body mass index (BMI) and socioeconomic status (SES) using Chi-square, Mann-Whitney U, Kruskal-Wallis tests, as well as logistic and Poisson regression. (3) Results: This study found a mean DMFT score of 7.36 and a 33.2% prevalence of untreated dental caries. A higher caries prevalence was correlated with a lower SES (p < 0.001), the male gender (p < 0.001), and a higher BMI (p < 0.001). Severe vitamin D deficiency (<25 nmol/L) doubled the risk of dental caries, with odds ratios of 2.261 and 1.953 after adjusting for demographic factors and BMI. (4) Conclusions: Our study confirms a significant relationship between low vitamin D levels and an increased risk of dental caries nationwide, even after accounting for sociodemographic factors, emphasizing the importance of maintaining sufficient vitamin D levels for preventing caries.

Dental treatment of children under general anesthesia during the period of matrial law.

OBJECTIVE: Aim: To summarize the experience of providing dental medical care under general anesthesia to children from different regions of Ukraine during the martial law, taking into account the factors affecting the choice of optimal conditions for dental treatment. PATIENTS AND METHODS: Materials and Methods: Dental treatment under general anesthesia of 1,258 children from different regions of Ukraine has been performed since March 2022. The condition of the teeth (df, df+DMF, DMF) and hygienic state of the oral cavity (OHI-S) were determined. The level of awareness of parents regarding the preservation of children's dental health was studied through a questionnaire. RESULTS: Results: An unsatisfactory oral hygiene, a high level of caries were found in the vast majority of children. The highest df was observed in the group of children aged 3 to 6 years (7.14±0.33), which is significantly higher than in the group of children under 3 years of age (4.32±1.04, p≤0.05). The worst oral hygiene was observed in children aged 6-12 years (OHI-S 2.62±0.32). An insufficient level of awareness of parents and children regarding dental health was revealed. A total of 1,712 operations under general anesthesia were performed. The majority of patients could not regularly appear for follow-up examinations due to the forced departure from the country. CONCLUSION: Conclusions: The organization of dental treatment under general anesthesia allows solving a number of problems of dental care for children during the war.

Prevalence of dental carries and its association with breastfeeding duration among young children in Addis Ababa, Ethiopia.

BACKGROUND: Breastfeeding is a crucial feeding practices that significantly contributes to the healthy development of children. However, the effect of breastfeeding duration on caries risk is unclear, as different studies have found different results. This study aims to assess the prevalence of dental caries and its association with breastfeeding duration among young children aged 12-36 months in selected health facilities of Addis Ababa, Ethiopia. METHODS: A cross-sectional study among 380 children aged 12-36 months from 11 health centers in Addis Ababa was conducted. Questionnaires and dental examinations were used to collect data. Dental caries was measured by the deft (decayed-extracted-filled teeth) index. Binary logistic regression was used to assess the association between dental caries and duration of breastfeeding, after adjusting for the confounders. RESULTS: The prevalence of dental caries was 53.4% (95% CI: 48.3, 58.5%), with 13.7% having high caries and 39.7% having low caries. Breastfeeding duration was not significantly associated with dental carries, after adjusting for confounders. However, sugar intake, older age, mothers' unemployment, and not being in marital union are risk factors for dental caries development. CONCLUSIONS: Promotion of healthy diet, especially limiting intake of sugar and sweets, and integration of oral health into primary health care programs are recommended. Further research using longitudinal design or meta-analysis is recommended to establish more concise evidence on the association between breastfeeding duration and dental caries.

Quantifying variations associated with dental caries reveals disparity in effect allele frequencies across diverse populations.

BACKGROUND: Dental caries (DC) is a multifaceted oral condition influenced by genetic and environmental factors. Recent advancements in genotyping and sequencing technologies, such as Genome-Wide Association Studies (GWAS) have helped researchers to identify numerous genetic variants associated with DC, but their prevalence and significance across diverse global populations remain poorly understood as most of the studies were conducted in European populations, and very few were conducted in Asians specifically in Indians. AIM: This study aimed to evaluate the genetic affinity of effect alleles associated with DC to understand the genetic relationship between global populations with respect to the Indian context. METHODOLOGY: This present study used an empirical approach in which variants associated with DC susceptibility were selected. These variants were identified and annotated using the GWAS summary. The genetic affinity was evaluated using Fst. RESULTS: The effect of allele frequencies among different populations was examined, revealing variations in allele distribution. African populations exhibited higher frequencies of specific risk alleles, whereas East Asian and European populations displayed distinct profiles. South Asian populations showed a unique genetic cluster. CONCLUSION: Our study emphasises the complex genetic landscape of DC and highlights the need for population-specific research as well as validation of GWAS-identified markers in Indians before defining them as established candidate genes.

Validation of an improved questionnaire assessing the social cognitive constructs of the Health Action Process Approach among parents regarding brushing their children's teeth.

OBJECTIVE: The Health Action Process Approach (HAPA) describes social cognitive constructs related to behaviour change. A validated questionnaire is needed to measure these constructs in paediatric dentistry. The aim of this study was to improve an existing HAPA-based questionnaire for parents regarding brushing their children's teeth and to assess its validity and reliability in a population of parents of high caries risk children. METHODS: Parents of high caries risk children of 3-10 years filled out the adjusted HAPA-based questionnaire. Mokken scale analysis, graded response model analyses, factor analyses and reliability analyses were performed according to the protocol of Dima. Discriminant validity was assessed by comparing the mean scores of the HAPA constructs between two groups of participants, based on different levels of caries experience, brushing frequency and education level of the mother. RESULTS: The Mokken scale analysis and factor analyses indicated a multidimensional eight factor scale. The graded response model did not fit our data. The subscale action control could be identified as a two-factor subscale. Reliability indices from the Dima protocol varied, for instance Cronbach alpha ranged from 0.73 to 0.96. The constructs coping self-efficacy, action planning and action control discriminated between brushing frequencies. CONCLUSIONS: The adjusted HAPA-based questionnaire is an improved, valid and reliable instrument that could be used to evaluate HAPA-based interventions to improve children's oral health.

Effectiveness of risk-based caries management among Chinese preschool children: a randomized controlled single-blind trial.

BACKGROUND: Early childhood caries (ECC) remain a serious oral health problem on a global scale. Risk-based caries management (RBCM) implemented in some parts of the world has been effective in preventing ECC. However, there is a lack of prospective research on the application of RBCM among Chinese children, and little is known about its effectiveness. The purpose of this study was to evaluate the effectiveness of RBCM in preventing caries among children aged 3-5 years in Wanzhou District, Chongqing Municipality, China. METHODS: Three- to five-year-old children from four kindergartens in Wanzhou were randomly selected for baseline dental examination and caries risk assessment (CRA) and randomly assigned to the experimental group (EG) or the control group (CG) according to the kindergarten. The EG received caries prevention measures of different intensities based on the child's caries risk level. The CG received full-mouth fluoride twice a year according to standard prevention, regardless of their caries risk. One year later, another dental examination and CRA were conducted, to observe changes in the decayed, missing, and filled teeth (dmft) index and caries risk, and to analyze potential factors that may affect the incidence of new caries. RESULTS: Complete data were collected from 291 children (EG, N = 140, 84.8%; CG, N = 181, 83.4%). A total of 25.7% of the EG and 50.3% of the CG children developed new caries, with newly added dmft scores of 0.54 ± 1.12 and 1.32 ± 1.72, respectively (P < 0.05). Multivariate logistic regression indicated that children living in rural areas, assigned to the CG, and rated as high-risk at baseline were more likely to develop new caries (P < 0.05). The proportion of children with an increased caries risk in the EG was significantly lower than that in the CG (P < 0.05). CONCLUSIONS: RBCM effectively prevented new caries in 3- to 5-year-old Wanzhou children and reduced the proportion of children at increased risk of caries. It is an effective approach for preventing ECC. CLINICAL TRIAL REGISTRATION: This trial was registered in the Chinese Clinical Trials Register. The registration number was ChiCTR230067551 (11/01/2023).

Phytochemical Analysis and Anti-Biofilm Potential That Cause Dental Caries from Black Cumin Seeds (Nigella sativa Linn.).

The oral cavity is an excellent place for various microorganisms to grow. Spectrococcus mutans and Spectrococcus sanguinis are Gram-negative bacteria found in the oral cavity as pioneer biofilm formers on the tooth surface that cause caries. Caries treatment has been done with antibiotics and therapeutics, but the resistance level of S. mutans and S. sanguinis bacteria necessitates the exploration of new drug compounds. Black cumin (Nigella sativa Linn.) is known to contain secondary metabolites that have antioxidant, antibacterial, anti-biofilm, anti-inflammatory and antifungal activities. The purpose of this review article is to present data on the potential of Nigella sativa Linn seeds as anti-biofilm. This article will discuss biofilm-forming bacteria, the resistance mechanism of antibiotics, the bioactivity of N. sativa extracts and seed isolates together with the Structure Activity Relationship (SAR) review of N. sativa compound isolates. We collected data from reliable references that will illustrate the potential of N. sativa seeds as anti-biofilm drug.

Silver modified atraumatic restorative treatment: a paradigm shift in dental caries management.

Silver diamine fluoride (SDF) and atraumatic restorative treatment (ART) are treatment modalities that are minimally invasive and used for the prevention and control of dental caries. The amalgamation of these two techniques has led to the development of silver modified atraumatic restorative treatment (SMART). In this approach the carious lesion is restored with glass-ionomer cement (GIC) after SDF application. SMART effectively arrests caries without removing additional tooth structure, making it a promising option for caries management in children who lack cooperative ability.This article reviews the literature on SMART, the evidence regarding its applications in dental practice, its advantages, drawbacks, the scope for research, and clinical use.

Caries and white spot lesion trajectories of orthodontic patients across an observation period of 20 years.

OBJECTIVES: Fixed orthodontic appliances may increase the risk for caries and white spot lesions. The aim of this retrospective study was to determine the long-term associations between both in orthodontic patients. MATERIALS AND METHODS: 103 patients aged 36.6 ± 6.5 years whose fixed appliance orthodontic treatment had finished at least 15 years ago were included. Current clinical data and photographs (T3), panoramic x-ray and photographs from before treatment (T0), after debonding (T1) and at 2-year follow-up (T2) were available. Parameters of interest were dentine caries, "Missing/Filled Teeth" (MFT), "White Spot Lesion" (WSL) index and "Periodontal Screening and Recording" index (PSR; T3 only). RESULTS: At T0, 30.4% had no caries experience decreasing to 25.6%, 22.4% and 6.8% at T1, T2 and T3 resp. The median MFT (95% CI) at T0, T1, T2 and T3 was 2 (1;3), 3 (2;4), 3 (2;4) and 7 (6;9) resp. increasing significantly at each time point (p < 0.001 each); 30.1% had WSL at debonding. Patients with caries experience at T0 had a 2.4-fold increased risk of WSL at debonding. Dentine caries, caries experience and WSL at T1 were significantly associated with incident caries at T2, but not at T3. PSR at T3 had a significant association with previous caries incidence and WSL. CONCLUSIONS: Caries experience prior to orthodontic treatment may constitute a risk indicator for WSL, and caries experience and WSL at its end for caries incidence in the near term. CLINICAL RELEVANCE: Present caries and WSL may help identifying orthodontic patients with special need for prevention and counselling.

Microleakage of Silver-Modified Atraumatic Restorative Technique (SMART) Restorations Using Silver Diammine Fluoride and High-Viscosity Glass Ionomer.

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.

Longitudinal Follow-up Comparing Future Care of Primary Teeth Treated with Silver Diammine Fluoride: A Private Dental Claims Review.

Purpose: The purpose of this study was to longitudinally evaluate follow-up treatment on primary teeth initially treated with silver diammine fluoride (SDF). Methods: This retrospective cohort evaluated private insurance (not Medicaid) claims data from 2018 to 2019 for children no older than 12 years with at least one primary tooth initially treated with SDF. Additional treatment per tooth was recorded over a follow-up of at least 24 months. Results: The mean and standard deviation (±SD) age of 46,884 patients was 5.7±2.3 and for SDF-treated teeth per patient was 2.6±2.1. Forty percent (95 percent confidence interval [95% CI] equals 39 to 40.7 percent) of teeth initially treated with SDF received additional treatment. The odds of SDF-treated teeth receiving future treatment significantly decreased with patient age by 22 percent per year (odds ratio equals 0.78; 95% CI equals 0.077 to 0.79; P<0.001). Pediatric dentists had only slightly lower odds than general dentists for providing additional treatment (0.91, P<0.001). Posterior teeth and teeth expected to exfoliate in two or more years had significantly higher odds of receiving additional treatment (2.47 and 1.27, respectively, P<0.001). Conclusions: Beginning at age four, patient age at placement of silver diammine fluoride was inversely proportional to future treatment provided. Posterior teeth and teeth expected to exfoliate in two or more years were more likely to receive additional treatment.

CONSORT statement adherence and risk of bias in randomized controlled trials on deep caries management: a meta-research.

BACKGROUND: Recently, trials have supported changes in deep caries management. However, reporting might lack details, affecting interpretation and implementation. Thus, we aimed to evaluate the adherence to the CONSORT statement and the risk of bias of randomized controlled trials (RCTs) on deep caries management published in pediatric dental journals. METHODS: We searched PubMed for RCTs in six pediatric dental journals between 2010 and 2022, focusing on deep caries lesion management. Adherence to the CONSORT guideline and the risk of bias were assessed using a modified tool with 19 items; each scored from 0 to 2 (maximum of 38 points), and the Cochrane risk-of-bias (RoB 2) tool. We performed descriptive and regression analyses (α = 5%). RESULTS: We analyzed 127 RCTs. The mean (standard deviation) CONSORT adherence score was 21.1 (6.7). Notably, 96.1% of the studies received a score of 2 for the "intervention" item, whereas 83.5% scored 0 for the "estimated effect size". The risk of bias assessment revealed that 40.2% of the RCTs were at high risk, 59% were at low risk, and 0.8% were at low risk. RCTs with a high risk of bias had lower CONSORT scores (p<0.001) than those with low or some concerns. RCTs published in journals without the endorsement of the CONSORT statement had lower scores than those in journals with the endorsement of the CONSORT statement. Older RCTs (6-10 years old and more than 10 years old) showed significantly lower CONSORT statement compliance than trials published recently within 5 years. CONCLUSION: Adherence to the CONSORT was relatively low among the investigated RCTs. Moreover, lower adherence to the CONSORT was associated with a higher risk of bias. TRIAL REGISTRATION: This study protocol was prospectively registered on the Open Science Framework - DOI ( 10.17605/OSF.IO/V6SYZ ).

Child Temperament and Early Childhood Caries: A Systematic Review and Meta-Analysis.

Purpose: The purpose of this study was to perform a systematic review to assess current evidence for the association between child temperament and early childhood caries (ECC). Methods: A systematic search was conducted using MEDLINE® through PubMed®, EMBASE®, Scopus®, LILACS, Web of Science™, and EBSCO up to January 2023. Studies measuring ECC and child temperament for children younger than or equal to six years of age using questionnaires, interviews, and surveys through case-control studies, cohort studies, and cross-sectional studies were included. Literature reviews were excluded. Medical subject heading (MeSH) terms like "temperament" and "dental caries" were used by two authors who independently extracted the data, and a third author resolved disagreements. Risk of bias assessment was done using the Newcastle-Ottawa assessment scale for case-control and cohort studies and the Appraisal tool for Cross-Sectional Studies (AXIS). The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations approach (GRADE approach). A chi-square test and I-square index were used to evaluate heterogeneity. Results: A total of 5,072 records were screened, resulting in 15 included studies that yielded data for 6,667 participants; sevenstudies were high, and eight were of moderate quality. Seven studies qualified for meta-analysis, which revealed that persistence did not affectthe presence or absence of ECC. However, there was a strong association between difficult temperament and ECC (odds ratio equals 2.63). Conclusion: A positive association between a child's temperament and early childhood caries exists that is supported by quantitative findings, indicating a connection with very low certainty.

A comparative study of microbial changes in dental plaque before and after single- and multiappointment treatments in patients with severe early childhood caries.

BACKGROUND: The status of dental caries is closely related to changes in the oral microbiome. In this study, we compared the diversity and structure of the dental plaque microbiome in children with severe early childhood caries (S-ECC) before and after general anaesthesia and outpatient treatment. METHODS: Forty children aged 3 to 5 years with S-ECC who had completed whole-mouth dental treatment under general anaesthesia (C1) or in outpatient settings (C2) were selected, 20 in each group. The basic information and oral health status of the children were recorded, and the microbial community structure and diversity of dental plaque before treatment (C1, C2), the day after treatment(C2_0D), 7 days after treatment (C1_7D, C2_7D), 1 month after treatment (C1_1M, C2_1M), and 3 months after treatment (C1_3M, C2_3M) were analysed via 16 S rRNA high-throughput sequencing technology. RESULTS: (1) The alpha diversity test showed that the flora richness in the multiappointment group was significantly greater at posttreatment than at pretreatment (P < 0.05), and the remaining alpha diversity index did not significantly differ between the 2 groups (P > 0.05). The beta diversity analysis revealed that the flora structures of the C1_7D group and the C2_3M group were significantly different from those of the other time points within the respective groups (P < 0.05). (2) The core flora existed in both the pre- and posttreatment groups, and the proportion of their flora abundance could be altered depending on the caries status of the children in both groups. Leptotrichia abundance was significantly (P < 0.05) lower at 7 days posttreatment in both the single- and multiappointment groups. Corynebacterium and Corynebacterium_matruchotii were significantly more abundant in the C1_1M and C1_3M groups than in the C1 and C1_7D groups (P < 0.05). Streptococcus, Haemophilus and Haemophilus_parainfluenzae were significantly more abundant in the C1_7D group than in the other groups (P < 0.05). CONCLUSION: A single session of treatment under general anaesthesia can cause dramatic changes in the microbial community structure and composition within 7 days after treatment, whereas treatment over multiple appointments may cause slow changes in oral flora diversity.