Oral Health and Preventive Dentistry

Purpose: This study aimed to compare insulin status and dysglycemia (prediabetes/diabetes) of patients with chronic (stage III, grade B) or aggressive periodontitis (stage III, grade C) to that of a healthy population. Materials and Methods: Patients with chronic (CP, n = 16) or aggressive periodontitis (AP, n = 15) and periodontally healthy controls (n = 32) were recruited. Body mass index was calculated. Glycemia, plasma insulin, glycated hemoglobin, C-reactive protein, and lipid levels were measured in fasting. The Homeostasis Model Assessment was used to calculate the insulin sensitivity (HOMA-%S), the beta-cell function (HOMA-%B), and their hyperbolic product (HOMA-%BxS). Results: The CP group showed statistically significantly insulin resistance with a lower HOMA-%S (p = 0.0003) and a reduced HOMA-%BxS (p = 0.049) despite a higher insulin level (p = 0.01) vs the control group, even after BMI adjustment. There was also a trend to dysglycemia (prediabetes/diabetes) in the chronic group. In patients with AP, no abnormalities in insulin status were observed and glycemic levels were comparable with controls. Additionally, patients in both AP and CP groups presented significantly higher CRP levels compared to those of the control group (p = 0.02). Conclusion: Patients with CP showed reduced insulin sensitivity, increased insulin levels but a reduced %BxS product and a trend to dysglycemia. These abnormalities were not observed in AP. Keywords: diabetes, periodontal disease, risk factor(s), systemic health/disease

Summary: Periodontal disease (PD) and Alzheimer’s disease (AD) are inflammatory diseases affecting the adult population of the world. PD is mainly caused by infection with Porphyromonas gingivalis (P. gingivalis) and by the synergistic action of various microorganisms. These microorganisms penetrate into the subgingival tissue and cause bacteremia, leading to disruption of the homeostasis of the internal environment of the body. Virulence factors known as gingipains, which are cysteine proteases and other toxins, including fimbria and lipopolysaccharides (LPS), are strongly associated with periodontitis and other systemic inflammation. PD has a known polymicrobial aetiology, and patients who eventually develop sporadic AD tend to have recurrent infections before a clinical diagnosis of dementia. AD, the most common neurodegenerative disease, is characterised by poor memory and specific hallmark proteins. An increasing number of studies have shown that periodontal pathogens are increasingly associated with this form of dementia. Many articles have shown that P. gingivalis infections directly increase the risk of PD and may indirectly lead to the development of AD. However, these links and probable pathogenesis remain to be explored. The aim of this review was to explore whether P. gingivalis periodontal infection is associated with AD and to provide possible mechanisms of association. Keywords: Alzheimer’s disease, neurodegenerative disease, periodontal disease, Porphyromonas gingivalis (P. gingivalis)

Purpose: The present study systematically reviewed randomised controlled trials (RCT) to investigate the efficacy of Er:YAG laser (ERL) as a debridement method in surgical treatment of advanced peri-implantitis. Materials and Methods: An electronic database search and a manual search were performed until March 2022. Outcome measures were clinical attachment level (CAL) gain, probing depth (PD) reduction, plaque index (PI) and bleeding on probing (BOP). The addressed PICO question was: Is ERL an effective debridement tool in the surgical treatment of advanced peri-implantitis? Results: Five eligible randomised clinical trials (RCTs) were included in the qualitative analysis, one of which had unclear risk of bias. One study reported a statistically significant difference in terms of implant CAL gain and PD reduction in favour of the experimental group vs the control group, while four studies did not report any difference between the two groups. Conclusion: Due to methodological heterogeneity, such as non-standard control groups and laser parameters, this systematic review demonstrated inconclusive findings in terms of the efficacy of Er:YAG laser as a debridement method in surgical treatment of advanced peri-implantitis. The results of this review should be considered preliminary and further, well-designed studies with standardised comparators with laser parameters are warranted. Keywords: efficacy, Er:YAG laser, peri-implantitis, systematic review

Purpose: To evaluate the relationship between self-rated oral health, subjective oral conditions, oral health behaviours, and oral health-related quality of life (OHRQoL) in Chinese college students. Materials and Methods: An online cross-sectional survey was conducted, inviting college students from eastern China to participate. A total of 1708 participants were included. A structural equation model was constructed to explain and assess the associations among self-rated oral health, subjective oral conditions, oral health behaviours, and OHRQoL. Results: Self-rated oral health had a direct positive effect on subjective oral conditions and OHRQoL. Oral health behaviours had direct negative impacts on subjective oral conditions and OHRQoL as well as on tooth condition perception and oral health interventions. Subjective oral conditions had a direct positive effect on OHRQoL. There was a positive correlation between oral health behaviours and self-rated oral health. In addition, subjective oral conditions partially mediated both the effect of oral health behaviours on OHRQoL and the effect of self-rated oral health on OHRQoL. Conclusion: There were influential associations between self-rated oral health, subjective oral conditions, oral health behaviours, and OHRQoL among college students in eastern China. Making the most of their association can be a guide to radically improving the oral health of college students. Keywords: oral health behaviours, oral health-related quality of life, self-rated oral health, structural equation modeling, subjective oral conditions

Purpose: To investigate the survival rate of dental implants in patients diagnosed with osteogenesis imperfecta (OI). Materials and Methods: The study is a retrospective analysis of six individuals (2 males, 4 females) with OI (type I, III and IV) with a total of 25 dental implants. Clinical examination included plaque index, gingival index, periodontal pocket depth for each implant, presence of pus, and loosening of the implant(s). Marginal bone loss was measured on radiographs. The observation period ranged from 2–17 years (mean:7.5 years, median: 5 years). Results: The overall implant survival rate was 80%. One patient with OI type III lost five implants. However, four out of five lost implants functioned for 11 years. Conclusion: Dental implant treatment seems to be a valid option for replacing missing teeth in OI patients. It is recommended that patients diagnosed with OI undergo the same preoperative evaluation as regular dental implant patients with special emphasis on a healthy periodontal status and ideal oral hygiene. Keywords: dental implants, implant success, implant survival, osteogenesis imperfecta

Purpose: To investigate the absolute wear caused by toothpastes with highly discrepant REA (Relative Enamel Abrasivity) and RDA (Relative Dentin Abrasivity) values on both enamel and dentin: Candida Peppermint (CP; REA: 1; RDA: 42), Colgate Total Original (CTO; REA: 4; RDA: 100), Signal White System (SWS; REA: 8; RDA: 143), and Candida White Diamond (CWD; REA 244; RDA: 12). Materials and Methods: Eighty (80) bovine enamel samples and 80 dentin samples were divided into four groups each (n = 20) and investigated after a 6-h brushing procedure (21,600 cycles, 60 cycles/min, load of 2.5 N) with the four toothpastes. The abrasive enamel and dentin wear were registered using a contact profilometer. The median and interquartile range (IQR) of the abrasive enamel and dentin wear were calculated for each group. Pairwise comparisons were conducted using the Wilcoxon signed-rank exact test, and the p-value was adjusted according to Holm (statistical significance set at 0.05). Results: CWD led to the highest abrasive enamel wear (9.86 μm [5.77]). CTO caused the highest abrasive dentin wear (166.70 μm [69.90]), being statistically significantly higher than the wear for CP (54.20 μm [24.00]) and CWD (17.00 μm [7.80]) (p = 0.00001). The abrasive dentin wear for CWD was statistically significantly lower in comparison to all other groups (p = 0.00001). Conclusion: Toothpastes with highly discrepant REA and RDA values presented statistically significantly different absolute wear on enamel and dentin. REA and RDA values should both be declared for every toothpaste. Keywords: abrasive dentin wear, abrasive enamel wear, RDA, REA, toothpaste abrasivity

Purpose: Periodontal disease is potentially related to certain kinds of cancer. This review aimed to summarize the relationship between periodontal disease and breast cancer, providing some strategies for the clinical treatment and periodontal health care of breast cancer patients. Materials and Methods: Systematic reviews, randomised controlled trials, prospective and retrospective clinical studies, case series and reports were collected using search terms entered into the PubMed, Google Scholar and JSTOR databases. Results: Research has provided some evidence that periodontal disease is related to the occurrence and development of breast cancer. Periodontal disease and breast cancer have some common pathogenic factors. Periodontal disease may affect the initiation and development of breast cancer involving microorganisms and inflammation. Periodontal health is affected by radiotherapy, chemotherapy, and endocrine therapy for breast cancer. Conclusions: Periodontal therapy for breast cancer patients should be performed differently according to the stage of cancer treatment. Adjuvant endocrine treatment (e.g. bisphosphonates) has a great impact on oral treatment. Periodontal therapy contributes to the primary prevention of breast cancer. Periodontal health care of breast cancer patients is worthy of clinician attention. Keywords: breast cancer, clinical treatment, periodontal disease, periodontal health care

Purpose: Periodontitis is associated with caspase and proinflammatory mediators, such as caspase-1 and tumor necrosis factor-alpha (TNF-α). The aim of this study was to evaluate the salivary levels of caspase-1 and TNF-α and determine their accuracy in differentiating periodontitis patients from individuals with a healthy periodontium. Materials and Methods: This case-control study enrolled 90 subjects, aged 30 to 55, attending the Department of Periodontics at Baghdad’s outpatient clinic. Patients were initially screened to evaluate their eligibility for recruitment. After applying inclusion/exclusion criteria, subjects with a healthy periodontium were included in group 1 (controls), while subjects with periodontitis were included in group 2 (patients). The salivary levels of caspase-1 and TNF-α in participants’ unstimulated saliva were measured using an enzyme-linked immunosorbent assay (ELISA). Then the periodontal status was determined using the following indices: full-mouth plaque, full-mouth bleeding on probing, probing pocket depth, clinical attachment level, and gingival recession. Results: TNF-α and caspase-1 salivary levels were higher in periodontitis patients than in healthy controls and were positively correlated with all clinical parameters. A positive significant correlation between TNF-α and caspase-1 salivary levels was noticed. For differentiating periodontal health and periodontitis, the area under the curve (AUC) values of TNF-α and caspase-1 were 0.978 and 0.998, while the proposed cut-off points were 128.163 pg/ml and 1.626 ng/ml, respectively. Conclusion: The present findings supported a previous discovery that periodontitis patients have significantly higher levels of salivary TNF-α. In addition, there was a positive correlation between the salivary levels of TNF-α and caspase-1. Furthermore, caspase-1 and TNF-α showed high sensitivity and specificity in the diagnosis of periodontitis, as well as distinguishing periodontitis from periodontal health. Keywords: caspase-1, periodontitis, saliva, TNF-α

Purpose: To evaluate the effect of bovine milk and yogurt on selected oral microorganisms and different oral biofilms. Materials and Methods: Milk was prepared from 0.5% fat (low-fat) and 16% fat (high fat) milk powder. For yogurt preparation, the strains Lactobacillus delbrueckii ssp. bulgarcius and Streptococcus thermophilus were added to the milk. Minimal inhibitory concentrations (MIC) and minimal microbiocidal concentrations (MMC) of the test compounds were measured against various microorganisms by the microbroth dilution technique. Cariogenic periodontal biofilms and one containing Candida were created on plastic surfaces coated with test substances. Further, preformed biofilms were exposed to the test substances at a concentration of 100% for 10 min and thereafter 10% for 50 min. Both colony forming units (cfu) and metabolic activity were quantified in the biofilms. Results: Neither high-fat milk, low-fat milk nor casein inhibited the growth of any species. Yogurt and L. delbrueckii ssp. bulgaricus at low MIC and MMC suppressed the growth of Porphyromonas gingivalis and other bacteria associated with periodontal disease. High-fat yogurt decreased cfu in the forming periodontal biofilm by 90%. Both low- and high-fat yogurts reduced metabolic activity in newly forming and preformed periodontal and Candida biofilms, but not in the cariogenic biofilm. Conclusions: Yogurt and L. delbru eckii ssp. bulgaricus, but not milk, were bactericidal against periodontopathogenic bacteria. Yoghurt reduced the metabolic activity of a Candida biofilm and a periodontal biofilm. Yogurt and L. delbrueckii ssp. bulgaricus may have potential in prevention and therapy of periodontal diseases and Candida infections. Keywords: Candida, caries, milk products, oral bacteria, periodontitis

Purpose: Education is well-known as a determinant of oral health and dental behaviours in high-income countries, but much less is known for countries with lower incomes. This study aimed to identify the extent to which education affects oral health and dental behaviours in Indonesia. Materials and Methods: This study used data from the Indonesian Basic Health Survey 2013. From this nationally representative sample of 945,057 people 5–100 years old, a series of mixed-effects Poisson regression models that accounted for sampling weights estimated the effect of educational attainment on edentulism, dental care utilisation, and toothbrushing behaviour. Results: Consistent educational gradients were found for all outcomes and across all model specifications. People without a formal educational degree had a 1.03 (95% CI: 1.03–1.04) times higher risk of not utilising any dental care, a 3.15 (95% CI: 2.47–4.02) times higher risk of being edentulous, and a 15.6 (95% CI: 12.76–19.02) times higher risk of having low toothbrushing frequency than people having a university degree or higher. Conclusions: Stark and consistent educational gradients were observed in the dentate status, dental services utilisation, and toothbrushing in Indonesia. Educational inequalities were much larger for toothbrushing behaviours than for dental care utilisation. Intervention points for health policy should urgently prioritise public health interventions to promote overall educational attainment, preventive services, and dental care targeted at those with lower educational attainment. Keywords: edentulism, educational inequality, dental service utilisation, population-based study, toothbrushing frequency

Purpose: To assess the levels of oral health-related quality of life (OHRQoL) in orthodontic patients both during the suspension of dental services caused by COVID-19 and after a year of dental service reinstatement, and to evaluate the associated factors for OHRQoL in those patients during the suspension period. Materials and Methods: A cross-sectional online study was conducted both during the suspension of dental service due to COVID-19 (T1) and after a year of dental service reinstatement (T2). The questionnaire – consisting of personal information, subjective complaints, OHIP-14 and oral health conditions – was completed by the participants at T1 and T2. Data were evaluated by the Χ2 test, the Wilcoxon rank-sum test, and multivariate logistic regression analysis. Results: 324 participants were ultimately included in the study sample. The participants reported higher OHIP-14 total scores at T1 than T2 (p < 0.001). Statistically significant differences were detected in the domains psychological discomfort, psychological disability, social disability and handicap (p < 0.001). The multivariate logistic regression analysis showed that wearing fixed appliances, being over 18 years old, having delayed orthodontic treatment and poor oral hygiene habits were statistically significantly associated with higher OHIP-14 total scores at T1 (p < 0.05). Conclusion: The OHRQoL in orthodontic patients was negatively impacted by the suspension of dental services during COVID-19, which was reflected in all the psychosocial domains. Types of appliances, ages, delays in follow-up visits and oral hygiene habits seemed to be the factors associated with OHRQoL in orthodontic patients during the suspension. Keywords: COVID-19, oral health, oral hygiene, psychosocial factors, quality of life

Purpose: Antibiotics play an important role in treating periodontal diseases. Due to the effectiveness of antibiotic therapies, their usage in dentistry has significantly increased. The aim of this study focused on the in-vitro susceptibility of different gram-negative oral bacteria species – which are associated with periodontal diseases (Fusobacterium spp., Capnocytophaga spp. and Leptotrichia buccalis) and have different geographical origins (Asia and Europe) – against antimicrobials that are clinically relevant in dental therapy. Materials and Methods: A total of 45 strains were tested (29 Fusobacterium spp., 13 Capnocytophaga spp. and 3 L. buccalis) that were either isolated from Chinese patients or were obtained from different strain collections. Their antimicrobial susceptibility to the antimicrobial agents benzylpenicillin, amoxicillin, amoxicillin-clavulanic acid, ciprofloxacin, moxifloxacin, clindamycin, doxycycline, tetracycline and metronidazole was tested using the E-Test. Strains with particular resistance to penicillin, clindamycin and metronidazole were further analysed for resistance genes. Results: All tested bacterial isolates were sensitive to amoxicillin, amoxicillin-clavulanic acid, doxycycline and tetracycline, but showed variable sensitivity towards other antibiotics such as benzylpenicillin, ciprofloxacin, moxifloxacin, clindamycin and metronidazole. Conclusion: The results of the present study suggest that certain periodontal disease-related bacterial strains can be resistant towards antimicrobial agents commonly used in adjuvant periodontal therapy. Keywords: antibiotics, resistance, oral bacteria, clinical isolates, E-test

Purpose: Since NaOCl acts as a strong oxidizing agent and presents potential toxicity, this study was adressed to evaluate the in-vitro safety of NaOCl solutions at concentrations below the limit of patient tolerance, i.e. ≥ 0.5%. Materials and Methods: First, an in-silico evaluation was conducted to predict the potential toxicity of NaOCl in terms of mutagenic, tumorigenic, irritant, and reproductive risks, as well as some drug-like properties of the molecule. The in-vitro experiments were based on 2D and 3D models. For the 2D approach, two selected cell lines – HaCaT (human skin keratinocytes) and HGF (human gingival fibroblasts) – were exposed to NaOCl at five concentrations (0.05 – 0.5%) for 10, 30, and 60 s to simulate possible clinical administration. The irritative potential of NaOCl 0.05% and 0.25% was assessed in a 3D in-vitro model (EpiDerm, reconstructed human epidermis). Statistical significance was set at p < 0.05. Results: The main findings suggest that NaOCl exerts cytotoxicity towards HaCaT immortalised keratinocytes and HGF primary gingival fibroblasts in a cell type-, dose- and time-dependent manner, with the most prominent effect being recorded in HaCaT cells after 60 s of treatment with NaOCl 0.5%. However, NaOCl was computationally predicted as free of mutagenic, tumorigenic, irritant, and reproductive toxicity, and showed no irritative potential in 3D reconstructed epidermis at concentrations of 0.05% and 0.25%. Conclusion: Further clinical and histological studies are required to confirm these results, as well as elucidate the potential cytotoxic mechanism induced by NaOCl in HaCaT and HGF cells at the tested concentrations. Keywords: periodontitis, primary gingival fibroblasts, sodium hypochlorite, toxicity

Purpose: Saudi children have poor oral health; however, little data are available on the effects of dental caries and its clinical complications on the oral health-related quality of life (OHRQoL) in school-aged children. This study evaluated the impact of caries and its clinical effects on the OHRQoL of a sample of 8- to 10-year-old children attending King Abdulaziz University Hospital. Materials and Methods: The following variables were assessed for each child: sociodemographic data, OHRQoL using an Arabic-validated Child Perception Questionnaire for 8- to 10-year-old children (CPQ8–10), and two global health rating questions. Caries and its clinical effects on oral health were also assessed using the decayed-missing-filled teeth (dmft/DMFT) and pulpal involvement, ulceration, fistula, and abscess (pufa/PUFA) indices. Descriptive statistics of the sociodemographic variables and responses to the CPQ8–10 questions are presented as absolute values and percentages. The CPQ8–10 scores between children with different dmft/DMFT and pufa/PUFA scores were compared. Results: In total, 169 children participated in this study. The means ± SD of dmft and DMFT were 5.03 ± 2.5 and 2.35 ± 1.7, respectively. However, the pufa and PUFA scores were 1.03 ± 1.6 and 0.05 ± 0.2, respectively. The most common oral health complaint affecting OHRQoL was food stuck to the teeth. Participants with higher dmft and pufa/PUFA scores had statistically significantly higher CPQ8–10 scores than did their counterparts. Conclusion: High dmft and pufa/PUFA scores have a statistically signifcantly negative effect on the OHRQoL among healthy 8- to 10-year-old children. Worse global health ratings correlate with lower OHRQoL. Keywords: dental caries, oral health, paediatric dentistry, quality of life, school-age population

Purpose: To determine the self-perceived oral health and general health as well as the oral health-related quality of life (OHRQoL) among parents in Kuwait. Materials and Methods: This cross-sectional study was conducted among parents visiting the School Oral Health Programme (SOHP) clinics in all the governorates in Kuwait. Being a parent and able to read and understand the Arabic language was the inclusion criterion. A convenience sample of parents (n = 2357) were enrolled in this study, which was conducted using a self-administered questionnaire in Arabic. The questionnaire included previously validated questions and also questions designed for this study. The parents completed and returned the questionnaire while waiting for their children in the waiting area of the SOHP clinic. Results: The mean age of the parents was 38.3 ± 7.3 years. The majority (75.2%) of the participants perceived their oral health ‘excellent’, ‘very good’ or ‘good’ and 76.4% also rated their general health as ‘excellent’, ‘very good’ or ‘good’. Overall, higher levels of perceived oral health were reported more frequently by younger participants, females, Kuwaitis, and those who had higher levels of education (p < 0.001). Most of the participants (72.3%) were satisfied with their oral health, (91.0%) enjoyed eating their food and (79.0%) liked their smile. Perceived difficulty in chewing food was stated by only 21.0%, and very few (5.0%) had speech difficulties. Almost half (45.0%) mentioned that they had never had any dental and/or gum problems that affected their daily activities during the past 6 months, nor did such problems influence their social activities. Nearly two-thirds (61.0%) stated that they never had any difficulty in conversation, and half (49.0%) did not report any disturbance in their sleep. Cronbach’s alpha (0.89) showed a high degree of internal consistency between different OHRQoL responses. Conclusion: Most of the parents were satisfied with their oral health, which had an impact on their quality of life. Keywords: general health perceptions, Kuwait, oral health perceptions, parents, quality of life

Purpose: The subgingival area is only reached to a limited extent during home oral hygiene with the aids available to date. The question was investigated whether a newly developed, flattened cross-sectional design of interdental brushes (IDBs) can extend their subgingival reach. Materials and Methods: In part I, the passage-hole diameters (PHD) of IDBs of different sizes and side-bristle lengths, with circular and flattened cross-sections, were compared according to the ISO standard 16409/2016. In part II, handling of flattened IDBs was described based on a case report of a patient with generalised stage 4, grade C periodontitis with locally persistent pockets. Results: Depending on the brush’s size, flattening of IDBs reduced the PHD by 1-18 intervals. IDBs with longer side bristles could thus be inserted into interdental spaces with equal force. This may increase the potential range of IDBs in the vertical dimension. Regular instruction and check-ups are necessary to enable correct handling, as the flattened brushes can only be used in two positions. The observations documented in the case report (duration: 1.5 years) showed that flattened IDBs were associated with reduced signs of inflammation (reduction of pocket depths from 6 to 3 mm, absence of bleeding on probing). Conclusion: IDBs with a flattened cross-sectional design have not been previously described in the literature. It was shown that flattening of IDBs leads to a size-dependent decrease in PHD. Based on a case report, it was hypothesised that the design change of the IDBs could be clinically relevant in the case of persistent deep pockets in narrow interdental spaces. However, this can only be verified or falsified by clinical studies. Keywords: flattened interdental brushes, preventive dentistry, subgingival oral hygiene

Purpose: To analyse whether the stage of apical development affects the effectiveness of regenerative endodontic treatment by comparing the outcomes for necrotic mature and immature permanent teeth treated with regenerative endodontic procedures. Materials and Methods: Multiple databases (PubMed, Cochrane Library, Web of Science, EMBASE and OpenGrey databases) were searched through February 17th, 2022. Inclusion criteria were randomised controlled trials that included treatment of necrotic immature or mature permanent teeth using any regenerative endodontic procedures (REPs) that aimed to achieve pulp revascularisation or regeneration. The Cochrane Risk of Bias 2.0 tool was used to assess risk of bias. The included indicators were asymptomatic sign, success, pulp sensitivity, and discolouration. The extracted data were expressed by percentage for statistical analysis. The random effect model was used to explain the results. Comprehensive Meta-Analysis Version 2 was used to perform the statistical analyses. Results: Twenty-seven RCTs were eligible for inclusion in the meta-analysis. The success rates of necrotic immature and mature permanent teeth were 95.6% (95% CI, 92.4%-97.5%; I2=34.9%) and 95.5% (95%CI, 87.9%-98.4%; I2=0%), respectively. The asymptomatic rates of necrotic immature and mature permanent teeth were 96.2% (95%CI, 93.5%-97.9%; I2=30.1%) and 97.0% (95%CI, 92.6%-98.8%; I2=0%), respectively. The treatment of immature and mature necrotic permanent teeth with REPs yields high success rates and low symptomatic rates. The incidence of positive sensitivity response for electric pulp testing in necrotic immature permanent teeth (25.2% [95% CI, 18.2%-33.8%; I2=0%]) was lower than that in necrotic mature permanent teeth (45.4% [95% CI, 27.2%–64.8%; I2=75.2%]), and this difference was statistically significant. The restoration of pulp sensitivity seems to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth. The crown discolouration rate of immature permanent teeth was 62.5% (95% CI, 49.7%-73.8%; I2=76.1%). Necrotic immature permanent teeth have a considerable crown discolouration rate. Conclusion: REPs for both immature and mature necrotic permanent teeth yield high success rates and promote root development. The vitality responses seem to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth. Keywords: dental pulp necrosis, meta-analysis, regenerative endodontics

Purpose: This study investigated the effect of toothbrush bristle stiffness and brushing force on the cleaning efficacy in vitro. Materials and Methods: Eighty bovine dentin samples were allocated to eight groups (n=10). Two custom-made toothbrushes of different bristle stiffness (soft and medium) were tested at four different brushing forces (1, 2, 3 and 4 N). Dentin samples were stained in black tea and brushed (60 strokes/min) for a total of 25 min in a brushing machine with an abrasive solution (RDA 67). Photographs were taken after 2 and 25 min of brushing time. Cleaning efficacy was measured planimetrically. Results: After 2 min of brushing, the soft-bristle toothbrush did not cause statistically significantly different cleaning efficacy at different brushing forces, while the medium-bristle toothbrush cleaned statistically significantly less efficaceously only at 1 N. Comparing the two different toothbrushes, higher cleaning efficacy was observed only at 1 N for the soft-bristle brush. At 25 min brushing time, the soft-bristle cleaned statistically significantly better at 4 N compared to 1 N and 2 N and at 3 N compared to 1 N. Using the medium-bristle, cleaning efficacy increased with increasing brushing force. After 25 min of brushing, no statistically significant difference was observed between the two different toothbrushes. Conclusion: Irrespective the brushing force, the use of a soft or medium toothbrush results in comparable cleaning efficacy. At 2 min brushing time, increasing the brushing force does not increase the cleaning efficacy. Keywords: bristle stiffness, brushing force, cleaning efficacy, toothbrush

Purpose: To investigate the prevalence, clinical manifestations and related risk factors of malocclusion in schoolchildren of Jinzhou City, China. Materials and Methods: A total of 2162 children aged 6–12 years were randomly selected from various districts of Jinzhou. Conventional clinical examination was performed by stomatologists, and the results were described based on different clinical manifestations of malocclusion and individual normal occlusion. Further, a questionnaire survey completed by children’s parents or guardians provided the demographic data, lifestyle, and oral habits. The distribution of individual normal occlusion and malocclusion was documented in percentage, and Pearson’s Χ2 was used for two-factor analysis. The data were statistically analysed using SPSS software (version 25.0) with a significance level of α = 0.05. Results: A total of 1129 boys and 1033 girls were included in this study, i.e. 52.2% and 47.8% of the total number of children, respectively. The prevalence of malocclusion in children aged 6–12 years old in Jinzhou was 67.9%, of which crowded dentition was the most common form, with a prevalence of 71.8%, followed by deep overbite, anterior crossbite, dental spacing, deep overjet, anterior edge-to-edge occlusion, and anterior open bite. In the logistic regression model, the results showed that BMI index had little effect on the occurrence of malocclusion (p > 0.05), while dental caries, bad oral habits, retained primary teeth, and a low labial frenum were all related to the occurrence of malocclusion (p < 0.05). Moreover, the higher frequency and duration of bad oral habits were associated with a higher likelihood of malocclusion. Conclusions: The prevalence of malocclusion in children aged 6–12 years in Jinzhou is high. In addition, bad oral habits (such as lip biting, tongue thrusting, biting/gnawing objects, unilateral chin supporting, and unilateral mastication) and other related risk factors (such as dental caries, mouth breathing, retention of primary teeth, and low labial frenum, etc) were associated with malocclusion. Keywords: children, epidemiological investigation, malocclusion, risk factors

Purpose: To assess the root surface roughness and substance loss induced by chemical and chemomechanical challenges on root surfaces pretreated with ultrasonic instrumentation, a hand scaler, or erythritol airflow. Materials and Methods: One hundred twenty (120) bovine dentin specimens were used in this study. Specimens were divided into eight groups and treated as follows: groups 1 and 2: polished with 2000- and 4000-grit carborundum papers but not instrumented (‘untreated’); groups 3 and 4: hand scaler; groups 5 and 6: ultrasonic instrumentation; groups 7 and 8: erythritol airflow. Samples from groups 1, 3, 5, and 7 then underwent a chemical challenge (5 x 2 min HCl [pH 2.7]), whereas samples from groups 2, 4, 6, and 8 were subjected to a chemomechanical challenge (5 x 2 min HCl [pH 2.7] + 2 min brushing). Surface roughness and substance loss were measured profilometrically. Results: The least substance loss through chemomechanical challenge was noted after erythritol airflow treatment (4.65 ± 0.93 µm), followed by ultrasonic instrumentation (7.30 ± 1.42 µm) and the hand scaler (8.30 ± 1.38 µm); the last two (hand scaler and ultrasonic tip) did not differ statistically significantly. The highest roughness after chemomechanical challenge was observed on ultrasonically treated specimens (1.25 ± 0.85 µm), followed by hand-scaled specimens (0.24 ± 0.16 µm) and those subject to erythritol airflow (0.18 ± 0.09 µm); there was no statistically signficant difference between the latter two, but they both differed statistically significantly from the ultrasonically treated specimens. No statistically significant difference in substance loss through the chemical challenge was observed between specimens pretreated by the hand scaler (0.75 ± 0.15 µm), ultrasonic tip (0.65 ± 0.15 µm), and erythritol airflow (0.75 ± 0.15 µm). The chemical challenge smoothed the surfaces treated with the hand scaler, ultrasonic tip, and erythritol airflow. Conclusion: Dentin pretreatment with erythritol powder airflow resulted in a higher resistance to chemomechanical challenge than did dentin treated ultrasonically or with the hand scaler. Keywords: erythritol airflow, hand scaler, ultrasonic, substance loss, surface roughness

Purpose: This study aimed to clarify the impact of the coronavirus disease 2019 (COVID-19) pandemic on individual dental-visit behaviour and examine the difference between elderly and other individuals regarding the impact on dental visits. Materials and Methods: An interrupted time-series analysis was performed to examine the change in data from the national database before and after the first declaration of a state of emergency. Results: The number of patients visiting a dental clinic (NPVDC), number of dental treatment days (NDTD) and dental expenses (DE) during the first declaration of a state of emergency decreased by 22.1%, 17.9%, and 12.5% in the group under 64 years of age and 26.1%, 26.3%, and 20.1% in the group over 65 years of age, respectively, compared with those in the same month of the previous year. Between March and June 2020, the monthly NPVDC and NDTD were significantly reduced (p < 0.001, p = 0.013) in those over 65 years of age. The DE did not change statistically significantly in either the under 64 group or the over 65 group. There was no statistically significant change in the slope of the regression line in the NPVDC, NDTD, and DE before and after the first state-of-emergency declaration. Conclusion: The first state of emergency greatly reduced the NPVDC, NDTD, and DE compared to those in the previous year. In people aged over 65 years, it might still be unresolved 2 years after the postponement of dental treatment owing to the first declaration of a state of emergency. Keywords: clinic visits, elderly, interrupted time-series analysis, stay at home orders, universal health insurance

Purpose: Pregnancy is a state particularly sensitive to oral pathologies (periodontal and decay). The oral health status of pregnant women can have an impact on the outcome of the pregnancy and the oral health of the child to come. As in the general population, the oral health of pregnant women is socially determined and dependent on psychosocial factors, including factors related to health behaviours. Research into the determinants of oral health in pregnant women will allow a better understanding of the mechanisms of action specific to this period of perinatality. Materials and Methods: The methodology of a scoping review was selected with the objective of investigating the contribution of knowledge, attitudes, practices (KAP) and oral health literacy on pregnant women’s oral health. Results: Of the 67 articles selected, 52 studied the ‘knowledge’ component, 27 the ‘attitude’ (including the perception and beliefs concerning health), and 54 the ‘practice’ component, while 6 articles examined literacy. The KAP components were studied in relation to socioeconomic determinants, oral health status, healthcare utilisation and oral health literacy. The level of oral health literacy of pregnant women is strongly related to their living environment and socioprofessional level which influences their attitudes and practices. Woman’s oral health practices before pregnancy can be a predictor of her practices during pregnancy. Conclusion: The complex nature of the attitude component (locus of control, sense of self-efficacy, perceived importance) is little discussed. The heterogeneity and exhaustiveness of topics related to KAP raises the question of how to more accurately assess KAP in pregnant women in a valid, reproducible, and transferable manner and the need to build a structured oral health consensus body of work. This review is a first step towards identifying the psychosocial factors that are essential for developing a model of educational intervention in oral health that combines the process of behavioural change and decision making while taking into account the concept of empowerment, and with the aim of reducing social inequalities in health. Keywords: health literacy, knowledge-attitude-pratice, oral health, pregnant women and child, scoping review

Purpose: To synthesise and characterise nanosilver sodium fluoride (NSSF) and assess the effect of applying this formulation in vitro on artificially demineralised root dentin lesions, compared with the application of silver diamine fluoride (SDF), sodium fluoride (NAF) or no treatment, in terms of mechanical, chemical and ultrastructural properties. Materials and Methods: NSSF was prepared using 0.5 wt% chitosan solution. On 40 extracted human molars, the buccal aspect of the cervical thirds of roots were prepared and divided into 4 groups of 10 each: control (no treatment), NSSF, SDF and NaF (n = 10). The specimens were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR), surface and cross-sectional microhardness and nano-indentation tests were performed to determine the mineral and carbonate content, microhardness, and nanohardness, respectively. Statistical analysis was performed to determine the differences between the different treatment groups for the set parameters using parametric and non-parametric tests. Tukey’s and Dunnet’s T3 post-hoc tests were further used for multiple comparisons between groups (α = 0.05). Results: The control group (no treatment) was found to have statistically significantly lower mean scores for surface and cross-sectional microhardness compared with all other test groups (NaF, NSSF and SDF) (p < 0.05). Spearman’s rank correlation test showed statistically insignificant differences between the mineral-to-matrix ratio (M:M) and carbonate content of all groups (p < 0.05). Conclusions: Treatment of root lesions with NSSF yielded comparable results to SDF and NaF under in-vitro conditions. Keywords: caries, demineralisation, fluoride, nanoparticles, root dentin, silver