Tooth wear prevalence in individuals with Down syndrome: a systematic review.

OBJECTIVES: This systematic review investigated the prevalence of tooth wear between patients with and without Down syndrome. METHODS: Six databases (Embase, LILACS, Livivo, PubMed, Scopus and Web of Science) and grey literature (Google Scholar, OpenGrey and ProQuest) were searched until March 7, 2022. Observational studies were included to assess the differences in tooth wear prevalence and/or severity in Down syndrome and non-syndromic controls. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) recommendations were followed. Three reviewers independently screened studies, extracted data, assessed the methodological quality (Joanna Briggs Institute) and graded the certainty of evidence through the Grading of Recommendations, Assessment, Development, Evaluation (GRADE) approach. Results were summarized through meta-analyses using a random-effects model. The protocol was registered at PROSPERO (CRD42021266997). RESULTS: Of the 1382 records identified, six cross-sectional studies were included. Individuals with Down syndrome had a higher prevalence and were more likely to have tooth wear than individuals without Down syndrome (44% × 15%; OR = 4.43; 95% CI 3.17-6.18; p < 0.00001; I2 = 8%). Also, the severity of tooth wear was higher in the Down syndrome group (n = 275) compared with the controls (n = 294). The certainty of evidence analysis was very low. CONCLUSIONS: Based on very low certainty of the evidence, patients with Down syndrome had a higher prevalence and likelihood and severity of tooth wear when compared to those without Down syndrome. CLINICAL RELEVANCE: Screening early tooth wear lesions should be carefully done in the Down syndrome population since its occurrence is remarkable compared to the general population.

Prevalence of dental attrition and its relationship with dental erosion and salivary function in young adults.

OBJECTIVES: The aim of this study was to estimate the prevalence of dental attrition in a young adult population and to explore associated factors. METHOD AND MATERIALS: Dental students aged 18 to 40 years old with a minimum of 24 natural teeth were invited to take part in this cross-sectional study. Their demographic information, medical history, perceived stress, frequency of dietary acid intake, and frequency of oral habits were obtained through several questionnaires. Assessment of each type of tooth wear (erosion, attrition, and abrasion) was performed according to the tooth wear evaluation system (TWES 1.0). All participants underwent salivary tests. Statistical analysis was performed by chi-squared or Mann-Whitney tests and logistic regression models. RESULTS: In total, 178 participants (88 women and 90 men) with a median age of 22 years were included and of those 74.7% (95% confidence interval [CI], 68% to 81%) had dental attrition. Univariate analysis revealed positive associations for male sex, age, body mass index, awake bruxism frequency, and erosive tooth wear with the presence of dental attrition. Multivariable logistic regression (Nagelkerke r2 = 0.31) indicated that dental attrition was associated with erosive tooth wear (adjusted odds ratio [aOR], 6.3; 95% CI, 2.8 to 14.2), body mass index (aOR, 1.3; 95% CI, 1.1-1.5), and age (aOR, 1.2; 95% CI 1.0 to 1.3). CONCLUSION: Dental attrition is present in most young adults of Catalonia. The associated factors were erosive tooth wear, body mass index, and age. Slight alterations of salivary parameters do not seem to predict dental attrition. (Quintessence Int 2023;54:168-175; doi: 10.3290/j.qi.b3622405).

Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study.

BACKGROUND: The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets. OBJECTIVES: We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level. METHODS: Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables. RESULTS: The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01). CONCLUSION: Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

3D segmentation of dental crown for volumetric age estimation with CBCT imaging.

In adult dental age estimation, segmentation of dental volumetric information from different tooth parts using cone-beam computed tomography (CBCT) has proven beneficial in improving the regression model reliability. This segmentation method can be expanded in the crown part since the volumetric information in the crown is affected by attrition in the enamel and secondary dentine in the dentine and pulp chamber. CBCT scans from 99 patients aged between 20 and 60 were collected retrospectively. A total of 80 eligible teeth for each tooth type were used in this study. The enamel to dentine volume ratio (EDVR), pulp to dentine volume ratio (PDVR) and sex were used as independent variables to predict chronological age (CA). The EDVR was not affected by PDVR. The highest R2 was calculated from the maxillary canine (R2 = 0.6). The current approach in crown segmentation has proven to improve model performance in anterior maxillary teeth.

Tooth wear due to dental attrition among 12-year-old adolescents / Desgaste dentário por atrição entre adolescentes de 12 anos de idade

Aim: To evaluate the prevalence and distribution of tooth wear due to dental attrition among 12-year-old adolescents according to their gender, reports of tooth grinding during sleep/while awake (bruxism), and sleep features related to sleep-disordered breathing. Methods: A cross-sectional study was conducted with 172 adolescents from southeast Brazil. Parents/caregivers answered questions about sociodemographic characteristics; reports of adolescents' tooth grinding during sleep, and sleep features (e.g. sleep duration and position, snoring, drooling on the pillow) in the previous two weeks. Adolescents self-reported the occurrence of tooth clenching/grinding while awake in the previous two weeks. Tooth wear due to dental attrition was assessed by a previously calibrated researcher, using a validated 5-point analogical ordinal occlusal/incisal tooth wear grading scale, with scores ranging from 0 (no wear) to 4 (loss of crown height ≥ 2/3), depending on tooth wear severity. Descriptive statistics and the Mann-Whitney test (p < 0.05) were performed to identify differences in tooth wear due to the distribution of dental attrition, according to adolescents' characteristics. Results: Most adolescents were female (58.0%) and 81.6% of the participants presented tooth wear due to dental attrition within the enamel. Adolescents who snored had a higher number of incisors with tooth wear due to dental attrition (p = 0.035). Females showed a higher number of canines with tooth wear due to dental attrition (p = 0.020). Adolescents whose parents reported tooth grinding during sleep presented a higher number of bicuspids with tooth wear due to dental attrition (p = 0.001). Conclusion:Tooth wear due to dental attrition within the enamel was observed in most adolescents. The distribution, depending on specific groups of teeth, was higher among female adolescents, adolescents' whose parents reported tooth grinding, and adolescents who snored during sleep.

Objetivos: Avaliar a prevalência e distribuição de DDA entre adolescentes de 12 anos de acordo com o sexo, relato de ranger de dentes durante o sono e vigília (bruxismo) e características relacionadas a desordens respiratórias do sono.Método: Desenvolveu-se um estudo transversal com 172 adolescentes do sudeste do Brasil. Seus pais/responsáveis responderam um questionário contendo informações sociodemográficas, relato sobre os filhos rangerem os dentes durante o sono e hábitos do sono dos filhos (duração do sono, posição que dorme, roncar, babar no travesseiro) nas duas últimas semanas. Adolescentes relataram ocorrência de ranger/apertar de dentes durante a vigília nas duas últimas semanas. DDA foi avaliado por um pesquisador previamente calibrado através de uma escala analógica ordinal de cinco pontos de desgaste dentário para faces oclusal/incisal previamente validada, com escores variando de 0 (sem desgaste) a 4 (perda da coroa em altura ≥ 2/3), dependendo da gravidade do desgaste. Análises descritivas e teste de Mann-Whitney (p < 0,05) foram realizados para identificar as diferenças na distribuição de DDA de acordo com as características dos adolescentes.Resultados: A maioria dos adolescentes eram meninas (58,0%) e 81,6% dos participantes apresentaram DDA em esmalte em algum elemento dentário. Adolescentes que rocavam apresentavam mais incisivos com DDA (p = 0.035). Meninas apresentaram maior número de caninos com DDA (p = 0.020). Adolescentes que rangiam os dentes durante a noite apresentaram maior número de pré-molares com DDA (p = 0.001).Conclusão: Desgaste dentário por atrição em esmalte foi observado na maioria dos adolescentes. A distribuição, dependendo de grupos de dentes específicos, foi maior entre meninas, adolescentes que roncavam durante o sono e que rangiam os dentes durante o sono.

In vitro attrition wear resistance of four types of paste-like bulk-fill composite resins.

BACKGROUND: Recently, the application of bulk-fill composite resins has increased significantly. Attrition wear and the consequently increased surface roughness of composite resins are among the causes of restoration failure in the posterior teeth. This study aimed to compare the attrition wear and surface roughness of four types of bulk-fill composite resins compared to a conventional composite resin. METHODS: EverX-Posterior, X-tra fil, SonicFill 2, and Filtek Bulk-Fill composites (bulk-fill) and Z250 composite (conventional resin composite) were evaluated. Thirty cylindrical specimens (n = 6) were weighed and monitored for 24 h until their weight was stabilized. The primary surface roughness of the specimens was measured by a profilometer. The specimens were then subjected to attrition wear in a chewing simulator. Next, the specimens were weighed, and the surface roughness was measured again. Data were analyzed by one-way ANOVA and Tukey's post-hoc test at P < 0.05 significance level. RESULTS: According to one-way ANOVA, the difference in weight loss was significant among the groups (P = 0.004) but the difference in surface roughness of the groups was not significant after the attrition wear (P > 0.05). Tukey's post-hoc test showed that the weight loss of bulk-fill composites was not significantly different from that of Z250 conventional composite after the attrition wear (P > 0.05). CONCLUSION: Within the limitations of this study, it appears that the tested bulk-fill composite resins are comparable to the conventional composite regarding their attrition wear, increased surface roughness, and weight loss.

Association between the severity of possible sleep bruxism and possible awake bruxism and attrition tooth wear facets in children and adolescents.

OBJECTIVE: To evaluate the association between the severity of possible sleep bruxism (PSB) and possible awake bruxism (PAB) and attrition tooth wear facets (ATWF) in children/adolescents. METHODS: Four hundred-thirty-four children/adolescents enrolled in schools in Lavras, Brazil, participated in this cross-sectional study. Caregivers answered a questionnaire about their childrens' PSB. Children/adolescents answered a questionnaire about the occurrence of PAB. RESULTS: ATWF among individuals without PSB and PAB was lower than those with moderate/severe PSB (p = 0.038) and moderate/severe PAB (p = 0.003). ATWF in anterior teeth was lower among individuals without PSB compared to those with mild (p = 0.015) and moderate/severe PSB (p = 0.032). ATWF in posterior teeth was lower among individuals without PAB compared to those with mild (p = 0.046) and moderate/severe PAB (p = 0.017). CONCLUSION: The number of attrition tooth wear facets is proportional to the severity of PSB and PAB.

Regressive changes of crown-root morphology and their volumetric segmentation for adult dental age estimation.

Cone-beam computed tomography (CBCT) enables the assessment of regressive morphological changes in teeth, which can be used to predict chronological age (CA) in adults. As each tooth region is known to have different correlations with CA, this study aimed to segment and quantify the sectional volumes of the tooth crown and root from CBCT scans to test their correlations with the chronological age (CA). Seventy-five CBCT scans from individuals with age between 20 and 60 years were collected retrospectively from an existing database. A total of 192 intact maxillary anterior teeth fulfilled the eligibility criteria. The upper tooth volume ratio (UTVR), lower tooth volume ratio (LTVR), and sex were used as predictor variables. The UTVR and LTVR parameters were both found to be differently correlated to CA and independent from each other. Regression models were derived from each tooth, with the highest R2 being the maxillary lateral incisor (R2  = 0.67). Additional single predictor models using each ratio were capable of reliably predicting the CA. The segmentation approach in volumetric adult dental age estimation proved to be beneficial in enhancing the reliability of the regression model.

Validation of a new diagnostic method for quantification of sleep bruxism activity.

OBJECTIVES: To validate a new diagnostic method (DIABRUX) for quantifying sleep bruxism (SB) activity using the current gold standard, polysomnography (PSG), as a criterion in an adequate sample size investigation. MATERIALS AND METHODS: For SB diagnosis, each participant received a two-night ambulatory PSG including audio-video recordings. The 0.5-mm-thick sheet is produced in a thermoforming process. After diagnosis via PSG, each subject wore the diagnostic sheet for five consecutive nights. The resulting total abrasion on the surface was automatically quantified in pixels by a software specially designed for this purpose. RESULTS: Forty-five participants (10 SB and 35 non-SB subjects) were included. The difference of the mean pixel score between the SB (M = 1,306, SD = 913) and the non-SB group (M = 381, SD = 483; 3.4 times higher for SB) was statistically significant (p < 0.001). The receiver operator characteristic (ROC) analysis revealed a value of 507 pixels as the most appropriate cut-off criterion with a sensitivity of 1.0, a specificity to 0.8, and an area under the curve (AUC) of 0.88. The positive and negative predictive value accounted for 0.59 and 1.0. CONCLUSIONS: The present data confirm that the new diagnostic method is valid and user-friendly that may be used for therapeutic evaluation, and for the acquisition of larger sample sizes within sophisticated study designs. CLINICAL RELEVANCE: The verified properties of the new diagnostic method allow estimating SB activity before damages occur due to long-standing bruxism activity. Therefore, it might be utilized for preventive dentistry. TRIAL REGISTRATION NUMBER: NC T03325920 (September 22, 2017).

Influence of masticating cycles and chewing patterns on inadvertent enamel wear caused by zirconia brackets.

Little information is available about enamel wear caused by zirconia brackets, an inadvertent side effect of orthodontic treatment. The purpose of this study was to examine potential enamel damage induced by contact with zirconia brackets. Sliding and impact wear simulations were performed using bovine enamel specimens positioned at a 25° slant to a zirconium ball to determine wear behaviour. Different chewing patterns, tapping and grinding, were simulated. Specimens were profiled using confocal laser scanning microscopy, and the mean maximum depth and surface roughness were measured. Scanning electron microscopy was also performed. The mean maximum depth of wear values differed according to the number of mastication cycles, with a higher number of cycles producing higher depths of wear. The facet wear depth was significantly greater with the tapping pattern than with the grinding pattern. Scanning electron microscopic observation of the wear facets revealed that surface textures at the edges were rougher than those at the centre of all facets. The results of this study indicated that enamel wear was induced by contact with zirconia brackets during the early period of mastication, and that the patterns and number of cycles of mastication affected the wear progression of enamel.

Estimation of Age by Evaluating the Occlusal Tooth Wear in Molars: A Study on Dakshina Kannada Population.

PURPOSE: Assessment of teeth to estimate age in the living as well as the dead is well documented in the literature. Though applied in conjunction with other parameters in Gustafson's technique, attrition of teeth solely is an underexplored indicator for age estimation mainly in India. Most of the studies using attrition of teeth have been conducted in bioarchaeology, and in populations where studies are being conducted in forensic contexts, the results are debatable. Thus, the present study aimed to evaluate the accuracy of age estimation using the Average Stage of Attrition (ASA) method by Li and Ji in adults of the Dakshina Kannada region. MATERIALS AND METHODS: This cross-sectional study assessed the degree of attrition in both maxillary and mandibular first and second molars of 136 adults of Dakshina Kannada origin (age range: 20-70 years) according to the 10 stages given by Li and Ji to derive population-specific linear regression equations. RESULTS: Univariate analysis of prediction of age with attrition showed a significant association of attrition score with age, stratified by sex, arch as well as in total (p-value <0.001) with a standard error of estimate of 9.231 years. The estimated age was within ±5 years of the actual age in 44.2% of the females and 50.0% of the males. A comparative review of 23 studies done to estimate age from attrition score clinically is documented in the manuscript. CONCLUSION: The findings of this study suggest that evaluation of tooth wear by the Average Stage of Attrition (ASA) method can be used as a non-invasive means to aid in the determination of age in adults of Dakshina Kannada origin. Although the error increases with age, this method provides a measurable means of seriation into older and younger categories.

Effects of dietary consistency on the occlusal changes in nonhuman mammals: A systematic review.

OBJECTIVES: This systematic review aimed to assess whether hard or soft foods interfere with the pattern of occlusal changes in nonhuman mammals. DESIGN: The electronic databases PubMed, Scopus, Web of Science, Cochrane Library, LILACS, OpenGrey and Google Scholar were examined. Only studies investigating the effects of dietary consistency on the occlusal characteristics in animal models were included. The risk of bias was performed based on the SYRCLE's tool, which assigned a low, high or uncertain assessment to each domain. RESULTS: After the removal of duplicates, a total of 8,977 articles remained. From those, 19 studies met the eligibility criteria. Although a great methodological heterogeneity was observed, the results of the included studies as a whole points to homogeneity in the findings obtained on rats, pigs, and monkeys. The increase in the masticatory load was associated with larger dental arch dimensions. Dental wear and dento-alveolar changes were more evident with an increase of diet consistency. Baseline characteristics, blinding of outcome assessors, other sources of bias, incomplete outcome data, and selective outcome reporting were best assessed, denoting a lower risk of bias. In sequence generation and allocation concealment, insufficient details were provided to improve the classification. Random housing and outcome assessment and blinding of researchers were poorly evaluated. CONCLUSION: Considering the limited evidence obtained from these findings, it seems that food consistency may interfere with the development of occlusal patterns and arch dimensions among growing animals. The findings suggest an environmental effect, even if minimal, on the occlusal characteristics.

Age Estimation from Attrition of Permanent Molars.

BACKGROUND: The average stage of attrition in permanent first and second molars is an established method of age estimation in the adult population. The study was conducted with an objective of age estimation from the average stage of attrition of permanent molars. METHODS: A total of 451 individuals of age more than 20 years were examined. Nepalese individuals with intact first and second permanent molars in the maxillary and mandibular arch on either side were included. The average stage of attrition of the maxillary first and second permanent molars on either side was calculated and subjected to regression analysis to derive equations. RESULTS: Among a total of 451 participants, 231 (51.22%) were females and 220 (48.78%) males, with a mean age of 44.3 ± 13.9 years. There was a strong correlation between age and average stage of attrition of molars. The correlation was stronger for upper molars compared to the lowers. Additionally, the mean of the difference between real age and estimated age was lower for maxillary compared to mandibular molars. Compared to age estimation by univariable regression, multivariable regression had greater accuracy. Similarly, estimation of age from maxillary molars was more accurate as compared to mandibular (difference in years: 3.82 ± 3.03 for maxillary molars and 5.17 ± 4.2 for mandibular molars). CONCLUSIONS: Maxillary teeth are better for age estimation and using both maxillary first and second permanent molars gives better accuracy.

A Etiologia da Lesão Cervical não Cariosa: Um Novo Desafio para o Cirurgião-Dentista do Século XXI / The Etiology of Noncarius Cervical Lesions: a New Challenge for the 21ST Century Dentist

O termo Lesões Cervicais Não Cariosas (LCNCs) refere-se à perda de tecido dentário duro na Junção Cemento-Esmalte (JCE), cuja etiologia não está relacionada com o envolvimento bacteriano. A origem e a progressão desses defeitos cervicais são consideradas multifatoriais, sendo atribuídas a três fatores principais, sendo eles: abfração, biocorrosão e abrasão. Tais fatores podem estar combinados e associados a eventos de força excessiva aplicada durante a escovação, juntamente com a abrasividade de dentifrícios, hábitos alimentares e/ou parafuncionais. Essas lesões podem ter morfologias diferentes de acordo com seu fator etiológico principal, podendo se apresentar em forma de cunha, oval ou arredondada. O objetivo deste trabalho foi realizar uma revisão de literatura a fim de apresentar os desafios do Cirurgião-Dentista na descoberta dos diferentes fatores etiológicos das LCNCs. O desafio em questão se dá pelo estudo da combinação desses diversos fatores, bem como a realização de um diagnóstico preciso, fazendo-se necessário o conhecimento adequado da etiologia a fim de prevenir futuras novas lesões, estagnar as existentes e assim, capacitar o Cirurgião-Dentista a realizar um tratamento eficaz e longínquo das LCNCs. No entanto, ainda existem muitas controvérsias na literatura, tornando necessária a elaboração de mais estudos para elucidar a etiologia das LCNCs

The term noncarious cervical lesions (NCCL) refers to the loss of hard tooth tissue at the Cemento-Enamel Junction (CEJ), whose etiology is not related to bacterial involvement. The origin and progression of these cervical defects are considered multifactorial, being attributed to three main factors: abfraction, biocorrosion and abrasion. Such factors may be combined and associated with excessive force events applied during brushing, along with the abrasiveness of dentifrices, eating and/or parafunctional habits. These lesions may have different morphologies according to their main etiological factor, and may be wedge-shaped, oval or rounded. Our aim in this paper was to perform a literature review in order to present the challenges of the dental surgeon in identifying the different etiological factors of NCCL. Such challenge regards the study of the combination of these factors, as well as the achievement of an accurate diagnosis, requiring adequate knowledge of the etiology in order to prevent future lesions, stagnate existing ones, thus enabling the Dental Surgeon to treat NCCL effectively in the long term. However, there are still many controversies in the literature, making it necessary to develop more studies to elucidate the etiology of NCCL

[Application of biocopy function of temporary crown occlusal morphology in patients with severe attrition].

OBJECTIVE: To explore the preliminary application of "biocopy function" in digital technology of temporary crown in severe tooth attrition, so as to reduce the difficulty of final restoration adjustment in severe tooth wear cases, and save clinical time. METHODS: Twelve patients aged between 40 and 65 years with severe tooth attrition were recruited in this study. The experimental group (6 cases, 3 females and 3 males) used the method of digital copy of temporary restoration shape when making the final restoration, and the control group (6 cases, 3 females and 3 males) used the traditional method to make the final restoration. The mean time of central occlusal adjustment and protrusive and lateral occlusal adjustment of each crown, the number of follow-up visits of the patients were recorded and statistically analyzed. The occlusal comfort of the first and the third months after wearing the prosthesis was evaluated by the patients, and the difference of the occlusal comfort of the final prosthesis made by the two methods was compared (the full score was 10 points). The occlusal adjustment time and occlusal comfort score were used as measurement data. Single sample t test was used. The number of follow-up visits was count data. Rank sum test was used for non-normal continuous variables. RESULTS: The mean occlusal time of each crown adjustment in the experimental group was significantly lower than that in the control group (P < 0.01), and the median number of follow-up visits in the experimental group was lower than that in the control group (P < 0.01). The average occlusal comfort score of the experimental group was higher than that of the control group at the first time (P < 0.01). After three months of crown wearing, the median occlusal comfort score of the experimental group was higher than that of the control group (P < 0.05). CONCLUSION: In the case of severe tooth attrition, it is feasible to use the "biocopy function" in the design software to design the final prosthesis, which is conducive to reduce the difficulty of adjustment and achieve predictable functional and aesthetic effects, which is of great significance to save clinical time and improve the accuracy of restoration.

Tooth wear in Swedish adults-A cross-sectional study.

BACKGROUND: Tooth wear has been recognised as a growing oral health problem in children and adolescents, with erosion often cited as the main cause of the tooth wear. Most studies on tooth wear have been conducted on children and adolescents, and only few studies focus on adults. Our aim was to study the prevalence of different types of tooth wear in an adult population and investigate related factors to tooth wear. METHODS: A total of 831 adults in Sweden participated in the study by completing a questionnaire about oral health, a clinical examination, saliva sample and intraoral photographs. Tooth wear was estimated according to the Basic Erosive Wear Examination index, and the aetiology was determined based on the clinical appearance. RESULTS: Almost 80% of the individuals had signs of erosion, and over 90% had signs of attrition. A high level of tooth wear was found in 4.6% of the individuals, few of who reported having received information about both attrition and erosion. Significantly, more men had tooth wear. Daily consumption of fruit had a stronger correlation to tooth wear than acidic drinks. DISCUSSION & CONCLUSION: A high level of tooth wear was found in 4.6% of the individuals, and it was more common in men than women. Aside from attrition, tooth wear due to erosion was a frequent finding in adults. Only a few of the individuals with a high level of tooth wear reported to have received information about tooth wear from their dentist or dental hygienist.

Application of biocopy function of temporary crown occlusal morphology in patients with severe attrition / 北京大学学报(医学版)

OBJECTIVE@#To explore the preliminary application of "biocopy function" in digital technology of temporary crown in severe tooth attrition, so as to reduce the difficulty of final restoration adjustment in severe tooth wear cases, and save clinical time.@*METHODS@#Twelve patients aged between 40 and 65 years with severe tooth attrition were recruited in this study. The experimental group (6 cases, 3 females and 3 males) used the method of digital copy of temporary restoration shape when making the final restoration, and the control group (6 cases, 3 females and 3 males) used the traditional method to make the final restoration. The mean time of central occlusal adjustment and protrusive and lateral occlusal adjustment of each crown, the number of follow-up visits of the patients were recorded and statistically analyzed. The occlusal comfort of the first and the third months after wearing the prosthesis was evaluated by the patients, and the difference of the occlusal comfort of the final prosthesis made by the two methods was compared (the full score was 10 points). The occlusal adjustment time and occlusal comfort score were used as measurement data. Single sample t test was used. The number of follow-up visits was count data. Rank sum test was used for non-normal continuous variables.@*RESULTS@#The mean occlusal time of each crown adjustment in the experimental group was significantly lower than that in the control group (P < 0.01), and the median number of follow-up visits in the experimental group was lower than that in the control group (P < 0.01). The average occlusal comfort score of the experimental group was higher than that of the control group at the first time (P < 0.01). After three months of crown wearing, the median occlusal comfort score of the experimental group was higher than that of the control group (P < 0.05).@*CONCLUSION@#In the case of severe tooth attrition, it is feasible to use the "biocopy function" in the design software to design the final prosthesis, which is conducive to reduce the difficulty of adjustment and achieve predictable functional and aesthetic effects, which is of great significance to save clinical time and improve the accuracy of restoration.

Analysis of enamel and material wear by digital microscope: an in-vitro study

Abstract: The objective of the study was to analyze the surface area (SA) of the wear caused by simulated chewing on human enamel and opposing restorative material, namely: composite resin (CR), porcelain fused to metal (PFM), lithium disilicate (LD), or monolithic zirconia (MZr). Forty-eight premolars were selected as enamel specimens and divided randomly into 4 groups (n = 48; n =12) used as antagonists in chewing simulation (250,000 loading cycles) against one of the four selected test materials. Enamel and material specimens were scanned and evaluated under digital microscope, and wear SA (mm2) were recorded. Descriptive statistics, paired t-test, one-way ANOVA, and post-hoc Tukey-HSD tests were used for statistics (p < 0.05). The smallest and largest SA were exhibited by enamel against LD (0.80 mm2) and PFM (1.74 mm2), respectively. PFM (3.48 mm2) showed the largest SA and CR (2.28 mm2) showed the smallest SA. Paired t-test for SA values showed significant difference (p < 0.05) in all wear comparisons between materials and enamel antagonists. The wear of materials were greater than that of their respective enamel antagonists (p < 0.05). One-way ANOVA of the logarithmic means of wear SA revealed significant differences (P<0.05). Post-hoc Tukey test revealed significance for PFM (p < 0.05) with other materials. Wear of all test materials was greater compared to the wear of enamel antagonists. PFM and LD caused the largest and the smallest enamel wear, respectively. CR, LD, and MZr are more resistant than PFM to wear after simulated chewing against enamel.

Influence of tobacco chewing on oral health: A hospital-based cross-sectional study in Odisha.

BACKGROUND: Smokeless tobacco use in the Indian subcontinent is a part of many religious and cultural rituals and has gained a degree of social acceptance. The deleterious effects of smokeless tobacco are not as well-known as those produced by smoking. OBJECTIVES: The study was carried out to assess the influence of tobacco chewing on the oral health of adult patients attending the dental outpatients department of Khordha district headquarter, Odisha. METHODS: A hospital-based cross-sectional study was conducted among 25-64-year-old patients attending the dental outpatient department of Gopabandhu Khordha district headquarter hospital. A total of 512 study participants, who were age and sex matched, were stratified into four age groups such as 25-34 years, 35-44 years, 45-54 years, and 55-64 years old. Oral health status of the participants was assessed using modified WHO Oral Health Assessment Form (2013). Pearson's Chi-square test, binary and multinomial logistic regression was performed to determine the relationship between oral health problems and tobacco chewing. RESULTS: Among the tobacco chewers, 59.8% had gingival bleeding, 40.6% had periodontal pockets, 30.1% had loss of attachment, 48.4% had attrition, and 4.3% had potentially malignant disorders. Compared to the nonchewers, these oral problems were significantly higher among the chewers. Whereas dental caries experience was significantly lower among the chewers (40.6%) compared to the nonchewers (54.7%). Compared to the nonchewers, chewers had 1.71 times increased odds for gingival bleeding, 1.71 times increased odds for periodontal pockets, 2.39 times increased odds for loss of attachment, and 2.49 times increased odds for attrition, which were statistically significant. CONCLUSION: Hence, the study revealed that tobacco chewing definitely had an influence on oral health, with statistically significant increase in oral health problems in chewers compared to nonchewers. Moreover, loss of attachment and potentially malignant disorders increased significantly with the frequency of tobacco chewing. Periodontal pockets, attrition, and loss of attachment significantly increased with the duration of the chewing habit.

Associations among Bruxism, Gastroesophageal Reflux Disease, and Tooth Wear.

The relationship between bruxism and tooth wear is contentious in the literature. The pathophysiological processes of tooth wear may be complicated by the relationship between bruxism and gastroesophageal reflux disease (GERD). The objective of this study was to evaluate the associations among bruxism, GERD, and tooth wear. Two complementary studies were performed: a case-control study to verify the linkage between GERD and bruxism and a cross-sectional study on the same cohort to establish the connection between GERD and tooth wear in bruxism patients. A cohort of 363 consecutive bruxism patients and 363 matched control participants were recruited. Gastroesophageal reflux disease was diagnosed in accordance with the Montreal criteria. Tooth wear was scored based on the index recommended by Smith and Knight. Logistic regression analyses were performed. After adjustment, GERD was identified as a risk factor of bruxism. Bruxism with reflux symptoms for extensive time-periods was associated with severe tooth wear for the whole dentition (odds ratio, 4.70, 95% confidence interval, 2.04⁻10.83). Increased odds ratios for severe tooth wear were also found in all tooth locations and palatal/lingual and occlusal/incisal surfaces of bruxism patients with GERD for extensive time-periods. In conclusion, strong associations were identified among bruxism, GERD, and tooth wear.