An index for measuring the wear of teeth

Treating Tooth Surface Loss: Adhesive Restoration of the Worn Anterior Dentition

The treatment of tooth surface loss (TSL) is becoming more common in primary health care and a diverse variety of patients are presenting with this condition are often being treated by general dental practitioners. This article highlights the importance of comprehensive planning and adept execution that can enhance the patient's outcome and experience. Stages of clinical planning and treatment approaches using a selection of restorative materials utilising various established adhesive clinical techniques will be presented and discussed.

Prevention and Management of Tooth Wear: The Role of Dental Technology

Tooth wear is a multifactorial condition and the term is used to describe all types of non-carious tooth substance loss: abrasion (produced by interaction between the teeth and other substances), attrition (produced during tooth-to-tooth contact), erosion (produced by a chemical process) and abfraction (produced through abnormal occlusal loading that predisposes tooth substance to mechanical and chemical wear). Dental technology has an important role in preventing, managing and monitoring tooth wear in a variety of ways. Hard poly(methyl methacrylate) or soft ethylene-vinyl acetate splints can be prescribed to alleviate bruxism, the most common cause of attrition. Thermoformed appliances can be used for the application of products that reduce dental erosion such as fluoride gel. Patients with significant tooth surface loss may require laboratory-made restorations, as well as removable appliances with bite planes that generate inter-occlusal space to facilitate restorations, or surgical templates to provide guidance in preparing restorations for those requiring surgical crown lengthening. Dental study models and digitised models can also prove valuable in terms of monitoring the condition. This paper presents a review of the role that dental technology plays in tooth wear prevention, management and monitoring.

Dentin bonding performance and interface observation of an MMA-based restorative material

The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.

Gastro-oesophageal reflux disease and dental erosions in adults: influence of acidified food intake and impact on quality of life

BACKGROUND AND AIM

Gastro-oesophageal reflux disease (GORD) and dental erosions (DE) have an established association. We assessed whether GORD is associated with DE controlling for acidified food intake and their relationships with quality of life (QOL).

METHODS

In this cross-sectional study, 419 adult patients who sought dentistry consultation were considered eligible. Patients responded to questionnaires for GORD symptoms, acidified food ingestion and World Health Organization quality of life (WHOQOL Bref), followed by an oral examination, in which DE were characterized according to the Smith & Knight criteria.

RESULTS

A total of 417 patients were included (43.8±13.7 years; 68.8% women). There were 143 patients with GORD (34.3%) and 274 controls without GORD. The prevalence of DE was higher in GORD patients compared with the controls (25.9 vs. 17.2%; P=0.041). GORD was associated with DE after adjusting for acidified food intake (P=0.035), with a prevalence ratio of 1.52 (0.95 confidence interval 1.03-2.22). The WHOQOL Bref score was significantly lower in the presence of GORD [median 17.2 (GORD-DE-) vs. 15.4 (GORD+DE+); P<0.01], irrespective of DE.

CONCLUSION

In adults examined in a referential dentistry centre in South America, DE were prevalent and significantly associated with GORD. This association was independent of the intake of acidified food in our study. Impairment in QOL was observed in GORD patients irrespective of the presence of DE.

Erosive Tooth Wear and Related Risk Factors in 8- and 14-Year-Old Greek Children

The aim of the present study was to investigate the erosive tooth wear of primary and permanent teeth and its association with related risk factors. Two groups of Greek children aged 8 (n = 329) and 14 years (n = 263) were examined in the classroom using the Basic Erosive Wear Examination (BEWE) index. Data concerning risk factors were collected using questionnaires. Dental caries (DMFS/dmfs) was also recorded. The data were analyzed using the t test, one-way ANOVA, multiple regression analysis, Fisher's exact test, and the χ2 test. In the 8-year-olds, the primary teeth showed a predominantly medium level of wear and the permanent teeth no wear. A majority of the 14-year-olds exhibited low risk levels of wear. The most frequently affected dental surface in both age groups was the occlusal surface of the mandibular posterior teeth. In the 8-year-olds, BEWE scores and the prevalence of wear in the primary teeth was influenced by gender (p = 0.020). In their permanent teeth, soft drink consumption (p < 0.0001) and preference for lemon/vinegar (p = 0.041) significantly affected wear prevalence and BEWE scores, while habitually retaining soft drinks in the mouth influenced wear prevalence (p = 0.008), risk (p = 0.004), and BEWE scores (p = 0.022). In the 14-year-olds, wear prevalence was significantly affected by the consumption of lemon-flavored candies (p = 0.016) and soft drinks (p = 0.050). BEWE scores were significantly affected by gender (p = 0.022) and soft drink consumption (p = 0.030). Gender influenced tooth wear risk in both age groups (p = 0.010 and p = 0.021, respectively). The results of this study indicate that erosive tooth wear differed between primary and permanent teeth and was influenced by gender and dietary factors.

Relationship Between Biotype and Bone Morphology in the Lower Anterior Mandible: An Observational Study

BACKGROUND

Different clinical parameters have been advocated as potential predictors of alveolar and basal jawbone morphology. The aim of this study is to describe, by tomographic means, alveolar and basal osseous dimensions of the anterior mandible in healthy individuals and evaluate potential correlations with biotype, along with other clinical parameters.

METHODS

One hundred consecutive healthy patients needing surgery in the posterior mandible were enrolled in this observational study (group 1 = 50 patients with thin biotype; group 2 = 50 patients with thick biotype). Data were collected for: 1) Little irregularity index for anterior crowding; 2) molar and canine class relationship; 3) previous orthodontic treatment; 4) gingival recession; and 5) band of keratinized gingiva for each of the six anterior mandibular teeth (#22 through #27). At the most mid-buccal computerized tomography slice of each tooth, other parameters were measured, including: 1) distance from the cemento-enamel junction to the bone crest; 2) tooth torque (TT); 3) labial cortical bone thickness (BT) for alveolar and basal bone; and 4) BT 5 and 10 mm apical to the tooth apex. Data were statistically analyzed, and significance was set at P ≤0.05.

RESULTS

Mean thickness of alveolar bone ranged from 6.66 to 4.51 mm (standard deviation [SD] = 1.46 for tooth #27; SD = 1.01 for tooth #25) whereas mean thickness of basal bone ranged from 8.9 to 8.2 mm (SD = 2.06 for tooth #22; SD = 2.06 for tooth #26). Mean thickness of bone at 5 mm from apex ranged from 11.94 to 10.47 mm (SD = 2.96 for tooth #25; SD = 2.22 for tooth #22), whereas mean thickness of bone at 10 mm from apex ranged from 13.75 to 11.08 mm (SD = 2.79 for tooth #25; SD = 2.53 for tooth #27). No statistically significant differences were detected among biotypes, whereas: 1) TT, 2) age, and 3) smoking habit were often predictors of reduction in BT in a multiple linear regression model. Male sex was often a predictor of positive changes in BT, and previous orthodontic therapy was a protective factor against developing bone loss >5 mm.

CONCLUSIONS

Although some differences were detected among biotypes, data indicate that biotype does not play a fundamental role in influencing alveolar BT, whereas other variables (i.e., TT, sex, age, and smoking habit) do influence alveolar BT. Further studies are needed to better understand the extent of influence of each clinical variable.

Age estimation based on pulp cavity/chamber volume of 13 types of tooth from cone beam computed tomography images

AIM

The aims of this study are to identify which type of tooth has the strong relationship between age and pulp cavity/chamber volume among 13 types of tooth from the same dentition and to determine whether the inclusion of multiple types of tooth may improve the accuracy of age estimation.

MATERIALS AND METHODS

Cone beam computed tomography (CBCT) images from 115 females and 125 males aged between 16 and 63 years were analyzed. The DICOM data of all the images were imported into ITK-SNAP 2.4 for the calculation of pulp cavity/chamber volumes. Logarithmic regression analysis and multiple linear regression analysis were applied to establish the relationship between age and pulp cavity/chamber volumes.

RESULTS

Among the 13 types of tooth, maxillary second molars have the largest R (2) (0.491, 0.642, and 0.498) and the smallest SEE (8.119, 6.754, and 8.022) in male, female, and pooled gender samples, respectively. The multiple linear regression analysis for the combination of multi-types of tooth indicated that a larger R (2) (0.627, 0.701, and 0.631) and smaller SEE (7.100, 6.258, and 6.970) than the counterpart calculated from the logarithmic regression analysis of a single type of tooth in male, female, and pooled gender samples, respectively.

CONCLUSION

The pulp chamber volume of the maxillary second molars has the largest correlation coefficient with age. Using multiple types of tooth may improve the accuracy of age estimation compared with only one type of tooth used.

Abfraction lesions: etiology, diagnosis, and treatment options

Abfraction is a type of noncarious cervical lesion (NCCL) characterized by loss of tooth tissues with different clinical appearances. Evidence supports that abfraction lesions, as any NCCLs, have a multifactorial etiology. Particularly, the cervical wear of abfraction can occur as a result of normal and abnormal tooth function and may also be accompanied by pathological wear, such as abrasion and erosion. The interaction between chemical, biological, and behavioral factors is critical and helps to explain why some individuals exhibit more than one type of cervical wear mechanism than others. In an era of personalized dentistry, patient risk factors for NCCLs must be identified and addressed before any treatment is performed. Marked variations exist in dental practice concerning the diagnosis and management of these lesions. The lack of understanding about the prognosis of these lesions with or without intervention may be a major contributor to variations in dentists’ management decisions. This review focuses on the current knowledge and available treatment strategies for abfraction lesions. By recognizing that progressive changes in the cervical area of the tooth are part of a physiologically dynamic process that occurs with aging, premature and unnecessary intervention can be avoided. In cases of asymptomatic teeth, where tooth vitality and function are not compromised, abfraction lesions should be monitored for at least 6 months before any invasive procedure is planned. In cases of abfraction associated with gingival recession, a combined restorative-surgical approach may be performed. Restorative intervention and occlusal adjustment are not indicated as treatment options to prevent further tooth loss or progression of abfraction. The clinical decision to restore abfraction lesions may be based on the need to replace form and function or to relieve hypersensitivity of severely compromised teeth or for esthetic reasons.

Assessment of the amount of tooth wear on dental casts and intra-oral photographs

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues. Many grading scales are available to assess the amount of tooth wear, one of which is the tooth wear evaluation system (TWES). A grading scale can be used chairside, on casts and on photographs. The aim was to test whether the grading scales of the TWES, used on casts and on photographs, resulted in comparable scores. In addition, it was tested whether these scales can be used to assess tooth wear reliably on photographs. Of 75 tooth wear patients, sets of casts and series of photographs were obtained and graded. Comparison of the grading on casts and on photographs revealed equal median values and percentiles for both occlusal/incisal grading and non-occlusal/non-incisal grading. The grading on casts and on photographs showed a high correlation for the occlusal/incisal grading and a low correlation for the non-occlusal/non-incisal grading (Spearman's rho = 0·74 and rho = 0·47; P < 0·001). Concerning the grading on photographs, the interexaminer reliability was fair-to-good (ICC = 0·41 to ICC = 0·55) while the intra-examiner reliability was fair-to-good to excellent (ICC = 0·68 to ICC = 0·86) for the occlusal/incisal grading. For the non-occlusal/non-incisal grading, the interexaminer reliability was poor to fair-to-good (ICC = 0·22 to ICC = 0·59), while the intra-examiner reliability was fair-to-good to excellent (ICC = 0·64 to ICC = 0·82). It was concluded that the scores obtained with the grading scales of the TWES on casts and on photographs are comparable. The grading scales can be used in a reliable way on photographs, which is especially the case for occlusal/incisal grading.

A 4 year prospective longitudinal study of progression of dental erosion associated to lifestyle in 13-14 year-old Swedish adolescents

OBJECTIVES

To evaluate the progression of dental erosion in 13-14 year-olds after 4 years, and its association with lifestyle and oral health.

METHODS

227 randomly selected 13-14 year-olds from a Public Dental Clinic, Örebro, Sweden, were investigated. A clinical examination was performed which included dental caries/gingival/plaque status, as well as grading of dental erosion at the tooth surface and participant levels in "marker teeth", including buccal/palatal surfaces of 6 maxillary anterior teeth (13-23), and occlusal surfaces of first molars. An interview and a questionnaire regarding drinking habits and other lifestyle factors were completed. All investigations were repeated at follow-up. The participants were divided into high and low progression erosion groups and logistic regression statistics were applied.

RESULTS

175 individuals participated at follow-up. Progression occurred in 35% of the 2566 tooth surfaces. 32% of the surfaces had deteriorated by one severity grade (n=51 individuals) and 3% by two grades (n=2 individuals). Boys showed more severe erosion than girls at the follow-up. Among the variables predicting greater progression, a lower severity of erosive wear at baseline had the highest OR (13.3), followed in descending order by a "retaining" drinking technique, more frequent intake of drinks between meals, low GBI and lesser sour milk intake, with reference to the baseline recording. Using these five variables, sensitivity and specificity were 87% and 67% respectively, for predicting progression of erosion.

CONCLUSIONS

Progression of erosive lesions in Swedish adolescents aged 13-14 years followed up to age 17-18 years was common and related to certain lifestyle factors.

CLINICAL SIGNIFICANCE

In permanent teeth, dental erosion may develop early in life and its progression is common. Dental health workers should be made aware of this fact and regular screenings for erosion and recording of associated lifestyle factors should be performed.

Evaluation of the effectiveness of the new tooth wear measurement parameters

Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. To overcome the problems of the existing qualitative tooth wear analysis method, virtual three-dimensional models have been used. This study was designed to develop and validate a new quantitative method using tooth wear measurement parameters with angles obtained from virtual vectors and planes of the three-dimensional models. Sixteen parameters were evaluated in the virtual models of 20 students (7.57±1.55 years old) and 20 adults (56.85±6.34 years old). There were 12 angle and 4 height parameters, and the number of parameters measured from the virtual planes and vectors were 10 and 6, respectively. For each parameter, means and standard deviations were calculated, and an unpaired sample t test was performed to compare the young and the adult groups. Also, differences between the means were determined and expressed as percentages. The results were statistically significant between the two groups (P<0.001). In general, parameters using virtual vectors showed greater change than virtual plane. Although there were statistically significant differences among all parameters using virtual planes (P<0.001), the changes of the three angles were similar, except distolingual cusp angle. It was found that the parameters using virtual vectors were effective and tooth wear took place in both buccal and lingual cusps. Likewise, the validation of the new measurement parameters suggests that they can also be applied in the assessment of tooth wear related to dental biomaterials.

Factors influencing the progression of noncarious cervical lesions: A 5-year prospective clinical evaluation

STATEMENT OF PROBLEM

The etiology (chemical, friction, abfraction) of noncarious cervical lesion (NCCL) progression is poorly understood.

PURPOSE

The purpose of this 5-year prospective clinical trial was to measure the relationship between NCCLs and various etiologic factors.

MATERIAL AND METHODS

After review board approval, 29 participants with NCCLs were enrolled. Polyvinyl siloxane impressions were made of each NCCL, and casts were poured at baseline, 1, 2, and 5 years. The casts were scanned with a noncontact profilometer, and 1-, 2-, and 5-year scans were superimposed over baseline scans to measure volumetric change in NCCLs. T-scan and Fujifilm Prescale films were used to record relative and absolute occlusal forces on teeth with NCCLs at the 5-year recall. Participant diet, medical condition, toothbrushing, and adverse oral habit questionnaires were given at the 5-year recall. Occlusal analysis was completed on mounted casts to determine the presence of wear facets and group function. Volumetric lesion progression from 1 to 5 years was correlated to absolute and relative occlusal force using mixed model analysis. The Kruskall-Wallis and Mann-Whitney analyses compared lesion progression with diet, medical condition, toothbrushing, adverse oral habits, wear facets, and group function.

RESULTS

The NCCL progression rate over 5 years was 1.50 ±0.92 mm(3)/yr. The rate of progression of NCCLs was related to mean occlusal stress (P=.011) and relative occlusal force (P=.032) in maximum intercuspation position. No difference was seen in NCCL progression between participants with any other factors.

CONCLUSION

Heavy occlusal forces play a significant role in the progression of NCCLs.

Risk Assessment for Tooth Wear

Tooth wear has an increasing prevalence in the UK population. The aetiology is commonly multifactorial, and the aetiopathology is through a combination of erosion, attrition, abrasion and abfraction. Erosion is associated with intrinsic or extrinsic acids, and therefore subjects with reflux disease and eating disorders are at increased risk. Fruit juice, fruits and carbonated drink consumption, frequency of consumption and specific habits are also risk factors. Attrition is more prevalent in bruxists. Other habits need to be considered when defining the risk of tooth wear. Abrasion is usually associated with toothbrushing and toothpastes, especially in an already acidic environment. Patients with extensive lesions that affect dentin may be at higher risk, as well as those presenting with unstained lesions. Monitoring of the progress of tooth wear is recommended to identify those with active tooth wear. Indices for tooth wear are a helpful aid.

Assessment of oral hygiene habits, oral hygiene practices and tooth wear among fertilizer factory workers of Northern India: A Cross sectional study

BACKGROUND

The association between oral hygiene habits & practices and severity of tooth wear lesion varies from community to community and also from occupation to occupation. The present study was conducted with to assess oral hygiene habits & practices and tooth wear among fertilizer factory workers of Punjab, India.

MATERIAL AND METHODS

A descriptive cross sectional survey was conducted among 965 male workers who were aged between 19-58 years, who were the workers of fertilizers factory of Bathinda, India. An interview on the demographic profile, oral hygiene practices, and adverse habits followed a clinical examination for recording the Tooth Wear (Smith and Knight Index 1984) using Type III examination. The Chi-square test and a Stepwise multiple linear regression analysis were used for the statistical analysis. Confidence interval and p-value set at 95% and ≤ 0.05 respectively.

RESULTS

In the present study majority (47.2%) of the study population used chew sticks for cleaning their teeth. Overall prevalence of adverse habits was reported (92.4%). Study population showed higher prevalence of tooth wear (77.1%). Best predictors identified for Tooth Wear were oral hygiene practices, adverse habits, years of work experience and age respectively.

CONCLUSIONS

Considerable percentages of fertilizer factory workers have demonstrated a higher prevalence of tooth surface loss. This may be useful in designing the investigations that aim to further explore the causes for these findings and more importantly to plan oral health promotion program implementing both preventive and curative strategies.

KEY WORDS

Tooth wear, smith & knight index, fertilizer factory.

A study of the periodontal state of a late Medieval United Kingdom population

OBJECTIVE

To study the severity of bone loss in a Medieval UK population, and compare this with other ancient UK populations from different time periods.

DESIGN

Skulls from a burial site in York (XI-XV century) were investigated. Skulls with a minimum of 17 teeth were included and were divided from childhood into five age groups. Direct measurements from the cement enamel junction (CEJ) to the alveolar crest (AC) were undertaken at six points around each tooth with a UNC 15 probe. The mean bone loss was calculated for each tooth type.

RESULTS

Seventy five skulls were included in the study (12-60 years of age). Bone loss was found to increase with age, but stabilized in older individuals (>45 years). The mean CEJ-AC distance varied from 2.1mm in the youngest group to a maximum of 4.1mm in 36-45 year olds. Results were compared with a Roman-British population (Whittaker et al., 1982) where comparable values for mean bone loss were 2.2mm and 5.4mm respectively, and a population of XVIII century Londoners (Whittaker et al., 1998) where bone loss of 1.1mm and 4.0mm was reported for the youngest and oldest age groups respectively.

CONCLUSION

Measuring the CEJ-AC distance in dried skulls from ancient populations may be used as a proxy for the levels of periodontal disease irrespective of tooth wear. The findings from the current study suggest that the severity of periodontitis as determined by measurements of alveolar bone loss on dried skulls from this ancient population, seems to have declined in the United Kingdom from the III-V century to XVIII century. This may be due to changes in environmental factors including living conditions and diet, together with individual characteristics including systemic illness and genetic make up.

The prevalence and risk indicators of tooth wear in 12- and 15-year-old adolescents in Central China

BACKGROUND

Tooth wear has been investigated in numerous countries, and the prevalence has varied. However, the data on tooth wear in China are scarce. The aim of this study was to describe the prevalence of tooth wear and to investigate the relative indicators associated with tooth wear in 12- and 15-year-old adolescents in Wuhan City, Hubei Province, Central China.

METHODS

A cross-sectional descriptive study was undertaken among 720 adolescents in Hubei Province, Central China. The age groups in this study were 12- and 15-year-old, and each group consisted of 360 participants in which females and males represented 50 % each. A modified version of the Basic Erosive Wear Examination (BEWE) tooth wear index was used for the buccal, cervical, occlusal/incisal and lingual surfaces of all of the teeth in the 720 adolescents. All of the participants were asked to answer a questionnaire consisting of questions about their current and historical dietary habits and oral hygiene.

RESULTS

The prevalence of tooth wear was 18.6 and 89.4 % in 12- and 15-year-old adolescents, respectively. The prevalence rates of dentin exposure were 1.9 and 5.6 %, respectively. A significantly higher prevalence of tooth wear and dentin exposure in 15-year-old adolescents was found than in 12-year-old adolescents (p < 0.001 and p = 0.011). Several factors such as drinking soft drinks and fruit juices immediately after sports, taking aspirin, reflux, unilateral chewing, tooth brushing once daily or less often, duration of brushing less than 2 min and swimming in the summer were found to be associated with tooth wear.

CONCLUSIONS

Tooth wear in 12- and 15-year-old adolescents in Central China is a significant problem and should receive greater attention. The prevalence of tooth wear increases with age and associated with socio-behavioral risk factors.

Association between poor oral health and eating disorders: systematic review and meta-analysis

BACKGROUND

There is a well-established link between oral pathology and eating disorders in the presence of self-induced vomiting. There is less information concerning this relationship in the absence of self-induced vomiting, in spite of risk factors such as psychotropic-induced dry mouth, nutritional deficiency or acidic diet.

AIMS

To determine the association between eating disorder and poor oral health, including any difference between patients with and without self-induced vomiting.

METHOD

A systematic search was made of Medline, PsycINFO, EMBASE and article bibliographies. Outcomes were dental erosion, salivary gland function and the mean number of decayed, missing and filled teeth or surfaces (DMFT/S).

RESULTS

Ten studies had sufficient data for a random effects meta-analysis (psychiatric patients n = 556, controls n = 556). Patients with an eating disorder had five times the odds of dental erosion compared with controls (95% CI 3.31-7.58); odds were highest in those with self-induced vomiting (odds ratio (OR) = 7.32). Patients also had significantly higher DMFS scores (mean difference 3.07, 95% CI 0.66-5.48) and reduced salivary flow (OR = 2.24, 95% CI 1.44-3.51).

CONCLUSIONS

These findings highlight the importance of collaboration between dental and medical practitioners. Dentists may be the first clinicians to suspect an eating disorder given patients' reluctance to present for psychiatric treatment, whereas mental health clinicians should be aware of the oral consequences of inappropriate diet, psychotropic medication and self-induced vomiting.

The tooth wear evaluation system: a modular clinical guideline for the diagnosis and management planning of worn dentitions

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues, viz. enamel and dentine. Tooth wear can be divided into the subtypes mechanical wear (attrition and abrasion) and chemical wear (erosion). Because of its multifactorial aetiology, tooth wear can manifest itself in many different representations, and therefore, it can be difficult to diagnose and manage the condition. A systematic approach is a sine qua non. In the below-described tooth wear evaluation system (TWES), all necessary tools for a clinical guideline are present in different modules. This allows the dental clinician, in a general practitioner setting as well as in a referral practice setting, to perform a state-of-the-art diagnostic process. To avoid the risk of a too cumbersome usage, the dental clinician can select only those modules that are appropriate for a given setting. The modules match with each other, which is indispensable and essential when different modules of the TWES are compared. With the TWES, it is possible to recognise the problem (qualifying), to grade its severity (quantifying), to diagnose the likely causes and to monitor (the progress of) the condition. In addition, a proposal for the classification of tooth wear is made. Further, it is possible to determine when to start a treatment, to make the decision which kind of treatment to apply and to estimate the level of difficulty of a restorative treatment.

3D Simulation Modeling of the Tooth Wear Process

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

Assessment of masticatory muscle activity and occlusion time in patients with advanced tooth wear

OBJECTIVE

Tooth wear is a basic physiological adjustment mechanism in the masticatory system. Unfortunately, it is not clear what the relationship is between the activity of the masticatory muscles and the tooth hard tissue loss (mainly enamel) in patients with advanced tooth wear. The aims of this study were (1) to compare the occlusion times and (2) to compare the EMG activity in maximal voluntary clench of the masseter and anterior temporalis muscles of patients with advanced tooth wear to the same activity of healthy volunteers.

DESIGN

50 (16F, 34M) patients and 30 (12F, 18M) age matched controls were clinically examined to assess the degree of wear (TWI). Each subject underwent electromyographic analysis (bilateral anterior temporalis, superficial masseter, anterior digastric and sternocleidomastoid muscles) and digital occlusal analysis.

RESULTS

Mean values of the electrical potentials of the mandible elevating muscles during clench were higher in the study group compared to the controls. A negative correlation was found between the temporalis and masseter muscle activities during clench and the mean value of TWI (r=-0.383, p=0.009; r=-0.447, p=0.002). Occlusion time was longer in the study group compared to controls (p<0.05).

CONCLUSIONS

Mandibular adductors demonstrated lower muscular activities during clenching in the tooth wear patients; however, the cause of this finding is not certain. Prolongation of occlusion time may exacerbate occlusal surfaces wear or excessive wear may prolong occlusion time.

Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear--diagnosis and management

OBJECTIVE

Due to an increased focus on erosive tooth wear (ETW), the European Federation of Conservative Dentistry (EFCD) considered ETW as a relevant topic for generating this consensus report.

MATERIALS AND METHODS

This report is based on a compilation of the scientific literature, an expert conference, and the approval by the General Assembly of EFCD.

RESULTS

ETW is a chemical-mechanical process resulting in a cumulative loss of hard dental tissue not caused by bacteria, and it is characterized by loss of the natural surface morphology and contour of the teeth. A suitable index for classification of ETW is the basic erosive wear examination (BEWE). Regarding the etiology, patient-related factors include the pre-disposition to erosion, reflux, vomiting, drinking and eating habits, as well as medications and dietary supplements. Nutritional factors relate to the composition of foods and beverages, e.g., with low pH and high buffer capacity (major risk factors), and calcium concentration (major protective factor). Occupational factors are exposition of workers to acidic liquids or vapors. Preventive management of ETW aims at reducing or stopping the progression of the lesions. Restorative management aims at reducing symptoms of pain and dentine hypersensitivity, or to restore esthetic and function, but it should only be used in conjunction with preventive strategies.

CONCLUSIONS

Effective management of ETW includes screening for early signs of ETW and evaluating all etiological factors.

CLINICAL RELEVANCE

ETW is a clinical condition, which calls for the increased attention of the dental community and is a challenge for the cooperation with other medical specialities.

Dental wear estimation using a digital intra-oral optical scanner and an automated 3D computer vision method

The objective of this work was to propose an automated and direct process to grade tooth wear intra-orally. Eight extracted teeth were etched with acid for different times to produce wear and scanned with an intra-oral optical scanner. Computer vision algorithms were used for alignment and comparison among models. Wear volume was estimated and visual scoring was achieved to determine reliability. Results demonstrated that it is possible to directly detect submillimeter differences in teeth surfaces with an automated method with results similar to those obtained by direct visual inspection. The investigated method proved to be reliable for comparison of measurements over time.

Age estimation based on pulp chamber volume of first molars from cone-beam computed tomography images

AIM

To establish a method that can be used for human age estimation on the basis of pulp chamber volume of first molars and to identify whether the method is good enough for age estimation in real human cases.

MATERIALS AND METHODS

CBCT images of 373 maxillary first molars and 372 mandibular first molars were collected to establish the mathematical model from 190 female and 213 male patients whose age between 12 and 69 years old. The inclusion criteria of the first molars were: no caries, no excessive tooth wear, no dental restorations, no artifacts due to metal restorative materials present in adjacent teeth, and no pulpal calcification. All the CBCT images were acquired with a CBCT unit NewTom VG (Quantitative Radiology, Verona, Italy) and reconstructed with a voxel-size of 0.15mm. The images were subsequently exported as DICOM data sets and imported into an open source 3D image semi-automatic segmenting and voxel-counting software ITK-SNAP 2.4 for the calculation of pulp chamber volumes. A logarithmic regression analysis was conducted with age as dependent variable and pulp chamber volume as independent variables to establish a mathematical model for the human age estimation. To identify the precision and accuracy of the model for human age estimation, another 104 maxillary first molars and 103 mandibular first molars from 55 female and 57 male patients whose age between 12 and 67 years old were collected, too. Mean absolute error and root mean square error between the actual age and estimated age were used to determine the precision and accuracy of the mathematical model. The study was approved by the Institutional Review Board of Peking University School and Hospital of Stomatology.

RESULTS

A mathematical model was suggested for: AGE=117.691-26.442×ln (pulp chamber volume). The regression was statistically significant (p=0.000<0.01). The coefficient of determination (R(2)) was 0.564. There is a mean absolute error of 8.122 and root mean square error of 5.603 between the actual age and estimated age for all the tested teeth.

CONCLUSION

The pulp chamber volume of first molar is a useful index for the estimation of human age with reasonable precision and accuracy.

Association Between Self-Reported Bruxism and Malocclusion in University Students: A Cross-Sectional Study

OBJECTIVES

Bruxism can result in temporomandibular disorders, oral pain, and tooth wear. However, it is unclear whether bruxism affects malocclusion. The aim of this study was to examine the association between self-reported bruxism and malocclusion in university students.

METHODS

Students (n = 1503; 896 men and 607 women) aged 18 and 19 years were examined. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need. The presence of buccal mucosa ridging, tooth wear, dental impression on the tongue, palatal/mandibular torus, and the number of teeth present were recorded, as well as body mass index (BMI). Additional information regarding gender, awareness of bruxism, orthodontic treatment, and oral habits was collected via questionnaire.

RESULTS

The proportion of students with malocclusion was 32% (n = 481). The awareness of clenching in males with malocclusion was significantly higher than in those with normal occlusion (chi square test, P < 0.01). According to logistic regression analysis, the probability of malocclusion was significantly associated with awareness of clenching (odds ratio [OR] 2.19; 95% confidence interval [CI], 1.22-3.93) and underweight (BMI <18.5 kg/m(2)) (OR 1.89; 95% CI, 1.31-2.71) in males but not in females. In subgroup analyses, the probability of crowding was also significantly associated with awareness of clenching and underweight (P < 0.01) in males.

CONCLUSIONS

Awareness of clenching and underweight were related to malocclusion (crowding) in university male students.

Dentine sensitivity: past, present and future

OBJECTIVE

This review defines dentine sensitivity (DS), its prevalence, its aetiology, the mechanism(s) responsible for DS, its diagnosis and its treatment. The review then examines the modes of action of various treatments for DS including potassium salts, strontium salts, bioglasses, arginine/calcium carbonate and professional treatments such as adhesives and oxalates. The methods used to evaluate the various treatment modalities are discussed, including laboratory studies and randomised controlled clinical trials.

DATA SOURCES AND STUDY SELECTION

A literature search was conducted using PubMed, Ovid Medline and Cochrane reviews for information on DS and its treatments, as well as laboratory and clinical studies used to evaluate the efficacy of various DS treatments. With regard to efficacy of treatments for DS only reports of clinical studies that were randomised, controlled and blinded were reviewed. The authors offer new insights into the shortcomings of the recent systematic review of the use of oxalates for DS.

CONCLUSION

The authors introduce the concept of a novel desensitising mouthrinse containing 1.4% potassium oxalate: Listerine® Advanced Defence Sensitive mouthrinse. Readers of this supplement issue of the Journal of Dentistry are invited to review the significance of managing the clinical problem of DS. They are also invited to assess data from laboratory and randomised controlled clinical studies in order to understand the advantages offered by regular use of 1.4% potassium oxalate-containing mouthrinse, Listerine Advanced Defence Sensitive, in particular its resistance to daily erosive and/or abrasive challenges.

Assessment of the progression of tooth wear on dental casts

Many methods are available for the grading of tooth wear, but their ability to assess the progression of wear over time has not been studied frequently. The aim was to assess whether the occlusal/incisal grading scale of the Tooth Wear Evaluation System (TWES) was sensitive enough for the detection of tooth wear progression from 14 to 23 years of age. A total of 120 sets of dental casts were gathered from 40 people, of whom impressions were made at 14, 18 and 23 years. The TWES was used to assess loss of clinical crown height throughout the entire dentition. There was a significant difference in the TWES scores between the three age groups on all teeth (Friedman tests; P < 0.005 in all cases). Post hoc Wilcoxon tests revealed that the difference between the scores between 14 and 18 years and between 18 and 23 was significant for most teeth. It was concluded that the TWES is sensitive enough to detect changes in tooth wear over time.

Age-specific prevalence of erosive tooth wear by acidic diet and gastroesophageal reflux in Japan

OBJECTIVES

To evaluate the age-specific prevalence of erosive tooth wear in Japanese adults.

METHODS

The study sample consisted of a total of 1108 adults aged 15-89 yrs in Tokyo, Japan. The subjects were asked to complete a self-administered nutrition-related questionnaire. Two examiners evaluated tooth wear in a full-mouth recording, using a modified tooth wear index developed based on the Smith and Knight Tooth Wear index. Subjects who had frequent acid consumption or gastric reflux and at least one tooth with an initial enamel wear were placed in an erosive wear positive group, and the rest of subjects were placed in the erosive wear negative group.

RESULTS

The median (IQR) prevalence of erosion was 19.1 (1.8) at enamel level and 6.5 (3.7) with dentin exposure. There were statistical differences in prevalence of erosive wear among different age groups (p<0.05). Dietary habits found to be frequent in erosive wear positive group included acidic juices for younger subjects (15-39 yrs), and acidic fruits for older subjects (60-89 yrs). The prevalence of gastroesophageal reflux and eating disorder was 3.5%. A severe loss of dental tissue was observed on labial and incisal surfaces of anterior teeth in the erosive wear positive group.

CONCLUSIONS

In the studied sample of Japanese adults, 26.1% had signs of erosive wear.

CLINICAL SIGNIFICANCE

Erosive wear, in combination with abrasion and attrition, results in severe loss of tooth tissue. Frequent consumption of acidic fruits and drinks was significantly associated with erosive tooth wear at different age groups.

Oral health among preschool children with autism spectrum disorders: A case-control study

AIM

To assess and compare the oral health status of preschool children with and without autism spectrum disorders.

METHODS

A random sample of 347 preschool children with autism spectrum disorder was recruited from 19 Special Child Care Centres in Hong Kong. An age- and gender-matched sample was recruited from mainstream preschools as the control group. Dental caries status, gingival health status, tooth wear, malocclusion, dental trauma and oral mucosal health were assessed and compared between the two groups.

RESULTS

It was feasible to conduct a comprehensive oral health screening among 74.1% (257) of the children with autism spectrum disorder. The mean age was 59 ± 10 months (range from 32 to 77 months), of whom 84.4% were males. Children with autism spectrum disorder had better gingival health than children without autism spectrum disorder (mean plaque score and gingival score p < 0.001). Children with autism spectrum disorder had less caries experiences than children without autism spectrum disorder (mean decayed, missing and filled surfaces and decayed surfaces, p < 0.05). Children with and without autism spectrum disorder had similar prevalence of tooth wear, malocclusion, dental trauma experience and oral mucosal lesions (p > 0.05).

CONCLUSION

Differences in oral health status exist among preschool children with and without autism spectrum disorder. Preschool children with autism spectrum disorder exhibited lower caries experiences and better gingival health than children without autism spectrum disorder.

Occlusal wear and occlusal condition in a convenience sample of young adults

OBJECTIVE

To study progression of tooth wear quantitatively in a convenient sample of young adults and to assess possible correlations with occlusal conditions.

METHODS

Twenty-eight dental students participated in a three-year follow up study on tooth wear. Visible wear facets on full arch gypsum casts were assessed using a flatbed scanner and measuring software. Regression analyses were used to assess possible associations between the registered occlusal conditions 'occlusal guidance scheme', 'vertical overbite', 'horizontal overbite', 'depth of sagittal curve', 'canine Angle class relation', 'history of orthodontic treatment', and 'self-reported grinding/clenching' (independent variables) and increase of wear facets (dependent variable).

RESULTS

Mean increase in facet surface areas ranged from 1.2 mm2 (premolars, incisors) to 3.4 mm2 (molars); the relative increase ranged from 15% to 23%. Backward regression analysis showed no significant relation for 'group function', 'vertical overbite', 'depth of sagittal curve', 'history of orthodontic treatment' nor 'self-reported clenching. The final multiple linear regression model showed significant associations amongst 'anterior protected articulation' and 'horizontal overbite' and increase of facet surface areas. For all teeth combined, only 'anterior protected articulation' had a significant effect. 'Self reported grinding' did not have a significant effect (p>0.07).

CONCLUSIONS

In this study 'anterior protected articulation' and 'horizontal overbite', were significantly associated with the progression of tooth wear. Self reported grinding was not significantly associated with progression of tooth wear.

CLINICAL SIGNIFICANCE

Occlusal conditions such as anterior protected articulation and horizontal overbite seem to have an effect on the progression of occlusal tooth wear in this convenient sample of young adults.

Chair Side Application of NovaMin for the Treatment of Dentinal Hypersensitivity- A Novel Technique

OBJECTIVE

To evaluate the efficacy of calcium sodium phosphosilicate bioactive glass (NovaMin) as a chair side desensitizing agent.

MATERIALS AND METHODS

The study was conducted on 60 subjects divided into 3 groups of 20 each as follows. Group I (NovaMin application without scaling and root planing), Group II (NovaMin application after scaling and root planing) and Group III (control group). Sensitivity was assessed using air blast and cold water stimulus at baseline, immediately after application, after half an hour and after 8d using Visual Analog Scale (VAS).

RESULTS

Mean VAS (air blast stimulus) for group I was 5.9 at baseline, 3.4 immediately after application, 3.05 after half an hour, and 3.0 after 8 days. In group II VAS score were 6.2, 3.35, 2.9, 2.75 and group III 6.6, 7.0, 7.0, 7.0 respectively. For cold water stimulus in group I VAS score were 5.6, 3.35, 3.15, 3.1, group II VAS score 5.7, 3.35, 3.1, 2.85 and group III 5.8, 6.1, 6.05, 6.05 respectively. VAS scores in between group I and group III and group II and group III were statistically significant (<0.001) immediately after application, after half an hour and after 8days (ANOVA).

CONCLUSION

Chair side application of calcium phosphosilicate bioactive glass can be a therapeutic adjunct to provide immediate relief for the patient with dentinal hypersensitivity.

Prevalence of dental erosion and association with lifestyle factors in Swedish 20-year olds

OBJECTIVE

To investigate the prevalence, distribution and severity of dental erosion and its association with lifestyle, oral and general health in young adults.

MATERIALS AND METHODS

Four hundred and ninety-four individuals, 20-years of age, participated. Dental erosion in molars and maxillary incisors was evaluated. Caries, plaque and gingivitis were registered. Saliva samples were taken and the subjects were interviewed about behavioural and dietary habits and oral and general health. Body mass index (BMI) was calculated. The individuals were sub-divided into two groups according to the presence and absence of dental erosion: within the group with erosion was a sub-group of individuals with extensive erosion.

RESULTS

Of the individuals 25% had no erosion, 75% had erosion and 18% had extensive erosion. Erosion was found in molars in 74% of the individuals and on buccal and palatal surfaces in maxillary incisors in 4% and 7%, respectively. Cupping was seen in 65% of individuals and severe erosion in molars in 1.6%. Compared to subjects with no erosion, those with extensive erosion had a higher consumption of soft drinks (p = 0.05), caries prevalence (p < 0.01), prevalence of mutans Streptococci (p < 0.01) and BMI (p < 0.05). Furthermore, subjects with erosion had higher caries prevalence (p < 0.01) and BMI (p < 0.01) than those with no erosion.

CONCLUSIONS

Swedish young adults have a high prevalence of dental erosion, but the level of severe erosion is low. The study disclosed a relationship between dental erosion and behavioural factors, oral health and BMI.

Predicting tooth surface loss using genetic algorithms-optimized artificial neural networks

Our aim was to predict tooth surface loss in individuals without the need to conduct clinical examinations. Artificial neural networks (ANNs) were used to construct a mathematical model. Input data consisted of age, smoker status, type of tooth brush, brushing, and consumption of pickled food, fizzy drinks, orange, apple, lemon, and dried seeds. Output data were the sum of tooth surface loss scores for selected teeth. The optimized constructed ANN consisted of 2-layer network with 15 neurons in the first layer and one neuron in the second layer. The data of 46 subjects were used to build the model, while the data of 15 subjects were used to test the model. Accepting an error of ±5 scores for all chosen teeth, the accuracy of the network becomes more than 80%. In conclusion, this study shows that modeling tooth surface loss using ANNs is possible and can be achieved with a high degree of accuracy.

Abfraction: A review

Abfraction (AF) is the pathological loss of tooth substance caused by biomechanical loading forces that result in flexure and failure of enamel and dentin at a location away from the loading. The theory of AF is based primarily on engineering analyses that demonstrate theoretical stress concentration at the cervical areas of the teeth. However, the theory is not yet proven and there are explanations against it. AF lesions present primarily at the cervical region of the dentition and are typically wedge-shaped, with sharp internal and external line angles. Diagnosis of AF plays a very important role in the management of patients. The aim of the present narrative review is to comprehensively discuss the historical, etiopathogenetic, clinical, and diagnostic and treatment aspects of AF.

Tooth wear in aging people: an investigation of the prevalence and the influential factors of incisal/occlusal tooth wear in northwest China

Background

The aim of this study was to estimate the prevalence of tooth wear in the aging population of northwest China and to investigate the factors associated with such tooth wear.

Methods

Cross-sectional analytic clinical and questionnaire study was performed in 704 participants who had a mean age of 46.5 ± 0.2 SD and of which 367(52.13%) were males and 337(47.87%) female. These participants were invited when they attended the hospital which located in northwest China for routine oral examination.

Results

In the maxilla of the examined patients, the rate of tooth wear varied from 85.51% for molar group, 89.77% for premolar group, 100.0% for canine group to 87.22% for incisor group. In the mandible, the rates were 86.36%, 88.92%, 100.0% and 91.19% for the four groups respectively. Moreover, both the incisor and canine groups of these patients showed median scores of 3, the premolar group showed a median score of 1, and the molar group had a median score of 2. Additionally, multiple factors were considered to contribute to these patterns of tooth wear, especially the habitual consumption of a hard or sour diet (P < 0.05,odds ratio 1.21, 95% confidence intervals 1.04-1.49).

Conclusions

Tooth wear is a common disease in which the anterior teeth exhibit greater wear than posterior teeth. The data support an association between tooth wear and dietary patterns.

Information for patients undergoing treatment for toothwear with resin composite restorations placed at an increased occlusal vertical dimension

Toothwear is affecting increasing numbers of the population. In the past, treatment of patients whose teeth were affected by toothwear often involved the reduction of these teeth for crowns; a severe form of toothwear. Contemporary management of such cases is by the bonding of resin composite restorations to the worn and wearing surfaces, with these restorations being placed at an increased occlusal vertical dimension. The advantage of the technique is its minimal- or non-intervention nature and its high reported degree of patient satisfaction. There are, however, short-term disadvantages to the technique, such as the potential for lisping, pain from the teeth which will be subject to axial orthodontic tooth movement, and difficulty in chewing on the posterior teeth if these are discluded. It is therefore important, as with any treatment, that the advantages and disadvantages are fully explained to the patient. This paper therefore describes the clinical technique and presents a Patient Information Leaflet that the author has used for over five years.

CLINICAL RELEVANCE

Patients should be advised regarding the disadvantages and advantages of any technique.

Age estimation of an Indian population by using the Kim's scoring system of occlusal tooth wear

CONTEXT

Age is one of the prime factors employed to establish the identity of an individual and the use of teeth for this purpose has been considered reliable. Tooth wear is widely accepted as a physiological consequence of aging and evaluation of tooth wear can be a simple and convenient tool to estimate age in adults.

AIMS

The present study was conducted to record the degree of tooth wear among Indian adults and to estimate their ages from the degree of tooth wear based on Kim's scoring system.

MATERIALS AND METHODS

Dental stone casts of 120 participants were used to assess the degree of occlusal tooth wear based on the criteria given by Kim et al.

STATISTICAL ANALYSIS USED

The age of all subjects was estimated based on these scores using multiple regression analysis function.

RESULTS

The degree of tooth wear showed a significant positive correlation with age in each and every examined tooth of both males and females. The predicted age was within ± 5 years of actual age in 70% of males and 68.3% females, and within ± 3 years of actual age in 50% of males and 50.1% of females.

CONCLUSIONS

Kim's scoring system has proven to be a useful tool in estimation of age using occlusal wear in an Indian population with a high level of accuracy in adults.

Occlusal tooth wear in the general population of Germany: effects of age, sex, and location of teeth

STATEMENT OF PROBLEM

Tooth wear is an increasing problem in a society where people are living longer.

PURPOSE

The purpose of this study was to assess the effect of age, sex, and location of teeth on the severity of tooth wear and to determine the prevalence of dentin exposure in the general population of Germany.

MATERIAL AND METHODS

Tooth wear was measured in casts of both jaws of 836 persons with a 6-point (0-5) ordinal rating scale. Linear random-intercept regression models with the covariates of age, sex, jaw, and tooth group (with the participant as a grouping variable) were computed to determine the association of these covariates with tooth wear of a single tooth.

RESULTS

The mean tooth wear score across all age groups, both sexes, and all teeth was 2.9 (standard deviation, 0.8), and the prevalence of teeth with exposed dentin was 23.4%. The participants' age was correlated with the mean tooth wear scores (r=0.51). The tooth wear level among women was on average 0.15 units lower than among men, and tooth wear was on average 0.59 units higher for anterior teeth than for posterior teeth.

CONCLUSIONS

Increased tooth wear in anterior teeth may be due to the initially predominant guidance by anterior teeth, with age-related linear progress in tooth wear. Occlusal tooth wear scores and dentin exposure increase with age.

Copper deficit as a potential pathogenic factor of reduced bone mineral density and severe tooth wear

The study evaluated if men and women with severe tooth wear were at increased risk of general bone loss. Enamel biopsies obtained from 50 subjects aged 47.5 ± 5 years showed decreased copper content, which was associated with reduced spine bone mineral density, suggesting deficits of this trace element contributing to bone demineralization, enamel attrition, and deteriorated quality of mineralized tissues.

INTRODUCTION

The objective of this cross-sectional study was to assess associations between enamel trace minerals and bone mineral density (BMD) in severe tooth wear. We hypothesized that similar factors contributed to both the excessive abrasion of dental enamel and reduced BMD in subjects with tooth wear.

METHODS

Fifty patients aged 47.5 ± 5 years with severe tooth wear and 20 age-, sex-, and body mass index (BMI)-matched healthy volunteers with normal dental status were studied regarding dietary intakes of trace elements, serum and salivary copper (Cu), zinc (Zn), and calcium (Ca) concentrations, and serum PTH, osteocalcin, and hydroxyvitamin D levels. Tooth wear was determined using clinical examination based on standard protocol according to Smith and Knight. In all subjects, acid biopsies of the maxillary central incisors were carried out to assess mineral composition of the enamel. Atomic absorption spectroscopy with an air/acetylene flame was used to measure Ca and Zn, and graphite furnace atomic absorption spectroscopy was used to analyze Cu content. BMD was examined using dual energy X-ray absorptiometry.

RESULTS

Tooth wear patients had reduced lumbar spine, but not femoral, BMD relative to controls (p < 0.001). No differences were found in enamel Ca concentration and Zn content was slightly higher in tooth wear patients than in controls whereas Cu content was significantly decreased in the patients: 19.59 ± 16.4 vs 36.86 ± 26.1 μg/l (p = 0.01) despite similar levels of Cu in serum and saliva. The differences were independent of serum 25-OH-D, osteocalcin concentrations or PTH either.

CONCLUSION

Severe tooth wear is associated with reduced spinal BMD. Enamel in adult individuals with severe tooth wear is low in copper content. Therefore, further work is needed to determine whether copper plays a role in bone pathophysiology in these patients.

Quantitative evaluation of dental abfraction and attrition using a swept-source optical coherence tomography system

A fast swept-source optical coherence tomography (SS-OCT) system is employed to acquire volumes of dental tissue, in order to monitor the temporal evolution of dental wear. An imaging method is developed to evaluate the volume of tissue lost in ex vivo artificially induced abfractions and attritions. The minimal volume (measured in air) that our system could measure is 2352 μm3. A volume of 25,000 A-scans is collected in 2.5 s. All these recommend the SS-OCT method as a valuable tool for dynamic evaluation of the abfraction and attrition with remarkable potential for clinical use.

A conservative and reversible approach for restoring worn teeth: a clinical report

A 48-year-old man presented with worn dentition due to daytime bruxism. His chief concern was compromised esthetics due to short teeth. The occlusal vertical dimension was increased by 2 to 3 mm in the premolar area, and a maxillary titanium overdenture with composite resin facings was fabricated to address his concern. The advantages of this treatment, as opposed to complete coverage restorations, include preservation of tooth structure, lower cost, and shorter treatment time. Four years after insertion, the titanium overdenture continues to function successfully and to address the patient's concerns.