Occlusal Surface Wear Research Articles

A case of direct restore using 4-META/MMA-TBB resin containing organic filler in patients with severe occlusal surface wear and enamel fracture

A case of direct restore using 4-META/MMA-TBB resin containing organic filler in patients with severe occlusal surface wear and enamel fracture

Evaluation of Dimensional Stability and Occlusal Wear of Additively and Subtractively Manufactured Resin-Based Crowns after Thermomechanical Aging

The knowledge on the surface deviations and wear of recently introduced additively or subtractively manufactured materials indicated for definitive prosthesis is limited. The aim of this present study was to evaluate the external surface and mesiodistal width deviation and the occlusal surface wear of one additively manufactured composite resin (MS) and three subtractively manufactured resins (nanographene-reinforced polymethylmethacrylate (GR), conventional polymethylmethacrylate (PMMA), and reinforced composite resin (BC)) after thermomechanical aging. Molar-shaped crowns were fabricated in the tested materials and digitized with an intraoral scanner (CEREC Primescan; Dentsply Sirona, Bensheim, Germany). Each crown was subjected to thermomechanical aging and rescanned with the same scanner. A three-dimensional analysis software (Geomagic Control X v.2022.1; 3D Systems, Rock Hill, SC, USA) was used to calculate the deviations on the external surface, mesiodistal width, and wear on the occlusal surfaces of the tested crowns. Data were analyzed using one-way ANOVA and Tukey’s tests (α = 0.05). MS had higher external surface deviations than PMMA and GR (p ≤ 0.038) and higher mesiodistal width deviations than PMMA and BC (p = 0.004). BC and GR had higher volume loss than PMMA (p ≤ 0.002). The additively manufactured composite resin was more prone to deviations, while reinforced composite resin had lower wear resistance than most of the tested materials.

A follow-up study of the severe occlusal surface wear of implant-supported full-arch prostheses

Objective: To evaluate the severe occlusal surface wear of implant-supported full-arch prostheses, and to explore the risk factors affecting the severe occlusal surface wear of implant-supported full-arch prostheses. Methods: Five hundred and thirty-five patients who received implant-supported fixed complete dental prostheses or implant-overdentures and completed at least one follow-up 3 months after the delivery of definitive prostheses were enrolled from October 1994 to October 2021 in this retrospective cohort study. The information on demographics, implants, definitive prostheses, and related outcomes was collected. Cox proportional hazard regression model was adopted to analyze the risk factors of the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Univariate analysis was performed on the factors that may affect the severe wear of occlusal surfaces, and the parameters of P<0.10 in univariate analysis were included in multivariate analysis to explore the risk factors affecting the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Results: Severe wear of the posterior occlusal surfaces was detected in 114 prostheses with a duration of 61.4 (33.3, 89.4) months. 13 cases occurred≤2 years after the delivery of definitive prostheses, 44 cases>2 years and≤5 years, 44 cases>5 years and≤10 years, and the other 13 cases>10 years. There was no significant difference in the average time of severe occlusal surface wear between implant-supported fixed complete dental prostheses and implant-overdentures in the maxilla (Z=-1.03, P=0.303). However, in the mandible, it was 48.2 (31.2, 80.2) and 79.2 (51.3, 119.1) months respectively, which was statistically significant (Z=-2.93, P=0.003). Cox proportional hazard regression model showed opposed fixed dentition, bruxism, and posterior resin occlusal surfaces were risk factors (P<0.05) affecting the severe wear of the occlusal surfaces. Conclusions: Severe occlusal surface wear was clinically common with the prolonged application of implant-supported full-arch prostheses. Prostheses opposed to fixed dentition, in patients with bruxism, and made of posterior resin materials were at higher risk of severe occlusal surface wear on the posterior artificial teeth. Regular follow-up, patients' behavior guidance, and clinicians' appropriate intervention were necessary to manage this complication.

Long-Term Follow-Up of Restorations of Equine Cheek Teeth Infundibula (2006-2017).

Background:Caries of the infundibula of equine cheek teeth can lead to significant dental disease including increased attritional wear, pulpar and apical disease, secondary sinusitis, and dental fracture. Restorations of cavities of equine cheek teeth infundibula have been performed since 1889. Recent advances in dental materials, instrumentation, and techniques have facilitated the use of dental restoration techniques by equine veterinary practitioners. No studies to date have demonstrated the safety or efficacy of restorations of equine cheek teeth infundibula.Objectives:To assess the long-term results of restorations of equine cheek teeth affected by infundibular caries, to report on the safety of the procedure, and to give guidelines for future restorative therapies.Study Design:Retrospective analysis of results of clinical and oroscopic examination of horses that underwent infundibular restoration procedures between 2006 and 2017.Methods:A total of 223 infundibula in 185 maxillary cheek teeth in 92 horses were restored using a variety of dental materials including glass ionomer cement, flowable and compactible resin composites. The time between restoration and re-examination was recorded along with findings of clinical signs in the interim, restorative material loss, and any further pathological changes of the teeth including caries progression, fracture, or apical disease. Follow-up examinations were performed over two study periods 2006–2012 and in 2017.Results:Over the full study period, 99% of treated horses available for follow-up examinations had no adverse clinical signs or developed any abnormalities of restored teeth observable on oroscopic examination. Of horses re-examined, 83% of restorations were shown to have minimal or no loss of the restoration material, with occlusal surface wear visibly comparable to other adjacent maxillary teeth. Statistical analysis showed success of the procedure was related to the restorative material used, the restoration technique, and the caries grade present at the time of restoration (grade 3 is more successful than grade 2).Main Limitations:There are no case controls in this study and therefore it is not clear if restoration of equine infundibula is a consistently beneficial procedure, or at which grade of caries progression restorations should be performed for optimum benefit. The procedures were not re-examined at consistent regular times creating some difficulties in standardizing results. Re-examinations of treated horses did not consistently include radiography or computed tomography and therefore some apical changes may have occurred in treated teeth without visual oroscopic or external clinical signs.Conclusion:Restoration of equine infundibula using materials developed for human dentistry including flowable resin composites is a safe and long-lasting procedure and appears to prevent the development of further pathological changes including apical infection and dental fracture.

3D analysis of occlusal surfaces of teeth and their contacts. Part II. Assessment of the degree of wear of occlusal surfaces

Of this study was to evaluate the informativeness of the developed tools for 3D analysis of occlusal surfaces and their mutual contacts on the example of tooth rows with different degrees of abrasion and bite features. The developed method of 3D analysis of occlusal contacts (in the range of 0-300 microns of occlusal surfaces separation) was tested in 50 people with different degrees of tooth abrasion. It is determined that the area of direct contacts (in the range of separation 0-50 microns) increases from 30 to 150% depending on the degree of abrasion of teeth during virtual optimization of contacts. The area of occlusal contacts increases as the teeth wear out, and the relief index decreases. With virtual alignment of abnormally placed teeth, the contact area also increases, with the exception of patients with tooth abrasion up to dentin. When teeth wear out, the proportion of direct contact zones increases relative to the total contact area and the proportion of near-contact zones decreases (200-300 microns). Four key indicators and ranges of their values for differential diagnosis of the degree of tooth abrasion were determined.

The embodiment of craft production in Bronze Age Portugal: Exceptional dental wear grooves in an individual from Monte do Vale do Ouro 2 (Ferreira do Alentejo, Portugal)

AbstractTwo human lateral mandibular incisors exhibiting exceptional dental wear in the form of lingual surface grooves along the cementoenamel junction were recovered from the superficial levels of a pit grave attributed to the Bronze Age at the archaeological site of Monte do Vale do Ouro 2 (Ferreira do Alentejo, Beja, Portugal). Although a number of analyses of dental wear features acknowledge the relatively common use of the dentition for nondietary purposes (using the ‘teeth as tools’) during the Early/Middle Bronze Age (2200–1200 BC) of southwest Iberia, the form of dental wear documented at Monte do Vale do Ouro 2 is not only a novel finding in this region but also has seldom been described in any bioarchaeological context. The present study provides a macroscopic and low‐magnification description of the atypical dental wear for this individual. Results indicate that the incisors are likely antimeres. In addition to the deep lingual grooves, asymmetrical wear removed a substantial portion of the laterolingual crown volume of each tooth. Occlusal and lingual surface wear accumulated slowly enough for tertiary dentin to form. An occlusal groove is also present on the right I2. A review of ethnohistoric and bioarchaeological literature suggests that some form of craft production involving the manipulation of cordage or fibre with the mouth and teeth can account for the unique wear patterns from Monte do Vale do Ouro 2. The hand‐spinning of flax requires wetting which can be accomplished by passing flax fibres through the mouth in a mediolateral direction while using a hand spindle. Similar habitual behaviours were probably practiced by the Bronze Age individual from Monte do Vale do Ouro 2. The wear grooves represent the embodiment of aspects of craft production and maintenance activities that occurred during this individual's lifecourse.

Periodontal health and the lifecourse approach in bioarchaeology

Healthy periodontal tissues are essential to maintaining attachment, stability, and retention of teeth. The concept of ‘health’ is problematic however and includes both physical and psycho-social characteristics. The challenge for bioarchaeologists is defining what physical expression begins to affect an individual’s well-being. Here we apply a lifecourse approach to the measurement of periodontal tissue depth (CEJ-AC) at M1 in a prehistoric sample (N = 162) from the American Southwest to test the hypothesis that age and sex differences bear the greatest impact on the expression of periodontitis. CEJ-AC at M1 increased significantly (p&lt;.001) across age stages from 1.5 ±0.5mm (15-20yo) to 4.25 ±0.25mm in the old age group (40-50yo). Occlusal surface wear and alveolar crest (AC) resorption were considerably variable (non-significant) between sexes; however, tooth loss at M1 is more than double among females compared to males in the final decades 40-50yo and 50-60yo. Results support the hypothesis that periodontal tissue loss differentially affects females across the lifecourse. Bacterial infection, chronic gingivitis, and bony resorption cause the physical symptoms of periodontal disease but may not be accompanied by pain or altered functionality. The outcome of the disease process is tooth loss, which can affect functionality and quality of life. Periodontal ‘health’ is therefore best interpreted in bioarchaeological samples around the point that alveolar recession results in tooth loss and altered functionality.

Wear of resin denture teeth in partial removable dental prostheses

PurposeTo investigate occlusal wear of resin denture teeth in partial removable dental prostheses worn by partially edentulous patients. MethodsThirty patients with partial removable dental prostheses were included in the study. Thirty-two patients with complete dentures served as a reference group. Occlusal wear after two years was evaluated indirectly using gypsum casts and a three-dimensional laser-scanner device. Overall wear of complete occlusal surfaces and maximum wear of occlusal contact areas were measured. Patient and prosthesis data were analyzed using univariate and multiple linear mixed models. ResultsOverall wear of denture teeth in partial removable dental prostheses was 91 (SD 85) μm, and maximum wear of occlusal contact areas was 329 (SD 204) μm (means and standard deviations). Average and maximum wear values for teeth in complete dentures were both lower than those for teeth in partial removable dental prostheses. However, differences between wear of different types of denture did not reach statistical significance after adjustment for gender, type of tooth, dental status of the opposing jaw, and antagonist material. Statistical analysis revealed that wear was greater for denture teeth occluding with ceramic crowns and/or fixed partial dentures as antagonists. ConclusionsResin denture teeth in partial removable and complete dental prostheses are subjected to clinically important occlusal wear that might destabilize occlusion and cause further problems. Patient-related factors and dental status affect wear behavior and should be taken into consideration when treating patients with removable dentures.

Full-mouth rehabilitation using twin-stage technique

The wear and tear of the occlusal surfaces of teeth keeps on happening throughout life. However, excessive occlusal wear may lead to occlusal disharmony, pulpal trauma, esthetic disfigurement, and impaired function. Tooth wear can be classified as attrition, abrasion, and erosion depending on the cause. Therefore, it is important to identify the factors which contribute to excessive wear and reduce the vertical dimension of occlusion. This case report presents the rehabilitation of complete maxillary and mandibular arch in a 45-year-old male patient with severe attrition. The patient was treated using the Hobo's twin-stage approach with porcelain-fused-to-metal crowns on all maxillary and mandibular teeth.

Masticatory overload due to areca nut chewing on dental implants

The habitual chewing of areca nut causes severe wear of incisal and occlusal surfaces of the tooth. However, in implant-supported occlusion, the effect of areca nut chewing is not documented in the literature. This study presents a case of areca nut chewing habit, which causes occlusal overload in the patient with implant-supported prosthesis. Areca nut chewing should be strictly avoided by implant patients, as it causes marginal bone loss due to overload and may lead to failure of prosthesis.

Dentistry in Ancient Egypt: Junkers' Teeth

The earliest known example of dental ligature was excavated from the Egyptian site of Cheops by Junker. Made of gold, the wire unites two molar teeth. For comparative purposes, we present two other molar teeth with the same occlusal surface wear. The teeth came from an Egyptian mummy recently autopsied.

Dental evidence for wild tuber processing among Titicaca Basin foragers 7000 ybp.

The objective of this work is to characterize dental wear in a skeletal sample dating to the Middle/Late Archaic period transition (8,000-6,700 cal. B.P.) from the Lake Titicaca Basin, Peru to better define subsistence behaviors of foragers prior to incipient sedentism and food production. The dental sample consists of 251 teeth from 11 individuals recovered from the site of Soro Mik'aya Patjxa (SMP), the earliest securely dated burial assemblage in the Lake Titicaca Basin and the only burial assemblage in the region from an unequivocal forager context. Occlusal surface wear was quantified according to Smith (1984) and Scott (1979a) to characterize diversity within the site and to facilitate comparison with other foraging groups worldwide. General linear modeling was used to assess observation error and principal axis analysis was used to compare molar wear rates and angles. Teeth were also examined for caries and specialized wear. Occlusal surface attrition is generally heavy across the dental arcade and tends to be flat among posterior teeth. Only one carious lesion was observed. Five of the 11 individuals exhibit lingual surface attrition of the maxillary anterior teeth (LSAMAT). Tooth wear rates, molar wear plane, and caries rates are consistent with terrestrial foraging and a diverse diet. The presence of LSAMAT indicates tuber processing. The results therefore contribute critical new data toward our understanding of forager diet in the Altiplano prior to plant and animal domestication in the south-central Andes.

Hyperglycemia simultaneously induces initial caries development and enhances spontaneous occlusal surface wear in molar teeth related to parotid gland disorder in alloxan-induced diabetic rats.

Diabetes and salivary gland dysfunction are major factors that induce dental caries in experimental animals, but there are no reports analyzing the association of dental caries and salivary glands in an animal model of diabetes mellitus (DM). To clarify the initial development of dental caries and preceding salivary gland disorder, we performed a histopathological analysis on teeth and salivary glands in diabetic Wistar rats 7 weeks after alloxan treatment (DM group) in comparison with nondiabetic rats (Non-DM group) and functional analysis on saliva secretion during the experimental period. Pilocarpine-induced salivary fluid secretion in diabetic rats gradually decreased with continuous hyperglycemia from immediately after alloxan treatment to the time of autopsy. Histopathologically, Oil Red O-positive lipid droplets accumulated in the acinar cells of the parotid gland. No tooth was stereoscopically defined as having dental caries in any of the rats in either group; however, the external appearance remarkably changed owing to occlusal wear in almost all molars in the DM group. The initial lesions of dental caries, appearing as micro-defects in dentin with bacterial colonization on the molar surface, were identified using histopathological analysis, and the incidence in the DM group was more than twice that in the Non-DM group. In conclusion, hyperglycemia simultaneously induces initial caries development and enhances spontaneous occlusal wear in molar teeth of Wistar rats 7 weeks after alloxan treatment. The parotid gland dysfunction caused by hyperglycemia may be mostly involved in the pathogenesis of occlusal wear as well as in dental caries in this diabetic model.

Laminin γ2 knockout mice rescued with the human protein exhibit enamel maturation defects

The epithelial ameloblasts are separated from the maturing enamel by an atypical basement membrane (BM) that is enriched in laminin 332 (LM-332). This heterotrimeric protein (α3, ß3 and γ2 chains) provides structural integrity to BMs and influences various epithelial cell processes including cell adhesion and differentiation. Mouse models that lack expression of individual LM-332 chains die shortly after birth. The lethal phenotype of laminin γ2 knockout mice can be rescued by human laminin γ2 (LAMC2) expressed using a doxycycline-inducible (Tet-on) cytokeratin 14 promoter-rtTA. These otherwise normal-looking rescued mice exhibit white spot lesions on incisors. We therefore investigated the effect of rescue with human LAMC2 on enamel maturation and structuring of the atypical BM. The maturation stage enamel organ in transgenic mice was severely altered as compared to wild type controls, a structured BM was no longer discernible, dystrophic matrix appeared in the maturing enamel layer, and there was residual enamel matrix late into the maturation stage. Microtomographic scans revealed excessive wear of occlusal surfaces on molars, chipping of enamel on incisor tips, and hypomineralization of the enamel layer. No structural alterations were observed at other epithelial sites, such as skin, palate and tongue. These results indicate that while this humanized mouse model is capable of rescue in various epithelial tissues, it is unable to sustain structuring of a proper BM at the interface between ameloblasts and maturing enamel. This failure may be related to the atypical composition of the BM in the maturation stage and reaffirms that the atypical BM is essential for enamel maturation.

Laminin‐332 deficient mice present defects during tooth enamel development (LB547)

The epithelial ameloblasts are separated from the maturing enamel surface by an atypical basal lamina (BL) that is enriched in laminin (Lm)‐332. This heterotrimeric protein (α3, ß3 and γ2 chains) provides structural integrity to BLs and exerts effects on various epithelial cell processes including cell adhesion. Mouse models that lack expression of individual Lm‐332 chains die shortly after birth. However, recently a viable mouse model of Lm‐332 deficiency has been developed which expresses a doxycycline‐controllable human Lm γ2 transgene under the cytokeratin 14 promoter on the Lm γ2 knockout background (PLoS One 7(9):e45546). To investigate the role of Lm‐332 in enamel development, we examined the upper and lower maxillae from ~8‐week‐old wt and Lm‐332 deficient mice. At the light microscope level, incisors from Lm‐332 deficient mice showed severe structural changes at the level of the enamel organ. In decalcified samples, the organic matrix of forming enamel was altered and residual matrix was found throughout the maturation stage, suggesting Lm‐332 is required for both formation and mineralization of enamel. CT‐scans and scanning electron microscope analyses showed that Lm‐332 deficient mice exhibited hypomineralized enamel layer and occlusal surface wear in molars. The alterations in enamel formation observed in this mouse model are similar to those in teeth of patient with junctional epidermolysis bullosa due to Lm‐332 mutations. These mice will be an invaluable tool to study the role of Lm‐332 in enamel formation and better understand the role of the atypical BL found at cell‐enamel interfaces.Grant Funding Source: Supported by CIHR, NIH/NHLBI P01HL029594, Shriners of North America

Seasonal Mortality Patterns in Primates: Implications for the Interpretation of Dental Microwear

The microscopic traces of use wear on teeth have been extensively studied to provide information that will assist in elucidating the dietary habits of extinct hominin species. It has been amply documented that dental microwear provides information pertaining to diet for living animals, where there is a strong and consistent association between dental microwear patterns and different types of foods that are chewed. The details of occlusal surface wear patterns are capable of distinguishing among diets when the constituent food items differ in their fracture properties. For example, the microwear traces left on the teeth of mammals that crush hard, brittle foods such as nuts are generally dominated by pits, whereas traces left on the teeth of mammals that shear tough items such as leaves tend to be characterized by scratches. These microwear features result from and thus record actual chewing events. As such, microwear patterns are expected to be variably ephemeral, as individual features are worn away and replaced or overprinted by others as the tooth wears down in subsequent bouts of mastication. Indeed, it has been demonstrated, both in the laboratory and the wild, that short-term dietary variation can result in the turnover of microwear. Because occlusal microwear potentially reflects an individual's diet for a short time (days, weeks, or months, depending on the nature of the foods being masticated), tooth surfaces sampled at different times will display differences that relate to temporal (for example, seasonal) differences in diet.

Tooth Wear Related to Marine Foraging, Agro‐Pastoralism and the Formative Transition on the Northern Chilean Coast

ABSTRACTOcclusal surface wear scores were examined in a sample of 200 Formative period (1500 bc–ad 500) skeletons from the lower Azapa Valley in northwest Chile. Wear rate and plane (angle) were additionally evaluated using a subsample of paired first and second mandibular molars. The Formative period represents the transition from marine foraging to agro‐pastoral dependence in the region, and differences in oral pathology indicate that diet varied by site location (coast vs valley interior) but not by archaeological phase (early vs late). We predicted that occlusal wear would demonstrate similar patterns, resulting from differences in food consistency, and therefore hypothesised that in coastal groups consuming greater quantities of foraged foods, occlusal surfaces should wear faster and exhibit flat molar wear, whereas among valley interior groups consuming greater quantities of agro‐pastoral products, these should wear slower but exhibit more angled molar wear. Heavier posterior tooth wear was identified among coastal residents, but rate and angle of molar occlusal attrition did not differ significantly by location. Heavier overall wear and a steeper molar wear plane were identified during the early phase indicating that food consistency varied somewhat over the course of the Formative period. Overall, the results indicate that, although limited differences in tooth wear exist by site location, wear varied more over time likely reflecting a gradual transition from foraging to agro‐pastoral dependence in the lower Azapa Valley. Although oral health indicators point to differences in dietary investment by location, maintenance of a mixed subsistence economy likely sustained a comparative consistency of foodstuffs. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Correlation between dental occlusal wear and approximal facet length

ABSTRACTThe aim of this paper is to examine the relationship between occlusal surface wear and approximal facet length in a North American archaeological sample of modern human hunter–gatherers (n = 111) and agriculturalists (n = 123).First maxillary molars (M1) were selected. The approximal wear facet was measured on the mesial surface of each M1 at the widest breadth using needle tipped digital callipers. Digital images were taken of the occlusal surface and wear was recorded as the percentage of dentine exposed to the total occlusal surface. Independent age estimate was based on age‐related changes, (pubic symphysis and auricular surface). Results show the hunter–gatherers had a significantly faster rate of wear on both tooth surfaces compared to the agriculturalists in each of the four age groups. Both lifeway groups showed a positive correlation between the two tooth surfaces during the early stages of tooth wear (less than 25% occlusal wear), where the percentage of occlusal wear and the length of the approximal facet increased at a similar rate. During the middle and final stages of tooth wear (occlusal wear greater than 35%) there was a strong negative correlation between the two surfaces in both groups. It is suggested this pattern is due to the shape and function of the M1. Both correlations were more extreme in the hunter–gatherers than the agriculturalists. When the per cent of occlusal wear exceeded 35% the length of the approximal facet started to decrease, and it is therefore recommended studies that include approximal wear exclude molars with heavy occlusal wear. Copyright © 2010 John Wiley &amp; Sons, Ltd.

Changes in food processing and occlusal dental wear during the early agricultural period in northwest Mexico

Crown dimensions and occlusal surface wear rate and wear plane were evaluated using paired first and second mandibular molars from a sample of 84 Early Agricultural period (1600 B.C.-A.D. 200) skeletons from northwest Mexico. Although this period represents a major shift in subsistence strategies in the Sonoran Desert, from food-foraging to agriculture, archaeological and dental pathology studies have identified this period as one of relative dietary stability. It was therefore predicted that very little variation in occlusal wear would have occurred between the early phase (San Pedro: 1600-800 B.C.) and late phase (Cienega: 800 B.C.-A.D. 200). Comparison of crown diameters identified some phenotypic differences between sexes but not between archaeological phases. Molar occlusal surfaces were then divided into four quadrants, and wear scores recorded for each quadrant. Principle axis analysis was performed between total wear scores of paired, adjacent first and second mandibular molars to assess rate and occlusal wear plane over time. The analysis demonstrated that both wear rate and wear plane increased from the early to the late phase of the Early Agricultural period. These results indicate that although diet may have indeed remained stable during this period in the Sonoran Desert increases in the rate of wear and wear plane may reflect changes in food-processing techniques. It is suggested that more intensive processing of agricultural products during the Cienega phase simultaneously softened the diet to create more tooth-contact wear and introduced more grit to cause faster and more angled wear on the molar occlusal surfaces.

Preliminary study of tooth measured by a noncontact 3D image survey system

To perform the quantitative study of tooth occlusal surface wear by a noncontact 3D image survey system. Thirty-two old people's complete dental casts in five years which had normal occlusion were studied. The same way was used to determine the individual reference surface, and the range of the maxillary first molar occlusal surface was delimited by the unite regulation. Then the quantity of wear in five years and wear rate of maxillary first molar occlusal surface were measured by the noncontact 3D image survey system. Wear of maxillary first molar occlusal surfaces was as follows: the mean height loss was 0.293 mm in five years and the mean wear rate was 0.059 mm/year; the mean volume loss was 97.881 mm(3) in five years and the mean wear rate was 19.576 mm(3)/year. Under the necessary conditions, the noncontact 3D image survey system is an effective method to measure the wear of dental occlusal surface, but some set-up conditions need to be improved further.