PURPOSE: The aim of this study was to investigate simulated localized and generalized wear of indirect composite resins used for implant supported provisional restorations. MATERIALS AND METHODS: The study investigated ten indirect composite resins. Two kinds of wear were simulated by 400,000 cycles in a Leinfelder-Suzuki (Alabama) machine. Localized wear was simulated with a stainless-steel ball bearing antagonist and generalized with a flat-ended stainless-steel cylinder antagonist. The tests were carried out in water slurry of polymethyl methacrylate beads. Wear was measured using a Proscan 2100 noncontact profilometer in conjunction with Proscan and AnSur 3D software. RESULTS: Both localized and generalized wear were significantly different (P<.05) among the indirect composite resins. SR Nexco and Gradia Plus showed significantly less wear than the other indirect composite resins. The rank order of wear was same in both types of wear simulation. CONCLUSION: Indirect composite resins are recommended when a provisional implant-supported restoration is required to function in place over a long period. Although only some indirect composite resins showed similar wear resistance to CAD/CAM composite resins, the wear resistance of all the indirect composite resins was higher than that of bis-acryl base provisional and polymethyl methacrylate resins.
Composite Resins ; Dental Prosthesis ; Dental Restoration Wear ; Polymethyl Methacrylate ; Water

OBJECTIVETo compare the wear between the enamel and two types of dental decoration porcelains for all-ceramic restorations (Vita-alpha, Vintage AL).

METHODSFriction coefficients, wear scar width, element concentrations and wear surface evolution were considered relatively to the tribology of that in vivo situation. The wear scars of the samples were characterized by means of dynamic atomic force microscopy (DFM). The different element concentrations of the surface before/after the wear test were determined with energy dispersion spectrometry (EDS).

RESULTSThe friction coefficient varied from time in each kind of material. The statistical differences between materials were observed in wear scar width and properties of materials (P<0.05). DFM results showed wear surface of natural tooth full of abrasive particles and denaturation of dental texture. Wear surface of veneering ceramics consisted mainly of abrasive particles, plough and microcracking. EDS results showed that the element concentration of Fe was obviously found on the samples after wear.

CONCLUSIONThe main underlying mechanisms of natural teeth wear are abrasive, and denaturation of dental texture. Abrasive wear, adhesion and fatigue of veneering ceramics characterize the wear patterns which plays different role in Vita-alpha and Vintage AL. The wear patterns of veneering ceramics can be described as mild wear.

Ceramics ; Dental Enamel ; Dental Porcelain ; Dental Restoration Wear ; Materials Testing ; Surface Properties ; Tooth Attrition

OBJECTIVETo evaluate wear resistance and hardness of three kinds of new composite resins.

METHODSThree kinds of new composite resins, Solidex, Spectrum, Filtek Z350, were tested. Enamel as control group. A refited MG-200 wear machine was used in this study. Scanning electron microscope (SEM) was used to observe the friction surface of each tested material. Hardness of each tested material was determined by Vickers indentation technique. The data of wear and hardness were analyzed by Mann-Whitney test and 1-way ANOVA. The relationship between the hardness of the composites and the amount of wear of them was determined by a regression analysis method.

RESULTSFiltek Z350 showed the lowest volumetric wear and highest Vickers hardness in the composites (P < 0.05). No significant differences in wear and hardness were observed between Solidex and Spectrum (P > 0.05). Significant relationships were observed between the hardness of the composites and the amount of wear of them (r = 0.968 6) (P < 0.05). Different wear characters of the friction surface of the tested materials were observed by SEM.

CONCLUSIONNanofilled composite was superior to the hybrid composite in wear resistance and hardness.

Composite Resins ; Dental Enamel ; Dental Materials ; Dental Restoration Wear ; Hardness ; In Vitro Techniques ; Materials Testing ; Surface Properties

PURPOSE: To assess function by identifying changes in swallowing and masticatory performance in maxillary obturator prosthesis wearers. MATERIALS AND METHODS: Sixty subjects were recruited for the study, of which 20 were obturator wearers, 20 were completely dentulous and 20 had removable partial/complete dentures with similar Eichner's Index. Swallowing ability was evaluated with and without obturator using the "Water Drinking Test"; Masticatory performance was evaluated with the Sieve test; and maximum occlusal force was recorded with the help of a digital bite sensor. The data was analyzed using the Statistical Package for Social Science version 15.0 with a confidence level at 95%. RESULTS: Profile, behavior of drinking and time taken to drink were significantly improved (P<.001) in subjects after wearing obturator. Masticatory performance was not significantly different (P=.252) in obturator wearer when compared with dentulous or removable partial/complete denture wearer, but significantly (P<.001) high inter group difference in maximum occlusal force existed. Correlation between masticatory performance and maximum occlusal force was not significant (P=.124). CONCLUSION: Swallowing ability was significantly improved after wearing obturator but masticatory performance was not significantly different from those having similar occlusal support zone in their dentition.
Bite Force ; Deglutition* ; Dental Restoration Wear ; Dentition ; Dentures ; Drinking ; Mastication ; Prostheses and Implants ; Social Sciences

Proper hygienic care of removable dentures is an important means of maintaining a healthy oral mucosa on denture wearers. Denture cleansing is often poor due to improper mechanical and the inefficient chemical cleansing of dentures. Dentists and patients should realize that microbial plaque on dentures may be harmful to both the oral mucosa and the patient's general health. This literature review was aimed to evaluate materials and methods for cleansing dentures and to discuss different means of keeping dentures plaque-free. A routine denture cleansing regimen should be designed to remove and prevent reaccumulation of microbial plaque and also to remove mucin, food debris, calculus, and exogenous discoloration. The combined use of chemical and mechanical cleansing is highly recommended for patients to clean their denture effciently.
Calculi ; Dental Restoration Wear ; Dentists ; Denture Cleansers* ; Dentures* ; Humans ; Mouth Mucosa ; Mucins

OBJECTIVETo investigate the tribology characteristics of two ceramic materials in vitro:feldspathic glass-ceramic (veneer porcelain) and lithium disilicate glass-ceramic (heat-pressed ceramic), and to evaluate the wear resistance of different ceramic materials from the dynamic chewing perspective.

METHODSWear tests were performed in simulated oral environment with stainless steel ball antagonists (r = 3 mm), veneer porcelain (CERAMCO 3) and heat-pressed ceramic (IPS e.max Press HT type) in the chewing simulator. The tribological tests were carried out under artificial saliva lubrication condition in room temperature with a vertical load of 10 N for 1.2×10(6) cycles (f = 1.5 Hz, uniform circular motion, revolving speed = 90 r/min, radius = 0.5 mm). The wear volumes were measured using three-dimensional profiling, and surface microscopic morphology were observed using scanning electron microscopy at time point of 200 000, 400 000, 600 000, 800 000, 1 000 000, and 1 200 000 cycles.

RESULTSIn a simulated oral environment, the wear rates of veneer porcelain were (0.001 20 ± 0.00 018) , (0.000 10 ± 0.000 03) , (0.000 50 ± 0.000 05), (0.000 10 ± 0.000 02) , (0.004 10 ± 0.000 38) , and (0.019 00 ± 0.003 53) (×10(-4) mm(3)/cycles) at 200 000, 400 000, 600 000, 800 000, 1 000 000, 1 200 000 cycles. The wear rates of heat-pressed ceramic were (0.139 50 ± 0.030 94), (0.124 40 ± 0.031 20), (0.054 80 ± 0.005 38), (0.038 80 ± 0.006 10), (0.011 10 ± 0.003 75), (0.198 90 ± 0.045 80) (×10(-4) mm(3)/cycles) at 200 000, 400 000, 600 000, 800 000, 1 000 000, 1 200 000 cycles. Three stages were observed in the wear loss process of the two materials: running-in stage, steady wear stage and severe wear stage. In running-in and steady wear stage, the shallow wear tracks of veneer porcelain were produced by the fatigue effect.While in severe wear stage, the wear tracks turned into ploughing. In running-in stage, the surface of heat-pressed ceramic was characterized by dense and shallow ploughing. In steady wear stage, the wear tracks turned into flake peeling produced by fatigue effect. At last, the whole layer was worn off by the effects of ploughing.

CONCLUSIONSIn a simulated oral environment, the wear rate and wear loss of heat-pressed ceramic are greater than that of veneer porcelain.

Analysis of Variance ; Ceramics ; Dental Porcelain ; Dental Restoration Wear ; Dental Veneers ; Glass ; Mastication ; Microscopy, Electron, Scanning ; Surface Properties

This investigation was designed to determine the effectiveness of the posterior occlusal schemes on masticatory activity during mastication in complete denture. Twelve edentulous subjects were selected for this study. All subjects had no past history and no functional abnormality on masticatory system and Tmjoint. And, they had residual ridge of favorable morphology, firm mucosa and Class I skeletal jaw relationship. The masticatory performance was analyzed by means of standard sieve(10, 16, 20, 30sieve), and the electrical activity from selected muscles(Temporalis and Masseter muscle)was recorded simultaneously with electromyography (Bio-Pak system) as the subject masticated test foods (rice, peanut and grm) with four different occlusal schemes. Mandibular movement was, also, measured with Sirognathography(Bio-Pak system). These recordings were performed in immediately, after 1 week and after 2 weeks of insertion of complete denture. The results were as follows; The average masticatory performance of 0-degree artificial teeth was higher than any other artificial teeth. Masticatory performance in denture wearer was affected preferentially by food and artificial occlusal schemes. During chewing, there was a statistical difference of EMG activity between masseter and temporal muscle (p<0.01). Especially, EMG activity of working masticatory muscle was highly affected by food rather than by artificial occlusal schemes. In denture wearer, the velocity of opening was not affected by food, whereas, the velocity of closing was faster in soft food chewing than in hard food chewing. And the amount of vertical displacement was grater in chewing of soft and large bolus than in chewing of hard and small bolus. However, the amount of lateral displacement showed conversely(p<0.05). It was considered that masticatory performance in denture wearer is not affected by the condition of residual ridge, the history of denture wear, the preference, the adaptation to artificial teeth and the total mesiodistal length of artificial posterior teeth.
Dental Restoration Wear ; Denture, Complete* ; Electromyography ; Jaw ; Mastication ; Masticatory Muscles ; Mucous Membrane ; Stomatognathic System ; Temporal Muscle ; Tooth ; Tooth, Artificial

STATEMENTS OF THE PROBLEM: Many denture wearers occasionally use denture adhesives to improve denture retention, stability and chewing efficiency. An ideal denture adhesive is nontoxic, non-irritating, and provides comfort to the oral mucosa. PURPOSE: The purpose of this study was to evaluate the cytotoxicity and adhesive properties of a selected denture adhesive. MATERIAL AND METHODS: To test cytotoxicity of the selected denture adhesive, mouse fibroblast cells were used in MTT testing. Cytotoxicity was examined according to the concentration of the denture adhesive and incubated for 1 to 4 days. To examine adhesive property, a denture base was fabricated on an edentulous dentiform. The adhesive was applied to the denture base, then tensile bond strength was measured, to evaluate the change in retention during 3 days. RESULTS AND CONCLUSION: 1. 1% and 2% concentration denture adhesive cream had no cytotoxicity. 2. The tensile bond strength of the group with both denture adhesive and artificial saliva was significantly higher than that of the group with only denture adhesive (P < .05). The tensile bond strength of the group with denture adhesive was significantly higher than that of with only artificial saliva (P < .05). 3. The tensile bond strength had no significant change during 1 hour, and then gradually decreased. After 1 day, it decrease to half. Within the limitation of this study, the tested denture adhesive had no cytotoxicilty and was effective in improving denture retention. The adhesive strength began to continuously decrease after 1 hour and it decreased to half at 1 day after application.
Adhesives ; Animals ; Dental Restoration Wear ; Denture Bases ; Denture Retention ; Dentures ; Fibroblasts ; Mastication ; Mice ; Mouth Mucosa ; Retention (Psychology) ; Saliva, Artificial

OBJECTIVES: The purpose of this study was to evaluate the effectiveness of a seniors' oral health promotion program for establishing a cooperation model between public and private sectors. METHODS: This study was carried out targeting the seniors frequenting a community center in the Sosa-gu district of Bucheon-si in the Gyeonggi-do province of South Korea. Data were obtained from self-administered questionnaires or personal interviews with elders after they participated in the oral health promotion program. Their perceived satisfaction with their oral health before and after the oral health program was compared. The data were analyzed by t-tests, ANOVA, paired t-tests, and logistic regression using SPSS to assess the effects of explanatory factors on the seniors' satisfaction of the oral health promotion program. RESULTS: In total, 22.7% of participants had a positive idea about the oral health promotion program before their participation. The mean score of change in and difference of satisfaction with oral health tended to increase in each of the following groups: women, aged 80-84 years, number of permanent teeth, full denture wearers, and those who did not require dentures. Satisfaction notably increased 0.4 points in the group of full denture wearers (P<0.05). Moreover, after 1 month, the satisfaction level of the subjects who participated in the oral health promotion program increased 5.2 times (95% CI, 1.04-25.49) compared to dissatisfaction levels. Ultimately, satisfaction with oral health shows a major impact on the satisfaction with an oral health promotion program. CONCLUSIONS: The subjects who received the oral health promotion program responded very positively, but this program needs overall consideration about work processes and further reliable evaluations.
Dental Restoration Wear ; Dentures ; Female ; Gyeonggi-do ; Humans ; Korea ; Logistic Models ; Oral Health* ; Private Sector* ; Surveys and Questionnaires ; Tooth

OBJECTIVETo evaluate the clinical application value of minimal prepared ceramic veneer in anterior teeth, by analyzing the esthetic effects and success rates.

METHODSForty-four anterior teeth in 30 patients with minor esthetic defect were included in this study. Less than 0.5 mm preparation or no preparaion technique was used in the clinical procedure. Glass ceramics veneers were delivered and 3M Relyx Veneer were used as the adhesive. The final appearance of each restoration was evaluated by patients on visual analogue scales (VAS) and by professional prosthodontists. Evaluation criteria included margin effects, color, shape and translucency. The success rate of all the restoration were analyzed in 6, 12 and 24 month after the treatment.

RESULTSThe patients' degree of satisfaction was 9.2 ± 0.4, while the excellent rate of esthetic effect of margin effect, color, shape and translucency was 89% (39/44), 91% (40/44), 98% (43/44) and 93% (41/44) by professional prosthodontist. The success rate of 6, 12 and 24 month were 100% (44/44), 98% (43/44) and 91% (40/44).

CONCLUSIONSThe minimal prepared venneers have a good esthetic effect and a satisfactory success rate, and is a suitable technique in esthetic treatment under the critical indications.

Ceramics ; Dental Restoration, Permanent ; methods ; Dental Veneers ; Esthetics, Dental ; Humans ; Incisor ; Patient Satisfaction ; Tooth Abnormalities ; therapy ; Tooth Preparation, Prosthodontic ; methods ; Tooth Wear ; therapy