SEARCH · PubMed Health

Results for “DENTAL RESTORATION, PERMANENT”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

PubMed2002

[The evaluation of color for the clinical application of thinner porcelain laminate restoration].

OBJECTIVE: The aim of this study was to evaluate the clinical application of the thinner porcelain laminate restoration, which is initiated in the West China College of Stomatology, Sichuan University. METHODS: The color of 51 ceramic veneers was evaluated using the chromatic instrument and visual observation. RESULTS: Among factors affecting the clinical results of the porcelain laminate, the hue of ceramic materials and bond composites played a more important role than the dentition. The brightness of ceramic materials and bond composites were closely correlated with the whole restoration brightness. There was also a close correlation between the brightness and the bond composite. CONCLUSION: Satisfactory restoration results can be achieved by clinical application of thinner porcelain laminate.

Adult↗

PubMed2002

Clinical application and effective assessment of cerinate porcelain laminate veneers.

OBJECTIVE: To study the esthetic and long-term effectiveness of cerinate porcelain laminate veneers. METHODS: A total of 736 front teeth were restored with cerinate porcelain laminate veneers, which were then tested at different time points by clinical tracking observation and appraisal. RESULTS: The short and long term rates of effectiveness were 96.6% and 96.2%, respectively. There was no relationship between clinical effectiveness and the length of restoration time. The failure rate was higher in 18 - 30 years old patients and those with discolored teeth. The major clinical performance was fold fissure and deciduous of porcelain laminate veneers. CONCLUSIONS: Cerinate porcelain laminate veneers are an ideal choice for dental esthetic restorations because they are unnoticeable, stable, strong and require no excessive dental preparation.

Adolescent↗

PubMed2002

[Effects of different class II cavity designs on stresses in restoration].

OBJECTIVE: To assess effects of different class II cavities on stresses of amalgam and composite resin restoration. METHODS: Five kinds of class II MO cavities were prepared on the first molars of mandibles. The cavities were filled by amalgam and composite resin, respectively. The stresses were analyzed by using three-dimensional finite element method, after vertical and lateral pressures were loaded on the teeth. RESULTS: The stresses were greater in traditional cavities than those in reformed cavities when 100 N vertical and lateral pressures were loaded on the teeth. But the pressing stress and shearing stress in cavities filled by amalgam were smaller in traditional cavities than those in reformed cavities. The stresses were smaller in cavities filled by resin than those in cavities filled by amalgam significantly, when the cavities were designed with slot retention groove, without slot retention groove and as plate form. The stresses were smaller in two kinds of slot and plate cavities than those in traditional and reformed cavities. CONCLUSION: It is better to design cavity with slot retention groove for amalgam restoration and to design cavity without slot retention groove for composite resin restoration.

Composite Resins↗

PubMed2002

Fracture resistance of teeth directly and indirectly restored with composite resin and indirectly restored with ceramic materials.

PURPOSE: To evaluate the fracture resistance of teeth restored with direct and indirect restorations of composite resin and restored with indirect ceramic restorations. MATERIAL AND METHODS: Fifty-six maxillary premolar teeth were chosen and divided at random into seven equal groups; Group 1 (control): intact teeth; Group 2: MOD cavity preparations, 1/2 intercuspal distance, with rounded internal angles, convergent walls, unrestored; Group 3: MOD cavity preparations, 1/2 intercuspal distance, divergent walls; Group 4: same preparation as Group 2, restored with direct composite resin (Single Bond/Filtek Z250-3M); Group 5: same as Group 3, restored with indirect composite resin (Artglass/Single Bond/Rely X); Group 6: same as Group 3, restored with indirect composite resin (Targis/Single Bond/Rely X); Group 7: same as Group 3, restored with indirect ceramic restoration (Empress/Single Bond/Rely X). The specimens were subjected to a compressive axial loading in a Universal testing machine at 0.5 mm/minute by means of a steel bar (8 mm in diameter). RESULTS: The mean fracture strength obtained was: Group 1: 1.91 kN; Group 2: 1.06 kN; Group 3: 0.93 kN; Group 4: 1.45 kN; Group 5: 1.81 kN; Group 6: 1.81 kN; Group 7: 1.77 kN. The restored teeth with direct composite restoration increased the fracture resistance of Group 4 up to 76% of a level comparable with the intact teeth (Group 1). However, statistical analysis indicated no significant (P < 0.05) differences between Group 1 (intact teeth) and restored teeth groups, with direct restorations as well as indirect restorations. Both cavity preparation designs weakened the remaining tooth structure. These results demonstrated that a bonded indirect restoration could satisfactorily be an ideal option for restoring teeth weakened by wide cavity preparation.

Aluminum Silicates↗

PubMed2003

[A finite element model of a cusp-replacing adhesive restoration].

This article describes the development of a three-dimensional finite element model of a premolar, based on a micro-scale computed tomographic data-acquisition technique. Using the model shrinkage stresses were analysed during and after the polymerisation process of resin composite. The stress patterns generated were three-dimensional. The results of this study indicate that failure of the interface is more probable than failure of the composite material. The described procedure is a relatively easy method to produce a highly detailed 3-D finite element model of a premolar with an adhesive cups-replacing restoration.

Bicuspid↗

PubMed2003

Fracture strength of cusp replacing resin composite restorations.

PURPOSE: To assess the influence of an additional shoulder preparation on the fracture strength of a cusp-replacing direct resin composite restoration in a premolar that previously had an amalgam MOD restoration followed by fracture of a cusp. MATERIALS AND METHODS: Two preparation designs were tested. In extracted sound premolars an MOD amalgam cavity was simulated followed by fracture of a cusp (Group A). Group B was the same as Group A but a shoulder was added along the cervical outline of the preparation. As a control group, cusp fracture was simulated but no MOD amalgam cavities were prepared. For each group, 14 preparations were made using a copy milling technique. All 42 preparations were restored using a direct resin composite restoration technique. Restorations were loaded until fracture. RESULTS: The fracture strength of the preparation with shoulder was not significantly different from the preparation without the shoulder. The fracture strength of the preparations in the reference group, which had no resistance form, was significantly less than in Groups A and B (ANOVA, P<0.05).

Analysis of Variance↗

PubMed2003

Fatigue behavior of the resin-resin bond of partially replaced resin-based composite restorations.

PURPOSES: (1) To evaluate different pre-treatment modes for partial resin-based composite repair using a shear bond strength fatigue design on aged specimens, and (2) to investigate the effect of these pre-treatments on aged and partially replaced Class II resin-based composite restorations. MATERIALS AND METHODS: (Study 1) 150 composite discs (Tetric Ceram) were light-cured, secondary cured, and stored in water for 365 days. The specimens were randomly assigned to five pretreatment groups (n=30): (1) Roughening with a finishing diamond bur + dentin bonding system (DBS, Syntac Classic), (2) Roughening with a silicon carbide bur + DBS, (3) Roughening with a silicon carbide bur + DBS + Tetric Flow, (4) silica-coating (CoJet) + DBS, and (5) silica-coating + dentin bonding agent + Tetric Flow. The disks were restored with fresh repair composite cylinders and after 24-hour water storage, initial bond strengths (n=10) and fatigue bond strengths (n=20; 5,000 cycles in shear mode) were evaluated and fracture modes determined under a SEM. (Study 2): 40 Class II restorations (EBS Multi/Pertac II) were placed in extracted human third molars. The specimens were stored for 365 days and then replaced partially by removing the proximal box and leaving the occlusal part. The partial repairs (Pertac II) were placed after identical pre-treatment modes A-E (n=8). After thermomechanical loading (100,000 x 50 N, simultaneously x2,500 at 5 degrees C/55 degrees C), marginal quality between old and fresh composite was evaluated by SEM at x200 magnification and dye penetration was observed by light microscopy under x50 magnification. RESULTS: Initial repair bond strengths were significantly higher for the groups with additional application of flowable composite compared to composite only (P<0.05; Mann Whitney U test). Diamond finishing revealed the lowest bond strengths. Fatigue bond strengths exhibited the worst results for Group 1 as well, but were similar for Groups 2-5. In the Class II partial repair simulation, Groups 3 and 5 with additional flowable lining exhibited significantly better marginal quality and significantly lower leakage, whereas the other groups revealed up to 100% separation between aged and freshly applied composite.

Composite Resins↗

PubMed2003

[Effects of dental cements on the stress distribution in amalgam-restored teeth].

OBJECTIVE: To evaluate the effects of 5 kinds of base materials on the stress distribution and deflection in amalgam- restored teeth. METHODS: A computerized two-dimensional finite-element of the tooth model first molar was established. Various dental cements with a thickness of 0.5 mm and amalgam restorations with thickness of 2 mm in the prepared cavity were simulated and subjected to microhardness test (load=45 kg). The stresses and deflections along the cavity wall interface were analyzed by finite-element method. RESULTS: High stress and deflection occurred mainly at the line angle of the cavity, this could be magnified by using cements with lower elasticity modulus. The maximum compressive stress at the line angle induced by common ZOE or Ca(HO)(2) was increased 3.3 times or 2 times and deflections increased by 40% and 25% respectively that by Zinc phosphate and glass ionomer. CONCLUSION: Modulus elasticity of cement plays an important role in affecting the fracture strength of the amalgam restored tooth. The lower the elasticity modulus, the higher the stresses and deflections induced in the dentine. From the point of mechanical property, zinc phosphate is one of the best dental cements.

Dental Amalgam↗

PubMedDate not supplied

Shear bond strength of 4th & 5th generation dentin bonding agents in the presence and absence of moisture. An in vitro study.

Extracated human molars were used for the study, flat dentinal surfaces were prepared on the occlusal surfaces, and then 4th and 5th generation dentin bonding agents were used in dry and moist conditions to bond composite resin onto the flat dentin surfaces. Shear Bond Strength was measured using Instron Universal Testing machine. Failures were recorded as adhesive, cohesive and mixed. Bond strength was highest in moist condition, because the moist surface permits more porous collagen network and hence greater infiltration of adhesive monomers, than do surfaces that are air dried. Moreover, those dentin bonding agents whose primers are based on acetone show improved bond strength, because acetone aggressively pursues and displaces water in the substrate, resulting in the primer resin being carried into tissue channels and porosities. When the dentin is air dried, the water that is supporting the collagen network evaporates causing the collagen network to collapse network is greatly reduced, which in turn decreases the premeability of intertubular dentin to adhesive resin and as a result causes decrease in bond strength. 5th generation dentin bonding agent showed significant improvement in the moist dentin bond strength.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2003

Simplified techniques for the placement of stratified polychromatic anterior and posterior direct composite restorations.

Although many tooth-colored indirect restorative materials are available, dentists frequently employ direct composite resins as a primary tooth-colored restorative material. Direct resin systems that are suited for stratification, or layering of various opacities and colors of dental composite, offer dentists the opportunity to accurately reproduce natural teeth in ways that rival the esthetics of most indirect systems. This article presents a simplified version of the classical three-layered technique originally described by Dietschi, and demonstrates the application of a recently introduced composite resin system.

Adult↗

PubMed2003

Polymerization contraction stresses of resin-based composite restorations within beveled cavity preparations of Class I restorations.

PURPOSE: To evaluate internal stresses resulting from polymerization of resin-based composite materials in cavity preparations beveled at the internal line angles or the cavosurface margin, compared with those in conventional butt-joint box-shaped cavity preparations. MATERIALS AND METHODS: Contraction stress generated in resin-based composite restorations placed in an experimental cavity preparation model was determined using micro-photoelastic analysis. Three types of cavity preparations simulating Class I restorations with bevels at internal line angles (1 mm and 2 mm deep), and at the cavosurface margin (2 mm deep) were prepared in a posterior composite model in order to obtain no marginal defect with the restorative composite. The transparent restorative composite was bulk-filled into the preparations and light-cured for 80 seconds. Specimens 2 mm thick for micro-photoelastic analysis were cut perpendicular to the long axis of the preparation. Fringe patterns for directions and magnitudes of stresses were obtained using transmitted and reflected polarized light. Then, the photoelastic stress analysis was performed to examine stresses in the preparations. The data were statistically compared with the previous data in conventional butt-joint box-shaped preparations by ANOVA and Scheffé's F test (P < 0.05). RESULTS: In 1 and 2 mm deep internal beveled cavity preparations, the maximum principal stress lines were parallel to the wall at the straight internal bevels. In the preparation with a round bevel at the cavosurface margin, the stress distribution in the bulk of the preparation was similar to that in the butt-joint preparation. Maximum stress values in 1 and 2 mm deep internal beveled preparations were 12.2 +/- 0.2 MPa and 18.8 +/- 2.8 MPa, respectively. For 2 mm-deep preparation, the maximum stress values in the internal beveled preparations were significantly lower than those values in butt-joint box-shaped cavity preparations. Maximum stress values in the preparations with the bevel at the cavosurface margin were 22.7 +/- 1.0 MPa, and were not significantly different from those values observed in the butt-joint preparations.

Analysis of Variance↗

PubMed2003

Dental anxiety in patients seeking care at the University Dental Hospital in Sri Lanka.

OBJECTIVE: The purpose of the study was to determine the prevalence and factors affecting dental anxiety in patients seeking dental care. DESIGN: A cross sectional study. PARTICIPANTS: 503 first visit patients attending the University Dental Hospital in Peradeniya, Sri Lanka. OUTCOME MEASURES: Corah's dental anxiety scale was used to assess the dental anxiety in these patients. RESULTS: The prevalence of dental anxiety was 32% (DAS score > or = 12) while 12% were considered to be extremely anxious (DAS score > or = 15). Females were found to be more dentally anxious than males. Level of education was associated with dental anxiety. Problem oriented attenders had a significantly higher mean DAS score than regular attenders. Those who had an extraction at the last dental visit were significantly more dentally anxious than those who had a restoration/scaling. Negative dental experience was not associated with dental anxiety. The logistic regression model revealed that gender, level of education and 'fear' which was cited as the reason for the delay in seeking care for the presenting complaint were significant predictors of dental anxiety. However, only 4% of the variation in dental anxiety could be explained by these independent variables. CONCLUSION: Socio-demographic factors and variables related to past dental experiences had a limited influence in explaining dental anxiety in this sample of dental patients.

Adolescent↗

PubMed2003

Computer-assisted functional risk assessment for the dentist, dental technician, and patient.

Functional disturbances due to malocclusion after dental work (which can also be ameliorated again through occlusal adjustment) are increasing. Restorative dentistry today creates significantly more occlusal disharmonies than it alleviates. Instrumental functional diagnostics or--what has always been wanted--the combination of clinical and instrumental functional diagnostics, is practically disregarded in the relevant literature. In the answers to certain questions, no relevance to the occlusion could be detected. Central questions are either not asked at all, or the findings to be evaluated are practically reduced to uselessness, so that differentiated answers cannot be expected. With Cognito, software has been created that can give answers to certain questions of great interest to the practitioner. Cognito fulfils the criteria for quality assurance and quality management in dentistry as well as the requirements of evidence-based dentistry.

Computer User Training↗

PubMed2003

[The direct composite veneer restoration].

The direct composite veneer restoration is a minimal invasive tooth-saving and relatively cheap technique suitable to improve the esthetics of the dentition in many cases. In this article factors in influencing the selection of materials are discussed. Furthermore, advantages and disadvantages of the direct composite veneer are listed and some cases are presented.

Composite Resins↗

PubMed1992

Chairside computer-generated ceramic restorations: the Cerec third generation improvements.

Cerec chairside computer-generated ceramic restorations have well passed a five-year clinical observation period with convincing clinical success. The new system COS 2.1 allows an essentially automatic design of inlays, the construction of 3/4 and 4/5 cusp protection onlays, and individually-shaped aesthetic laminate veneers. The new E-drive grinding increases the machining capacity by factor 3 to 4, reduces edge roughness by 50%, and doubles machining precision. Cementation gap width at the cervical margin is 37-48 microns in normal-depth preparations and 54-76 microns in deep cavities. It is the purpose of this article to review the third generation improvements of this method.

Adult↗

PubMed1992

Aesthetic all-porcelain anterior restorations.

The translucence of all-porcelain restorative materials very closely resembles that of natural teeth, thereby enabling the nearest possible emulation of natural teeth. Because of this quality and the suitability for bonding, all-porcelain has become the choice material for anterior jackets, three quarters, and veneers. In this article, the author uses actual cases to substantiate and illustrate her evaluation.

Crowns↗

PubMed2003

Comparison of restorative dentistry referrals to a district general hospital and to a teaching hospital using a pilot Index of Restorative Dental Treatment Need.

The purpose of this study was to identify differences between referral patterns and the clinical conditions of patients referred to consultant-led Restorative Dentistry clinics in a district general hospital and a London dental teaching hospital. The Index of Restorative Dental Treatment Need was used to classify patients into those patients whose treatment was appropriate for any dental graduate in general practice, for an experienced dentist in general practice, and for a dentist with specialist training. Demographic and clinical details were recorded for one hundred patients at each hospital. The results of the study showed that the proposed treatment of 21% of the patients seen at the district general hospital and 16% of the patients seen at the teaching hospital was appropriate for specialist care. The results support the expansion of specialist restorative dentistry services in district general hospitals.

Adult↗

PubMedDate not supplied

Simultaneous activation technique: an alternative for bonding composite resin to glass ionomer.

PURPOSE: The purpose of this study was to evaluate a new simultaneous activation technique (SAT)-for the union between glass ionomer cements and composite resins. METHODS: Forty primary molars were embedded in self-curing acrylic resin. Class I cavity preparations were performed on the dentin surface and the teeth were randomly divided into 4 groups (N = 10). Two groups were restored with the SAT and 2 by etching the ionomer surface/sandwich technique (ST). The materials tested were Vidrion F (SS/ White), Vitremer (3M), and Z100 (3M). After 24 hours in aqueous solution at 37 degrees C, a tensile test was performed. The microleakage study was also performed by selecting 40 primary molars which were distributed in the same way as in the bond strength test. Furthermore, 1 tooth from each group of the microleakage test was evaluated by means of scanning electron microscopy. RESULTS: The SAT and ST did not show statistically significant differences in both tests. CONCLUSIONS: The SAT is a less complex, quicker, and feasible alternative for the bonding of glass ionomer cements to composite resins in primary molars.

Acid Etching, Dental↗