The aim of this study was to evaluate the dimensional changes of denture bases made from different resins after different storage periods. For this purpose, 25 sets of plaster models/resin bases were prepared using 4 acrylic resins submitted to two types of polymerization: 1-QC-20 submitted to polymerization by microwave energy; 2-QC-20 submitted to polymerization by water hot bath; 3-Vipi Cril submitted to polymerization by water hot bath; 4-Vipi Wave submitted to polymerization by microwave energy; and 5-Onda Cryl submitted to polymerization by microwave energy. After polymerization, the specimens were sectioned for accuracy readings using a comparison microscope. Readings were taken at 3 points: the crests of the right (A) and left (B) ridges, and the median region of the palate, in 4 different periods. The data obtained were submitted to two-way ANOVA and Tukey's test at 5% significance level. The greatest distortions were found in the posterior palatal region of the base (M), with statistically significant difference (p<0.05) for the studied resins. All acrylic resins presented dimensional changes and the storage period influenced these alterations.
The objective of this in vitro study was to evaluate demineralization around restorations. Class V preparations were made on the buccal and lingual surfaces of each tooth. TPH (Group 1), Fuji II LC (Group 2), Tetric (Group 3), Dyract (Group 4), GS 80 (Group 5) and Chelon Fil (Group 6) were randomly placed in equal numbers of teeth. The teeth were submitted to a pH-cycling model associated with a thermocycling model. Sections were made and the specimens were examined for the presence of demineralization under polarized light microscopy. Demineralization was significantly reduced with Chelon Fil (Group 6). Furthermore, a similar inhibitory effect on the development of demineralization was observed in Groups 2, 4 and 5.
This study carried out an in vitro evaluation and comparison of the occurrence of marginal leakage in bonded restorations using mechanical or chemical-mechanical (Carisolv) removal of carious tissue. For that purpose, 40 extracted decayed human molars were divided into 4 groups: GI (burs + Prime & Bond NT + TPH), GII (Carisolv + Prime & Bond NT + TPH), GIII (burs + SBMP + Z100) and GIV (Carisolv + SBMP + Z100). After accomplishment of the restorations and thermal cycling, the teeth were exposed to dye, sectioned and qualitatively evaluated. The results demonstrated that the system of removal of carious tissue did not influence the results of microleakage at any of the cavity margins. At dentinal margins, use of the Prime & Bond NT + TPH restorative system allowed the occurrence of less microleakage than the SBMP + Z100 system.
Aim The present case report described the use of contact lens of thin porcelain veneers as a restorative therapy to solve anterior teeth disharmony. Background Fragments of thin veneers are minimally invasive restorations with little or no dental preparation and present thickness ranging from 0.2 to 0.5 mm. They are used in case of diastema closure, small changes of teeth, color and restoration of teeth with small fractures. Case report A 25-year-old man was admitted at a dental clinic complaining about the diastema presence on the upper anterior teeth. Patient was referred to an orthodontic treatment in order to provide better distribution of the diastemas and harmonious proportion of the teeth. Afterwards, contact lens of thin porcelain veneers were fabricated on the six upper anterior teeth. Conclusion Based on the outcomes of this clinical report, we considered the use of fragments of thin veneers as a successful treatment option after 3 years of follow-up. Clinical significance The fragments of thin veneers have been established to be an interesting alternative to esthetically restore the anterior teeth with minimal invasiveness. However, since it is a new treatment modality, longitudinal studies are necessary to understand the material's behavior. How to cite this article Okida RC, Filho AJV, Barão VAR, dos Santos DM, Goiato MC. The Use of Fragments of Thin Veneers as a Restorative Therapy for Anterior Teeth Disharmony: A Case Report with 3 Years of Follow-up. J Contemp Dent Pract 2012;13(3):416-420.
The gastroesophageal reflux disease (GERD) is one of the main causes of dental erosion. The aim of this case presented is to describe the prosthetic rehabilitation of a patient with GERD after 4 years of followup. A 33-year-old male patient complained about tooth sensitivity. The lingual surface of the maxillary anterior teeth and the cusps of the upper and lower posterior teeth presented wear. It was suspected that the feeling of heartburn reported by the patient associated with the intake of sports supplements (isotonics) was causing gastroesophageal changes. The patient was referred to a gastroenterologist and was diagnosed with GERD. Dental treatment was performed with metal-free crowns and porcelain veneers after medical treatment of the disease. With the change in eating habits, the treatment of GERD and lithium disilicate ceramics provided excellent cosmetic results after 4 years and the patient reported satisfaction with the treatment.
The aim of this study was to evaluate the influence of the polishing period on surface roughness (Ra) before and after thermal aging in four composite resins - CR (Durafill VS, Vittra APS, Filtek Z350XT and Spectra Smart). This in vitro study evaluated: (1) CR in 4 levels; (2) polishing period (PP) in three levels (immediate, 7 and 14 days) and (3) artificial aging in two levels: without aging and after 10,000 cycles. For this, 240 CR specimens were allocated into 12 groups (n=20) according to PP with SofLex Pop On disks. For Ra, 3 measurements on the top surface of each specimen were performed with a diamond tip and constant load of 4mN and 0.25mm/s. Next, the specimens were aged in thermocycling, with temperatures of 5° and 55°C, during 30 seconds in each temperature, and repeated testing afterwards. The data were submitted to statistical tests with 5% significance. The alteration in Ra was observed only in the late polishing in the period of 7 days, where the Durafill VS CR showed higher Ra in comparison to the other CRs. After thermocycling, the groups showed significant difference only with late polishing in the 21-day period; the nanoparticulated RCs (Z350XT˂Vittra APS) recorded the highest Ra values, followed by the microhybrid (DurafillVS) and nanohybrid (Spectra Smart) RCs, respectively. Thus, late polishing in the 7-day and immediate period provided higher Ra values, especially for the nanohybrid and microhybrid composite resins.
Clinical performance of composite resins depends largely on their mechanical properties, and those are influenced by several factors, such as the light-curing mode. The purpose of this study was to evaluate the influence of different light sources on degree of conversion (DC), Knoop hardness (KHN) and plasticization (P) of a composite resin. Disc-shaped specimens (5 x 2 mm) of Esthet-X (Dentsply) methacrylate-based microhybrid composite were light-cured using quartz-tungsten-halogen (QTH) Optilight Plus (Gnatus) or light-emitting diode (LED) Ultraled (Dabi Atlante) curing units at 400 and 340 mW/cm2 of irradiance, respectively. After 24 h, absorption spectra of composite were obtained using Nexus 670 (Nicolet) FT-IR spectrometer in order to calculate the DC. The KHN was measured in the HMV-2000 (Shimadzu) microhardness tester under 50 g loads for 15 s, and P was evaluated by percentage reduction of hardness after 24 h of alcohol storage. Data were subjected to t-Student test (alpha = 0.05). QTH device showed lower P and higher KHN than LED (p < 0.05), and no difference between the light-curing units was found for DC (p > 0.05). The halogen-curing unit with higher irradiance promoted higher KHN and lower softening in alcohol than LED.
<p class="TAMainText"><strong><span lang="EN-US">Objective</span></strong><em><span lang="EN-US">:</span></em><span lang="EN-US"> The aim of this study was to evaluate the clinical performance of class V restorations made by undergraduate students and determine the factors that might influence retention of restorations. <strong>Material and Methods</strong><em>:</em> A survey of the clinical records created between 2007 and 2009 was used to collect data on patients with dental restorations. The USPHS (United States Public Health Service) criteria were used to perform evaluations by direct clinical observation. Statistical analyses were performed using Fisher’s exact test, Chi-square test, and Logistic regression analysis. <strong>Results</strong><em>:</em> Clinical records were analyzed, of which 282 (21.3%) described class V restorations performed on a total of 781 teeth. These patients were contacted, and 67 (23.76%) attended the clinic for assessment. Out of the 221 (28.3%) evaluated teeth, 37 restorations were replaced and 184 were analyzed. The logistic regression analysis showed that gingival bleeding index (GBI), decay-missing-filled teeth (DMFT) index, and pulpal protection influenced the retention of the restorations. The association tests demonstrated superiority of the composite resin over the glass ionomer cement with regard to retention, wear, and anatomical form. <strong>Conclusion</strong><em>:</em><strong> </strong>In this study, retention of cervical composite resin restorations was higher than that of the glass ionomer cement restorations when performed by undergraduate students.</span></p><p class="TAMainText"><strong><span lang="EN-US">Key Words:</span></strong><span lang="EN-US"> Composite resins; Glass ionomer cements; Retrospective study. </span></p>
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