Showing papers by "Franklin Garcia-Godoy published in 2000"

Clinical evaluation of fiber-reinforced epoxy resin posts and cast post and cores.

Abstract: PURPOSE This retrospective study evaluated treatment outcome of cast post and core and Composipost systems after 4 yrs of clinical service. MATERIALS AND METHODS 200 patients were included in the study. They were divided in two groups of 100 endodontically treated teeth restored with a post. Group 1: Composipost systems were luted into root canal following the manufacturer's instructions. Group 2: Cast post and cores were cemented into root canal preparations with a traditional technique. The patients were recalled after 6 months, 1, 2 and 4 yrs and clinical and radiographic examinations were completed. Endodontic and prosthodontic results were recorded. RESULTS Group 1: 95% of the teeth restored with Composiposts showed clinical success; 3% of these samples were excluded for noncompliance and 2% showed endodontic failure. Group 2: Clinical success was found with 84% of teeth restored with cast post and core. 2% of these samples were excluded for noncompliance, 9% showed root fracture, 2% dislodgment of crown and 3% endodontic failure. Statistical evaluation showed significant differences between Groups 1 and 2 (P < 0.001). The results of this retrospective study indicated that the Composipost system was superior to the conventional cast post and core system after 4 yrs of clinical service.

Clinical results and new developments of direct posterior restorations.

Abstract: PURPOSE To (1) review the literature and analyze the longevity and reasons for failure of direct resin-based composite (RBC), amalgam, and glass-ionomer cement (GIC) restorations in stress-bearing posterior cavities and (2) to assess new material developments and treatment techniques to restore these cavities. MATERIALS AND METHODS This work reviewed the dental literature predominately of the last decade for longitudinal, controlled clinical studies and retrospective cross-sectional studies. Only studies investigating the clinical performance of restorations in permanent teeth were included. Annual failure rates of direct resin-based composite, amalgam, and GIC restorations were determined and failure reasons were discussed. RESULTS Annual failure rates in posterior stress-bearing cavities were determined to be: 0-9% for direct RBC restorations, 0-7% for amalgam restorations, and 1.9-14.4% for GIC restorations. The median annual failure rate of longitudinal studies for amalgam was calculated with 1.1%, for RBCs 2.1% and for GICs 7.7%. GIC is significantly worse compared with amalgam and RBC. Main reasons for failure were secondary caries, marginal deficiencies, fracture, and wear. Longitudinal studies showed a strong trend towards a higher longevity compared with cross-sectional investigations.

Resorption of a calcium hydroxide/iodoform paste (Vitapex) in root canal therapy for primary teeth: a case report.

Abstract: This case report presents a clinical and radiographic follow-up (38 months) of pulpectomy treatment performed on maxillary primary anterior teeth using Vitapex. Vitapex was resorbed extraradicularly and intraradicularly without apparent ill effect, and proved to be clinically and radiographically successful. The present case report illustrates that even if the paste resorbs within the canals, the clinical and radiographical outcome is excellent. A longer follow-up is recommended to evaluate if there is any effect on the permanent succedaneous tooth.

Fluoride-releasing sealant and caries-like enamel lesion formation in vitro.

Abstract: OBJECTIVE The aim of this laboratory study was to evaluate the effects of a fluoride-releasing pit and fissure sealant (FS) and a conventional non-fluoride-containing pit and fissure sealant (CS) on caries-like lesion formation in enamel. DESIGN Twelve extracted, macroscopically caries-free human molar teeth underwent fluoride-free prophylaxis and were sectioned into toothquarters. Cavity preparations were placed in buccal and lingual surfaces of the toothquarters, acid-etched and filled with sealant material (per the manufacturer's instructions) as follows: 1) mesiobuccal and mesiolingual quarters--FS (Fissurit-F, VocoChemie); and 2) distobuccal and distolingual quarters--CS (Fissurit, VocoChemie). Prior to caries formation in an acidified gel, the toothquarters were thermocycled (500 cycles) in artificial saliva. Sections were taken following caries initiation (6 week gel exposure) and caries progression (9 week gel exposure), and examined by polarized light microscopy to determine mean primary surface lesion depth and presence or absence of wall lesions. RESULTS Mean surface lesion depths were significantly different between FS and CS groups following caries initiation (FS = 119 microns; CS = 157 microns, p 0.05, paired t-test). CONCLUSION A pit and fissure sealant containing releasable fluoride provided a caries inhibiting effect with a significant reduction in lesion depth in the surface enamel adjacent to the fluoride-releasing sealant and a tendency toward reduction in the frequency of wall lesions. CLINICAL SIGNIFICANCE Fluoride release by pit and fissure sealants may provide additional protection against caries formation in cuspal incline enamel and smooth surfaces adjacent to sealed pits and fissures, and act as a fluoride reservoir with long-term release of fluoride into the immediately adjacent oral environment.

Effect of 1.23 percent APF gel on fluoride-releasing restorative materials.

Abstract: This study evaluated the effect of a 1.23 percent APF gel on the surface morphological characteristics and surface roughness of one high-viscosity (Fuji IX GP), three polyacid-modified resin-based composites (Dyract AP, F2000 and Compoglass F) (PMRC), and two resin-modified glass-ionomer cements (Vitremer and Fuji II LC). A microfilled nonfluoridated resin-based composite (Silux Plus) was used as a control. All materials were handled according to the manufacturers' instructions. The fluoride gel used in the study was a 1.23 percent acidulated phosphate fluoride gel (APF) (Nupro APF). The specimens were repeatedly exposed to the APF gel with cotton applicators for a period that simulated the equivalent of 4 yrs (1 min/6 mo) under prophylactic fluoride treatment. Average surface roughness (Ra) of the control and treated specimens was measured. Three separate Ra measurements along the direction of rotation of the finishing and perpendicular to the finishing direction and edge of the mold were made for each specimen surface. In each group, specimens with Ra closest to the mean were removed from the molds, sputter-coated with gold and examined using a scanning electron microscope. The results showed that all tested materials, except Vitremer, displayed increased surface roughness values following APF treatment. However, this was not statistically significant for Compoglass F, Vitremer and Fuji II LC. Among PMRC materials, F2000 displayed the highest Ra average value, although the differences between F2000 and Dyract AP and of Compoglass F and Dyract AP was not statistically significant. Comparisons of the Ra values between Silux Plus and the other test materials revealed statistically significant differences except for Dyract AP and Compoglass F. No statistically significant difference was found between the Ra values of Vitremer and Fuji II LC following APF treatment. Among all groups, Fuji IX GP displayed the highest surface roughness.

Effect of etching agent on dentinal adhesive interface in primary teeth.

Abstract: The purpose of this study was to evaluate in vitro the effect of a phosphoric acid etchant containing benzalkonium chloride on the dentin/adhesive interface in primary teeth. The teeth had caries lesions involving enamel and dentin, and were stored in a 2% glutaraldehyde solution for 2-4 hours. The teeth were divided into five groups of five teeth each: Group 1: Etching for 15 seconds with a semigel 32% phosphoric acid containing benzalkonium chloride; Group 2: Etching with 35% phosphoric acid for 15 seconds; Group 3: Treated with a 2% benzalkonium chloride in a alcoholic solution; Group 4: Conditioned with a 3% benzalkonium chloride in a alcoholic solution (control group); Group 5: The teeth were untreated (control group). The carious tissue was removed with a carbide bur in high-speed and copious air water spray. The overall dimensions and depths of the cavities were determined by the carious tissue removal. After the caries lesion was removed, the cavity was cleaned with an air-water spray and the dentin was treated according to the specific group. The teeth were then restored with Scotchbond Multi-Purpose Plus (3M, St. Paul, MN) and Z-100 resin-based composite (3M, St. Paul, MN) according to the manufacturer's instructions. After the teeth were restored they were stored in water for 24 hours at room temperature and the restorations polished. After storage the teeth were thermally challenged for 500 cycles in temperatures of 50 C and 550 C and then stored in 100% humidity until the sectioning procedures. The teeth were cut into two sections along the longitudinal axis through the center of the teeth and passed the mesial-distal surfaces through the restoration by using a double-face diamond disc with water coolant. The specimens were ground with 320 up to 600 grit silicon carbide paper and polished with 6 mm and 1 mm diamond paste and 0.25 pm alumina solution. The specimens were etched with 10% citric acid for 1 minute and washed with deionized water. After that, they were deproteinized with 10% NaOCl for 5 seconds. The specimens were dried at room temperature sputter-coated with gold and observed with an SEM for assessment of the morphology of the bonded interface. The interface was observed to determine the presence/absence of hybrid layer formation, resin tags, and gaps. In the groups treated only with benzalkonium chloride solutions, spaces were observed in the resin/dentin interface. Similar findings were observed in the control group, which received no treatment on the dentin before primer application. In these groups neither resin tags or hybrid layer formation was observed. The presence of an amorphous layer, which was unremoved smear layer, was noted. The group treated with 35% phosphoric acid showed a hybrid layer formation (8.15 microns). This layer was linked intimately with the peritubular and intertubular dentin. Tags formation was observed towards the pulp under the hybrid layer. In these specimens the gaps were not observed between the dentin layer and bonding materials. The total removal of the smear layer was observed using 37% phosphoric acid with benzalkonium chloride. A hybrid layer (+/- 7.32 microns) and resin-tags attached to this layer were observed similar to the group in which the 35% phosphoric acid was used. The samples showed total removal of the smear layer and no gaps were observed in the dentin/adhesive interface.