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Biomedical subjects

F Garcia-Godoy

Publications and source records attributed to F Garcia-Godoy.

At least 19 recordsLinked to original sources

Effect of a fluoridated etchant on the shear bond strength of a composite resin to enamel.

The purpose of this study was to evaluate the effect of a fluoridated etching gel on the shear bond strength of a composite resin to enamel. A total of 75 extracted human permanent molars were used. A flat enamel surface was obtained with 600-grit silicon carbide paper and cleaned with a rubber cup and a water slurry of fine flour of pumice. The teeth were randomly distributed into 5 groups of 15 teeth each and etched as follows: group 1: 37% non-fluoridated phosphoric acid gel (Coe) for 60 seconds (control); group 2: 60% phosphoric acid gel with 0.5% NaF (Orthoprep) for 5 seconds; group 3: Orthoprep for 15 seconds; group 4: Orthoprep for 30 seconds; group 5: Orthoprep for 60 seconds. After etching, rinsing and drying, an unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured composite resin (Occlusin). The teeth were thermocyled (100x), mounted in plastic cups and plaster, and sheared with a knife-edged blade in an Instron machine running at a crosshead speed of 1 mm/min. The results in MPa were as follows: group 1: 14.49 +/- 4.43; group 2: 10.81 +/- 3.70; group 3: 13.51 +/- 3.21; group 4: 14.79 +/- 3.76; group 5: 15.47 +/- 4.07. An analysis of variance showed that the results in groups 1, 4 and 5 were not significantly different but that the bond strengths in groups 2 and 3 were significantly lower. Fracture within the enamel occurred in 8 specimens in group 1, 5 in group 2, 6 in group 3, 8 in group 4, and 13 in group 5. In the fluoridated etchant groups the number of specimens showing enamel fracture increased as the application time of the etchant increased.

Acid Etching, Dental

Traumatic injuries to primary teeth in Mexico City children.

The purpose of this retrospective study was to analyse traumatic injuries to primary teeth in children attending an emergency dental service in a pediatric hospital in Mexico City. A total of 563 children 6-mo to 7 yrs-old were treated during the period from January 1981 to December 1987. The 563 children presented 936 traumatic dental injuries. The most common type of trauma was soft tissue injury, followed by luxation and avulsion. More males presented with traumatic injuries (61.8%) than females (38.2%). In both sexes, maxillary teeth received more traumatic injuries than mandibular teeth. Children 2-3 yrs old presented the highest number of injuries (195) followed by the 4-5 and 6-7 year-olds. The largest number of injuries were seen during winter (36%) followed by summer (25%), spring (21%) and fall (18%).

Age Factors

Effect of etching time and acid concentration on resin shear bond strength to primary tooth enamel.

The present study compared the shear bond strength of two commercially available systems to human primary enamel. Ground and unground enamel was conditioned for 15 seconds with 37% phosphoric acid siliceous gel. A 60-second application was used as a standard reference. Ten percent phosphoric acid in a polymer gel was also evaluated following a 20-second application to ground and unground primary enamel. No statistically significant difference was demonstrated between the mean values determined for each group. Compared with tests on permanent enamel with the same materials and conditions, it was concluded that no statistically significant difference exists between shear bond strengths to the enamel of the two dentitions.

Acid Etching, Dental

Dentin surface treatment and shear bond strength of a light-cured glass ionomer.

This study evaluated the effect of dentin surface treatment with polyacrylic acid on the shear bond strength of Fuji Lining LC light-cured glass ionomer lining cement (GIC). A total of 40 human, noncarious extracted permanent molars stored in distilled water were used. A flat buccal dentin surface was ground wet on 600-grit silicon carbide paper. The teeth were then randomly distributed into four groups of 10 teeth each: Group 1: dentin rinsed with distilled water, dried with oil-free compressed air, placement of cylindrical GIC samples and sheared at 15 minutes post-curing. Group 2: same as group 1, but sheared 7 days post-curing. Group 3: dentin treated with GC Conditioner for 10 seconds, rinsed with distilled water, dried with oil-free compressed air, placement of the GIC and sheared 15 minutes post-curing. Group 4: same as group 3, but sheared 7 days post-curing. The GIC was mixed in a 1:1 powder-liquid ratio. The samples were stored in distilled water until sheared with an Instron. The results revealed that dentin surface treatment with the polyacrylic acid significantly increased the shear bond strength to dentin when tested at 7 days post-curing.

Acid Etching, Dental

Triclosan/copolymer/NAF dentifrice prophylaxis, reduced etching time and shear bond strength of a resin composite to enamel.

This study evaluated the effect of a prophylaxis with a triclosan/copolymer/NaF dentifrice (Colgate Gum Protection Formula) and a reduced etching time with 37% phosphoric acid gel on the shear bond strength of a resin composite to enamel. 60 human extracted permanent molars were used. A flat enamel surface was obtained with 600 grit SiC paper and cleaned with a rubber cup and a water slurry of fine flour of pumice. The teeth were randomly distributed into 4 groups of 15 teeth each: Group 1: Pumice prophylaxis with a rubber cup, etched for 30 seconds; Group 2: Pumice prophylaxis, etched for 60 seconds; Group 3: Triclosan/copolymer/NaF dentifrice prophylaxis, etched for 30 seconds; Group 4: Triclosan/copolymer/NaF dentifrice prophylaxis, etched for 60 seconds. After etching, rinsing and drying, an unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured resin composite (Occlusin). The teeth were thermocycled for 500 cycles and sheared with a knife-edged blade in an Instron running at a crosshead speed of 1 mm/min. The results in MPa were as follows: Group 1: 18.84 +/- 7.08; Group 2: 22.65 +/- 4.37; Group 3: 18.79 +/- 5.77; Group 4: 19.62 +/- 6.13. An ANOVA showed that there was no statistically significant difference among the groups. Enamel fracture occurred in 20% (3/15) in Group 1, 53% (8/15) in Group 2, 20% (3/15) in Group 3, and 47% (7/15) in Group 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Etching, Dental

Shear bond strength of two resin adhesives for acid-etched metal prostheses.

This study compared the shear bond strength of Panavia EX and Comspan Opaque adhesive resins with electrolytically etched or sandblasted Rexillium III or Litecast B metals bonded to extracted teeth. An analysis of variance revealed that there is no difference in bonding strength among etched or sandblasted Rexillium III metal with either Panavia EX or Comspan Opaque resins. With Litecast B metal, sandblasting produced a greater bond strength than etching with Panavia Ex resin (38.19 MPa sandblasted; 30.53 MPa etched). Conversely, Comspan Opaque resin had a value of 30.10 MPa etched and 15.40 MPa sandblasted. The etched Rexillium III and Panavia EX resins recorded a greater bond strength (38.38 MPa) than Comspan Opaque resin (27.83 MPa) or sandblasted Rexillium III metal (Rexillium III 34.74 MPa; Comspan Opaque 20.39 MPa) and Litecast B metal (Panavia EX 38.19 MPa; Comspan Opaque 15.40 MPa). Eighty percent of the failures occurred at the cement-metal interface with both cements.

Acid Etching, Dental

Effect of a fluoridated etching gel on enamel morphology and shear bond strength of orthodontic brackets.

The purpose of this study was to compare the enamel morphology and shear bond strengths of orthodontic brackets bonded to enamel etched with a fluoridated or a nonfluoridated phosphoric acid gel. Ten extracted third molars were used for the enamel morphology evaluation. The buccal surfaces were divided in two sections separated by an occlusogingival groove. One side was etched for 60 seconds with a 38% phosphoric acid gel, and the other side was etched with a 60% phosphoric acid gel containing 0.5% sodium fluoride. The specimens were then examined with a scanning electron microscope. For the shear bond strength tests, 30 extracted third molars were used. The buccal enamel surfaces of the mesial cusp were used, and the teeth were randomly divided into two groups of 15 teeth each--group 1, 38% phosphoric acid gel for 60 seconds; group 2, 60% phosphoric acid gel with 0.5% sodium fluoride for 60 seconds. Orthodontic lingual buttons were bonded to the etched surfaces with a composite resin. The results showed that the overall morphologic etching effect was similar in both groups. The mean shear bond strength for group 1 was 11.8 MPa +/- 4.2, and for group 2 it was 16.5 MPa +/- 5.1. This difference was statistically significant (p less than 0.01).

Acid Etching, Dental

Reviewing pulp treatment for primary teeth.

Deficiencies of pulpotomy and pulpectomy treatment of primary teeth have promoted considerable laboratory and clinical research. Some of these findings and their implications are reviewed.

Calcium Hydroxide

Long-term fluoride release from glass ionomer-lined amalgam restorations.

This in vitro study evaluated the amount of fluoride released from glass ionomer-lined amalgam restorations over a period of 1 year. Class V cavities (2 x 2 x 7 mm) were prepared on the facial and lingual surfaces of 50 extracted human molars randomly distributed into 5 groups: Group 1: No restorations; Group 2: Dispersalloy amalgam alone; Group 3: same as Group 2 except 1 mm of Ketac-Silver was placed on the axial wall before amalgam insertion; Group 4: GC Lining/amalgam; and Group 5: Miracle Mix/amalgam. After restoration, each tooth was thermocycled (100x) at 5 degrees C and 55 degrees C with a dwell time of 30 seconds for baseline fluoride release levels. The teeth were placed in a polyethylene vial containing 4 ml of deionized water. At weekly intervals, each tooth was transferred to a fresh vial. Fluoride release was measured with a fluoride ion specific electrode for 10 consecutive weeks and then again at the end of 1 year. Calibration curves for low level measurements were prepared so the readings could be expressed in micrograms/ml F. At 1 year, fluoride released in micrograms/ml was: Group 1: less than 0.08; Group 2: less than 0.08; Group 3: 0.28; Group 4: 0.68; Group 5: 1.12. An ANOVA was used to evaluate the statistical difference between the groups. At the end of 1 year, measurable amounts of fluoride were recorded for all glass ionomer-lined groups with Miracle Mix and GC Lining releasing significantly more fluoride than Ketac-Silver (P less than 0.002).

Analysis of Variance

Effect of dentin adhesives on sealant bond strength.

This study evaluated the effect of four dentin adhesives on sealant shear bond strength. Five groups of 15 human extracted teeth (75 in total) were prepared to receive the following treatments: group 1, sealant only; group 2, sealant plus gluma primer; group 3, sealant plus gluma primer and sealer, group 4, sealant plus C & B Metabond. Each tooth had a bonding site prepared for each material by grinding a flat plane on the enamel with 600 grit. The enamel site was etched for 30 seconds, washed for 20 seconds and dried. Each material was mixed according to the instructions of the manufacturer. The sealant (Concise) was placed in a nylon cylinder, light-cured, stored in distilled water for 24 hours, thermocycled (100 cycles at 5 to 55 degrees C) and shear bond strength determined with a knife-edge blade in an Instron running at a crosshead speed of 0.5 mm/min. The results in MPa were: group 1, 11.8 +/- 4.5; group 2, 12.3 +/- 5.0; group 3, 10.3 +/- 1.9; group 4, 12.5 +/- 8.6; and group 5, 15.8 +/- 5.2. Statistically (ANOVA one way) there was no significant difference in the groups.

Acrylic Resins

Effect of etching times and mechanical pretreatment on the enamel of primary teeth: an SEM study.

The purpose of this SEM study was to evaluate the micromorphology of the enamel of primary teeth etched for 15, 30, 60 or 120 seconds, with or without previous mechanical pretreatment. A total of 40 non-carious primary teeth were used. One half of the facial surface of each tooth was ground with a #169 diamond bur mounted in a high-speed handpiece. The other half was left intact. A 37% phosphoric acid gel was applied with a small brush to the facial enamel and left undisturbed for 15, 30, 60 or 120 seconds. Each group had 10 teeth. All teeth were examined under the SEM. The results revealed that etching time had no significant effect on the micromorphology of the enamel surface of primary teeth. Grinding the enamel with the diamond bur before etching produced a uniform distribution of prismatic structure regardless of the etching time. If the enamel surface was not ground, a "coral-like" porous retentive surface was apparent in most of the cases with no defined prismatic structure. The term "coral-like" enamel is a better descriptor of the etched "prismless" enamel surface while observed under the SEM.

Acid Etching, Dental

Effect of a triclosan/copolymer/fluoride dentifrice prophylaxis on the shear bond strength of a composite resin to enamel.

A new fluoride dentifrice formulation containing triclosan and a copolymer has been introduced. The purpose of this study was to evaluate the shear bond strength of a resin composite bonded to enamel previously cleaned with this new dentifrice formulation. A total of 45 human extracted permanent molars were used. A flat enamel surface was obtained with 600 grit SiC paper and the teeth randomly distributed into 3 groups of 15 teeth each: Group 1: Pumice prophylaxis with a rubber cup and slow-speed handpiece; Group 2: Prophylaxis with a conventional fluoridated dentifrice (Colgate); Group 3: Prophylaxis with a triclosan/copolymer/NaF dentifrice (Colgate). After prophylaxis, the teeth were acid-etched with a 37% phosphoric acid gel for 30 seconds, rinsed and dried. An unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured resin composite (Occlusin). The teeth were thermocycled for 100 cycles, mounted in plastic cups and plaster, and sheared with a knife-edged blade in an Instron running at a crosshead speed of 1 mm/min. The results in MPa were as follows: Group 1: 11.34 +/- 4.57; Group 2: 13.46 +/- 3.60; Group 3: 13.84 +/- 4.33. An ANOVA showed that there was no statistically significant difference among the groups. Fracture within the enamel occurred in 27% in Group 1, 47% in Group 2, and 67% in Group 3. The results support the use of the fluoride dentifrices tested in this study for prophylaxis prior to bonding procedures.

Analysis of Variance

Traumatic dental injuries in 3- to 13-year-old boys in Monterrey, Mexico.

The purpose of this retrospective study was to analyze, by age, the prevalence of traumatic injuries to primary and permanent incisors, and their distribution according to type in a group of boys from private schools in Monterrey, Mexico. The sample consisted of 1010 boys aged 3-13 years enrolled in 4 private schools in the city. Garcia-Godoy's classification for traumatic injuries was used. The prevalence of injuries was 28.4%; 72.2% of the 4-year-olds examined presented signs of traumatic dental injuries. Thirty-seven percent of the 11-year-olds examined had evidence of traumatic dental injuries. The most common type of injury in the primary and permanent dentitions was enamel fracture (58.5% and 69.6%, respectively).

Adolescent

Effect of a copal varnish, ZOE or glass ionomer cement bases on microleakage of amalgam restorations.

The purpose of this study was to evaluate the sealing ability of four cavity preparation treatment modalities under amalgam restorations. Class V cavity preparations were placed in 20 extracted teeth and randomly divided into four groups of five teeth each (10 restorations for each group): 1) no liner; 2) two applications of Copalite; 3) a base of IRM; and 4) a base of Chelon-Silver. After assigned cavity preparation treatment was accomplished, the teeth were restored with amalgam. The restored teeth were subjected to thermocycling and subsequently stained with basic fuchsin. The teeth were longitudinally sectioned and dye penetration recorded. Amalgam restorations with a Copalite or Chelon-Silver base exhibited significantly less microleakage than those amalgam restorations with an IRM base or no cavity preparation treatment. With the Copalite varnish, microleakage extended beyond the axial wall (toward the pulp chamber through the dentinal tubules) while with the Chelon-Silver base, microleakage was limited to the restoration-tooth interface.

Dental Amalgam

Artificial recurrent caries in glass ionomer-lined amalgam restorations.

The purpose of this study was to examine artificial recurrent caries when a conventional glass ionomer liner was placed under amalgam restorations. An additional aim was to evaluate the effect of using an unfilled resin with or without etching on the margins of the amalgam restoration. Class V preparations in extracted third molars were used with gingival margins on root surfaces. Ten restorations were used for each of the following groups: 1) Amalgam alone; 2) Two layers of copal varnish and amalgam; 3) Glass ionomer, amalgam; 4) Glass ionomer, amalgam, unfilled resin; 5) Glass ionomer, amalgam, acid-etching, unfilled resin. The teeth were thermocycled and artificial caries were created using a liquid system acidified to pH 4.10 and saturated with HAP but without fluoride. The teeth were sectioned, polished and photographed using polarized light. Areas of recurrent caries were measured using a sonic digitizing pad. The data were analyzed using ANOVA and Duncan's Multiple Range Test. Areas for enamel lesions for the different groups were: 1) 1.29 +/- 0.41; 2) 1.61 +/- 0.49; 3) 0.92 +/- 0.26; 4) 0.87 +/- 0.31; 5) 0.99 +/- 0.39. Root lesions areas were: 1) 2.17 +/- 0.35; 2) 1.90 +/- 0.40; 3) 1.40 +/- 0.27; 4) 0.82 +/- 0.25; 5) 1.34 +/- 0.31. Duncan's groups for root lesions were A = B/ C = D/ and E separately. This study indicates that artificial recurrent caries under amalgam can be reduced with a conventional glass ionomer. An additional benefit was observed when unfilled resin was placed on the cavosurface margins but not when it was acid-etched first.

Dental Amalgam

Fluoride release from amalgam restorations lined with a silver-reinforced glass ionomer.

This study evaluated the amount of fluoride released from amalgam restorations lined with a silver-reinforced glass ionomer. Thirty human extracted molars were divided into three groups of 10 teeth each. Group 1: Class V cavities were made on the facial surfaces and restored with Dispersalloy amalgam. Group 2: Same as Group 1 except 1 mm of GC Lining glass ionomer cement (GIC) was placed on the axial wall before amalgam insertion. Group 3: Same as Group 2 except 1 mm of Miracle Mix silver-reinforced glass ionomer cement (GIC) was placed on the axial wall before amalgam insertion. Before any treatment, all samples were placed in polyethylene vials with 4 ml of deionized water and thermocycled (100x) for baseline fluoride release levels. After restoration, each tooth was replaced in a vial with 4 ml of deionized water. At weekly intervals, each tooth was removed from its aqueous medium and transferred to another vial containing 4 ml of deionized water. Fluoride release was measured four times at weekly intervals with an Orion #9609 fluoride-ion electrode. At 1 and 4 weeks, Miracle Mix released significantly more fluoride than GC Lining (P less than 0.0001).

Dental Amalgam

Effect of a triclosan/copolymer/fluoride dentifrice on plaque formation and gingivitis: a 7-month clinical study.

A total of 108 adult male and female subjects completed a 7-month, double-blind clinical study designed to compare the effect of a dentifrice containing 0.3% triclosan and 2% of a copolymer of methoxyethylene and maleic acid on plaque formation and gingivitis, as compared to a placebo dentifrice. The subjects were stratified into two balanced groups according to baseline plaque and baseline gingivitis scores. They then received an oral prophylaxis and were assigned to the use of either a placebo dentifrice or the triclosan/copolymer dentifrice for the next 7 months. After this time, the dentifrice containing triclosan/copolymer provided a 58.96% statistically significant (99% level of confidence) reduction in plaque [corrected], as compared to the placebo dentifrice. Further, after 7-months' use, the dentifrice containing triclosan/copolymer also provided a 30.17% statistically significant (99% level of confidence) reduction in gingivitis as compared to the placebo dentifrice. The results after 7 months also indicated that the dentifrice containing triclosan/copolymer provided a 97.74% statistically significant (99% level of confidence) reduction in the supragingival plaque deposits on those tooth surfaces with the greatest amount of plaque formation, when compared to the placebo dentifrice. The dentifrice containing triclosan/copolymer also provided 87.56% less sites with the most severe amount of gingival disease, as compared to the placebo dentifrice. This decrease in diseased gingival sites was statistically significant at the 99% level of confidence. It was concluded that the twice daily use of a dentifrice containing 0.3% triclosan and 2% of a copolymer reduces supragingival plaque deposit formation and gingivitis to a highly significant degree, without any extrinsic stains observed.

Adult