Biomedical subjects

Marcelo Giannini

Publications and source records attributed to Marcelo Giannini.

At least 19 recordsLinked to original sources

PubMed2006

Long-term TEM analysis of the nanoleakage patterns in resin-dentin interfaces produced by different bonding strategies.

OBJECTIVES: The aim of this study was to evaluate the ability of etch-and-rinse and self-etching adhesive systems to prevent time- and water-induced nanoleakage in resin-dentin interfaces over a 6-month storage period. METHODS: Five commercial adhesives were tested, which comprise three different strategies of bonding resins to tooth hard tissues: one single-step self-etching adhesive (One-up Bond F (OB), Tokuyama); two two-step self-etching primers (Clearfil SE Bond (SE) and an antibacterial fluoride-containing system, Clearfil Protect Bond (CP), Kuraray Inc.); two two-step etch-and-rinse adhesives (Single Bond (SB), 3M ESPE and Prime&Bond NT (PB), Dentsply). Restored teeth were sectioned into 0.9 mm thick slabs and stored in water or mineral oil for 24 h, 3 or 6 months. A silver tracer solution was used to reveal nanometer-sized water-filled spaces and changes that occurred over time within resin-dentin interfaces. Characterization of interfaces was performed with the TEM. RESULTS: The two two-step self-etching primers showed little silver uptake during the 6-month experiment. Etch-and-rinse adhesives exhibited silver deposits predominantly within the hybrid layer (HL), which significantly increased for SB after water-storage. The one-step self-etching adhesive OB presented massive silver accumulation within the HL and water-trees protruding into the adhesive layer, which increased in size and quantity after water-storage. After storage in oil, reduced silver deposition was observed at the interfaces for all groups. SIGNIFICANCE: Different levels of water-induced nanoleakage were observed for the different bonding strategies. The two-step self-etching primers, especially the antibacterial fluoride-containing system CP, showed the least nanoleakage after 6 months of storage in water.

Acid Etching, Dental↗

PubMed2006

Effect of dentinal surface preparation on bond strength of self-etching adhesive systems.

The aim of this study was to evaluate the effects of dentin surface treatments on the tensile bond strength (TBS) of the self-etching primer Clearfil SE Bond (CSE) and the one-step self-etching One-Up Bond F (OUB). The exposed flat dentin surfaces of twenty-four sound third molars were prepared with diamond bur at high-speed, carbide bur at low-speed or wet ground with #600 grit SiC paper. The adhesive systems were applied to the dentin surfaces and light-cured according to the manufacturers' instructions. A 6-mm high composite crown was incrementally built-up and each increment was light-cured for 40 seconds. After being stored in water (37 degrees C/24 h), the samples were serially sectioned parallel to the long axis, forming beams (n = 20) with a cross-sectional area of approximately 0.8 mm(2). The specimens were tested in a Universal Testing Machine at 0.5 mm/min. The cross-sectional area was measured and the results (MPa) were analyzed by two-way ANOVA and Tukey Test (p < 0.05). Overall, the groups treated with CSE exhibited the highest TBS for all surface treatments. Dentin surfaces prepared with carbide bur at low speed reduced TBS in the CSE group; however, OUB was not affected by surface treatments. The effect of surface abrasive methods on TBS was material-dependent.

Acid Etching, Dental↗

PubMed2006

Provisional anterior tooth replacement using nonimpregnated fiber and fiber-reinforced composite resin materials: a clinical report.

The loss of anterior teeth is often a serious esthetic concern. While conventional fixed partial dentures and implant-supported restorations may be the treatments of choice, nonimpregnated fibers (NFs) and fiber-reinforced composite (FRC) resins offer a conservative alternative for improving esthetics. This article describes 2 clinical situations in which NF glass ribbon and FRC were successfully used to provisionally restore anterior edentulous areas in an esthetic, functional, and timely manner.

Acrylic Resins↗

PubMed2006

Influence of light-activated and auto- and dual-polymerizing adhesive systems on bond strength of indirect composite resin to dentin.

STATEMENT OF PROBLEM: Clinicians must be aware of the bonding effectiveness of auto- and dual- polymerizing adhesive systems before choosing the material and technique of cementing inlay/onlays to dentin. An inadequate choice may compromise the success of indirect restorations. PURPOSE: This study compared the microtensile bond strength (MTBS) of indirect composite resin bonded to dentin by light-activated, autopolymerizing, and dual-polymerizing adhesive systems. MATERIAL AND METHODS: Occlusal dentin surfaces of 36 human third molars were exposed and flattened. Teeth were assigned to 1 of the following 6 groups (n=6) of adhesive luting systems: 2 dual-polymerizing systems (Scotchbond Multipurpose Plus/Rely X [SBMP] and Prime & Bond NT Dual Cure/Enforce [PBDC]); 1 autopolymerizing system (ED Primer/Panavia F [EDP]); and 3 light-activated systems (control groups) (Adper Single Bond/Rely X [SB], Prime & Bond NT/Enforce [PB], and Clearfil SE Bond/Panavia F [CF]). The restorative materials were applied according to manufacturer's directions. A 2-mm-thick prepolymerized composite resin (Clearfil APX) disc was cemented with the resin cements on the bonded dentin. Teeth were stored in water at 37 degrees C for 24 hours. Afterwards, teeth were sectioned both mesial-distally and buccal-lingually to obtain multiple bonded beam specimens with 0.8 mm(2) of cross-sectional area. Each specimen was tested in tension at a crosshead speed of 0.5 mm/min until failure. Data (MPa) were analyzed by 1-way analysis of variance and the Tukey post hoc test (alpha=.05). Failure patterns of tested specimens were analyzed using scanning electron microscopy. RESULTS: Mean MTBS values (MPa) for experimental groups were as follows: SBMP, 32.89 +/- 3.26(a); SB, 26.74 +/- 7.45(ab); PB, 26.11 +/- 4.48(ab); CF, 25.30 +/- 6.42(ab); EDP, 16.82 +/- 5.53(bc); PBDC, 11.20 +/- 5.89(c) (P<.001). Groups with similar lowercase letters were not significantly different. Failure pattern of fractured specimens varied according to the polymerization mode. CONCLUSION: The autopolymerizing system and one of the dual-polymerizing systems were as effective as the light-activated systems in bonding indirect composite restorations to dentin.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2006

Evaluation of antibacterial and fluoride-releasing adhesive system on dentin--microtensile bond strength and acid-base challenge.

This study evaluated the influence of a fluoride-containing adhesive on microtensile bond strength (microTBS) to dentin, as well as analyzed the dentin-adhesive interface after acid-base challenge. Experimental groups were: G1--Clearfil SE Bond control (SE); G2--Clearfil Protect Bond control (PB); G3--Primer[SE]/Adhesive[PB]; G4--Primer[PB]/Adhesive[SE]. For microTBS evaluation, dentin surfaces were ground, bonded, and composite resin crowns were built up to obtain beams to be tested. For interfacial analysis, adhesive system was applied on dentin surface and a low-viscosity resin was placed between two dentin disks. Then, the specimens were subjected to acid-base challenge, sectioned, and polished to be observed by SEM. microTBS data showed no statistical differences among the groups (GI: 51.3, G2: 47.6, G3: 55.0, G4: 53.9; mean in MPa). Through SEM, it was observed that a thick acid-base resistant zone adjacent to the hybrid layer was created only when the fluoride-releasing adhesive was used. In conclusion, the presence of fluoride in an adhesive contributed significantly to preventing secondary caries, and did not interfere with dentin-adhesive bond strength.

Adhesives↗

PubMed2005

Influence of composite restorative materials and light-curing units on diametrical tensile strength.

The aim of this study was to evaluate the diametrical tensile strength (DTS) of three light-curing photo-activated composites with two different light curing units (LCU). Three types of dental restorative composites were used in this study: micro filled A110 (3M Espe); P60 (3M Espe) for posterior restorations, and micro-hybrid Charisma (Heraeus-Kulzer). The two LCUs were: halogen light (HAL) (Degulux, Degussa) and blue light emitting diode (LED) (Ultrablue, DMC). Resin composite specimens were inserted incrementally into a Teflon split mold measuring 3 mm in depth and 6 mm in internal diameter, and cured using either LCU (n = 10). Specimens were placed into a dark bottle containing distilled water at 37 degrees C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). Data were submitted to two-way ANOVA and Tukey's test. Results were (MPa): A110/HAL: 276.50 +/- 62.94a; A110/LED: 306.01 +/- 65.16a; P60/HAL: 568.29 +/- 60.77b and P60/LED: 543.01 +/- 83.65b; Charisma/HAL: 430.94 +/- 67.28c; Charisma/LED: 435.52 +/- 105.12c. Results suggested that no significant difference in DTS was obtained with LCUs for the same composite. However, resin composite restorative materials presented different DTS.

Analysis of Variance↗

PubMed2005

Use of statistical procedures in Brazilian and international dental journals.

A descriptive survey was performed in order to assess the statistical content and quality of Brazilian and international dental journals, and compare their evolution throughout the last decades. The authors identified the reporting and accuracy of statistical techniques in 1000 papers published from 1970 to 2000 in seven dental journals: three Brazilian (Brazilian Dental Journal, Revista de Odontologia da Universidade de Sao Paulo and Revista de Odontologia da UNESP) and four international journals (Journal of the American Dental Association, Journal of Dental Research, Caries Research and Journal of Periodontology). Papers were divided into two time periods: from 1970 to 1989, and from 1990 to 2000. A slight increase in the number of articles that presented some form of statistical technique was noticed for Brazilian journals (from 61.0 to 66.7%), whereas for international journals, a significant increase was observed (65.8 to 92.6%). In addition, a decrease in the number of statistical errors was verified. The most commonly used statistical tests as well as the most frequent errors found in dental journals were assessed. Hopefully, this investigation will encourage dental educators to better plan the teaching of biostatistics, and to improve the statistical quality of submitted manuscripts.

Bibliometrics↗

PubMed2005

Fluoride release and secondary caries inhibition by adhesive systems on root dentine.

This study tested the fluoride-release rate and the root caries inhibitory effect of dental adhesives. In phase 1, the fluoride released from samples (n = 5) of the adhesives A (Optibond Solo), B (One-up Bond F), C (Prime & Bond NT), D (Tenure Quick), and also of the controls [+] (glass-ionomer cement) and [-] (non-fluoride releasing adhesive), was quantified on a daily basis during a pH-cycling, caries-simulating phenomenon. In phase 2, restorations were made in bovine root dentine slabs (n = 16) with the same adhesives associated with a non-fluoridated composite. Control [+] restorations were made entirely with glass-ionomer cement. Specimens were thermocycled and submitted to the pH-cycling regimen. Demineralization areas and the presence of the wall lesion (WL) and the inhibition zone (IZ) were determined by polarizing light microscopy in dentine adjacent to the restoration. The highest concentration of fluoride was released by the control [+]; adhesives A, B and C, also released fluoride. No detectable amount of fluoride was released by D or [-]. Smaller areas of demineralization were found with control [+], whereas the demineralization areas of adhesives A-D and [-] did not differ from each other. No WL was detected, and higher percentages of IZ were recorded to [+] and to adhesive A. Although some dental adhesives were able to release fluoride, they could not inhibit secondary caries development as well as the glass-ionomer cement.

Animals↗

PubMed2005

Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness.

This in vitro study evaluated the surface microhardness of human enamel submitted to bleaching with 10% carbamide peroxide (CP) containing calcium or fluoride. Ninety-eight dental blocks (5 x 5 mm2) with polished enamel surfaces were randomly assigned to 7 treatment groups (n=14), as follows: without bleaching and storage in artificial saliva (control); 10% CP; 10% CP + 0.05% calcium; 10% CP + 0.1% calcium; 10% CP + 0.2% calcium; 10% CP + 0.2% fluoride; and 10% CP + 0.5% fluoride. During 14 days, enamel surfaces were daily exposed to a 6-h bleaching regimen followed by storage in artificial saliva. Surface microhardness was measured before (baseline), during (7th day), immediately after bleaching (14th day) and 1 week post bleaching. Data were analyzed by two-way ANOVA and Tukey's test (p<0.05). All treatments reduced SM significantly during the bleaching cycle (7th day), immediately after bleaching (14th day) and 1 week post bleaching, compared to baseline and to the unbleached control group. In conclusion, in spite of the addition of calcium and fluoride, all bleaching treatments affected the enamel surface microhardness.

Calcium↗

PubMed2004

Ultramorphological analysis of resin-dentin interfaces produced with water-based single-step and two-step adhesives: nanoleakage expression.

This study evaluated the nanoleakage patterns in bonded interfaces using two single-step, self-etching adhesives (Adper Prompt-AD, and One-up Bond F-OB), two two-step, self-etching primers (Clearfil SE Bond-CF, and Unifil Bond-UB), and one two-step, total-etch adhesive (Single Bond-SB). Dentin surfaces were bonded with the adhesive systems and stored in water at 37 degrees C for 1 week and 6 months. After storage periods, teeth were sectioned into 0.8 mm-thick slabs, coated with nail varnish except for the bonded interfaces, and immersed in ammoniacal AgNO(3) for 24 h. After immersion in photodeveloping solution, bonded sections were prepared and observed under a SEM using the backscattered electron mode. Undemineralized, unstained, epoxy resin-embedded sections were prepared for TEM. Nanoleakage patterns were qualitatively compared between periods. Nanoleakage was observed in all bonded specimens at both periods. CF and UB presented silver deposits predominantly restricted to the thin (0.5 microm) hybrid layer (HL) at both periods. Although no evident differences were observed in the nanoleakage pattern of UB at 7 days and 6 months, CF presented enlarged areas of silver impregnation after 6 months. SB presented accumulation of silver particles mostly within the HL at 7 days, which was intensified after 6 months. AD and OB presented massive silver accumulation within the HL and the overlying adhesive layer. No evident differences were noticed between storage periods. Silver impregnation increased for all adhesive systems from 7 days to 6 months, except for UB.

Adhesives↗

PubMed2004

Effect of carbamide peroxide bleaching agents on tensile strength of human enamel.

OBJECTIVES: The aim of this study was to evaluate the effects of low concentrations of carbamide peroxide bleaching agents (CP) on the ultimate tensile strength of enamel (UTS). METHODS: Resin composite structure was built-up on the bonded occlusal surface of 12 sound third molars to facilitate specimen preparation for microtensile testing. The bonded teeth were sectioned in a bucco-lingual direction in slices approximately 0.7 mm thick. Each slice was trimmed with a fine diamond bur to reduce the buccal, internal slope enamel of the cusps to a dumb-bell shape with a cross-sectional area at the 'neck' of less than 1 mm2. The sample was randomly divided into six groups of 10 specimens each: Control (C-untreated); Opalescence 10% (O10), Opalescence 15% (O15), Opalescence 20% (O20), Whiteness 10% (W10) and Whiteness 16% (W16). Specimens in each group received the application of the CP for 6 h/day, at 37 degrees C, during 14 days and were stored in artificial saliva in between each application. After the bleaching regimen, specimens were tested with the microtensile method at 0.5 mm/min. Data were analyzed by ANOVA and Tukey test (5%). RESULTS: Mean tensile strengths were (MPa): C = 47.5 +/- 6.2a; O10 = 37.6 +/- 5.8b; O15 = 33.2 +/- 6.0b; O20 = 31.2 +/- 3.5b; W10 = 32.5 +/- 6.1b; W16 = 30.6 +/- 7.7b. Specimens subjected to the bleaching regimen presented significantly lower UTS than the control group. No differences were found among the type and concentration of the bleaching agents. SIGNIFICANCE: Results suggested that bleaching enamel with CP could significantly reduce its UTS within a 14 days treatment.

Analysis of Variance↗

PubMed2004

Ultimate tensile strength of tooth structures.

OBJECTIVE: This study determined the ultimate tensile strength (UTS) of enamel (E), dentin (D) and dentin-enamel junction (DEJ) using the microtensile technique. It was hypothesized that the UTS of dental structures varies according to location and nature. METHODS: Intact occlusal enamel surfaces from extracted human third molars were etched with 37% phosphoric acid and bonded with a one-bottle adhesive system. The bonded occlusal surfaces received a resin composite build-up and teeth were serially, vertically sectioned into several 0.7 mm thick slabs. Each slab was then trimmed to a dumbbell-shaped specimen with irrigated diamond burs to reduce the cross-sectional area to approximately 0.5 mm2 at E, D or DEJ. E was tested according to its prismatic orientation (parallel, EP; and transversally, ET) and D as function of depth (superficial, DS; middle, DM and deep, DD). Specimens were tested in tension in an Instron testing machine at 0.5 mm/min. Results were analyzed by one-way ANOVA and Duncan's Multiple Range test. RESULTS: UTS mean values (N = 20) were, MPa (SD): DEJ, 46.9 (13.7)b; EP, 42.1 (11.9)b; ET, 11.5 (4.7)d; DS, 61.6 (16.2)a; DM, 48.7 (16.6)b and DD, 33.9 (7.9)c. Enamel stressed transversally to its prismatic orientation was significantly weaker (p < 0.05) Dentin depth significantly affected its UTS (p < 0.05) DEJ presented UTS that was similar to EP and DM (p > 0.05) SIGNIFICANCE: The UTS of dental structures varies according to its nature and location.

Analysis of Variance↗

PubMed2004

Influence of the mineral content and morphological pattern of artificial root caries lesion on composite resin bond strength.

Dentine substrates with different mineral contents and morphological patterns were created by submitting root slabs to the following treatments: (A) immersion in artificial saliva during the experimental period (control), (B) demineralization for 32 h to induce caries lesion (demineralized group), and (C) demineralization for 32 h followed by remineralization for 8 d (remineralized group). The slabs were longitudinally sectioned, the mineral content was determined by cross-sectional microhardness, and the bond strength of an adhesive system/composite resin was assessed using a microtensile bond strength test. The dentine morphology after the treatments as well as the failure pattern of the debonded specimens was examined by scanning electron microscopy. Statistically significant differences were found in mineral content. Morphological analysis showed marked differences between the patterns of demineralized and remineralized substrates. The bond strength mean value of the control A did not differ from the group B, but was statistically higher than the group C. Since no linear relationship was found between dentine mineral content and bond strength values, it could be suggested that the morphological pattern may be more relevant than the mineral content to explain the bond strength of composite resin to dentine.

Analysis of Variance↗

PubMed2004

Effects of additional and extended acid etching on bonding to caries-affected dentine.

This study evaluated the effects of additional and extended acid etching on microtensile bond strength ( micro TBS) of two adhesive systems to sound (SD) and caries-affected dentine (CAD). Flat surfaces of CAD surrounded by SD of 36 extracted carious third molars were assigned to four treatments (i): self-etching adhesive system (Clearfil SE Bond) applied to dentine surfaces following manufacturer's instructions (MI); (ii) after additional etching for 15 s (35% phosphoric acid, PA); (iii) total-etch one-bottle adhesive (Single Bond) applied to dentine surfaces following MI; or (iv), after etching for 45 s with PA. Composite 'blocks' were built on bonded surfaces and restored teeth were vertically sectioned to obtain bonded slices of 0.7 mm thick. Slices were trimmed to create hourglass-shaped specimens (cross-sectional area of 1 mm(2)), which were tested under tension in a universal testing machine. Additional CAD and SD samples were prepared for scanning electron microscopy observations. Additional and extended etching significantly increased micro TBS to CAD; however, micro TBS of both adhesives to CAD were significantly lower than to SD. Additional and extended etching can improve bonding to CAD; however, adhesives applied on SD showed the best results for bonding.

Acid Etching, Dental↗

PubMed2004

Effects of pre- and post-bonding hydration on bond strength to dentin.

PURPOSE: This study tested the hypothesis that the hydration condition of the tooth during bonding or storage may affect the bond strength of a single-step, self-etching adhesive to dentin. MATERIALS AND METHODS: Twelve extracted human third molars were transversally sectioned to expose flat, mid-dentin surfaces. Six teeth were dehydrated in ascending ethanol concentrations for several days while 6 teeth were kept hydrated in distilled water. The teeth were bonded with the single-step, self-etching adhesive One-Up Bond F (Tokuyama, Japan) according to directions. Resin composite buildups were constructed incrementally with Z 250 (3M ESPE). The bonded hydrated and dehydrated teeth were then divided into 2 subgroups and stored either in distilled water or in a dry condition for 24 h before being prepared for the microtensile bond strength test. Bonded beams of approximately 0.8 mm2 were tested in tension at 0.5 mm/min in a testing machine. Separate dentin disks were bonded with the adhesive and prepared for transmission electron microscopy (TEM). RESULTS: Bond strengths of specimens stored in water were: 25.0 +/- 10.6 and 18.9 +/- 9.1 MPa for hydrated and dehydrated teeth, respectively. Bond strengths of specimens stored dry were significantly higher (p < 0.001): 46.1 +/- 21.4 and 40.9 +/- 19.1, for hydrated and dehydrated teeth, respectively. Two-way ANOVA showed that previous hydration condition of the teeth had no effect on the bond strength, regardless of the storage condition (p > 0.05). However, storage of the bonded teeth in water caused significant reductions in the bond strength, regardless of the previous hydration condition of the teeth. TEM showed massive silver nitrate impregnation in the adhesive layer of water-stored specimens. CONCLUSIONS: Postbonding water exposure had a highlysignificant effect on bond strength of the single-step, self-etching adhesive.

Analysis of Variance↗

PubMed2004

Fracture resistance of teeth restored with indirect-composite and ceramic inlay systems.

Fracture resistance of dentin-bonded inlays may be influenced by the restorative material used. The purpose of this study was to evaluate, in vitro, the fracture resistance of teeth restored with four tooth-colored materials: feldspathic ceramic, Duceram LFC, and three laboratory resins, Solidex, Artglass, and Targis. Sixty mandibular molar teeth were placed in resin cylinders, reproducing the periodontal ligaments. Mesial-occlusal-distal (MOD) inlay preparations were made in a standard cavity preparation appliance. Subsequently, the teeth were molded, and the restorations were prepared following the manufacturer's instructions. The inlays were cemented with resin composite cement, Rely X, and stored at 37 degrees C and 100% humidity for 24 hours. The samples were then submitted to an axial compression load at a speed of 0.5 mm/minute. Statistical analysis by one-way ANOVA and Tukey's multiple comparison test revealed that the teeth restored with Duceram LFC (205.44 +/- 39.51 kgf) showed statistically inferior fracture resistance than the three other groups restored with indirect resin composites (Solidex [293.16 +/- 45.86 kgf], Artglass [299.87 +/- 41.08 kgf], and Targis [304.23 +/- 52.52 kgf]).

Aluminum Silicates↗

PubMed2004

Comparison of microtensile bond strength to enamel and dentin of human, bovine, and porcine teeth.

PURPOSE: To determine the bond strengths promoted by an adhesive system to human, bovine, and porcine enamel and dentin, and compare their etched micromorphology by scanning electron microscopy. MATERIALS AND METHODS: Thirty sound freshly extracted teeth were used in this study: ten human third molars, ten bovine incisors, and ten porcine molars. The crowns of human (H), bovine (B), and porcine (P) teeth were ground with 600-grit SiC paper to expose either enamel (E) or mid-depth dentin (D) surfaces. After application of the adhesive resin, composite crowns approximately 8 mm high were built up with TPH Spectrum composite. After 24 h of water storage, specimens were serially sectioned in the buccal-lingual direction to obtain 0.8 mm slabs, which were trimmed to an hourglass shape of approximately 0.8 mm2 at the bonded interface. Specimens were tested in tension in a universal testing machine (0.5 mm/min). Results were statistically analyzed with ANOVA and Tukey's test at the 95% confidence level. RESULTS: Tukey's test showed significant differences between bond strengths obtained on enamel and dentin (p < 0.05). However, there were no statistically significant differences in microTBS between human, bovine, and porcine teeth. SEM observations revealed a similar dentinal morphology for the three species. However, porcine enamel specimens presented a very different distribution of enamel prisms. CONCLUSION: Bovine teeth proved to be possible substitutes for human teeth in either dentin or enamel bond testing. However, even though porcine teeth provided enamel and dentin bond strengths similar to human and bovine teeth, enamel morphology presented a very different configuration.

Acid Etching, Dental↗

PubMed2004

Occlusion of dentin tubules by desensitizing agents.

PURPOSE: To evaluate the occluding effect of five desensitizing agents on human dentin tubules. METHODS: 30 buccal and lingual surfaces were prepared from 15 extracted intact third molars. Each surface was polished with aluminum oxide abrasive papers to remove enamel and to expose the underlying dentin in cervical area. The flat dentin surfaces were treated with 0.5 M EDTA for 2 minutes to expose dentin tubule orifices. The samples were randomly divided into six groups: AS - immersed in artificial saliva at 37 degrees C for 2 weeks (control); OX - Oxagel (monopotassium oxalate), DU - Duraphat (sodium fluoride), DE - Desensibilize (strontium chloride), OD - Odahcam (acidulated phosphate fluoride) and SE - Sensodyne (strontium chloride + calcium carbonate abrasive). Dentin desensitizers were applied during 2 weeks and after each application the samples were kept in artificial saliva at 37 degrees C. The samples were prepared according to the scanning electron microscope procedures and were examined at x2000 magnification. RESULTS: The results were expressed in percent (%) of tubule occlusion and analyzed by ANOVA and Duncan's multiple range test (P < 0.05): AS- 45.41 +/- 11.65a; OX- 42.65 +/- 11.79a; DU- 47.25 +/- 8.59ab; DE- 49.36 +/- 18.27ab; OD- 64.43 +/- 15.55b and SE- 65.44 +/- 10.93b. Results suggest that the dentin surfaces treated with OD and SE showed higher tubule occlusion when compared to AS and OX, but were not different compared to DU and DE treatments.

Acidulated Phosphate Fluoride↗