Effect of hydrofluoric acid concentration and etching time on bond strength to lithium disilicate glass ceramic

The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (μSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickness, were randomly distributed into five groups according to the HF concentrations (n=50): 1%, 2.5%, 5%, 7.5%, and 10%. Further random distribution into subgroups was performed according to the following etching times (n=10): 20, 40, 60, 120, and 20 + 20 seconds. After etching, all blocks were treated with a silane coupling agent followed by a thin layer of an unfilled resin. Three resin cement cylinders (∅︀=1 mm) were made on each EMX surface, which was then stored in deionized water at 37°C for 24 hours before testing. The μSBS was in a universal testing machine at a crosshead speed of 1 mm/min until failure. Data were submitted to two-way analysis of variance, and multiple comparisons were performed using the Tukey post hoc test (α=0.05). One representative EMX sample was etched according to the description of each subgroup and evaluated using scanning electron microscopy for surface characterization. The HF concentrations of 5%, 7.5%, and 10% provided significantly higher μSBS values than 1% and 2.5% (p0.05). The effect of re-etching was more evident for 1% and 2.5% HF (p<0.05). Different HF concentrations/etching times directly influenced the bond strength and surface morphology of EMX426606615CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES304493/2014-7Sem informaçã

Inhibitory Effects Of A Cured Antibacterial Bonding System On Viability And Metabolic Activity Of Oral Bacteria

Objectives To evaluate the antimicrobial efficacy of Clearfil SE Protect (CP) and Clearfil SE Bond (CB) after curing and rinsed against five individual oral microorganisms as well as a mixture of bacterial culture prepared from the selected test organisms. Methods Bacterial suspensions were prepared from single species of Streptococcus mutans, Streptococcus sobrinus, Streptococcus gordonii, Actinomyces viscosus and Lactobacillus lactis, as well as mixed bacterial suspensions from these organisms. Dentin bonding system discs (6 mm × 2 mm) were prepared, cured, washed and placed on the bacterial suspension of single species or multispecies bacteria for 15, 30 and 60 min. MTT, Live/Dead bacterial viability (antibacterial effect), and XTT (metabolic activity) assays were used to test the two dentin system's antibacterial effect. All assays were done in triplicates and each experiment repeated at least three times. Data were submitted to ANOVA and Scheffe's f-test (5%). Results Greater than 40% bacteria killing was seen within 15 min, and the killing progressed with increasing time of incubation with CP discs. However, a longer (60 min) period of incubation was required by CP to achieve similar antimicrobial effect against mixed bacterial suspension. CB had no significant effect on the viability or metabolic activity of the test microorganisms when compared to the control bacterial culture. CP was significantly effective in reducing the viability and metabolic activity of the test organisms. Significance The results demonstrated the antimicrobial efficacy of CP both on single and multispecies bacterial culture. CP may be beneficial in reducing bacterial infections in cavity preparations in clinical dentistry. © 2014 Academy of Dental Materials.309e238e244Ricketts, D., Kidd, E., Innes, N.P.T., Clarkson, J.E., Complete or ultraconservative removal of decayed tissue in unfilled teeth (2006) Cochrane Database Syst Rev, 19, p. 003808Wicht, M.J., Haak, R., Schütt-Gerwitt, H., Kneist, S., Noack, Mj., Suppression of caries-related microorganisms in dentine lesions after short-term chlorhexidine or antibiotic treatment (2004) Caries Res, 38, pp. 436-441Imazato, S., Kuramoto, A., Kaneko, T., Ebisu, S., Russell, R.R.B., Comparison of antibacterial activity of simplified adhesive systems (2002) Am J Dent, 15, pp. 356-360Imazato, S., Ohmori, K., Russell, R.R.B., McCabe, J.F., Momoi, Y., Maeda, N., Determination of bactericidal activity of antibacterial monomer MDPB by a viability staining method (2008) Dent Mater J, 7, pp. 145-148Imazato, S., Ehara, A., Torii, M., Ebisu, S., Antibacterial activity of dentin primer containing MDPB after curing (1998) J Dent, 26, pp. 267-271Imazato, S., Tay, F.R., Kaneshiro, A.V., Takahashi, Y., Ebisua, S., An in vivo evaluation of bonding ability of comprehensive antibacterial adhesive system incorporating MDPB (2007) Dent Mater, 23, pp. 170-176Izutani, N., Imazato, S., Nakajo, K., Takahashi, N., Takahashi, Y., Ebisu, S., Effects of the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on bacterial viability and metabolism (2011) Eur J Oral Sci, 119, pp. 175-181Imazato, S., Torii, M., Tsuchitani, Y., McCabe, J.F., Russell, R.R.B., Incorporation of bacterial inhibitor into resin composite (1994) J Dent Res, 3, pp. 1437-1443Gondin, J.O., Duque, C., Hebling, J., Giro, E.M.A., Influence of human dentin on the antibacterial activity of self-etching adhesive systems against cariogenic bacteria (2008) J Dent, 36, pp. 241-248Feuerstein, O., Matalon, S., Slutzky, H., Weiss, E.I., Antibacterial properties of self-etching dental adhesive systems (2007) J Am Dent Assoc, 138, pp. 96-98Lobo, M.M., Goncalves, R.B., Pimenta, L.A., Bedran-Russo, A.K., Pereira, P.N., In vitro evaluation of caries inhibition promoted by self-etching adhesive systems containing antibacterial agents (2005) J Biomed Mater Res B Appl Biomater, 75, pp. 122-127Teixeira, P.C., Leite, G.M., Domingues, R.J., Paul, J.S., Gibbs, A., Ferreira, J.P., Antimicrobial effects of a microemulsion and a nanoemulsion on enteric and other pathogens and biofilms (2007) Int J Food Microbiol, 118, pp. 15-19Al-Ahmad, A., Wunder, A., Auschill, T.M., Follo, M., Braun, G., Hellwig, E., The in vivo dynamics of Streptococcus spp., Actinomyces naeslundii, Fusobacterium nucleatum and Veillonella spp. in dental plaque biofilm as analysed by five-colour multiplex fluorescence in situ hybridization (2007) J Med Microbiol, 56, pp. 681-687Palmer, Jr.R.J., Gordon, S.M., Cisar, J.O., Kolenbrander, P.E., Coaggregation-mediated interactions of streptococci and actinomyces detected in initial human dental plaque (2003) J Bacteriol, 185, pp. 3400-3409Loesche, W., Dental caries and periodontitis: Contrasting two infections that have medical implications (2007) Infect Dis Clin North Am, 21, pp. 471-502Takahashi, N., Nyvad, B., The role of bacteria in the caries process: Ecological perspectives (2011) J Dent Res, 90, pp. 294-303Bagramian, R.A., Garcia-Godoy, F., Volpe, A.R., The global increase in dental caries. A pending public health crisis (2009) Am J Dent, 22, pp. 3-8Turkun, M., Turkun, L.S., Ergucu, Z., Ates, M., Is an antibacterial adhesive system more effective than cavity disinfectants? (2006) Am J Dent, 19, pp. 166-170Zhang, K., Melo, M.A., Cheng, L., Weir, M.D., Bai, Y., Xu, H.H., Effect of quaternary ammonium and silver nanoparticle-containing adhesives on dentin bond strength and dental plaque microcosm biofilms (2012) Dent Mater, 28, pp. 842-852Scheie, A.A., Modes of action of currently known chemical anti-plaque agents other than chlorhexidine (1989) J Dent Res, 68, pp. 1609-1616Kuramoto, A., Imazato, S., Walls, A.W., Ebisu, S., Inhibition of root caries progression by an antibacterial adhesive (2005) J Dent Res, 84, pp. 89-93Yoshikawa, K., Clark, D.T., Brailsford, S.R., Beighton, D., Watson, T.F., Imazato, S., The effect of antibacterial monomer MDPB on the growth of organisms associated with root caries (2007) Dent Mater J, 26, pp. 388-392Carvalho, F.G., Puppin-Rontani, R.M., Fúcio, S.B., Negrini Tde, C., Carlo, H.L., Garcia-Godoy, F., Analysis by confocal laser scanning microscopy of the MDPB bactericidal effect on S. Mutans biofilm CLSM analysis of MDPB bactericidal effect on biofilm (2012) J Appl Oral Sci, 20, pp. 568-575Imazato, S., Kinomoto, Y., Tarumi, H., Torii, M., Russell, R.R.B., McCabe, J.F., Incorporation of antibacterial monomer MDPB in dentin primer (1997) J Dent Res, 76, pp. 768-772Imazato, S., Kuramoto, A., Takahashi, Y., Ebisu, S., Peters, M.C., In vitro antibacterial effects of the dentin primer of Clearfil Protect Bond (2006) Dent Mater, 22, pp. 527-532Hiraishi, N., Yiu, C.K., King, N.M., Tay, F.R., Effect of chlorhexidine incorporation into a self-etching primer on dentine bond strength of a luting cement (2010) J Dent, 38, pp. 496-502Bergenholtz, G., Evidence for bacterial causation of adverse pulpal responses in resin-based dental restorations (2000) Crit Rev Oral Biol Med, 11, pp. 467-48

Microcomputed tomography evaluation of polymerization shrinkage of class I flowable resin composite restorations

The present study aimed to characterize the pattern and volume of polymerization shrinkage of flowable resin composites, including one conventional, two bulk fill, and one self-adhesive. Standardized class I preparations (2.5 mm depth × 4 mm length × 4 mm wide) were performed in 24 caries-free human third molars that were randomly divided in four groups, according to the resin composite and adhesive system used: group 1 = Permaflo + Peak Universal Bond (PP); group 2 = Filtek Bulk Fill + Scotchbond Universal (FS); group 3 = Surefil SDR + XP Bond (SX); and group 4 = Vertise flow self-adhering (VE) (n=6). Each tooth was scanned three times using a microcomputed tomography (μCT) apparatus. The first scan was done after the cavity preparation, the second after cavity filling with the flowable resin composite before curing, and the third after it was cured. The μCT images were imported into three-dimensional rendering software, and volumetric polymerization shrinkage percentage was calculated for each sample. Data were submitted to one-way analysis of variance and post hoc comparisons. No significant difference was observed among PP, FS, and VE. SX bulk fill resin composite presented the lowest values of volumetric shrinkage. Shrinkage was mostly observed along the occlusal surface and part of the pulpal floor. In conclusion, polymerization shrinkage outcomes in a 2.5-mm deep class I cavity were material dependent, although most materials did not differ. The location of shrinkage was mainly at the occlusal surface.421E16E23CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES1777-2014309475/2014-7; 307217/2014-

Self-assembling peptide-laden electrospun scaffolds for guided mineralized tissue regeneration

OBJECTIVES: Electrospun scaffolds are a versatile biomaterial platform to mimic fibrillar structure of native tissues extracellular matrix, and facilitate the incorporation of biomolecules for regenerative therapies. Self-assembling peptide P 11-4 has emerged as a promising strategy to induce mineralization; however, P 11-4 application has been mostly addressed for early caries lesions repair on dental enamel. Here, to investigate P 11-4's efficacy on bone regeneration, polymeric electrospun scaffolds were developed, and then distinct concentrations of P 11-4 were physically adsorbed on the scaffolds. METHODS: P 11-4-laden and pristine (P 11-4-free) electrospun scaffolds were immersed in simulated body fluid and mineral precipitation identified by SEM. Functional groups and crystalline phases were analyzed by FTIR and XRD, respectively. Cytocompatibility, mineralization, and gene expression assays were conducted using stem cells from human exfoliated deciduous teeth. To investigate P 11-4-laden scaffolds potential to induce in vivo mineralization, an established rat calvaria critical-size defect model was used. RESULTS: We successfully synthesized nanofibrous (∼ 500 nm fiber diameter) scaffolds and observed that functionalization with P 11-4 did not affect the fibers' diameter. SEM images indicated mineral precipitation, while FTIR and XRD confirmed apatite-like formation and crystallization for P 11-4-laden scaffolds. In addition, P 11-4-laden scaffolds were cytocompatible, highly stimulated cell-mediated mineral deposition, and upregulated the expression of mineralization-related genes compared to pristine scaffolds. P 11-4-laden scaffolds led to enhanced in vivo bone regeneration after 8 weeks compared to pristine PCL. SIGNIFICANCE: Electrospun scaffolds functionalized with P 11-4 are a promising strategy for inducing mineralized tissues regeneration in the craniomaxillofacial complex

Effect of restorative system and thermal cycling on the tooth-restoration interface – OCT evaluation

The present study evaluated the tooth/noncarious cervical lesion restoration interface when using different adhesive systems and resin composites, submitted to thermal cycling (TC), using optical coherence tomography (OCT). Noncarious cervical lesion (NCCL) preparations (0.7 mm depth × 2 mm diameter) were performed on 60 human third molars and randomly divided into six groups, according to the adhesive system and resin composite used: group 1 = Adper Single Bond 2 (SB2) + Aelite LS Posterior (AP); group 2 = SB2 + Venus Diamond (VD); group = SB2 + Filtek Z250XT (Z250); group 4 = Clearfil SE Bond (CSE) + AP; group 5 = CSE + VD; group 6 = CSE + Z250. Selective enamel etching was performed for 30 seconds on groups 4, 5, and 6, while groups 1, 2, and 3 were etched for 30 seconds in enamel and 15 seconds in dentin. All groups were evaluated using OCT before and after TC (n=10). Images were analyzed using Image J software; enamel and dentin margins were separately evaluated. Data from OCT were submitted to PROC MIXED for repeated measurements and Tukey Kramer test (α = 0.05). No marginal gaps were observed in etched enamel, either before or after TC, for all adhesive and resin composite systems. A significant interaction was found between adhesive system and TC for the dentin groups; after TC, restorations with CSE showed smaller gaps at the dentin/restoration interface compared with SB2 for all resin composites. Increased gap percentages were noticed after TC compared with the gaps before TC for all groups. In conclusion, TC affected marginal integrity only in dentin margins, whereas etched enamel margins remained stable even after TC. Dentin margins restored with CSE adhesive system showed better marginal adaptation than those restored with SB2. Resin composites did not influence marginal integrity of NCCL restorations41216217

Degree of Conversion of Simplified Contemporary Adhesive Systems as Influenced by Extended Air-Activated or Passive Solvent Volatilization Modes

Made available in DSpace on 2019-09-12T16:57:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2012Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This study evaluated the effect of five methods of solvent volatilization on the degree of conversion (DC) of nine one-bottle adhesive systems using Fourier transform infrared/attenuated total reflectance (FTIR/ATR) analysis. Nine adhesives were tested: Adper Single Bond 2 (SB), Adper Easy One (EO), One Up Bond F Plus (OUP), One Coat Bond SL (OC), XP Bond (RP), Ambar (AM), Natural Bond (NB), GO, and Stae. The adhesive systems were applied to a zinc-selenide pellet and 1) cured without solvent volatilization, 2) left undisturbed for 10 seconds before curing, 3) left undisturbed for 60 seconds before curing, 4) air-dried with an air stream for 10 seconds before curing, and 5) air-dried with an air stream for 60 seconds before curing. FTIR/ATR spectra were obtained, and the DC was calculated by comparing the aliphatic bonds/reference peaks before and after light activation for 10 seconds (FlashLite 1401). The DC means of each material were analyzed by one-way analysis of variance and post hoc Tukey test (p<0.05). The DC of GO and Stae adhesive systems was not affected by the five evaporation conditions. Air-drying for 60 seconds before curing yielded the highest DC for SB, EO, and OC. Extended solvent volatilization time (60 seconds) either with or without air-drying before curing provided the highest DC for AM, NB, XP, and OUP. Thus, the monomer conversion of adhesive systems was material dependent. In general, the 60-second passive or active air-drying modes to volatilize solvents before curing enhanced the degree of conversion for the one-bottle simplified adhesive systems.[Borges, B. C. D.] Laureate Int Univ, Potiguar Univ, Dept Dent, Natal, RN, Brazil[Brandt, W. C.] Universidade de Taubaté (Unitau), Dept Prosthodont, Sao Paulo, Brazil[Loguercio, A. D.] Univ Estadual Ponta Grossa, Ponta Grossa, Brazil[Montes, M. A. J. R.] Univ Pernambuco, Dept Restorat Dent, Recife, PE, Brazil[Sinhoreti, M. A. C.] Univ Estadual Campinas, Piracicaba Dent Sch, Sao Paulo, Brazil[Souza-Junior, E. J.] State Univ Campinas UNICAMP, Piracicaba Dent Sch, Sao Paulo, Brazi

Effect of a Self-Assembly Peptide on Surface Roughness and Hardness of Bleached Enamel

After bleaching, enamel surfaces are damaged, contributing to erosion and tooth sensitivity. Although fluoride is used after bleaching to try and revert alterations, it is not capable of repairing tooth structure. This study compared the effect of a self-assembly peptide (P11-4), with and without fluoride, and sodium fluoride (NaF 2%) on the Knoop microhardness (KHN) and surface roughness (Ra (&mu;m)) of bleached enamel with an in-office bleaching regimen. Enamel blocks of bovine teeth (5 &times; 5 &times; 2 mm) with standardized surface hardness were bleached with 35% carbamide peroxide, following the manufacturer&rsquo;s instructions. The teeth were randomly divided into the following groups (n = 7) according to post-bleaching treatment: no treatment (negative control) (C-); 2% NaF (NaF); Curodont&trade; Repair (Repair); and Curodont&trade; Protect (Protect). Specimens were stored in artificial saliva at 37 &deg;C. To evaluate the effect of the post-bleaching treatments, KHN and Ra were measured before bleaching (baseline) and 24 h and 7 days after bleaching. Data were submitted to repeated measures ANOVA and Bonferroni tests (&alpha; = 0.05). There were significant interactions between the study factors (p = 0.001). After 7 days, Repair (572.50 &plusmn; 79.04) and Protect (583.00 &plusmn; 74.76) specimens showed increased surface KHN, with values higher than the NaF (465.50 &plusmn; 41.50) and C- (475.22 &plusmn; 58.95) baseline values. There was no significant difference in KHN at 24 h among groups (p = 0.587). At 24 h after bleaching, Repair was significantly different from all groups (p &lt; 0.05). Repair showed the lowest Ra (&mu;m) values (0.133 &plusmn; 0.035). After seven days, there was no significant difference in Ra values among groups when compared to the baseline. The use of P11-4-based materials after bleaching resulted in the fastest recovery to baseline enamel properties