Influence of cigarette smoke combined with different toothpastes on enamel erosion

This in vitro study aimed to evaluate the effect of different toothpastes on dental enamel subjected to an erosive cycle with and without exposure to cigarette smoke. Bovine enamel specimens were randomly allocated into 12 groups (n = 12). For the in vitro simulation of smoking, half the groups underwent an exposure cycle of 20 cigarettes per day for 5 days. Subsequently, all groups were subjected to a 5-day erosion cycle intercalating demineralization (1 min; 1% citric acid; pH = 3.5) and treatment with toothpaste slurries (2 min) of NaF, SnF2, F/Sn/Chitosan, F/CaSiO3/Na3PO4, and F/bioactive glass. The control group was immersed in distilled water. Surface microhardness (SMH) was measured initially, after exposure to smoke, and after the erosive cycle, and %SMH was calculated. At the end of the experimental cycle, surface roughness, profilometry, and atomic force microscopy (AFM) were performed. SMH increased after exposure to cigarette smoke (p 0.05). Besides increasing enamel SMH, cigarette smoke did not prevent enamel loss after the erosion cycle (p < 0.05). In profilometry, roughness and surface loss had the lowest values in the groups treated with SnF2 and F/Sn/Chitosan (p < 0.05). AFM showed lower mineral loss with F/CaSiO3/Na3PO4 and F/Sn/Chitosan. For all groups, except F/CaSiO3/Na3PO4, cigarette smoke resulted in higher enamel wear. F/Sn/Chitosan showed the best results against erosion3

Effect of iodonium salt and chitosan on the physical and antibacterial properties of experimental infiltrants

Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics3

Effectiveness Of Dental Bleaching In Depth After Using Different Bleaching Agents

This study evaluated the effectiveness of low- and high-concentration bleaching agents on enamel and deep dentin. Study design: Stained bovine incisors fragments were randomized placed into 10 groups (n=5), according to the sample thicknesses (2.0 mm or 3.5 mm) and bleaching agent: 10% carbamide peroxide (CP) (4 h a day/21 days); 6% hydrogen peroxide (HP) with calcium (1:30 h a day/21 days); HP 20% with calcium (50 min a day/3 sessions with a 7-day interval); HP 35% (3 x 15 min a day/3 sessions with a 7-day interval); HP 35% with calcium (40 min a day/3 sessions with a 7-day interval). The samples were stored in artificial saliva during the experiment. The color change was evaluated using a spectrophotometer at the initial analysis, after artificially staining with black tea and after each of the bleaching weeks, and data was expressed in CIE Lab System values. The L* coordinate data was submitted to analysis of variance and Tukey-Kramer test and the E values data was submitted for analysis of variance in a split-plot ANOVA and Tukey's test (α=0.05). Results: None of the bleaching agents tested differed from the reflectance values on the enamel surface. For deep dentin HP 20% and HP 35%, both with calcium, showed the lowest reflectance values, which differed from CP 10%. Conclusion: It is concluded that high concentration hydrogen peroxide with calcium was less effective in deep dentin than 10% carbamide peroxide.52e100e107Joiner, A., Review of the effects of peroxide on enamel and dentine properties (2007) J Dent, 35 (12), pp. 889-896Haywood, V.B., Heymann, H.O., Nightguard vital bleaching (1989) Quintessence Int, 20 (3), pp. 173-176Buchalla, W., Attin, T., External bleaching therapy with activa-tion by heat, light or laser--a systematic review (2007) Dent Mater, 23 (5), pp. 586-596Kim, Y.S., Kwon, H.K., Kim, B.I., Effect of nano-carbonate apa-tite to prevent re-stain after dental bleaching in vitro (2011) J Dent, 39 (9), pp. 636-642Sun, G., The role of lasers in cosmetic dentistry (2000) Dent Clin North Am, 44 (4), pp. 831-850Hanks, C.T., Fat, J.C., Wataha, J.C., Corcoran, J.F., Cytotoxicity and den-tin permeability of carbamide peroxide and hydrogen peroxide vital bleaching materials, in vitro (1993) J Dent Res, 72 (5), pp. 931-938Lima, D.A., Aguiar, F.H., Liporoni, P.C., Munin, E., Ambrosano, G.M., Lovadino, J.R., In vitro evaluation of the effectiveness of bleaching agents activated by different light sources (2009) J Prosthodont, 18 (3), pp. 249-254Matis, B.A., Mousa, H.N., Cochran, M.A., Eckert, G.J., Clinical evaluation of bleaching agents of different concentrations (2000) Quintessence Int, 31 (5), pp. 303-310Meireles, S.S., Heckmann, S.S., Santos, I.S., Della Bona, A., Demarco, F.F., A double blind randomized clinical trial of at-home tooth bleaching using two carbamide peroxide concentrations: 6-month follow-up (2008) J Dent, 36 (11), pp. 878-884Sulieman, M., An overview of bleaching techniques: I. History, chemistry, safety and legal aspects (2004) Dent Update, 31 (10), pp. 608-610. , 12-4,16Bernardon, J.K., Sartori, N., Ballarin, A., Perdigao, J., Lopes, G.C., Bara-tieri, L.N., Clinical performance of vital bleaching techniques (2010) Oper Dent, 35 (1), pp. 3-10Dietschi, D., Rossier, S., Krejci, I., In vitro colorimetric evaluation of theeffcacy of various bleaching methods and products (2006) Quintessence Int, 37 (7), pp. 515-526Wiegand, A., Vollmer, D., Foitzik, M., Attin, R., Attin, T., Effcacy of different whitening modalities on bovine enamel and dentin (2005) Clin Oral Investig, 9 (2), pp. 91-97Kihn, P.W., Barnes, D.M., Romberg, E., Peterson, K., A clinical evaluation of 10 percent vs. 15 percent carbamide peroxide tooth-whitening agents (2000) J Am Dent Assoc., 131 (10), pp. 1478-1484Barghi, N., Making a clinical decision for vital tooth bleaching: at-home or in-offce (1998) Compend Contin Educ Dent, 19 (8), pp. 831-838. , quiz 40Garber, D.A., Dentist-monitored bleaching: a discussion of combination andlaser bleaching (1997) J Am Dent Assoc, 128 (SUPPL.), pp. 26S-30SJoiner, A., Tooth colour: a review of the literature (2004) J Dent, 32 (1 SUPPL.), pp. 3-12Sulieman, M., Addy, M., Rees, J.S., Development and evaluation of a method in vitro to study the effectiveness of tooth bleaching (2003) J Dent, 31 (6), pp. 415-422D'Arce, M.B., Lima, D.A., Aguiar, F.H., Ambrosano, G.M., Munin, E., Lo-vadino, J.R., Evaluation of ultrasound and light sources as bleaching catalysts - an in vitro study (2012) Eur J Esthet Dent, 7 (2), pp. 176-184Dietschi, D., Benbachir, N., Krejci, I., In vitro colorimetric evaluation of the effcacy of home bleaching and over-the-counter bleaching products (2010) Quintessence Int, 41 (6), pp. 505-516Hannig, C., Weinhold, H.C., Becker, K., Attin, T., Diffusion of peroxides through dentine in vitro with and without prior use of a desensitizing varnish (2011) Clin Oral Investig, 15 (6), pp. 863-868Attia, M.L., Aguiar, F.H., Mathias, P., Ambrosano, G.M., Fontes, C.M., Li-poroni, P.C., The effect of coffee solution on tooth color during home bleaching applications (2009) Am J Dent, 22 (3), pp. 175-179Matis, B.A., Cochran, M.A., Eckert, G., Review of the effectiveness of various tooth whitening systems (2009) Oper Dent, 34 (2), pp. 230-235Marshall, K., Berry, T.G., Woolum, J., Tooth whitening: current status (2010) Compend Contin Educ Dent, 31 (7), pp. 486-492. , 94-5quiz 96, 508Kwon, Y.H., Huo, M.S., Kim, K.H., Kim, S.K., Kim, Y.J., Effects of hydrogen peroxide on the light refectance and morphology of bovine enamel (2002) J Oral Rehabil, 29 (5), pp. 473-477Hughes, J.A., West, N.X., Parker, D.M., van den Braak, M.H., Addy, M., Effects of pH and concentration of citric, malic and lactic acids on enamel, in vitro (2000) J Dent, 28 (2), pp. 147-152Gao, X.J., Elliott, J.C., Anderson, P., Scanning and contact microradio-graphic study of the effect of degree of saturation on the rate of enamel demineralization (1991) J Dent Res, 70 (10), pp. 1332-1337Turkun, M., Celik, E.U., Aladag, A., Gokay, N., One-year clinical evaluation of the effcacy of a new daytime at-home bleaching technique (2010) J Esthet Restor Dent, 22 (2), pp. 139-146Zekonis, R., Matis, B.A., Cochran, M.A., Al Shetri, S.E., Eckert, G.J., Carlson, T.J., Clinical evaluation of in-offce and at-home bleaching treatments (2003) Oper Dent, 28 (2), pp. 114-121Sulieman, M., Addy, M., MacDonald, E., Rees, J.S., The effect of hydrogen peroxide concentration on the outcome of tooth whitening: an in vitro study (2004) J Dent, 32 (4), pp. 295-29

Metal-free restorations: Esthetic considerations, treatment planning, preparation, manufacturing, luting, and followup

PubMedID: 26793716[No abstract available

Does An Additional Uv Led Improve The Degree Of Conversion And Knoop Hardness Of Light-shade Composite Resins?

Objective: The purpose of this study was to evaluate the degree of conversion (DC) using FTRaman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5. Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces. For DC (n=10), both the T and B surfaces were analyzed. Results: For KHN, the three composites differed in hardens. There was a "LCU-surface" interaction, in whichRadii Cal showed significantly greater hardens in the B surface. For DC, there was a "composite-surface-LCU" interaction. For the "composite" factor, there was no significant difference between the groups, except for Supreme XT-Radii Cal (T or B surfaces). For the "LCU" factor there was a significant difference for Supreme XT T surface, Ultralume 5 obtained a higher DC. For the Z350 T surface, a significant difference in the DC in which Radii Cal obtained better results. For the "surface" factor, all groups presented T surfaces with a higher DC than the B surfaces, the sole exceptions involved Esthet X-Radii Cal and Z350-Ultralume 5. Conclusion: Knowledge regarding composite composition and the characteristics of LCUs are important for effective polymerization.64396401Jimenez-planas, A., Martin, J., Abalos, C., Llamas, R., Developments in polymerization lamps (2008) Quintessence Int., 39, pp. e74-e84Polydorou, O., Manolakis, A., Hellwig, E., Hahn, P., Evaluation of the curing depth of two translucent composite materials using a halogen and two LED curing units (2008) Clin. Oral. Investig., 12, pp. 45-51Cavalcante, L.M., Valentino, T.A., Carlini Jr., B., Silikas, N., Pimenta, L.A., Influence of different exposure time required to stabilize hardness values of composite resin restorations (2009) J. Contemp. Dent. Pract., 10, pp. 42-50Ruttermann, S., Tomruk, S., Raab, W.H., Janda, R., Effect of Energy Density on the Physical Properties of Resin-Based Restorative Materials when Polymerized with Quartz-Tungsten Halogen or LED-Light (2010) Eur. J. Dent., 4, pp. 183-191Ceballos, L., Fuentes, M.V., Tafalla, H., Martinez, A., Flores, J., Rodriguez, J., Curing effectiveness of resin composites at different exposure times using LED and halogen units (2009) Med. Oral. Patol. Oral. Cir. Bucal., 14, pp. E51-E56Beriat, N.C., Ertan, A.A., Canay, S., Gurpinar, A., Onur, M.A., Effect of different polymerization methods on the cytotoxicity of dental composites (2010) Eur. J. Dent., 4, pp. 287-292Kramer, N., Lohbauer, U., Garcia-godoy, F., Frankenberger, R., Light curing of resin-based composites in the LED era (2008) Am. J. Dent., 21, pp. 135-142Antonson, S.A., Antonson, D.E., Hardigan, P.C., Should my new curing light be an LED? (2008) Oper. Dent., 33, pp. 400-407Price, R.B., Felix, C.A., Andreou, P., Third-generation vs a second-generation LED curing light: effect on Knoop microhardness (2006) Compend. Contin. Educ. Dent., 27, pp. 490-496. , quiz 497, 518Hammesfahr, P.D., O'connor, M.T., Wang, X., Light-curing technology: past, present, and future (2002) Compend. Contin. Educ. Dent., 23, pp. 18-24Burgess, J.O., Degoes, M., Walker, R., Ripps, A.H., An evaluation of four light-curing units comparing soft and hard curing (1999) Pract. Periodontics Aesthet. Dent., 11, pp. 125-132. , quiz 134Price, R.B., Derand, T., Loney, R.W., Andreou, P., Effect of light source and specimen thickness on the surface hardness of resin composite (2002) Am. J. Dent., 15, pp. 47-53Cassoni, A., Jde, O.F., Shibli, J.A., Kawano, Y., Knoop microhardness and FT-Raman spectroscopic evaluation of a resin- based dental material light-cured by an argon ion laser and halogen lamp: an in vitro study (2008) Photomed. Laser. Surg., 26, pp. 531-539Yazici, A.R., Kugel, G., Gul, G., The Knoop hardness of a composite resin polymerized with different curing lights and different modes (2007) J. Contemp. Dent. Pract., 8, pp. 52-59Arikawa, H., Fujii, K., Kanie, T., Inoue, K., Light transmittance characteristics of light-cured composite resins (1998) Dent. Mater., 14, pp. 405-411Beun, S., Glorieux, T., Devaux, J., Vreven, J., Leloup, G., Characterization of nanofilled compared to universal and microfilled composites (2007) Dent. Mater., 23, pp. 51-59Fan, P.L., Stanford, C.M., Stanford, W.B., Leung, R., Stanford, J.W., Effects of backing reflectance and mold size on polymerization of photo-activated composite resin (1984) J. Dent. Res., 63, pp. 1245-1247Schattenberg, A., Lichtenberg, D., Stender, E., Willershausen, B., Ernst, C.P., Minimal exposure time of different LED-curing devices (2008) Dent. Mater., 24, pp. 1043-1049El-mowafy, O., El-badrawy, W., Wasef, M., Omar, H., Kermanshahi, S., Efficacy of new LED light-curing units in hardening of Class II composite restorations (2007) J. Can. Dent. Assoc., 73, p. 253Soh, M.S., Yap, A.U., Yu, T., Shen, Z.X., Analysis of the degree of conversion of LED and halogen lights using micro-Raman spectroscopy (2004) Oper. Dent., 29, pp. 571-577Pilo, R., Cardash, H.S., Post-irradiation polymerization of different anterior and posterior visible light-activated resin composites (1992) Dent. Mater., 8, pp. 299-30

Long-term Effect Of Chlorhexidine On The Dentin Microtensile Bond Strength Of Conventional And Self-adhesive Resin Cements: A Two-year In Vitro Study

Since degradation of the adhesive interface plays an important role on dental restoration failure overtime, bonding protocols containing metalloproteinase synthetic inhibitors could be a valuable approach to preserve the bond strength of indirect restorations. A flat dentin surface was created on 40 recently extracted non-carious human third molars (n=10). Resin-composite blocks were randomly cemented using two resin cements: a self-adhesive and a conventional. A buffer-free 2% chlorhexidine digluconate solution was used as dentin pretreatment on experimental groups. Microtensile bond strength test was performed immediately and after specimen aging for two-years in artificial saliva. Fracture patterns were determined by SEM. Even after significant reduction in bonding effectiveness with aging, dentin bond strength values of the conventional resin cement remained higher compared to those of the self-adhesive resin cement especially when chlorhexidine pretreatment was performed. No statistical differences were observed between immediate and aged specimens luted with the self-adhesive resin cement. Chlorhexidine was effective to preserve dentin bond strength of indirect restorations when the conventional resin cement was used. © 2014 Elsevier Ltd.50228234Furukawa, K., Inai, N., Tagami, J., The effects of luting resin bond to dentin on the strength of dentin supported by indirect resin composite (2002) Dental Materials, 18 (2), pp. 136-142. , DOI 10.1016/S0109-5641(01)00032-X, PII S010956410100032XPiwowarczyk, A., Bender, R., Ottl, P., Lauer, H.-C., Long-term bond between dual-polymerizing cementing agents and human hard dental tissue (2007) Dental Materials, 23 (2), pp. 211-217. , DOI 10.1016/j.dental.2006.01.012, PII S0109564106000170Yang, B., Ludwig, K., Adelung, R., Kern, M., Micro-tensile bond strength of three luting resins to human regional dentin (2006) Dental Materials, 22 (1), pp. 45-56. , DOI 10.1016/j.dental.2005.02.009, PII S0109564105001272Gerth, H.U.V., Dammaschke, T., Zuchner, H., Schafer, E., Chemical analysis and bonding reaction of RelyX Unicem and Bifix composites-A comparative study (2006) Dental Materials, 22 (10), pp. 934-941. , DOI 10.1016/j.dental.2005.10.004, PII S0109564105003088Nakamura, T., Wakabayashi, K., Kinuta, S., Nishida, H., Miyamae, M., Yatani, H., Mechanical properties of new self-adhesive resin-based cement (2010) J Prosthodont Res, 54 (2), pp. 59-64Radovic, I., Monticelli, F., Goracci, C., Vulicevic, Z.R., Ferrari, M., Self-adhesive resin cements: A literature review (2008) J Adhes Dent, 10 (4), pp. 251-258Hashimoto, M., Ohno, H., Sano, H., Kaga, M., Oguchi, H., In vitro degradation of resin-dentin bonds analyzed by microtensile bond test, scanning and transmission electron microscopy (2003) Biomaterials, 24 (21), pp. 3795-3803. , DOI 10.1016/S0142-9612(03)00262-XDe Munck, J., Van Landuyt, K., Peumans, M., Poitevin, A., Lambrechts, P., Braem, M., Van Meerbeek, B., A critical review of the durability of adhesion to tooth tissue: Methods and results (2005) Journal of Dental Research, 84 (2), pp. 118-132. , DOI 10.1177/154405910508400204Monticelli, F., Osorio, R., Mazzitelli, C., Ferrari, M., Toledano, M., Limited decalcification/diffusion of self-adhesive cements into dentin (2008) J Dent Res, 87 (10), pp. 974-979Wang, Y., Spencer, P., Hybridization efficiency of the adhesive/dentin interface with wet bonding (2003) Journal of Dental Research, 82 (2), pp. 141-145Spencer, P., Wang, Y., Katz, J.L., Identification of collagen encapsulation at the dentin/adhesive interface (2004) Journal of Adhesive Dentistry, 6 (2), pp. 91-95Pashley, D.H., Tay, F.R., Yiu, C., Hashimoto, M., Breschi, L., Carvalho, R.M., Ito, S., Collagen degradation by host-derived enzymes during aging (2004) Journal of Dental Research, 83 (3), pp. 216-221Garcia-Godoy, F., Tay, F.R., Pashley, D.H., Feilzer, A., Tjaderhane, L., Pashley, E.L., Degradation of resin-bonded human dentin after 3 years of storage (2007) Am J Dent, 20 (2), pp. 109-113Carrilho, M.R., Geraldeli, S., Tay, F., De Goes, M.F., Carvalho, R.M., Tjaderhane, L., Reis, A.F., Pashley, D., In vivo preservation of the hybrid layer by chlorhexidine (2007) J Dent Res, 86 (6), pp. 529-533Martin-De Las Heras, S., Valenzuela, A., Overall, C.M., The matrix metalloproteinase gelatinase A in human dentine (2000) Archives of Oral Biology, 45 (9), pp. 757-765. , DOI 10.1016/S0003-9969(00)00052-2, PII S0003996900000522Sulkala, M., Larmas, M., Sorsa, T., Salo, T., Tjaderhane, L., The localization of matrix metalloproteinase-20 (MMP-20, enamelysin) in mature human teeth (2002) J Dent Res, 81 (9), pp. 603-607Mazzoni, A., Pashley, D.H., Nishitani, Y., Breschi, L., Mannello, F., Tjaderhane, L., Toledano, M., Tay, F.R., Reactivation of inactivated endogenous proteolytic activities in phosphoric acid-etched dentine by etch-and-rinse adhesives (2006) Biomaterials, 27 (25), pp. 4470-4476. , DOI 10.1016/j.biomaterials.2006.01.040, PII S0142961206001256Mazzoni, A., Papa, V., Nato, F., Carrilho, M., Tjaderhane, L., Ruggeri, Jr.A., Gobbi, P., Breschi, L., Immunohistochemical and biochemical assay of MMP-3 in human dentine (2011) J Dent, 39 (3), pp. 231-237Lehmann, N., Debret, R., Romeas, A., Magloire, H., Degrange, M., Bleicher, F., Sommer, P., Seux, D., Self-etching increases matrix metalloproteinase expression in the dentin-pulp complex (2009) J Dent Res, 88 (1), pp. 77-82Nishitani, Y., Yoshiyama, M., Wadgaonkar, B., Breschi, L., Mannello, F., Mazzoni, A., Carvalho, R.M., Pashley, D.H., Activation of gelatinolytic/collagenolytic activity in dentin by self-etching adhesives (2006) European Journal of Oral Sciences, 114 (2), pp. 160-166. , DOI 10.1111/j.1600-0722.2006.00342.xLindblad, R.M., Lassila, L.V., Salo, V., Vallittu, P.K., Tjaderhane, L., One year effect of chlorhexidine on bonding of fibre-reinforced composite root canal post to dentine (2012) J Dent, 40 (9), pp. 718-722Tay, F.R., Pashley, D.H., Loushine, R.J., Weller, R.N., Monticelli, F., Osorio, R., Self-Etching Adhesives Increase Collagenolytic Activity in Radicular Dentin (2006) Journal of Endodontics, 32 (9), pp. 862-868. , DOI 10.1016/j.joen.2006.04.005, PII S009923990600416XOliveira, S.S.A., Marshall, S.J., Habelitz, S., Gansky, S.A., Wilson, R.S., Marshall Jr., G.W., The effect of a self-etching primer on the continuous demineralization of dentin (2004) European Journal of Oral Sciences, 112 (4), pp. 376-383. , DOI 10.1111/j.1600-0722.2004.00142.xFardal, O., Turnbull, R.S., A review of the literature on use of chlorhexidine in dentistry (1986) J Am Dent Assoc, 112 (6), pp. 863-869Gendron, R., Grenier, D., Sorsa, T., Mayrand, D., Inhibition of the activities of matrix metalloproteinases 2, 8, and 9 by chlorhexidine (1999) Clinical and Diagnostic Laboratory Immunology, 6 (3), pp. 437-439Hebling, J., Pashley, D.H., Tjaderhane, L., Tay, F.R., Chlorhexidine arrests subclinical degradation of dentin hybrid layers in vivo (2005) J Dent Res, 84 (8), pp. 741-746Carrilho, M.R., Carvalho, R.M., De Goes, M.F., Di Hipolito, V., Geraldeli, S., Tay, F.R., Pashley, D.H., Tjäderhane, L., Chlorhexidine preserves dentin bond in vitro (2007) J Dent Res, 86 (1), pp. 90-94Hashimoto, M., Ohno, H., Kaga, M., Endo, K., Sano, H., Oguchi, H., Resin-tooth adhesive interfaces after long-term function (2001) American Journal of Dentistry, 14 (4), pp. 211-215Hashimoto, M., Ohno, H., Kaga, M., Endo, K., Sano, H., Oguchi, H., In vivo degradation of resin-dentin bonds in humans over 1 to 3 years (2000) Journal of Dental Research, 79 (6), pp. 1385-1391Goracci, C., Cury, A.H., Cantoro, A., Papacchini, F., Tay, F.R., Ferrari, M., Microtensile bond strength and interfacial properties of self-etching and self-adhesive resin cements used to lute composite onlays under different seating forces (2006) Journal of Adhesive Dentistry, 8 (5), pp. 327-335Shono, Y., Ogawa, T., Terashita, M., Carvalho, R.M., Pashley, E.L., Pashley, D.H., Regional measurement of resin-dentin bonding as an array (1999) Journal of Dental Research, 78 (2), pp. 699-705El Zohairy, A.A., De Gee, A.J., Mohsen, M.M., Feilzer, A.J., Effect of conditioning time of self-etching primers on dentin bond strength of three adhesive resin cements (2005) Dental Materials, 21 (2), pp. 83-93. , DOI 10.1016/j.dental.2003.12.002, PII S0109564104000363Al-Assaf, K., Chakmakchi, M., Palaghias, G., Karanika-Kouma, A., Eliades, G., Interfacial characteristics of adhesive luting resins and composites with dentine (2007) Dental Materials, 23 (7), pp. 829-839. , DOI 10.1016/j.dental.2006.06.023, PII S0109564106001837Tay, F.R., Smales, R.J., Ngo, H., Wei, S.H.Y., Pashley, D.H., Effect of different conditioning protocols on adhesion of a GIC to dentin (2001) Journal of Adhesive Dentistry, 3 (2), pp. 153-167Hikita, K., Van Meerbeek, B., De Munck, J., Ikeda, T., Van Landuyt, K., Maida, T., Lambrechts, P., Peumans, M., Bonding effectiveness of adhesive luting agents to enamel and dentin (2007) Dental Materials, 23 (1), pp. 71-80. , DOI 10.1016/j.dental.2005.12.002, PII S0109564105003611Pashley, D.H., Carvalho, R.M., Sano, H., Nakajima, M., Yoshiyama, M., Shono, Y., Fernandes, C.A., Tay, F., The microtensile bond test: A review (1999) J Adhes Dent, 1 (4), pp. 299-309Salz, U., Bock, T., Testing adhesion of direct restoratives to dental hard tissue - A review (2010) J Adhes Dent, 12 (5), pp. 343-371Breschi, L., Perdigao, J., Gobbi, P., Mazzotti, G., Falconi, M., Lopes, M., Immunocytochemical identification of Type I collagen in acid-etched dentin (2003) Journal of Biomedical Materials Research - Part A, 66 (4), pp. 764-769Mazzitelli, C., Monticelli, F., Toledano, M., Ferrari, M., Osorio, R., Dentin treatment effects on the bonding performance of self-adhesive resin cements (2010) Eur J Oral Sci, 118 (1), pp. 80-86Tjaderhane, L., Larjava, H., Sorsa, T., Uitto, V.-J., Larmas, M., Salo, T., The activation and function of host matrix metalloproteinases in dentin matrix breakdown in caries lesions (1998) Journal of Dental Research, 77 (8), pp. 1622-1629Yiu, C.K.Y., King, N.M., Pashley, D.H., Suh, B.I., Carvalho, R.M., Carrilho, M.R.O., Tay, F.R., Effect of resin hydrophilicity and water storage on resin strength (2004) Biomaterials, 25 (26), pp. 5789-5796. , DOI 10.1016/j.biomaterials.2004.01.026, PII S0142961204000626Tay, F.R., Hashimoto, M., Pashley, D.H., Peters, M.C., Lai, S.C.N., Yiu, C.K.Y., Cheong, C., Aging affects two modes of nanoleakage expression in bonded dentin (2003) Journal of Dental Research, 82 (7), pp. 537-541Shafiei, F., Memarpour, M., Effect of chlorhexidine application on long-term shear bond strength of resin cements to dentin (2010) J Prosthodont Res, 54 (4), pp. 153-158Lindblad, R.M., Lassila, L.V., Salo, V., Vallittu, P.K., Tjaderhane, L., Effect of chlorhexidine on initial adhesion of fiber-reinforced post to root canal (2010) J Dent, 38 (10), pp. 796-801Stape, T., Menezes, M., Barreto, B., Aguiar, F., Martins, L., Quagliatto, P., Influence of matrix metalloproteinase synthetic inhibitors on dentin microtensile bond strength of resin cements (2012) Oper Dent, 37 (4), pp. 386-396Kim, J., Uchiyama, T., Carrilho, M., Agee, K.A., Mazzoni, A., Breschi, L., Carvalho, R.M., Pashley, D.H., Chlorhexidine binding to mineralized versus demineralized dentin powder (2010) Dent Mater, 26 (8), pp. 771-778Hiraishi, N., Yiu, C.K., King, N.M., Tay, F.R., Effect of 2% chlorhexidine on dentin microtensile bond strengths and nanoleakage of luting cements (2009) J Dent, 37 (6), pp. 440-448Di Hipolito, V., Rodrigues, F.P., Piveta, F.B., Azevedo Lda, C., Bruschi Alonso, R.C., Silikas, N., Carvalho, R.M., Perlatti D'Alpino, P.H., Effectiveness of self-adhesive luting cements in bonding to chlorhexidine-treated dentin (2012) Dent Mater, 28 (5), pp. 495-501Freire, L.G., Carvalho, C.N., Ferrari, P.H., Siqueira, E.L., Gavini, Influence of dentin on pH of 2% chlorhexidine gel and calcium hydroxide alone or in scombination (2010) Dent Traumatol, 26 (3), pp. 276-28

Influence Of Successive Light-activation On Degree Of Conversion And Knoop Hardness Of The First Layered Composite Increment

Purpose: To evaluate the influence of light-activation of second, third and fourth increments on degree of conversion (DC) and microhardness (KHN) of the top (T) and bottom (B) surface of the first increment. Materials and methods. Forty samples (n = 5) were prepared. In groups 1-4, after each increment light-activation (multiple irradiation), T and B of the first increment were measured in DC and KHN. In groups 5-8, only the first increment was made (single irradiation) and measurements of DC and KHN were taken at 15 min intervals. The light-activation modes were (XL) 500 mW/cm2 × 38 s (G1/G5); (S) 1000 mW/cm2 × 19 s (G2/G6), (HP) 1400 mW/cm2 × 14 s (G3/G7); (PE) 3200 mW/cm2 × 6 s (G4/G8). Data for DC and KHN were analyzed separately by using PROC MIXED for repeated measures and Tukey-Kramer test (α = 0.05). Results. For KHN, B showed lower values than T. PE resulted in lower values of KHN in B surface. For single and multiple irradiations, T and B of first measurement showed the lowest KHN and the fourth measurement showed the highest, with significant difference between them. For single irradiation, first and second increments presented similar KHN, different from the third and fourth increment, which did not differ between them. For multiple irradiations, the second light-activation resulted in KHN similar to fi rst, third and fourth increments. For DC, except QTH, T presented higher DC than B. Conclusion. The light-activation of successive increments was not able to influence the KHN and DC of the fi rst increment.732126131Ferracane, J.L., Resin composite-State of the art (2011) Dent Mater, 27, pp. 29-38Knezevic, A., Tarle, Z., Menigaia, A., Sutalo, J., Pichler, G., Ristic, M., Degree of conversion and temperature rise during polymerization of composite resin samples with blue diodes (2012) J Oral Rehabil, 8, pp. 586-591Aguiar, F.H.B., Oliveira, T.R.V., Danl, L., Ambrosano, G.M., Lovadino, J.R., Microhardness of different thickness by conventional photocuring at different distances (2008) Gen Dent, 56, pp. 144-148Hansen, E.K., Asmussen, E., Visible-light curing units: Correlation between depth of cure and distance between exit window and resin surface (1997) Acta Odontol Scand, 55, pp. 162-166Rode, K.M., Kawano, Y., Turbino, M.L., Evaluation of curing light distance on resin composite microhardness and polymerization (2007) Oper Dent, 32, pp. 571-578Arikawa, H., Fujii, K., Kanie, T., Inoue, K., Light transmittance characteristics of light-cured composite resins (1998) Dent Mater, 14, pp. 401-411El-Mowafy, O., El-Badrawy, W., Wasef, M., Omar, H., Kermanshahi, S., Efficacy of new light-curing units in hardening of class IIcomposite restoration (2007) J Can Dent Assoc, 73, p. 253Ilie, N., Bauer, H., Draenert, M., Hickel, R., Resin-based composite light-cured properties assessed by laboratory standards and simulated clinical conditions (2013) Oper Dent, 38, pp. 159-167Rueggeberg, F.A., State-of-the-art: Dental photocuring - A review (2011) Dent Mater, 27, pp. 39-52Nomoto, R., Asada, M., McCabe, J., Hirano, S., Light exposure required for optimum conversion of light activated resin systems (2006) Dent Mater, 22, pp. 1135-1142Catelan, A., Mainardi, M.C.A.J., Soares, G.P., Lima, A.F., Ambrosanao, G.M.B., Lima, D.A.N.L., Effect of light curing protocol on degree of conversion of composites (2014) Acta Odontol Scand, 26, pp. 1-5Lima, A.F., Andrade, K.M.G., Alves, L.E.C., Soares, G.P., Marchi, G.M., Aguiar, F.H., Infl uence of light source and extended time of curing on microhardness and degree of conversion of different regions of a nanofilled composite resin (2012) Eur J Dent, 6, pp. 153-157Aguiar, F.H., Lazzari, C.R., Lima, D.A., Ambrosano, G.M., Lovadino, J.R., Effect of light curing tip distance and resin shade on microhardness of a hybrid resin composite (2005) Braz Oral Res, 19, pp. 302-306Niu, Y., Ma, X., Fan, M., Zhu, S., Effects of layering techniques on the micro-tensile bond strength to dentin in resin composite restorations (2009) Dent Mater, 25, pp. 129-134Dos Santos, G.B., Molte Alto, R.V., Sampaio Filho, H.R., Da Silva, E.M., Fellows, C.E., Light transmission on dental resin composites (2008) Dent Mater, 24, pp. 571-576Watts, D.C., Amer, O.M., Combe, E.C., Surface hardness development in light-cured composites (1987) Dent Mater, 3, pp. 265-269Yap, A.U., Wong, W., Siow, K.S., Composite cure and shrinkage associated with a high intensity curing unit (2003) Oper Dent, 28, pp. 357-364Hubbezoglu, I., Bolayir, G., Dogan, O.M., Dogan, A., Ozer, A., Bek, B., Microhardness evaluation of resin composite polymerized by three different light sources (2007) Dent Mater J, 26, pp. 845-853Sakaguchi, R.L., Berge, H.X., Reduced light energy density decreases post-gel contraction while maintaining degree of conversion in composites (1998) J Dent, 26, pp. 695-698Bracket, W.W., Hisch, L.D., Covey, D.A., Effect of plasma arc curing on microleakage of class V resin-based composite restoration (2000) Am J Dent, 13, pp. 121-122Oesterle, L.J., Newman, S.M., Shellhart, W.C., Rapid curing of bonding composite with a xenon plasma arc light (2001) Am J Orthod Dentofacial Orthop, 119, pp. 610-616Halvorson, R.H., Erickson, R.L., Davidson, C.L., Energy dependent polymerization of resin-based composite (2002) Dent Mater, 18, pp. 463-469Witzel, M.F., Calheiros, F.C., Gonc¸alves, F., Kawano, Y., Braga, R.R., Influence of photoactivation method on conversion, mechanical properties, degradation in ethanol and contraction stress of resin-based materials (2005) J Dent, 33, pp. 773-77

Mechanical properties of aged yttria-stabilized tetragonal zirconia polycrystal after abrasion with different aluminum oxide particles

A consensus on the benefits of airborne-particle abrasion of zirconia with alumina particles of different sizes is still lacking. Larger particle size may improve micromechanical retention but may generate deep microcracks on the zirconia surface. The purpose of this in vitro study was to evaluate the effect of different size of Al2O3 particles used for surface abrasion on the mechanical properties of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Sixty Y-TZP specimens were divided into 6 groups according to the treatment: control (without treatment) or airborne-particle abrasion with Al2O3 particles (45 μm or 150 μm). Half the specimens were stored for 24 hours in water while the other half was exposed to 1.5×106 mechanical cycles before flexural strength analysis at 1 mm/min crosshead speed. Specimens were also characterized by micro-Raman spectroscopy and X-ray diffraction (XRD) to evaluate the crystalline composition. The data were subjected to 2-way ANOVA and Tukey HSD test (α=.05). Airborne-particle abrasion with alumina (P=.030) and mechanical fatigue (P<.001) had a significant effect on flexural strength. Specimens abraded with 45-μm Al2O3 particles (847 ±204 MPa) presented higher flexural strength than those of the control group (670 ±210 MPa). The size of the alumina particles was not significant for flexural strength. Flexural resistance (664 MPa) significantly decreased after mechanical fatigue. All groups showed only the tetragonal phase on the micro-Raman spectra, which was confirmed by XRD. Airborne-particle abrasion with smaller Al2O3 particles increased the flexural strength on Y-TZP without causing phase transformation. However, flexural strength was decreased after mechanical fatigue