Laboratory plaque reduction by three floss products

 

Samuel L. Yankell, ms, phd, rdh, Xiuren Shi, dds,  Christine M. Spirgel, ms,  Leoncio Angel Gonzalez, bse, mba &  James Cwik, bsba, mba

 

Abstract: Purpose: A new laboratory method was developed to compare GUM Expanding floss, Reach Mint Waxed and Oral-B Glide Pro-Health Deep Clean for their ability to reduce artificial plaque. Methods: The floss product to be evaluated was affixed to the testing device and placed around interproximal surfaces of plaque-covered posterior-shaped teeth extending to a 60° angle. The testing apparatus was set to move in a vertical direction to the tooth apex at two strokes per second with a 5 mm stroke for 15 seconds. The plaque substrate was then evaluated for maximum depth of the plaque removed. Results for all comparisons were statistically analyzed using the post hoc Tukey test for multiple pairwise comparisons and t-tests, assuming unequal variance, were used to compare mean depth of plaque removed for the same product under differing flossing pressures. Results: The mean plaque depth removed by GUM Expanding floss was greater than the mean plaque removed by the Reach Mint Waxed at 50 g (P< 0.05) and at 150 g (P< 0.001). The mean plaque depth removed by GUM Expanding floss was also greater than the Oral-B Glide Pro-Health Deep Clean mean plaque depth removal at both 50 g and 150 g (P< 0.001). Reach Mint Waxed floss plaque removal efficacy was superior to the Oral-B Glide Pro-Health Deep Clean at 50 and 150 g (P< 0.001 for each). Both the GUM Expanding floss and Reach Mint Waxed floss removed more plaque at 150 g than at 50 g (P< 0.001 for GUM Expanding and P< 0.01 for Reach Mint Waxed). (Am J Dent 2019;32:267-270).

 

 

Mail: Dr. S.L. Yankell, Yankell Research Consultants Inc., 15 East Maple Avenue, Moorestown, NJ 08057 USA, E-mail: YRCInc@aol.com

 

 

Effect of surface treatment and cement type on dentin bonding of processed resin composite

 

André V. Ritter, dds, ms, mba, Taiseer A. Sulaiman, bds, phd, Brandon M. Rodgers, bdsc, Flares Baratto-Filho, dds, ms, phd, Leonardo Cunha, dds, ms, phd, Carla Castiglia Gonzaga, dds, phd &  Gisele M. Correr, dds, ms, phd

 

Abstract: Purpose: To examine the effect of surface treatment and cement type on dentin bonding of processed resin composite restorations. Methods: Bovine incisors were sectioned to expose mid-dentin, and randomly assigned to four different groups: Group ULT, Lava Ultimate composite blocks were bonded to dentin with RelyX Ultimate; Group ULT-CJ was treated as in Group ULT but CoJet was used to treat the intaglio surface prior to bonding; Group UNC was bonded with RelyX Unicem 2; and Group UNC-CJ was treated as in Group UNC but CoJet was used to treat the intaglio surface. RelyX Unicem 2 was used as a self-adhesive resin cement, while RelyX Ultimate was used as an adhesive resin cement with Scotchbond Universal. All adhesives and resin composites were polymerized with a high-irradiance LED polymerizing light (Elipar DeepCure-S). After bonding, all specimens were kept in 100% humidity and 37°C for 7 days and then processed for microtensile bond strength (µTBS) testing (n=15). The failure mode was analyzed under SEM as cohesive, adhesive, or mixed. Data were analyzed for statistical significance using two-way ANOVA and Tukey’s HSD post-hoc test (α=0.05). Results: Mean µTBS values ranged from 8.83 MPa (±3.13 MPa) for UNC to 25.63 MPa (±5.94 MPa) for ULT-CJ. Means were statistically significantly higher for the adhesive cement when compared with the self-adhesive cement (P< 0.05), and, for the adhesive cement, CoJet resulted in statistically significantly higher means (P< 0.05). The number of pre-test failures was uniform across groups (n=2-4). Failures were predominantly adhesive and mixed. The adhesive resin cement RelyX Ultimate performed significantly better than the self-adhesive resin cement RelyX Unicem 2, and surface treatment with CoJet improved bond strengths of Lava Ultimate to dentin. (Am J Dent 2019;32:271-275).

 

 

Mail: Dr. André V. Ritter, Dept. of Cariology & Comprehensive Care, NYU College of Dentistry, 345 East 24^th Street, Ste 10W, New York, NY  10010 USA.  E-mail: avr6@nyu.edu

 

 

Antibacterial properties of silver-loaded gelatin sponges prepared with silver diamine fluoride

 

Linfeng Wu, phd, Shelly K. Gareiss, dds, Brian R. Morrow, ms, Jegdish P. Babu, phd, Timothy Hottel, dds, ms, mba, dba, Franklin Garcia-Godoy, dds, ms, phd, phd, Feng Li, phd &  Liang Hong, dds, ms, phd

 

Abstract: Purpose: To evaluate the antibacterial efficiency of silver-loaded gelatin sponges prepared from gelatin and silver diamine fluoride, Ag(NH₃)₂F. Methods: A series of novel silver-loaded gelatin sponges were prepared from gelatin and silver diamine fluoride. They were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activities against one oral bacteria model S. mutans were evaluated using the agar disk diffusion method and biofilm-grown bacteria assay. For the purpose of comparison, a second series of silver-loaded sponges were prepared using silver nitrate (AgNO₃) as the silver source. Results: FT-IR, SEM and EDX results confirmed the successful preparation of silver-loaded gelatin sponges from both silver diamine fluoride and silver nitrate. Agar disk diffusion assays revealed that the antibacterial activity of silver-loaded sponges was strongly correlated with the silver content, and also depending on the silver source used in the preparation of sponges. Sustained inhibition of S. mutans in agar plates was observed for silver-loaded gelatin sponges containing about 5 wt% Ag or more. Biofilm assays showed different viabilities when treated with different formulations, with the viability of 11.4±3.1% for the sponges containing 5.30±1.18 wt% Ag prepared from silver diamine fluoride, and the viability of 15.4±3.1% for the sponges containing 29.13±10.34 wt% Ag prepared from silver nitrate. (Am J Dent 2019;32:276-280).

 

 

Mail: Dr. Liang Hong, College of Dentistry, University of Tennessee Health Science Center, 875 Union Ave, Memphis, Tennessee, 38163, USA.  E-mail: lhong2@uthsc.edu

 

 

Coating of enamel and dentin with bioactive materials: Effect on adhesive interface of class V restorations

 

Francois Bonnafous, med dent, Ivo Krejci, dr med dent, pd  &  Tissiana Bortolotto, dr med dent, msc, phd, pd

 

Abstract: Purpose: To evaluate the effect of coating enamel and dentin with a calcium phosphate powder, a calcium fluoride silicon polymer, an oxalate and a functionalized tricalcium phosphate, on marginal adaptation of class V cavities restored with a universal adhesive containing the adhesive monomer with chemical bonding potential 10-MDP (Clearfil Universal Bond) and a hybrid composite (Clearfil APX). Methods: Class V cavities with margins located in enamel and dentin were coated with the different bioactive materials prior to the application of the adhesive and composite. After restoration polishing, the samples were subjected to a thermo-mechanical fatigue test. Gold coated resin-based replicas were readied to analyze the percentages of continuous margins (%CM) before and after loading to evidence differences between different enamel/dentin pre-treatments (Kruskal-Wallis, Duncan post hoc test). Results: The highest %CM was observed in the group in which enamel and dentin were coated with calcium phosphate powder prior to the application of the 10-MDP-containing adhesive. This was also the most stress-resistant group. (Am J Dent 2019;32:281-287).

 

 

Mail: Dr. Tissiana Bortolotto, Division of Cariology and Endodontology, University Clinic of Dental Medicine, Faculty of Medicine, University of Geneva, 19, rue Lombard, CH-1205 Geneva, Switzerland.  E-mail: Tissiana.Bortolotto@unige.ch

 

 

 

Effect of bleaching agents and toothpastes on the enamel: An in situ study

 

Manoelito Ferreira Silva-Junior, dds, ms, phd, Polyana Sanches da Cruz, dds, Antônio César Bozzi, eng, ms, phd, Luiz Gustavo Dias Daroz, dds, ms, phd  &  Claudia Batitucci dos Santos-Daroz, dds, ms, phd

 

Abstract: Purpose: To evaluate in situ the effect of different types of toothpaste on enamel surface topography, microhardness and surface roughness (Ra) after bleaching with 7.5% hydrogen peroxide (H₂O₂). Methods: This was a single-center, triple-blind, randomized, two-period, crossover in situ study in 15 subjects with 60 bovine enamel blocks (9.0×9.0×3.0mm) fixed to acrylic palatal devices which divided into six groups (n=10): G1: control: placebo toothpaste (PT) and placebo bleaching (PB); G2: conventional toothpaste (CT) and PB; G3: whitening toothpaste (WT) and PB; G4: PT and H₂O₂; G5: CT and H₂O₂; and G6: WT and H₂O₂. After 14 days of whitening and brushing regime, the mineral volumetric loss of the enamel surface was evaluated according qualitative scores, Ra was measured using 3D surface topography while Vickers microhardness (VH) (50g/10s) comparing the test area with the control area and using scanning electron microscopy imaging. Results: G1 and G2 showed no visible volumetric loss of the enamel mineral content. G5 and G6 showed higher volumetric loss of the enamel surface compared to the other groups (P< 0.05). There was no difference between the groups in terms of VH (P= 0.596). For all groups, except for G1 (P= 0.197), VH decreased in the test area as compared to the control area (paired t-test; P< 0.05). G4 showed less surface roughness than the other groups, although it did not differ from G1. G3 showed higher surface roughness than G1, G4 and G5, but did not differ from G2 or G6 (P< 0.05). For G2, G3, G5 and G6, it was seen that Ra increased in the test area when compared to the control area (P< 0.05). Bleaching gel and toothpaste had effect on the microhardness and roughness in the test area when compared to the control area. The change in enamel surface topography and roughness was related to the use of both conventional and bleaching toothpastes, independent of using bleaching gel. (Am J Dent 2019;32:288-292).

 

 

Mail: Dr. Claudia Batitucci dos Santos Daroz, Department of Prosthodontics, Avenue Marechal Campos 1468, Maruípe, Vitória-ES, Brazil 29040-090.  E-mail: claudiabatitucci@yahoo.com.br

 

 

Effects of mouthrinses on discoloration of CAD-CAM manufactured restorative materials

 

Mustafa Hayati Atala, dds, phd,  Elif Yeğin, dds, dclindent,  Nagehan Atala, dds,  Esra Şenlen, dds &  Serdar Bağlar, dds, phd

 

Abstract: Purpose: To investigate the in vitro effect of four different mouthrinses on discoloration of popular CAD-CAM blocks. Methods: 40 specimens were prepared and then were divided into five groups (n = 8) for each CAD-CAM block (Vitablocks Mark II, IPS e-max CAD, GC LRF, Enamic, Cerasmart). In total, four different mouthrinses for each group (Listerine Zero, Parodontax, Kloroben, Oral B Pro-Expert) and distilled water for the control group were used. The specimens were immersed in 20 ml solution for 2 minutes, twice a day for 21 days with a 12-hour interval. Color changes were measured with a digital spectrophotometer (Vita Easyshade) after 7, 14 and 21 days and specimens were prepared. For statistical analysis, color changes (∆E) were calculated and Kruskal Wallis and Wilcoxon tests were used. Results: There was not a significant difference in ΔE1 and ΔE2 values (P> 0.005) while there was a significant one in ΔE3 (P= 0.001) after Bonferroni correction for CAD-CAM materials were carried out as it is independent of the mouthrinse. Listerine Zero brought about the most noticeable color change in all CAD-CAM materials except e.Max after 21 days. (Am J Dent 2019;32:293-298).

 

 

Mail: Dr. Elif Yeğin, Department of Prosthodontics, Faculty of Dentistry, Biruni University, Zeytinburnu-Istanbul, Turkey.  E-mail: dtelifyegin@gmail.com

 

 

 

Incorporation of ZnCl₂ into an etch-and-rinse adhesive system and effect on flexural strength, degree of conversion and bond durability to caries-affected dentin

 

Cérida Aurelia Rodrigues Oliveira, dds, ms,  Rosa Maria Peixoto Campos, dds, ms, Júlia Peixoto Campos Macedo, dds, ms, phd,  Anderson Rodrigo Silva, dds, ms, phd, Leandro Nériton Cândido Máximo, dds, ms,  Tânia Mara Silva, dds, ms, Fabiana Mantovani Gomes França, dds, ms, phd,  Roberta Tarkany Basting, dds, ms, phd, Cecilia Pedroso Turssi, dds, ms, phd,  Sérgio Eduardo de Paiva Gonçalves, dds, ms, phd &  Flávia Lucisano Botelho Amaral, dds, ms, phd

 

Abstract: Purpose: To evaluate the effect of a zinc chloride (ZnCl₂) solution (2% wt), incorporated into a two-step etch-and-rinse adhesive system (AS), on microtensile bond strength (μTBS) to caries-affected dentin (CAD). Methods: First, the degree of conversion (DC) of the AS with and without the ZnCl₂ solution was evaluated by Fourier transform infrared spectroscopy (FTIR). Second, beam-shaped samples (7 mm × 2 mm × 1 mm) were prepared with the AS containing the ZnCl₂ solution to perform flexural strength (FS) tests. For μTBS testing purposes, CAD surfaces were etched with phosphoric acid and randomly divided into three groups (n=10): ZnCl₂- AS with ZnCl₂; NT (no treatment)- AS without ZnCl₂; and CHX - pretreatment with 2% chlorhexidine solution. AS (Adper Single Bond 2) was applied according to the manufacturer's instruction, and resin composite restorations were built up. After 24 hours, the resin-dentin blocks were sectioned into specimens (0.8 mm²), and then subjected to μTBS testing immediately following, or after 6 or 12 months of water storage (WS). The adhesive interface was evaluated by scanning electron microscope. Both μTBS and FS tests were performed using a universal testing machine (0.5 mm/minute). FS and DC data were submitted to the Student t-test, and μTBS data were subjected to two-way ANOVA and Tukey's test (α= 0.05). Results: DC was not affected by ZnCl₂ incorporation into AS (P= 0.2527). Higher FS values were obtained in the group with ZnCl₂ added to AS. Regarding μTBS, the mean of the NT group was statistically higher than that of the ZnCl₂ or the CHX groups (P< 0.001), regardless of WS, but the latter groups did not differ from each other. μTBS at 24 hours was statistically superior to that of 6 and 12 months of WS (P< 0.001). (Am J Dent 2019;32:299-305).

 

 

Mail: Prof. Dr. Flavia Lucisano Botelho do Amaral, School of Dentistry, São Leopoldo Mandic Institute and Dental Research Center, Rua José Rocha Junqueira, 13, Ponte Preta, Campinas, SP 13045-755, Brazil. E-mail: flbamaral@gmail.com

 

 

Efficacy of a propolis solution for cleaning complete dentures

 

Raphael Freitas de Souza, dds, msc, phd, Cláudia Helena Silva-Lovato, dds, msc, phd, Carolina Noronha Ferraz de Arruda, dds, msc, phd, Rômulo Rocha Regis, dds, msc, phd, Ana Paula Zanini, dds, Daniele Lucca Longo, dds, msc, phd, Amanda Peracini, dds, msc, phd, Ingrid Machado de Andrade, dds, msc, phd, Evandro Watanabe, bsc, msc, phd &  Helena de Freitas Oliveira Paranhos, dds, msc, phd

 

Abstract: Purpose: The efficacy of a propolis solution against denture biofilm was evaluated by means of an in vitro assessment and a cross-over randomized clinical trial. Methods: Acrylic resin specimens were contaminated by Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Candida albicans, Candida glabrata, Candida parapsilosis, immersed in a (A) propolis solution, (B) saline or (C) alkaline peroxide, applied onto Petri plates with culture medium and after incubation the number of colonies was counted. For clinical trial, 30 complete denture wearers were randomly assigned to groups (A) propolis solution, and (B) saline, following one of the sequences (I) A/B or (II) B/A. After each intervention, biofilm was quantified by means of digital photos taken from the intaglio surface and a microbiological quantification of Candida spp. and mutans streptococci was conducted. Results: Both propolis solution and alkaline peroxide reduced the microbial counts for S. mutans and C. albicans with significant and greater effect for group C (P< 0.05). However, no difference was found clinically between the interventions. The propolis solution showed an intermediate antimicrobial effect against S. mutans and C. albicans. Also, it did not exert an immediate effect on denture biofilm. (Am J Dent 2019;32:306-310).

 

 

Mail: Dr. Cláudia Helena Silva-Lovato, Department of Dental Materials and Prosthetics, School of Dentistry of Ribeirão Preto, University of São Paulo, Av. do Café s/n, 14040-904 Ribeirão Preto, SP, Brazil.  E-mail: chl@forp.usp.br

 

 

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                                                                                                                      Review & Meta-analysis Article

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Manual vs. rotary instrumentation in endodontic treatment of permanent teeth: A systematic review and meta-analysis

 

Mariela Peralta-Mamani, dds, ms, Daniela Rios, dds, ms, phd, Marco Antonio Hungaro Duarte, dds, ms, phd, Joel Ferreira Santiago Junior, dds, ms, phd  &  Heitor Marques Honório, dds, ms, phd

 

Abstract: Purpose: To systematically review all studies comparing manual instrumentation with at least one rotary instrument in the preparation of the root canal of permanent human teeth. Methods: The electronic databases PubMed, EMBASE, LILACS, IBECS and BBO were searched. In vitro studies published until 27 of September, 2016 were included. For statistical analysis, we used the Comprehensive Meta-Analysis software (Biostat), considering P< 0.05 significant. Results: A total of 1,104 articles published until September 27, 2016 were obtained, with 57 meeting the eligibility criteria. The studies were grouped according to the main methodology used (computerized tomography, periapical radiography, image amplification and scanning electron microscope). Due to the wide variability of the methodologies and evaluated parameters, a subgroup analysis was performed based on the evaluated parameter. The meta-analysis revealed that rotary instruments caused a significant reduction in instrumentation time and a smaller change of the canal curvature than manual instruments. The rotary instrumentation presented better results regarding root canal transportation, ability of centralization within the canal path and shaping of the canal. Manual instrumentation performed better with regard to the smear layer and debris production, more instrumented canal surfaces and fewer dentin defects. (Am J Dent 2019;32:311-324).

 

 

Mail: Dr. Heitor Marques Honório, Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry - University of São Paulo (FOB-USP), Alameda Octávio Pinheiro Brisola, 9-75, Vila Universitária, Zip Code 17012-901 Bauru, SP, Brazil.  E-mail: heitorhonorio@usp.br