^{April 2023 Abstracts}

Dentin abrasion using whitening toothpaste with various hydrogen peroxide concentrations

 

Jae-Heon Kim, ms, Soyeon Kim, bs, Franklin Garcia-Godoy, dds, ms, phd, phd  &  Young-Seok Park, dds, phd

 

Abstract: Purpose: To compare the amount of abrasion of four whitening toothpastes, two conventional toothpastes, and seven experimental toothpastes with varying concentrations of hydrogen peroxide. Methods: Bovine dentin specimens were treated with the four whitening toothpastes (containing three different concentrations of hydrogen peroxide; 0.75%, 1.50%, and 2.80%), two conventional toothpastes without hydrogen peroxide, seven experimental toothpastes (concen-trations of hydrogen peroxide: 0.75%, 1.50%, 3.0%, 4.50%, 6.0%, 7.50%, and 9.0%), and distilled water. After 10,000 strokes of toothbrushing, the amount of abrasion on the dentin surface was measured with a contactless 3D surface profiler (n= 8). The pH of all solutions, the weight percentages of the particles, and the component of particles in the toothpaste were analyzed. The correlations between the dentin abrasion, pH, and weight percentages of the particles in the toothpastes were investigated. Results: The amount of abrasion of the two conventional toothpastes were 1.1-3.6 times higher than those of the four whitening toothpastes. Likewise, the pH of the conventional toothpaste was higher than those of the other whitening toothpastes. No significant differences were found among the four whitening toothpastes. The four whitening toothpastes consisted of a relatively lower weight percentage of particles compared to the two conventional toothpastes. A strong positive correlation was observed between the dentin abrasion and the weight percentages of the particles (r= 0.913; P< 0.05). Furthermore, no significant differences in the amount of abrasion were observed between the specimens treated with seven experimental toothpastes and those treated with distilled water. (Am J Dent 2023;36;55-61).

 

 

 

Mail: Prof. Young-Seok Park, Department of Oral Anatomy and Dental Research Institute, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, S. Korea. E-mail: ayoayo7@snu.ac.kr

 

 

 

Denture cleanser effect on resilient liners with distinct optical characteristics

 

 

Isabella Rocha Pinheiro Coelho, dds, Cláudia Helena Silva-Lovato, dds, msc, phd, Carolina Noronha Ferraz de Arruda, dds, msc, phd, Eliseu Aldrighi Münchow, dds, msc, phd, Gabriella Rodrigues Cherubino Silveira, dds, Rodrigo Furtado de Carvalho, dds, msc, phd &  Mauricio Malheiros Badaró, dds, msc, phd

 

Abstract: Purpose: To evaluate denture cleansing solutions regarding the surface roughness and color stability of two resilient liners with distinct optical characteristics used for the maximum recommended period of use. Methods: The specimens of each resilient liner, transparent and white, were randomly distributed into groups (n= 15) of a daily 20-minute immersion simulation of 0.25%, 0.5% and 1% sodium hypochlorite (SH) and 4% acetic acid solutions. Surface roughness (Ra) and color stability (ΔE CIELab formula and NBS systems) were measured after 7, 14, 21, 30, 60, 90, 180, and 270 days. The factors of variations analyzed were material, solutions, and time of immersion. Statistical analysis used three-way ANOVA and Tukey tests (Ra), and repeated measure ANOVA (ΔE and NBS systems), P< 0.05. Results: For Ra analysis, the variations occurred regardless of time and solution, as the white liner showed the greatest changes (P< 0.001). Regarding interactions between solution and time, in the period of 21 days until 270 days, Ra was equivalent for all solutions (P= 0.001). ΔE analysis showed a difference between solutions (P= 0.000) and interaction between time and solution (P= 0.000). For the transparent liner, the greatest changes were found for 1% SH after 60 days, however, at 270 days there was a color change equivalence with 0.5% SH, while 4% acetic acid solution showed intermediate values. For the white liner, 1% SH showed the highest color changes for all evaluated times, and the other evaluated solutions were similar after 270 days. For both resilient liners, 0.25% SH showed the smallest changes for the evaluated properties. (Am J Dent 2023;36:62-68).

 

 

 

 

 

 

Mail: Prof. Dr. Maurício Malheiros Badaró, Department of Dentistry. Federal University of Santa Catarina (UFSC). Delfino Conti st., 1240 - Trindade, Florianópolis - SC, 88040-535, Brazil.  E-mail: mauricio.badaro@ufsc.br

 

 

 

Needle-free anesthetic polymeric device for dental anesthesia in children: A randomized clinical trial

 

Gisele Carvalho Inácio, dds, msc, Vinícius Pedrazzi, dds, msc, phd, Osvaldo de Freitas, msc, phd, Maíra Peres Ferreira Duarte, msc, phd, Raquel Assed Bezerra da Silva, dds, msc, phd, Paulo Nelson-Filho, dds, msc, phd, Francisco Wanderley Garcia de Paula-Silva, dds, msc, phd, 

Fabrício Kitazono de Carvalho, dds, msc, phd, Marília Pacífico Lucisano, dds, msc, phd &  Alexandra Mussolino de Queiroz, dds, msc, phd

 

Abstract: Purpose: To evaluate efficacy of an anesthetic mucoadhesive film with a polymeric device (PD) in promoting anesthesia compared to conventional local infiltration (LA) in children. Methods: 50 children aged 6-10 years (both genders) needing similar procedures on homologous teeth on the maxilla were included. The parents and children were asked about perception of dental treatment. The child’s heart rate per minute (bpm) and blood pressure were evaluated before and after each anesthetic technique (AT) procedure. Anesthesia efficacy was measured by reporting pain using Wong-Baker Faces Scale. Children’s behavior and AT preferences were also evaluated. Paired T-test, chi-square and Wilcoxon test were used for statistical comparisons. Results: Fear of anesthesia was reported by 50% of caregivers and by 66% of children. No difference was observed in systolic (P= 0.282) and diastolic (P= 0.251) blood pressure, comparing both AT. Difference was observed regarding the child’s behavior when the PD was used (P= 0.0028). Evaluating the face scale, 74% of the children selected the “no pain” (face 0) (P< 0.0001) for PD, and 26% for LA. PD was preferred by 86% of children. Only 20% of the PD anesthesia needed to be complemented by LA. (Am J Dent 2023;36:69-74).

 

 

Mail: Dr. Marília Pacífico Lucisano, Department of Pediatric Dentistry, Faculty of Dentistry of Ribeirão Preto – USP, Av. do Café, s/n, Monte Alegre, 14040-904 Ribeirão Preto, SP, Brazil. E-mail: marilia.lucisano@forp.usp.br

 

 

 

Effect of effervescent tablets on removable partial denture hygiene

 

Victor Garone Morelli, dds, msc,  Viviane de Cássia Oliveira, bsc, msc, phd, Glenda Lara Lopes Vasconcelos, dds, msc, phd,  Patricia Almeida Curylofo, dds, msc, phd, Rachel Maciel Monteiro, b-bmed, msc, phd,  Ana Paula Macedo, bee, msc, phd &  Valéria Oliveira Pagnano, dds, msc, phd

 

Abstract: Purpose: To evaluate the effectiveness of five alkaline peroxide-based effervescent tablets in reducing both biofilms and the food layer adhered on the cobalt-chromium surface. Methods: Cobalt-chromium metal alloy specimens were contaminated with Candida albicans, Candida glabrata, Streptococcus mutans and Staphylococcus aureus. After biofilm maturation, the specimens were immersed in Polident 3 Minute, Polident for Partials, Efferdent, Steradent, Corega Tabs or distilled water (control). Residual biofilm rates were determined by colony forming units counts and biofilm biomass. In parallel, to investigate the denture cleaning capability of effervescent tablets, artificially contaminated removable partial dentures were treated with each cleanser. Data were analyzed by Kruskal-Wallis followed by Dunn post hoc test or ANOVA followed by Tukey post hoc test (α= 0.05). Results: None of the hygiene solutions reduced C. albicans biofilm. Efferdent and Corega Tabs promoted reduction of C. glabrata biofilm, while Steradent was favorable against S. aureus biofilm. For S. mutans, lower biofilm rates were observed after immersion in Polident for Partials and Steradent. The effervescent tablets showed good cleaning performance, removing an artificial layer with carbohydrates, proteins, and fats, however, they were not effective in removing aggregated mature biofilm. (Am J Dent 2023;36:75-80).

 

 

Mail: Dr. Viviane de Cássia Oliveira, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Avenida do Café, S/N, 14040-904, Ribeirão Preto, SP, Brazil. E-mail: vivianecassia@usp.br

 

 

 

Clinical evaluation of thermo-viscous and sonic fill-activated bulk fill composite restorations

 

 

Kholood El sayed Morsy, dds, ms,  Mirvat Mohamed Salama, dds, ms, phd &  Thuraia Mohamed Genaid, dds, ms, phd

 

 

Abstract: Purpose: To evaluate the clinical performance of VisCalor and SonicFill versus the conventionally applied bulk fill composite restorations in Class I cavities over 18-month follow-up periods. Methods: 60 posterior teeth were used in this study in 20 patients (age ranging from 25-40). They were randomly divided into three equal groups (n=20) based on the type of restorative material employed. Each resin composite restorative system with the recommended manufacturer’s adhesive was applied and cured according to the manufacturer’s instructions. All restorations were evaluated clinically at baseline (after 24 hours), 6, 12, and 18 months according to the modified United States Public Health Service (USPHS) by two examiners for retention, marginal adaptation, marginal discoloration, secondary caries, postoperative sensitivity, color match, and anatomical form. Results: All tested groups exhibited no significant difference regarding all the clinical evaluation criteria at all evaluation periods, except for marginal adaptation and discoloration. Marginal changes (Bravo score) were detected only after 12 months in 15% of Filtek bulk fill restorations (Group 1) only while all VisCalor bulk fill restorations in Group 2 and SonicFill 2 restorations in Group 3 recorded 100% Alpha scoring, with no statistically significant difference among the groups (P= 0.050). After 18 months, Bravo scores increased to 30% in Group 1, while 5 and 10% Bravo scores were recorded in restorations of Groups 2 and 3, respectively with a statistically significant difference (P= 0.049) among them. Marginal discoloration was observed after 12 months in Group 1 only, however, no statistically significant difference was found among the groups (P= 0.126). At 18 months, all tested groups had a statistically significant difference between them (P= 0.027). (Am J Dent 2023;36:81-85).

 

 

 

Mail: Dr. Kholood El Sayed Morsy, Faculty of Dentistry, Tanta University, Egypt. E-mail: khlood_morsy@yahoo.com

 

 

 

Multicenter study on visual color difference thresholds. A secondary analysis of light, medium, and dark tooth-colored specimens

 

Eman H. Ismail, dds, ms, phd,  Razvan I.  Ghinea, ms, phd,  Luis J. Herrera,  ms, phd,  Esam Tashkandi, Bds, ms, phd &  Rade D. Paravina, dds, ms, phD

 

Abstract: Purpose: This secondary analysis further analyzed variations in the 50:50% perceptibility and acceptability thresholds (PT and AT, respectively) pertaining to light, medium, and dark tooth-colored specimen sets. Methods: Primary raw data from the original study was retrieved. Visual thresholds (Perceptibility - PT and Acceptability - AT) were analyzed among the three specimen sets - light, medium, and dark. The Wilcoxon signed-rank test was used for paired specimens, and the Wilcoxon rank-sum nonparametric test was used for independent specimens (α= 0.001). Results: The 50:50% CIEDE2000 PT and AT values were significantly higher for the light-colored specimen set when compared with the medium and dark-colored specimens: 1.2, 0.7, 0.6, respectively (PT) and 2.2, 16, 14 (AT), respectively (P< 0.001). Independent of the observer group, the highest PT and AT values were always found for the light-colored specimen sets (P< 0.001). Dental laboratory technicians had the lowest visual thresholds, but not significantly different from the other observer groups studied (P> 0.001). Similarly, all research sites had statistically higher visual thresholds for the light-colored specimen set than for the medium- or dark-colored sets, except for two sites that showed statistically similar results for medium-colored specimens but were significantly different from the dark-colored set. Among the different research sites, sites 2 and 5 registered significantly higher PT thresholds for the light specimens (1.5 and 1.6, respectively), and site number 1 had a significantly higher AT threshold relative to the other sites. The 50:50% perceptibility and acceptability thresholds were significantly different among light-, medium-, and dark-colored specimens for different research sites and observer groups. (Am J Dent 2023;36:86-90).

 

 

 

 

Mail: Dr. Eman H. Ismail, Clinical Dental Sciences Department, College of Dentistry, Princess Nourah Bint Abdulrahman University, Airport Road, Riyadh, Kingdom of Saudi Arabia. E-mail: ismail.e.h@hotmail.com, ehismail@pnu.edu.sa

 

 

 

Antibacterial effects of surface pre-reacted glass-ionomer (S-PRG) filler eluate on polymicrobial biofilms

 

Kiyoshi Tomiyama, phd,  Masato Ishizawa, phd,  Kiyoko Watanabe, phd, Akira Kawata, phd, Nobushiro Hamada, phd  &  Yoshiharu Mukai, phd

 

Abstract: Purpose: To analyze the effects of surface pre-reacted glass-ionomer (S-PRG) filler eluate on polymicrobial biofilm metabolism and live bacterial count. Methods: Biofilm was formed using glass disks 12 mm in diameter and 150 µm in thickness. Stimulated saliva was diluted 50-fold with buffered McBain 2005 and cultured in anaerobic conditions at 37°C for 24 hours in anaerobic conditions (10% CO₂, 10% H₂, 80% N₂) to form the biofilm on the glass disks. Following this, biofilms were treated with (1) sterilized deionized water (control), (2) 0.2% chlorhexidine digluconate (0.2CX), (3) S-PRG eluate diluted to 10% (10% S-PRG)，(4) 20% S-PRG，(5) 40% S-PRG，(6) 80% S-PRG，and (7) S-PRG for 15 minutes (n= 10 per group), and samples were subdivided into two groups for measuring live bacterial count immediately after treatment and after 48 hours of culturing after treatment. The pH of the spent medium collected at the time of culture medium exchange was tested. Results: Immediately after treatment, the live bacterial count of samples treated with drug solutions was significantly lower than the control (8.2 × 10⁸), and the counts of samples treated with 0.2CX (1.3 × 10⁷) and S-PRG (1.4 × 10⁷) were significantly lower than those treated with diluted S-PRG (4.4 × 10⁷–1.4 × 10⁸). When the medium was measured again after culturing for 48 hours, growth was continually inhibited in all treatment groups and the bacterial count of samples treated with S-PRG (9.2 × 10⁷) was significantly lower than that of samples treated with 0.2CX (1.8 × 10⁸). The pH of spent medium immediately after treatment was significantly higher in groups treated with drug solutions (5.5–6.8) than the controls (4.2), and it was highest in the S-PRG-treated group (6.8). Thereafter, when culturing was continued for 48 hours, the pH of all treated groups decreased; however, the pH of the S-PRG-treated group was significantly higher than groups treated with other drug solutions. (Am J Dent 2023;36:91-94).

 

 

Mail: Prof. Yoshiharu Mukai, Department of Restorative Dentistry, Kanagawa Dental University, 82 Inaokachō, Yokosuka, Kanagawa 238-8580, Japan.  E-mail: mukai@kdu.ac.jp

 

 

 

Evaluation of oral and perioral irritation and sensitization potential of a whitening gel and a whitening toothpaste containing potassium monopersulfate

 

Yiming Li, dds, msd, phd,  Montry S. Suprono, dds, msd,  Connie Cheung, phd,  Daniella Urbach-Ross, phd, Brian A. Wall, phd,  Cajetan Dogo-Isonagie, phd,  Michele Arambula, bs  &  Xing Xin, phd

 

Abstract: Purpose: Two clinical trials were conducted to investigate the oral and perioral irritation and sensitization potential of a tooth whitening leave-on-gel alone and in combination with a whitening toothpaste, each containing 1.0% of the active ingredient potassium monopersulfate (MPS). Methods: Both clinical trials were Institutional Review Board (IRB) approved, double-blind, randomized, and parallel group designed studies. For the MPS leave-on gel study, 200 qualifying and consented subjects were randomly assigned to two groups: (1) 0.1% hydrogen peroxide (H₂O₂) gel pen (34 subjects); and (2) 0.1% H₂O₂ + 1.0% MPS gel pen (166 subjects). Subjects used the assigned products according to instructions provided and returned on Days 22 and 36 for oral and perioral tissue examination (pre-challenge). At the Day 36 visit, the subject applied the assigned gel on site (challenge) and received oral and perioral tissue examinations 1 and 24 hours following the application to detect any post-challenge tissue reactions. For the MPS toothpaste/MPS gel pen study, 200 qualifying and consented subjects were randomly assigned to three groups: (1) Placebo toothpaste + placebo gel pen (66 subjects); (2) 1.0% MPS toothpaste + 1.0% MPS gel pen (67 subjects); and (3) 1.0% MPS toothpaste + placebo gel pen (67 subjects). The study design and procedures were the same as those for the MPS gel pen study described above. Results: For the MPS gel pen study, 192 subjects completed the study. None of the eight dropouts was related to the product use. The demographic data were com-parable between the two groups. No evidence of tissue irritation and sensitization was detected in any subjects at any visit, and the findings were comparable between the groups. The detected and self-reported tissue issues were minimal and minor, and they were comparable between the two groups. For the MPS toothpaste/MPS gel pen study, 200 subjects were enrolled with 12 dropped from the study, resulting in an overall dropout rate of 6%. Of the 12 that did not complete the study, none were due to product-related use. The demographic data were comparable among the three groups. The detected and self-reported tissue issues were minimal and minor, and they were comparable among the three groups. (Am J Dent 2023;36:95-100).

 

 

Mail: Dr. Yiming Li, Loma Linda University School of Dentistry, 11175 Campus Street, A1010, Loma Linda, CA 92350, USA. E-mail: yli@llu.edu

 

 

 

Mechanical properties of bulk-fill resin composites with single increment up to 4 mm: A novel mechanical strength test

 

Jiaxue Yang, mds, Ying Chen, mds, Hongliang Meng, mds, Jiadi Shen, mds, Mengyuan Liao, mds &  Haifeng Xie, phd

 

Abstract: Purpose: To evaluate the mechanical properties of two brands of bulk-fill resin composites placed in a single increment up to 4 mm thickness via a novel mechanical strength test and provide related explanations. Methods: Light transmission (LT), translucency parameter (TP), color difference (ΔE), Vickers hardness (HV) of two bulk-fill resin composites (Filtek Bulk Fill Posterior, Tetric N-Ceram Bulk Fill) and two conventional resin composites (Z100, Spectrum TPH) were evaluated. A novel flexural strength (FS) test method was applied for bulk-fill resin composite to determine the FS value of the bottom composites at depths of 1, 2, 3, and 4 mm after 24 hours of aging treatment (3 months water storage and 15,000 thermal cycles). The conventional resin composites were also tested for FS and all the FS results were subjected to Weibull analysis. Degree of conversion (DC) in the bulk-fill resin composites, light-cured at depths of 1, 2, 3, and 4 mm and conventional resin composites at depths of 2 and 4 mm, were assessed by FTIR. Results: Both bulk-fill resin composites showed higher light transmission and translucency than that of conventional ones at each of the same thicknesses (1, 2, 3, 4 mm), wherein their flexural strength was not affected by depth. The Weibull analysis suggested both bulk-fill resin composites achieved good reliability and structural integrity under each curing thickness. Vickers hardness was affected by the material type and thickness. Bulk-fill resin composites showed a decrease in degree of conversion between 1 mm and 4 mm, but both were over 55%. (Am J Dent 2023;36:101-108).

 

 

 

 

 

 

Mail: Dr. Haifeng Xie, Stomatological Hospital of Jiangsu Province, Han-Zhong Road 136th, Nanjing 210029, China. E-mail: xhf-1980@126.com