^{June 2021 Abstracts}

 

 

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                                                                                                                           Research Article

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Plaque reduction and tensile strength evaluations of three dental floss products

 

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

 

Abstract: Purpose: To compare GUM ButlerWeave Mint waxed floss, Reach Mint waxed floss and Oral-B Glide Pro-Health Original waxed floss for the tensile strength parameters, load and elongation, and for their ability to reduce artificial plaque. Also examined is the potential relationship between the tensile strength physical attributes and floss efficacy. Methods: For artificial plaque removal, floss products were placed around interproximal surfaces of artificial plaque-covered posterior-shaped teeth extending to a 60° angle. The testing apparatus moved the floss in a vertical direction to the tooth apex at two strokes per second with a 5 mm stroke for 15 seconds at a pressure of 150 g. The artificial plaque substrate was then evaluated for depth of artificial plaque removed (DPR) using a color comparison scale. Two tensile strength assays measuring maximum load and elongation also were conducted; the assays were based on the guidelines of the American Society for Testing and Materials. Twenty cm floss segments were pulled apart using a constant velocity, a load cell of 5 kN and a test speed of 1000 mm/minute until each floss segment broke apart. For each floss segment, the maximum load was measured in pounds and the elongation was measured in millimeters. Results for artificial plaque removal and tensile strength assays were statistically analyzed using the post hoc Tukey test for multiple pairwise comparisons and t-tests, assuming unequal variance, to compare the DPR, load, and elongation means. Results: In the artificial plaque removal assay, the mean DPR for GUM ButlerWeave Mint waxed floss was greater than the mean DPR for Reach Mint Waxed floss and Oral-B Glide Pro Health Original Waxed floss (P< 0.001). The mean DPR for Reach Mint waxed floss was also greater than Oral-B Glide Pro Health Original waxed floss mean DPR (P< 0.005). In the tensile strength load assay, both Oral-B Glide Pro Health Original waxed floss and GUM ButlerWeave Mint waxed floss had statistically higher means than Reach Mint waxed floss (P< 0.001 for each). There was no significant difference between the Oral-B Glide Pro Health and GUM ButlerWeave Mint waxed floss means (P> 0.05). In the elongation assay, the GUM ButlerWeave Mint waxed floss and Reach Mint waxed floss have statistically higher means than Oral-B Glide Pro Health floss (P< 0.001 for each). There was no statistically significant difference between the GUM ButlerWeave Mint waxed floss and Reach Mint waxed floss means (P> 0.05). In these laboratory assays there were no clear relationships, causal or otherwise, between artificial plaque removal and the testing tensile strength evaluations conducted. (Am J Dent 2021;34:123-126).

 

 

Mail: Mr. L. Angel Gonzalez, Sunstar Americas Inc., 301 E Central Rd, Schaumburg, IL 60195 USA. E-mail: Angel.Gonzalez@us.sunstar.com

 

 

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                                                                                                                           Research Article

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Effect of cigarette smoke on color stability and surface roughness of different soft denture lining materials. An in vitro study

 

 

Mohammed Sayed, bds, mds, phd, Saurabh Jain, bds, mds, Meena Jain, bds, mds, phd, Khalid R. Kubaisi, bds, Mohammed A.A.A. Alhazmi, bds, Emad A.O. Kamli, bds  &  Aparna Aggarwal, bds, mds

 

Abstract: Purpose: To evaluate the effect of cigarette smoke on the surface roughness and color stability of three different soft denture liners. Methods: Three commonly used commercially available, chair-side, long-term vinyl polysiloxane soft denture liners were used for this study [Sofreliner Tough (S) Soft, Silagum Comfort Soft Relining, and GC Reline Soft]. Thirty disk-shaped specimens of each material, with a diameter of 25 mm and thickness of 2 mm, were fabricated. Initial color and surface roughness readings were recorded. The specimens of each group were randomly divided into two groups (n= 15): the control group (C) and the study group (S). The control group specimens were stored in distilled water and the study group samples were exposed to cigarette smoke in a custom-made smoking chamber. Final color and surface roughness readings were recorded. A single operator performed all the measurements. The differences in color and surface roughness were calculated. Statistical analysis was performed using two-way ANOVA, post-hoc Tukey test, and paired t-test. For all the analyses, a P< 0.05 was regarded as statistically significant. Results: After exposure to smoke, all groups showed a significantly perceptible color change (ΔE > 3.7). The greatest color change was seen in the Silagum group (ΔE= 8.94 ± 0.42), followed by the Sofreliner group (ΔE= 7.85 ± 0.47), with the least change in the GC reline group (ΔE= 3.87 ± 0.46). The mean color change after smoke exposure showed a statistically significant difference among all three study groups. The highest change in surface roughness was observed in the Silagum group (ΔR= 0.687 ± 0.14) followed by the GC reline group (ΔR= 0.265 ± 0.12), with the least change in the Sofreliner group (ΔR= 0.238 ± 0.06). There was a statistically significant difference between each group before and after exposure to smoke. Exposure to cigarette smoke caused significant changes in the color and surface roughness of all three soft denture liners tested in this study. The extent of these changes varied for each material. (Am J Dent 2021:34:132-136).

 

 

 

 

 

Mail: Dr. Saurabh Jain, Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia, 45142.  E-mail: drsaurabhjain79@gmail.com

 

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Cleaning of dental handpieces and associated parameters: Internal and external cleaning, drying and rotation

 

Damien Offner, dds, phd, Julie Scholler, pharmd, phd  &  Anne-Marie Musset, dds, phd

 

Abstract: Purpose: To evaluate the cleaning of dental handpieces and its associated parameters, internal, external cleaning and drying, and rotation, for two washer-disinfectors: Teon+ by W&H, and a dental rack for WD290 by Belimed. Methods: An original method was developed with resin flags on dental burs to assess the inner rotation during the cleaning cycle. Concerning the cleaning and drying evaluation, three groups (9, 24 and 22 handpieces) were used in different conditions: soiled with Soil Test, soiled with heparinized blood, used in real conditions after a dental procedure, and clean (as control). Cycles were performed with the two washer-disinfectors, followed by a visual evaluation and a biuret reaction test. Results: The method we developed was effective to assess the inner rotation of handpieces. The internal cleaning was successful for real conditions and control handpieces, but unsuccessful for all the artificially soiled handpieces except one. All the handpieces showed substantial humidity on their inner surfaces after cleaning. The internal cleaning of handpieces and its evaluation are both difficult to perform. A questioning about the relevance of some tests required in the ISO 15883 about handpieces requires further study. Cleaning devices and their parameters should be optimized to offer better cleaning skills, and testing-tools should be developed and validated to easily assess their performances. (Am J Dent 2021;34:137-142).

 

 

 

 

 

 

Mail:  Dr. Damien Offner, Unit of Medicine and Oral Surgery, University Hospital of Strasbourg, 1 Place de l’Hôpital, F-67000 Strasbourg, France.  E-mail: doffner@unistra.fr

 

 

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Bulk-fill versus layering pure ormocer posterior restorations: A randomized split-mouth clinical trial

 

Carlos Rocha Gomes Torres, dds, phd, Ana Luiza Barbosa Jurema, dds, ms, Mauricio Yugo de Souza, dds, ms, Rebeca Di Nicoló, dds, ms, phd  &  Alessandra Bühler Borges, dds, ms, phd

 

Abstract: Purpose: To evaluate the clinical performance of Class II restorations made with bulk-fill or layering pure ormocer materials, as well as the time necessary to fill the preparations. Methods: After ethics approval, a randomized controlled split-mouth clinical trial was performed. 30 subjects were selected according to the inclusion/exclusion criteria, and two restorations were randomly performed in each first or second molar that presented caries, fracture, or cosmetic needs. One restoration was done with the bulk-fill material Admira Fusion x-tra, applied with increments up to 4 mm (intervention group), while the second was performed with the regular Admira Fusion, applied by a 2 mm layering technique (control group). The universal adhesive system Futurabond U was used for both groups. The subjects and examiners were blinded, and the examiners were previously calibrated. The restorations were evaluated according to FDI criteria, after 7 days, 6, 12 and 24 months, and the outcome was success rate based on esthetic, functional and biological properties. The time necessary for application of both materials into the preparations was also measured. Results: After 24 months, 26 patients attended the recall and 52 restorations were evaluated. The Fisher’s statistical analysis (α= 5%) showed non-significant differences between techniques for esthetic, biological and functional properties in all evaluations (P> 0.05). After 2 years, 96% of the subjects for both groups did not show any sign of post-operative sensitivity and 100% of the teeth were vital and without secondary caries. Around 70% of the restorations received score excellent for surface luster, more than 83% for surface staining and 63% for color match. In relation to marginal adaptation and marginal staining, more than 80% for the layering material and 63% for the bulk showed excellent scores. Only three restorations of the 60 performed showed small fractures, although not affecting the esthetics or function. The time for composite application was significantly shorter for the bulk material (P= 0.0454). After 24 months of intraoral service, the restorations made with both materials presented similar and excellent clinical performance for all parameters analyzed. The bulk-fill material required significantly less chair time to apply than the layering one, simplifying and accelerating the restorative technique. (Am J Dent 2021;34:143-149).

 

 

Mail: Dr. Carlos Rocha Gomes Torres, Department of Restorative Dentistry, São Paulo State University - UNESP, Institute of Science and Technology, Avenida Engenheiro Francisco José Longo, 777, São José dos Campos, São Paulo, Brazil 12245-000. E-mail: carlos.rg.torres@unesp.br

 

 

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Biological and physical properties of a reline acrylic resin after immersion in liquid antiseptic soaps

 

Isadora Ferreira Malavolta, dds,  Camilla Olga Tasso, dds, msc,  Túlio Moradin Ferrise, dds, msc, phd, Jacqueline de Oliveira Zoccolotti, dds, msc,  Maria Isabel Amaya Arbeláez, dds, msc, phd, Paula Volpato Sanitá, dds, msc, phd  &  Janaina Habib Jorge, dds, msc, phd

 

Abstract: Purpose: To evaluate some biological (Candida albicans biofilm formation and cytotoxicity) and mechanical (roughness and hardness) properties of a hard reline acrylic resin after immersion in liquid disinfectant soaps. Methods: Reline samples were made (14 mm in diameter and 1.2 mm in thickness) and immersed in different disinfectant solutions: DW: distilled water at 37°C (control group); DS: Dettol liquid soap; and LS: Lifebuoy liquid soap. After immersion in the different groups, the properties of C. albicans biofilm formation, cytotoxicity, hardness, and roughness were evaluated. Each sample was immersed in the disinfectant solutions for 8 hours for microbiological testing and for 0, 7, 14, 21, and 28 days, with daily immersion cycles, for cytotoxicity and mechanical testing. Data were tabulated and analyzed by Shapiro-Wilk and Levene statistical tests. Based on these results, the appropriate tests for finding statistically significant differences were applied (α= 0.05). Results: There was a reduction of roughness after immersion of the samples in DS for 21 days (P= 0.0001) and LS for 28 days (P= 0.0218). Hardness values significantly increased after storage of samples in solutions (0.0007≥ P≥ 0.0076), especially considering the longer period of immersion (28 days). The viability and metabolic activity of the biofilm formed on the hard reline samples were significantly reduced (P< 0.05) after soaking in Lifebuoy liquid soap in relation to DW. In addition, the samples immersed in the different solutions were not cytotoxic, as they inhibited less than 25% in relation to the control group (100% of cell viability). (Am J Dent 2021;34:150-156).

 

 

 

 

Mail: Dr. Janaina Habib Jorge, Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araraquara, R. Humaitá, n 1680, Araraquara, SP, CEP 14801-903, Brazil. E-mail: habib.jorge@unesp.br

 

 

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                                                                                                                           Research Article

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Loading stress distribution in posterior teeth restored by different core materials under fixed zirconia partial denture: A 3D-FEA study

 

Larissa Mendes Campaner, dds, msc,  Amanda de Oliveira Pinto Ribeiro, dds, msc, João Paulo Mendes Tribst, dds, msc, phd,  Alexandre Luiz Souto Borges, dds, msc, phd, Alessandro Espedito di Lauro, dds, msc, phd,  Antonio Lanzotti, eng, phd, Franklin Garcia-Godoy, dds, ms, phd, phd  &  Pietro Ausiello, dds, ms, phd

 

Abstract: Purpose: To evaluate the effect of different substrate stiffness [sound dentin (SD), resin composite core (RC) or metal core (MC)] on the stress distribution of a zirconia posterior three-unit fixed partial denture (FPD). Methods: The abutment teeth (first molar and first premolar) were modeled, containing 1.5 mm of axial reduction, and converging axial walls. A static structural analysis was performed using a finite element method and the maximum principal stress criterion to analyze the fixed partial denture (FPD) and the cement layers of both abutment teeth. The materials were considered isotropic, linear, elastic, homogeneous and with bonded contacts. An axial load (300 N) was applied to the occlusal surface of the second premolar. Results: The region of the prosthetic connectors showed the highest tensile stress magnitude in the FPD structure depending on the substrate stiffness with different core materials. The highest stress peak was observed with the use of MC (116.4 MPa) compared to RC and SD. For the cement layer, RC showed the highest values in the molar abutment (14.7 MPa) and the highest values for the premolar abutment (14.4 MPa) compared to SD (14.1 and 13.4 MPa) and MC (13.8 and 13.3 MPa). Both metal core and resin composite core produced adequate stress concentration in the zirconia fixed partial denture during the load incidence. However, more flexible substrates, such as composite cores, can increase the tensile stress magnitude on the cement. (Am J Dent 2021;34:157-162).

 

 

Mail: Dr. Pietro Ausiello, Via Sergio Pansini, 5/E17, 80131 Naples NA, Italy. E-mail: pietausi@gmail.com

 

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Prevalence of periapical abscesses in vitamin D deficient patients

 

Ilan Rotstein, dds  &  Joseph Katz, dmd

 

Abstract: Purpose: To assess the prevalence of periapical abscesses (PAs) in individuals with vitamin D deficiency who are not treated and in individuals treated with a vitamin D supplement (calciferol). Methods: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for periapical abscess and vitamin D deficiency were retrieved by searching the appropriate query in the database. The Risk Ratio (RR) for periapical abscesses, its association with vitamin D deficiency and intake of calciferol were calculated and analyzed statistically. Results: The RR for prevalence of periapical abscesses in patients with vitamin D deficiency was 3.44. Presence of PAs was significantly higher in patients with vitamin D deficiency compared to patients without vitamin D deficiency (P< 0.0001). The RR and the prevalence of PAs for patients treated with calciferol were significantly lower compared to untreated patients (P< 0.0001). (Am J Dent 2021;34:163-165).

 

 

Mail: Dr. Ilan Rotstein, 3585 S. Vermont Avenue, Unit 7877, Los Angeles, CA 90007, USA. E-mail: ilan@usc.edu

 

 

 

 

 

 

 

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The effect of SARS-CoV-2 effective mouthwashes on the staining, translucency and surface roughness of a nanofill resin composite

 

Yusuf Bayraktar, dds, msc, phd, Kübra Karaduman, dds, Baturalp Ayhan, dds &  Meltem Karsiyaka Hendek, dds, msc, phd

 

Abstract: Purpose: To evaluate the effect of SARS CoV-2 effective mouthwashes on the color change (ΔE), translucency parameter (TP) and average surface roughness (Ra) of a nanofill resin composite (Filtek Ultimate). Methods: 91 composite specimens (10 mm in diameter, 1 mm thickness) were prepared using a stainless-steel mold and randomly divided to seven groups as follows: Group 1 (CHX): 0.12% CHX digluconate + 0.15% benzydamine hydrochloride (96% alcohol), Group 2 (HAc): hypochlorous acid (500 ppm), Group 3 (PVP-I): 1% povidone iodine, Group 4 (H₂O₂): 1.5% hydrogen peroxide, Group 5 (CHX + C): 0.09% chlorhexidine digluconate + cyclodextrin + citrox, Group 6 (CPC): 0.075% cetylpyridinium hydrochloride, Group 7 (Control): artificial saliva. The initial color values were determined by a spectrophotometer on both white and black backgrounds. The specimens were immersed in 20 mL mouthwash for 1 minute with a 12-hour interval. The Ra, ΔE and TP were determined after 1, 2 and 3 weeks. Data were analyzed using repeated measures ANOVA, one-way ANOVA, post-hoc Bonferroni and Tukey tests (P< 0.05). Results: The highest and the lowest ΔE3 (after 3 weeks) value were observed in H₂O₂ (1.57± 0.29) and CHX (0.92± 0.17) groups, respectively. The CHX and CPC groups demonstrated significantly lower ΔE3 values than the control group (P< 0.05). CHX, HAc and PVP-I significantly affected the TP (P< 0.05). None of the groups demonstrated any significant changes of Ra scores (P> 0.05). (Am J Dent 2021;34:166-170).

 

 

 

 

Mail:  Dr. Yusuf Bayraktar, Department of Restorative Dentistry, Faculty of Dentistry, Kırıkkale University, Yenişehir mah. Çelebi sk. No. 1, Yahşihan, 71450, Kırıkkale, Turkey.  E-mail: yusufbayraktar@kku.edu.tr

 

 

 

 

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                                                                                                                           Research Article

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Influence of material and loading location on stress distribution of inlays

 

Vitor C.B. da Costa, dds, ms,  Alexandre C. Machado, dds, ms, phd,  Paulo V. Soares, dds, ms, phd,  

Luís Henrique A. Raposo, dds, ms, phd  &  Adalberto Bastos de Vasconcellos, dds, ms, phd

 

Abstract: Purpose: To evaluate the stress distribution of inlays fabricated with restorative materials of different elastic moduli under two functional loading conditions by using three-dimensional (3D) finite element analysis (FEA) models of a second maxillary premolar. Methods: A 3D model of a sound maxillary left second premolar and its supporting bone was generated in a previous study and reutilized under permission of the authors for the present study. Inlay models obtained from the sound tooth were then assigned according to the type and inherent elastic modulus of the restorative material used, as follows: microhybrid composite (Filtek Z250); indirect resin composite (Paradigm); lithium disilicate reinforced glass ceramic (IPS e.max Press); and type III gold alloy. The geometric models were then exported for 3D FEA. All materials were considered isotropic, homogeneous, and linear-elastic. A static load of 100 N was applied in two conditions: axially at both cusps (axial loading) and at the mesial marginal ridge (proximal loading). Maximum principal and von Mises stresses were used to analyze the stress distribution pattern in inlays and sound premolar models. Results: Under axial loading condition, either resin composite, ceramic or type III gold alloy inlays generated a similar biomechanical behavior, especially in terms of stress distribution in the remaining tooth structure and cusp deflection. However, higher tensile stresses were observed along the proximal gingival margin of the preparation under proximal loading in the Z250 and Paradigm models, as well as a greater cusp deflection. In contrast, a deflection like the sound model was observed in the ceramic and gold inlay models. (Am J Dent 2021:34:171-176).

 

 

 

 

Mail: Dr. Adalberto Bastos de Vasconcellos, Division of Comprehensive Oral Health, Operative Dentistry, University of North Carolina, School of Dentistry, 438 Brauer Hall, CB#7450, Chapel Hill, NC 27599-7450, USA. E-mail: bert_vasconcellos@unc.edu

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                                                                                                                               Review Article

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Screening test for COVID-19 in dental practice: Best Options

 

Sandra López -Verdín, phd, José Roberto Prieto-Correa, bsc, Nelly Molina-Frechero, phd &  Ronell Bologna-Molina, phd

 

Abstract: Purpose: To review diverse tests that could serve as a screening tool for the dental community to identify patients with potential COVID-19. Methods: Detailed automated searches of Medline, PubMed and EBM Review, including ACP Journal Club, the Cochrane Controlled Trials Register, and the Cochrane Database of Systematic Reviews of Effectiveness from 2019 to 2020 were conducted. Real-time polymerase chain reaction (RT-PCR) or quantitative (q) RT-PCR and Western blot assays were excluded. Results: Real time loop-mediated isothermal amplification (RT-LAMP) and Real time recombinase polymerase amplification (RT-RAP) are the most promising methodologies developed as screening tools, and could be a screening test option in dental practice to identify patients potentially carrying SARS-CoV-2 and to prevent cross-infection between patients and dental personnel. (Am J Dent 2021;34:127-131).

 

 

Mail: Prof. Sandra López Verdín, Health Science University Center, Dental Research Institute, University of Guadalajara. Sierra Mojada 950, Jalisco, México. E-mail: patologiabucal@live.com.mx