^{October 2021 Abstracts}

 

 

 

Micro computed tomography analysis of abrasivity of toothpaste tablets compared to conventional toothpaste

 

Mohammed Shaikh, rdh, Guada Lund, rdh,  Julia Ko, Gina Roque-Torres, dds, ms, phd, Udochukwu Oyoyo, mph  &  So Ran Kwon, dds, ms, phd

 

Abstract: Purpose: To evaluate with microCT dentin and enamel abrasion depth caused by toothpaste tablets when compared to conventional toothpastes. Methods: Dentin (N= 64) and enamel blocks (N=64) were randomized into four experimental groups of 16 specimens each for dentin and enamel. CP: Colgate Cavity Protection, served as the low abrasive toothpaste; AW: Colgate Total Advanced Whitening was used to represent a highly abrasive toothpaste. Two different types of toothpaste tablets were used. DT: Denttabs and BT: Bite tabs. To prepare the slurries, 40 mL of water was added to 25 g of each toothpaste and 4.4 g of each toothpaste tab. Blocks were brushed for a total of 10,000 and 40,000 strokes for dentin and enamel, respectively following ISO standard 11609. On completion of brushing, specimens were scanned with a microCT system. Tomographic 3D reconstruction followed by abrasion depths measurements were performed. Kruskal-Wallis procedure tested abrasion depths among the different groups. Tests of hypotheses were two-sided with an alpha level at 0.05. Results: There was a statistically significant difference in dentin abrasion depth among the groups (P< 0.001). The mean dentin/enamel abrasion depths in microns were 25.3/4.4, 36.8/4.4, 66.8/3.0, and 230.3/15.5 for DT, BT, CP, and AW respectively. Dentin and enamel abrasion depth of AW was the highest and was different from all other groups after multiple comparisons (P< 0.05). (Am J Dent 2021;34:235-239).

 

 

Mail: Dr. So Ran Kwon, Division of General Dentistry, School of Dentistry, Loma Linda University, 11092 Anderson St. PH #4403, Loma Linda, CA, 92350, USA.  E-mail: sorankwon@llu.edu

 

 

 

Staining and whitening products induce color change in resin composites

 

Hayley B. Parks, dds,  Brian R. Morrow, ms,  Cornelis Pameijer, dmd, mscd, dsc, phd &  Franklin Garcia-Godoy, dds, ms, phd, phd

 

Abstract: Purpose: To evaluate color and gloss changes of three different resin composites after staining and whitening. Methods: 57 disc-shaped composite samples were made for each of three resin composite materials [Activa BioActive Restorative (Activa), Filtek Supreme (Filtek), and TPH Spectra (TPH)], producing 19 samples per composite (n=19). Each group of resin samples was divided among four solutions: red wine, coffee, tea, and water (control), producing six samples per staining group (n=6) and one control (n=1). Samples were stained for 40 days for 3 hours/day at room temperature. When not undergoing staining/whitening, samples were stored in DI water at 37°C. Measurements were obtained for color and gloss before staining, after staining, and after whitening. Illuminant source specular component excluded (SCE) and included (SCI), with both CIE L*a*b* and CIE 2000 L*C*h* systems, were obtained with colorimetric measurements. The standard ΔE (total color change) = 3.3 was used as a clinically acceptable value. Stained groups were divided into two groups (n= 9 each) for each whitening product: Opalescence Boost and Opalescence PF. Both were applied according to manufacturer’s instructions. Results: Staining of all samples consistently showed decreased lightness. Filtek showed the most colorimetric changes, especially with wine, while TPH and Activa composites showed few changes; most changes were with tea. Whitening altogether showed generalized increased lightness. All Activa specimens returned to clinically acceptable levels, but the other two materials tested varied. Gloss was most affected for TPH, followed by Filtek; and gloss improved with Activa groups. Overall, Filtek’s color varied most, with Activa and TPH being less. All Activa groups returned to clinically acceptable values. However, multiple TPH and Filtek groups had ΔE> 3.3. Furthermore, TPH had the most gloss changes. Activa composites appeared the most stable under the conditions of this study. (Am J Dent 2021;34:240-244).

 

 

 

 

 

Mail: Dr. Franklin Garcia-Godoy, Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, 875 Union Avenue, Memphis, TN 38163, USA. E-mail: fgarciagodoy@gmail.com

 

Low torque is a risk factor for non-carious cervical lesions (NCCLs) in maxillary premolars

 

Jiayin Yan, Wenting Xie, Lu Zhang, Jing Wang, Jiangwei Wang, Keyuan Liu  &  Linkun Zhang, phd

 

Abstract: Purpose: To determine the prevalence of non-carious cervical lesions (NCCLs) in maxillary premolars of different torques and simulated cervical stress profiles of the premolars under coincident loadings using finite element analysis (FEA). Methods: The CBCT scans of 616 maxillary premolars from 154 subjects were retrospectively evaluated. The premolars were ascribed into low torque group (LTG) <-10.9°, medium torque group (MTG) -10.9° to -3.9°, and high torque group (HTG) >-3.9°, when the torque was referring to the occlusion plane. The prevalence of NCCLs in each group was evaluated. Then finite element models of a maxillary first premolar, its adjacent teeth and alveolar bone were established. The models were prepared with ANSYS software generating the premolars presenting different torques. The mastication scenario for the premolars in maximum intercuspation position was simulated. Results: The prevalence of NCCLs was 15.7% in LTG, 7.9% in MTG and 5.5% in HTG. The prevalence of LTG was significantly higher than that of MTG (P< 0.05) and HTG (P< 0.01). As for FEA, the stresses at the buccal necks of the premolars basically increased with decrease of the torque. The tensile stress peaks were in the cemento-enamel junction in most premolars of the LTG, while in the middle of the crowns in premolars of MTG and HTG. (Am J Dent 2021;34:245-249).

 

 

 

 

Mail: Dr. Linkun Zhang, Department of Orthodontics, Tianjin Stomatological Hospital, 75 Dagu Road, Tianjin China. E-mail: linkunzhang@nankai.edu.cn

 

 

 

Effects of polishing systems and storage media on color stability and surface roughness of bulk-fill restorative composites

 

Enes Kılıç, dds,  Emine Şirin Karaarslan, dds, phd,  Hüseyin Hatırlı, dds, phd  &  Fikret Yılmaz, dds, phd

 

Abstract: Purpose: To determine the effect of polishing systems and storage media on surface roughness and color change of four bulk-fill restorative composites. Methods: Four bulk-fill restorative composites and one micro-hybrid resin composite were used in this study. 72 cylindrical specimens were prepared for each resin composite. The specimens were divided into three polishing groups and further solution subgroups (n= 8). Surface roughness (Ra) and color were measured before and after the immersion periods. Statistical analyses were performed using three-way analysis of variance and Bonferroni tests (P˂ 0.05). Results: Baseline Ra values were lower in the unpolished groups. Immersion in solutions increased the Ra of all resin composites tested. The lowest ΔE*ab was observed in Filtek One Bulk-Fill groups immersed in artificial saliva. Filtek One Bulk-Fill polished with Twist Dia showed lower ΔE*ab values than polished with Sof-Lex and the unpolished groups (P< 0.05). A weak positive correlation was observed between the baseline Ra and ΔE*ab. (Am J Dent 2021:34:250-256).

 

 

 

 

Mail: Dr. Hüseyin Hatirli, Department of Restorative Dentistry, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, 60030, Turkey.  E-mail: huseyinhatirli@gmail.com

 

 

 

Association of tracking oral hygiene with dental outcomes in a general dental practice

 

Zach Pederson, bs, Alex Madrahimov, bs, Kaeli Samson, ma, mph  &  Richard A. Reinhardt, dds, phd

 

Abstract: Purpose: To track plaque scores on a subset of teeth in general dental practice patients to determine if plaque scores could improve along with periodontal, restorative and extraction outcomes. Methods: Percentage of surfaces with subgingival plaque were recorded and graphed on five teeth (#3, 8, 14, 19, 30) at each appointment, followed by focused oral hygiene instructions, in 343 patients over a 5-10-year period. Patient age, gender, prophylaxes/year, and experimental teeth periodontitis stage, % 4-5 and ≥ 6 mm pockets, % bleeding on probing, % surfaces restored and patients with extractions were recorded. Relationships among average plaque scores and the longitudinal periodontal, restorative and extraction changes were analyzed using Chi-Square, Kruskal-Wallis, and Wilcoxon Rank Sum tests. Results: Plaque scores improved from median 40% to 25% (P< 0.0001) over the 5-10 years. Plaque scores and periodontitis stages were associated (P= 0.03) with few periodontally healthy patients (9%) having poor plaque scores (> 50% plaque surfaces). Furthermore, good plaque scores (≤ 25%) and periodontal health (Stage I) were linked to the need for few restorations (P< 0.0001), while prophylaxes/year had no significant relationship. Extractions were related more with Stage III/IV (advanced) periodontitis (P< 0.0001) than with plaque score (NS). (Am J Dent 2021;34:257-260).

 

 

 

 

 

 

Mail: Dr. Richard A. Reinhardt, UNMC College of Dentistry, 4000 East Campus Loop, Lincoln, NE 68583-0740, USA. E-mail: rareinha@unmc.edu

 

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Influence of fatigue load  on various adhesive resin luting agents in a zirconia-reinforced lithium silicate ceramic bonded to dentin

 

Ratikorn Watananiyom, dds  &  Sirivimol Srisawasdi, dds, ms, phd

 

Abstract: Purpose: To examine fatigue failure load value of etch-and-rinse and self-adhesive luting systems used to bond ZLS to dentin. Moreover, this study seeks to evaluate whether the application of unfilled resin on silanated ceramic intaglio surface could improve fatigue failure load value. Methods: Vita Suprinity (VS) blocks were sectioned into a cylindrical shape (5 mm in diameter and 1.5 mm in height). All VS were crystallized, and bonded surfaces were either treated with Heliobond (HB) application after silanization or without application of HB. Each VS was cemented to each flat occlusal dentin surface of the extracted human molar, following the adhesive luting systems: Optibond FL (FL) with Nexus3 (NX3), RelyX Unicem (UC), and Maxcem Elite (ME). 24-hour mean fatigue failure load was determined using a staircase approach (500,000 cycles, 20 Hz, initial load = 844 N, step size = 42 N). Representatives of failed specimens were evaluated by a scanning electron microscope (SEM). Results: The Behrens-Fisher T-test revealed that ZLS cemented to dentin using self-adhesive resin luting cements (UC and ME) had a statistically significantly lower mean fatigue failure load value than etch-and-rinse resin luting cement (FLNX3) (alpha= 0.05). Meanwhile, the HB application groups did not achieve a statistically significant difference in fatigue failure load value when compared to non-application groups (alpha= 0.05). (Am J Dent 2021;34:261-266).

 

 

 

Mail: Dr. Sirivimol Srisawasdi, Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, 34 Henri-Dunant Rd., Patumwan, Bangkok, Thailand, 10300.  E-mail: sirivimol.s@chula.ac.th

 

 

Evaluation of adipokine levels in obese women with periodontitis: A cohort study

 

Begum Alkan, dds, msd  &  Esra Guzeldemir-Akcakanat, dds, phd

 

Abstract: Purpose: To evaluate the inflammation-related adipokine levels in the body fluids of obese female participants with and without periodontitis using healthy participants as a control group. Methods: A cohort design study was carried out at Kocaeli University between December 2014 and June 2015. The study sample comprised 25 obese female participants with periodontitis (Group 1), 31 obese female participants without periodontitis (Group 2), and 15 lean female participants with healthy periodontium (Group 3), from whom body mass index, clinical periodontal parameters were measured, and serum, saliva, and gingival crevicular fluid (GCF) samples were collected. The three groups’ periodontal parameters and adipokine levels were evaluated and compared, and the primary outcome was the difference in local and systemic adipokine levels between the study groups. Results: In the participants’ serum samples, tumor necrosis factor-α (TNF-α) and leptin levels were lower, whereas adiponectin levels were significantly higher in Group 3 than in the obese groups (P< 0.05). In the participants’ saliva samples, interleukin-1β, TNF-α, and resistin levels were lowest in Group 3, but adiponectin was lowest in Group 2 (P< 0.05). In the participants’ GCF samples, interleukin-1β, resistin, and adiponectin levels were higher in Group 1 (P< 0.05). This study showed that the amounts of the adipokines could differ in serum, saliva, and GCF samples from obese female participants with and without periodontitis and from lean female participants with healthy periodontium. (Am J Dent 2021;34:267-272).

 

 

 

Mail: Dr. Begum Alkan, Istanbul Medipol University, Dis Hekimligi Fakultesi, Periodontoloji Ana Bilim Dali, 34230, Esenler, Istanbul, Turkey.  E-mail: alkan.bgm@gmail.com

 

Carica papaya mouthrinse as an inhibitor of Streptococcus mutans: Randomized controlled clinical trial

 

Diego Cespedes, dds, Julieta Mendez, dds, msc  &  Ulises  Villasanti, dds, msc

 

Abstract: Purpose: To evaluate the effect of Carica papaya mouthrinse as an inhibitor of Streptococcus mutans. Methods: This was a double blind (subject and evaluator) randomized controlled trial in 40 subjects distributed in two groups: Carica papaya mouthrinse intervention (n= 20) or chlorhexidine (n= 20). The antibacterial effect was determined by counting colony-forming units per milliliter (CFU/ml) of S. mutans in saliva sample cultures; taken both before mouthrinse, immediately after 10 minutes mouthrinsing, and 8 days after mouthrinsing. The data was statistically analyzed with Student’s t-test (P ≤ 0.05). Results: The difference before and immediately after (10 minutes) use of Carica papaya mouthrinse was of 764 CFUs. After 8 days use the difference was 212 CFUs. For the control group (0.12% chlorhexidine) the difference before and immediately after use (10 minutes) was 683 CFUs. After 8 days use the difference was 455 CFU. When comparing between groups applying t-test, no statistical differences were found in the (CFU/ml) of S. mutans before and after 10 minutes mouthrinse (P= 0.8060), 10 minutes and 8 days after mouthrinsing (P= 0.7104) before and 8 days after mouthrinsing (P= 0.4419). (Am J Dent 2021;34:273-276).

 

 

*: Dr. Julieta Méndez, Instituto Regional de Investigación en Salud, Universidad Nacional de Caaguazú, Coronel Oviedo, Paraguay. E-mail: julieta_mendez92@hotmail.com

 

 

The effect of 1,450 and 5,000 ppm sodium fluoride on polished dentin after citric acid erosion using change in step height

 

Sami Almohefer, bds, ms,  Rebecca Moazzez, bds, msc, fds, phd  &  David Bartlett, bds, mrd fds, phd, fds

 

Abstract: Purpose:  To measure step height change, using profilometry on dentin, after pre-treatment with sodium fluoride at 1,450 and 5,000 ppm and then erosion with citric acid.  Methods:  Dentin specimens (n= 150), sectioned from the coronal aspect of extracted human molars were randomly divided into three groups of 60 samples each and fully immersed in deionized water (control), or solutions of NaF with 1,450 ppm (F1450) or 5,000 ppm (F5000) for 3 minutes and then artificial saliva (not containing proteins) for 30 minutes. The samples were eroded for 10, 15, 20 or 25 minutes in 0.3% citric acid at pH 2.7. The mean step height change was calculated using confocal non-contact white light laser profilometry.  Results:  The mean (SD) step height for the control group at 25 minutes of acid exposure was 9.08 μm (± 0.74), for the F1450 fluoride group 8.74 μm (± 0.58) and for F5000 group 7.01 μm (± 0.56) μm, respect-tively. There were no statistically significant differences between the control group to the F1450 at any immersion times, whereas at F5000 there were statistically significant differences at all times (P< 0.0001). Within the limitations of this in vitro study, step height in dentin increased with time of exposure to citric acid and 5,000 ppm of sodium fluoride significantly reduced step height with artificial saliva. (Am J Dent 2021;34:277-280).

 

 

 

 

 

 

Mail: Dr. David Bartlett, Center for Clinical, Oral and Translational Sciences, King’s College London, Oral and Craniofacial Sciences, Floor 17 Guy’s Tower, Great Maze Pond, London, SE1 9RT, United Kingdom.  E-mail:  david.bartlett@kcl.ac.uk

 

In-office bleaching with complete cervical third protection protocol: A split-mouth, double-blind, randomized clinical trial

 

Juliana Lopes de Sá, dds, ms,  Jardel dos Santos Silva, dds, ms,  Fernando José Herkrath, dds, ms phd, Michael Willian Favoreto, dds,  Alessandra Reis, dds, phd,  Luciana Mendonça Silva, dds, ms, phd, Alessandro D. Loguercio, dds, ms, phd  &  Leandro Moura Martins, dds, ms, phd

 

Abstract: Purpose: To evaluate the bleaching sensitivity and the bleaching effectiveness of in-office bleaching, following a protocol of complete cervical third protection with gingival dam in comparison with a traditional manner of applying gingival dam (used only in the gingival sulcus area). Methods: 35 participants were selected for this double-blind split-mouth randomized clinical trial. The control group received the gingival barrier in the traditional manner, and in the experimental group the barrier was extended by about 3 mm to include the cervical region. The bleaching agent was applied in two sessions. The risk and intensity of bleaching sensitivity were assessed using two scales. The bleaching effectiveness was evaluated with a digital spectrophotometer with the tip placed in the cervical area. The absolute risk of bleaching sensitivity was compared by the McNemar’s test and bleaching effectiveness (ΔEab, ΔE00 and ΔWi) and intensity of bleaching sensitivity was evaluated by Wilcoxon-paired test (α= 0.05). Results: No significant difference at risk (P= 1.0) and intensity of bleaching sensitivity (P> 0.45) was seen between groups. After 30 days, bleaching effectiveness had no statistical difference between the groups (P> 0.09). (Am J Dent 2021;34:281-285).

 

 

Mail: Prof. Alessandro D. Loguercio, State University of Ponta Grossa, Avenida Carlos Cavalcanti, 4748, Bloco M, Sala 04, Ponta Grossa, Paraná, CEP: 84.030-900, Brazil.  E-mail: aloguercio@hotmail.com

 

 

 

Effect of ion-releasing filler-containing gel application on dentin remineralization using optical coherent tomography

 

Takeo Okuwaki, dds, Runa Sugimura, dds, Hiroyasu Kurokawa, dds, phd, Akimasa Tsujimoto, dds, phd, Toshiki Takamizawa, dds, phd, Masashi Miyazaki, dds, phd  &  Franklin García-Godoy, dds, ms, phd, phd

 

Abstract: Purpose: To examine the effects of an ion-releasing filler-containing gel on the remineralization of dentin using optical coherence tomography (OCT). Methods: Dentin slabs of bovine teeth were sliced and shaped into a rectangular form. Specimens were treated with undersaturated 0.1 M lactic acid buffer solution (pH 4.75) for 10 minutes and then placed in artificial saliva (pH 7.0). This procedure was repeated three times a day for 28 days. The dentin remineralization effects of a fluoride/S-PRG filler-containing gel (PRG) and a 38% SDF solution (SDF) on dentin slabs of bovine teeth were compared. After treatment, the dentin slabs were immersed in a 0.1 M lactic acid buffer solution and then placed in artificial saliva. This procedure was repeated three times a day for 28 days. OCT imaging was conducted on the selected location of the dentin surface. The peak intensity and width at 1/e² were recorded in each of the six areas on the sample and averaged. Each group had a sample size of 10. Knoop hardness number (KHN) measurements and scanning electron microscopy (SEM) observations were also conducted. The data for each group were subjected to a one-way repeated-measures ANOVA and Tukey tests (α= 0.05). The samples were also observed using SEM. Results: The peak signal intensities of SDF and PRG decreased on day 7 and then slightly increased during the experimental period for the one-off application groups and then decreased for frequent-time application groups. Although the width at 1/e² in the untreated specimens decreased over the test period, SDF and PRG for the one-off application groups exhibited an increase in widths on day 7 followed by a slight decrease, whereas it increased for the frequent-time application groups. The average KHN of the dentin samples exhibited the same tendency as the width at 1/e². Closure of the dentin tubules and crystal precipitation were detected on the surface of both SDF and PRG groups. (Am J Dent 2021;34:286-292).

 

 

 

 

Mail: Dr. Hiroyasu Kurokawa, Department of Operative Dentistry, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.  E-mail: kurokawa.hiroyasu@nihon-u.ac.jp