^{December 2021 Abstracts}

 

 

Effect of charcoal dentifrices on tooth whitening and enamel surface roughness

 

Mohammed Shaikh, rdh, ddsc, Hyun Sung, rdh, ddsc, Teresita Lopez, rdh, Rachelle Andra, rdh, ddsc, Brett McKean, rdh, ddsc, Jenifer Jesson, dds, Claudie Pascal, dds, Anna Chavez, dds, msc, Kristen Schwieterman, rdh, dds, Udochukwu Oyoyo, mph  &  So Ran Kwon, dds, ms, phd, ms

 

Abstract: Purpose: To evaluate tooth color change and surface roughness after the use of charcoal dentifrices. Methods: Bovine teeth (n= 64) used for color measurements were stained in tea solution and embedded in acrylic resin. Specimens were randomized into four groups of 16 specimens each. Cavity Protection (Colgate-Palmolive) was the negative control. Whitening dentifrices used were Black is White (Curaden AG); and My Magic Mud (Carbon and Clay Company) containing activated charcoal and Optic White (Colgate-Palmolive) containing hydrogen peroxide. Instrumental color measurements were performed at baseline, 1-week post-brushing, 30-day post-brushing, and 1-month follow-up. Another set of bovine teeth (n= 64) used for roughness measurements were embedded in acrylic resin and the surface ground flat. The experimental groups and brushing protocol were the same as for the color evaluation part. Surface roughness was measured with a contact type profilometer at baseline and after the last brushing session. Kruskal-Wallis procedure tested changes in color and surface roughness among the different groups. All post-hoc comparisons were conducted with Bonferroni corrections. Tests of hypotheses were two-sided with an alpha level at 0.05. Results: Overall color change was not significantly different among groups at 1-week post-brushing and at 1-month follow-up. However, the hydrogen peroxide group had a significantly higher reduction in chroma in the yellow-blue axis when compared to negative control group at 30-day post-brushing and 1-month follow-up (P< 0.05). There was no significant difference in roughness among the groups at baseline (P= 0.2973) and post treatment (P= 0.8169). (Am J Dent 2021;34:295-299).

 

 

 

 

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

 

 

 

Effect of whitening dentifrices on color, surface roughness and microhardnessof dental enamel in vitro

 

Isabel Cristina Gavazzoni Bandeira de Andrade, dds, msc,  Bruna Monteiro Silva, dds, msc, Cecília Pedroso Turssi, dds, ms, phd,  Flávia Lucisano Botelho do Amaral, dds, ms, phd, Roberta Tarkany Basting, dds, ms, phd, Evelise Machado de souza dds, ms, phd &  Fabiana Mantovani Gomes França, dds, ms, phd

 

Abstract: Purpose: To evaluate the color, surface roughness and microhardness of human dental enamel subjected to brushing with whitening dentifrices. Methods: The enamel samples (4 ´ 4 ´ 2 mm) were darkened using 0.2% chlorhexidine and black tea, and were randomly divided into seven groups (n = 15) for brushing cycles with only water; control; conventional dentifrice (Colgate Maximum Anticaries Protection); dentifrice containing 2% hydrogen peroxide (Colgate Luminous White Advanced); dentifrice containing sodium tripolyphosphate (Sensodyne True White); dentifrice containing activated charcoal (Black is White); and dentifrice containing blue covarine (Close Up White Now). The samples were submitted to 1,000 and 30,000 brushing cycles. The color values (CIE L*a*b*), surface roughness (Ra) and microhardness (Knoop) were recorded at four time points: baseline, after staining, after 1,000 and after 30,000 brushing cycles. The data were submitted to statistical analyses using paired t-test, ANOVA and Tukey. Results: The color analysis, roughness and microhardness results showed interaction between the effect of the dentifrices and the time point (P< 0.001). The bleaching dentifrices brought about color changes (∆E) significantly greater than those obtained with conventional dentifrices and the control; however, there were no significant color changes among the bleaching dentifrices. When the color coordinates were evaluated individually, the L* values increased and the a* and b* values decreased throughout the experiment. The conventional toothpaste and the toothpastes containing blue covarine, activated charcoal or hydrogen peroxide promoted a statistically significant increase in the surface roughness of the samples after the last brushing cycle. The sodium tripolyphosphate dentifrice caused a progressive reduction in roughness. The microhardness increased statistically after 30,000 cycles for the conventional toothpaste, blue covarine and hydrogen peroxide. It was concluded that the whitening dentifrices lightened the samples, which evidenced greater luminosity and reduction in reddish and yellow tones. Moreover, they did not have deleterious effects on microhardness, and caused acceptable changes in surface roughness. (Am J Dent 2021;34:300-306).

 

 

 

 

Mail: Dr. Isabel Cristina Gavazzoni Bandeira de Andrade, Faculdade São Leopoldo Mandic or Universidade Regional de Blumenau (FURB), Rua José Rocha Junqueira, 13, Campinas, SP, CEP: 13045-755, Brazil or Rua São Paulo 2171, Itoupava Seca, Blumenau, SC, CEP:89030-001, Brazil.  E-mail: iandradegb@gmail.com or iandrade@furb.br

 

 

 

Biomimetic tooth-whitening effect of hydroxyapatite-containing mouthrinses after long-term simulated oral rinsing

 

Ren Shang, mcss  &  Karl-Heinz Kunzelmann, drmeddent

 

Abstract: Purpose: To investigate the tooth-whitening effects of mouthrinses containing different sizes of hydroxyapatite (HAP) particles after prolonged application time and compare them with a commercial whitening mouthrinse. Methods: 50 bovine incisors were stained and randomly distributed into five groups: the HAP groups with 3 µm, 200 nm and 50 nm particle size, the commercial whitening mouthrinse group and the distilled water group. The teeth underwent prolonged mouthrinse applications that were equivalent to simulated 3- and 6-month mouthrinsing. Tooth color was measured and calculated before and after mouthrinsing. The group and application time effects were analyzed with a nonparametric analysis of longitudinal data using the nparLD package in R and ANOVA-type statistic was reported. Pairwise Wilcoxon rank-sum tests with BH correction were performed to compare the tooth color changes of individual groups. The mouthrinse-treated enamel was observed by SEM. Results: The whitening effect of HAP mouthrinses after the prolonged application time was confirmed. The HAP mouthrinses exhibited similar whitening effects to the commercial mouthrinses. The particle size and application time could significantly affect the whitening performance of HAP mouthrinses. The 50 nm HAP group exhibited significantly higher △E values than the 3 μm group after the 6-month-equivalent application (P= 0.024). A longer period of application increased significantly the △E and △L values (P< 0.05). The HAP-treated enamel surfaces were entirely covered with HAP after the 6-month-equivalent application. (Am J Dent 2021;34:307-312).

 

 

Mail:  Dr. Ren Shang, Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestrasse 70, D-80336 Munich, Germany.  E-mail:  ren.shang@campus.lmu.de

 

 

 

Increased occurrence of temporomandibular joint disorders in COVID-19 confirmed patients

 

Megan Tirrell  &  Joseph Katz, dmd

 

Abstract: Purpose: To examine the prevalence of temporomandibular joint disorders (TMJD) in COVID-19 confirmed patients before and after adjustments for risk factors such as fibromyalgia, nocturnal bruxism, and anxiety disorders. Methods: The i2b2 database was used to query searches of patient records at University of Florida Health Centers. Queries were submitted for the number of total hospital patients, TMJD cases, COVID-19 cases, and TMJD with COVID-19 cases from December 2019 to July 2021. Additional searches excluded fibromyalgia, nocturnal bruxism, and anxiety to examine their prevalence as risk factors. Results: Out of the 548,646 total hospital patients, 86 had a diagnosis of both COVID-19 and TMJD, 14,836 had only COVID-19, and 1,856 had only TMJD. The odds ratio (OR) for having TMJD with COVID-19 was 1.7, with around 80% of TMJD occurring in young adult females. Excluding fibromyalgia and nocturnal bruxism did not change the OR. Anxiety was present in 37% of COVID-19 with TMJD cases and exclusion of this population significantly diminished the odds ratio to 1.08. These results demonstrate a correlation between COVID-19 and TMJD that dissolves when adjusting for stress. Thus, anxiety is a significant factor in the prevalence of TMJD in COVID-19 patients. (Am J Dent 2021;34:313-316).

 

 

Mail: Dr. Joseph Katz, Department of Oral Diagnostic Sciences, College of Dentistry, University of Florida, 1600 SW Archer Road, PO Box 100414, Gainesville, FL 32610, USA. E-mail: jkatz@dental.ufl.edu

 

 

Use of crack cocaine increases tooth loss

 

Raquel Pippi Antoniazzi, dds, phd, Rafaela Varallo Palmeira, dds, Caroline Schöffer, msd, Bianca Zimmermann dos Santos, dds, phd, Fabricio Batistin Zanatta, dds, phd &  Carlos Alberto Feldens, dds, phd

 

Abstract: Purpose: To evaluate the occurrence of tooth loss among crack cocaine users. Methods: A cross-sectional study was conducted with 106 crack cocaine users and 106 controls matched for age, gender, and tobacco use. Data were collected on socio-demographic characteristics, drug use, use of dental services, dental caries, periodontal disease, and the outcome (tooth loss). Results: Crack cocaine users had a greater frequency of tooth loss (55.7% vs. 36.8%), severity of dental caries and periodontal disease and less use of dental services than the controls (P< 0.05). After adjustments, tooth loss was 46% more frequent among crack cocaine users (PR= 1.46; 95%, CI: 1.10-1.93) as well as significantly more frequent among non-whites, those older than 24 years of age and those with high dental caries severity. Occurrence of tooth loss was significantly higher among crack cocaine users. These findings can contribute to the planning and implementation of prevention strategies and oral health care for individuals with a chemical dependence. (Am J Dent 2021;34:317-321).

 

 

Mail:  Dr. Raquel Pippi Antoniazzi, Department of Stomatology, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Av Roraima 1000, Bairro Camobi, 97105-900 Santa Maria, RS, Brazil.  E-mail: raquelantoniazzi@hotmail.com

 

 

 

Comparative effects on acrylic resin properties of short- and long-term immersion in alkaline peroxide solution

 

Carolina Noronha Ferraz de Arruda, dds, msc, phd,  Marcela Moreira Salles, dds, msc, phd, Amanda Peracini, dds, msc, phd,  Viviane de Cássia Oliveira, bsc, msc, phd,  Ana Paula Macedo, be, msc, phd, Cláudia Helena Lovato da Silva, dds, msc, phd  &  Helena de Freitas Oliveira Paranhos, dds, msc, phd

 

Abstract: Purpose: To evaluate the color stability (∆E), surface roughness (∆Ra), and flexural strength of denture base acrylic resin after short (20 minutes) and long-term (8 hours) immersions simulating a period of 5 years of use. Methods: 120 disk-shaped (16 mm × 4 mm) and 120 rectangular (65 mm × 10 mm × 3.3 mm) specimens were prepared (Lucitone 550) and distributed into three groups (n=20): distilled water (Control); Corega Tabs (CT) and Polident (Po), for immersions of 20 minutes and 8 hours. ∆E were determined by a colorimeter, ∆Ra by a profilometer and the flexural strength by a universal testing machine. Data were evaluated by two-way ANOVA followed by Tukey’s test and Bonferroni correction (α= 0.05). Results: Short-term immersions for 20 minutes resulted in significant differences in ∆E, as CT values (1.46 ± 1.41) were higher than Po (0.55 ± 0.25) and Control (0.47 ± 0.21). Specimens immersed for 8 hours showed more extensive alterations overall than the control (∆E [Po: 7.27 ± 0.53; CT: 5.58 ± 0.49; Control: 1.26 ± 0.23]; ∆Ra [Po: 0.16 ± 0.08; CT: 0.12 ± 0.11; Control: 0.07 ± 0.06]; flexural strength [Po: 42.99 ± 9.34; CT: 63.96 ± 12.98; Control: 64.59 ± 12.87]). The tested alkaline peroxide-based solutions promoted significant alteration on acrylic resin properties after overnight immersion. Therefore, short-term immersions seem to be more suitable for daily denture hygiene. (Am J Dent 2021;34:322-326).

 

 

 

Mail:  Dr. Carolina Noronha Ferraz de Arruda, Avenida do Café, s/n, 14040-904, Ribeirão Preto, SP, Brazil.  E-mail: carolina.arruda@usp.br

 

 

 

 

Deep margin elevation with resin composite and resin-modified glass-ionomer on marginal sealing of CAD-CAM ceramic inlays: An in vitro study

 

Jaraswan Vichitgomen, dds  &  Sirivimol Srisawasdi, dds, ms, phd

 

Abstract: Purpose: To evaluate the marginal sealing ability of different restorative materials used in deep margin elevation (DME) on zirconia-reinforced lithium silicate CAD-CAM ceramic restorations. Methods: A total of 30 Class II cavities were prepared in freshly extracted human molars with the proximal margin located 1 mm below the cemento-enamel junction (CEJ). All specimens were randomly assigned to one of three groups (n=10): control group, resin composite group (Filtek Z350 XT), and resin-modified glass-ionomer group (RMGI) (Vitremer Tricure). In Group 1, control group, no DME was performed. The inlay margin of the control group was placed directly on the dentin. In Groups 2 and 3, DME was used to elevate the margin to 1 mm above the CEJ with resin composite and RMGI, respectively. Zirconia-reinforced lithium silicate CAD-CAM ceramic restorations were manufactured and bonded on all specimens with universal bonding and resin luting cement. All specimens were aged by water storage for 6 months. Marginal sealing ability at different interfaces was evaluated with a stereomicroscope at 40´ magnification by scoring the depth of silver nitrate penetrating along the adhesive surfaces. Statistical differences between groups were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: At the dentin interface, there was no significant difference in microleakage scores in the control group and resin composite group (P= 0.577); however, the RMGI group had significantly higher microleakage compared to the control group (P= 0.004) and resin composite group (P= 0.007). (Am J Dent 2021;34:327-332).

 

 

 

 

 

 

Mail: Dr. Jaraswan Vichitgomen, Esthetic Restorative and Implant Dentistry International Program, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. E-mail: jaratwan.v@gmail.com

 

 

In vitro inhibition of demineralization from bioglass-containing adhesive and composite

 

Chan-Te Huang, dds, ms,  Nathan R. Smith, dmd, mph, John O. Burgess, dds, ms  &  Nathaniel C. Lawson, dmd, phd

 

Abstract: Purpose: To measure and compare the area of inhibition around a bioglass-containing adhesive and resin-based composite following an in vitro artificial caries model in human extracted teeth. Methods: Preparations were made at the CEJ of extracted human molars (40, n=10/material) and restored with combinations of a bioglass-containing adhesive (BA, Regen), a reference adhesive which served as a negative control (RA), a bioglass-containing composite (BC, Regen), and a reference composite which served as a negative control (RC): BABC, RABC, BARC, RARC. All materials were light-cured and then finished with a polishing disc. Teeth were incubated (37°C) for 24 hours in water. A demineralization solution composed of 0.1 M lactic acid, 3 mM Ca₃(PO₄)₂, 0.1% thymol, and NaOH (to adjust pH= 4.5) and a remineralization solution composed of 1.5 mM Ca, 0.9 mM P, and 20 mM Tris(hydroxymethil)–aminomethane (pH= 7.0) were prepared. Specimens were placed in the demineralization solution for 4 hours followed by a remineralization solution for 20 hours and cycled daily for 30 days. The specimens were embedded, sectioned into 100 µm sections, and the interface between the adhesive/composite and root dentin margin was viewed with polarized light. A line was drawn parallel with the zone of demineralization for each tooth. The area of “inhibition” (defined as the area external to the line) or “wall lesion” (defined as the area internal to the line) was traced with internal image evaluation software and measured. Areas of inhibition were measured as positive values and areas of wall lesions were measured as negative values. Results: A one-way ANOVA found significant differences between materials for “inhibition/wall lesion” areas in root dentin (P< 0.001). Tukey post-hoc analysis ranked materials (µm², mean± SD): BABC (3590± 2847)a RABC (1903± 1025)a, BARC (-792± 850)b, RARC (-2544± 1760)b. (Am J Dent 2021;34:333-337).

 

 

 

 

Mail: Dr. Chan-Te Huang, Department of Dentistry, Chang Gung Memorial Hospital at Keelung, 5F, No. 222, Maijin Rd., Anle Dist., Keelung City 204, Taiwan. E-mail: resplendia@xuite.net

 

 

 

 

Comparative plaque removal efficacy of a new children’s powered toothbrush and a manual toothbrush: Randomized, single use clinical study

 

Mary Francis, phd, William J. Hooper, phd, Drew Worob, bs, Gerhart Huy, bs, Sylvia Santos, rdh, C. Ram Goyal, dds, Kathleen Qaqish, rdh, Jimmy G. Qaqish, bs & Annahita Ghassemi, phd

 

Abstract: Purpose: To compare the plaque removal efficacy of a new children’s powered toothbrush to a children’s manual toothbrush. Methods: 55 subjects aged 5-8 years old, who met entry criteria, participated in this single-center, two-cell, examiner-blind, randomized, crossover, single use clinical study. Subjects brushed at home with their first assigned toothbrush and fluoride toothpaste, under supervision of a parent or legal guardian, at least once daily for 2 minutes during a 1-week acclimation period. After refraining from oral hygiene for 12-16-hours, and from eating and drinking for 4 hours, subjects returned to the clinical site where they were assessed for plaque using the Rustogi Modified Navy Plaque Index (RMNPI). Subjects then brushed their teeth with their assigned toothbrush and toothpaste for 2 minutes and plaque levels were reassessed. Subjects were then given their second assigned toothbrush and the acclimation period and clinical site visit were repeated. Safety-in-use was also assessed during each clinic visit. Differences between pre-and post-brushing scores were analyzed for each toothbrush and between toothbrush groups for whole mouth plaque and 12 subset sites using baseline adjusted ANCOVA. Results: Both toothbrushes significantly (P< 0.0001) reduced whole mouth and 12 subset site plaque scores from the pre-brushing baseline. Between treatment comparisons showed that use of the powered toothbrush resulted in statistically significant reductions in whole mouth plaque (55%, P< 0.0001) and in 12 subset site scores (40-208%) compared to the manual brush. This clinical study showed that brushing with a new children’s powered toothbrush was safe and significantly more effective than brushing with a manual toothbrush in reducing whole mouth plaque scores, as well as plaque scores at a range of subset sites in the mouth. (Am J Dent 2021;34:338-344).

 

 

 

 

 

 

Mail:  Dr. Annahita Ghassemi, 469 N. Harrison St., Princeton, NJ 08543, USA.  E-mail:  annahita.ghassemi@churchdwight.com