^{August 2021 Abstracts}

 

 

 

Effect of various resin cements and immediate dentin sealing on tooth fracture resistance of zirconia inlay restorations

 

Yuki Iketani, dds, Mikihiro Kobayashi, dds, phd, Yuiko Niizuma, dds, phd, Rintaro Sugai, dds &  Atsufumi Manabe, dds, phd

 

Abstract: Purpose: To compare the effect of the immediate dentin sealing (IDS) and resin cement type on fracture resistance of Class II mesio-occluso-distal (MOD) zirconia inlay restorations. Methods: 90 Class II MOD cavities on freshly extracted human mandibular third molars, prepared with a high-speed handpiece, were divided into two groups: those with IDS (CR+) and without IDS (CR-). The CEREC system was used to prepare zirconia inlays from Katana super translucent multi-layered blocks. The inlays were cemented with one of three resin cements: RelyX Unicem 2 (RU), Multilink Automix (MA), or Super-Bond (SB). These specimens were stored in water at 37ºC for 24 hours and exposed to 5,000 thermal cycles. A vertical load was applied with a metal sphere (Φ 6-mm) on a material testing system, with a crosshead speed of 0.5 mm/minute, until the specimen fractured. Fracture resistance was measured for each tooth, and the fractures were categorized according to Burke’s classification. Statistical analyses were conducted using two-way ANOVA and Tukey’s honest significant difference tests (P< 0.05). Results: No significant differences in tooth fracture resistance were identified between the CR+ and CR- groups. The SB group had a significantly higher fracture resistance compared to that of the MA group. Fracture morphology showed many mode IV fractures in all groups. IDS did not affect tooth fracture resistance, although there was a significant difference in tooth fracture resistance for different resin cement types used with Class II MOD zirconia inlay restorations. (Am J Dent 2021:34:179-185).

 

 

 

 

 

 

 

Mail: Dr. Yuki Iketani, Department of Conservative Dentistry, Division of Aesthetic Dentistry and Clinical Cariology, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ota-ku, Tokyo, Japan.  E-mail: iketani.y@dent.showa-u.ac.jp

 

 

 

How to select proper interdental brush size in periodontitis patients: Comparison of the reliability of two methods among novice and expert users

 

Jérome Petit, dds,  Christopher Huon, dds,  Thomas Nicolas, dds,  Kadiatou Sy, dds, phd,  Marie Dubar, dds, phd &  Kevimy Agossa, dds, phd

 

Abstract: Purpose: To compare two methods used by novice and expert operators for selecting interdental brush (IDB) size for periodontitis patients: (1) sequential testing or (2) using a color-coded taper tip device (CTD) corresponding to color-coded brush sizes. Methods: Six operators, one experienced and five dental students, employed both methods to determine the IDB with best fit for 204 interdental spaces in 34 periodontitis patients. The percentage of agreement and the inter-methods reliability was evaluated. The influence of anatomical features on differences between the operators or method was also investigated. Results: Moderate to substantial correlation was found between the two methods but the reliability was stronger when different operators used the same method, irrespective of the method, than when they used a different method. Among the anatomical factors studied, only sites in molar regions were associated with significant differences. (Am J Dent 2021;34:186-189).

 

 

Mail: Dr. Kevimy Agossa, Faculty of Dental Surgery, University of Lille, Place de Verdun, 59000 Lille, France. E-mail: kevimy.agossa@univ-lille.fr

 

In vitro anti-erosive property of a mint containing bioactive ingredients

 

Camila A. Zamperini, dds, phd,  Adriana C. Padron, dds,  Jose Villanueva, dmd, Mathew T. Mathew, phd   &  Ana K. Bedran-Russo, dds, ms, phd

 

Abstract: Purpose: To evaluate the in vitro protective effect of a mint formulation containing (−)-epigallocatechin-3-gallate (EGCg-mint) on root dentin exposed to a highly erosive environment in the presence and absence of proteolytic challenge. Methods: Root dentin specimens were subjected to an erosion-remineralization cycling model (6 ×/day; 5 days) that included 5-minute immersion in 1% citric acid and 60-minute immersion in remineralization solution (RS). At the remineralization half-time, the specimens were treated (n= 20) with EGCg-mint, RS (negative control) or sodium fluoride (1,000 ppm of NaF; positive control). Half of the specimens were kept overnight in RS (pH cycling) and the other half in RS with Clostridium histolyticum collagenase (pH-proteolytic cycling). Erosion depth was measured using optical profilometry and data analyzed by two-way ANOVA and Tukey tests (α= 0.05). Results: Under pH-cycling, NaF resulted in statistically lower erosion depth compared to EGCg-mint (P= 0.020) and RS (P= 0.005). Under pH-proteolytic cycling, EGCg-mint and NaF significantly decreased the tissue loss (erosion depth, P< 0.001) compared to the RS. The EGCg-mint exhibited an anti-erosion property on root dentin under a proteolytic challenge. NaF presented an anti-erosion property regardless of the erosive cycling model. (Am J Dent 2021;34:191-194).

 

 

Mail: Dr. Ana K. Bedran-Russo, Department of General Dental Sciences, Marquette University School of Dentistry, 1801 W. Wisconsin Ave, room 336C, Milwaukee, WI 53233, USA.  E-mail: ana.bedran-russo@marquette.edu

 

 

 

A randomized, blinded, clinical investigation of breath odor reduction efficacy of a stabilized chlorine-dioxide containing flavored mouthwash

 

Sean S. Lee, dds, Montry S. Suprono, dds, msd, Jonelle Stephens, rdh, ms, eds, Shelly A. Withers, rdh, ms, phd, Udochukwu Oyoyo, mph  &  Yiming Li, dds, msd, phd

 

Abstract: Purpose: To evaluate the efficacy of a flavored, non-fluoridated, alcohol-free mouthwash containing 0.1% chlorine dioxide in reducing oral malodor. Methods: This was a randomized, 8-week, single site, double blind, crossover design with a 2-week washout period between crossover phases. Ffity subjects with clinically diagnosed intrinsic oral malodor were enrolled according to inclusion/exclusion criteria and randomized to one of two groups. Washout period initiated at end of Phase I and crossover design implemented prior to Phase II. Calibration for organoleptic judges performed at baseline for both phases. Results: 48 subjects completed the study. No significant differences in intensity scores at baseline were found for both groups during both phases (P> 0.05). Within group comparisons for placebo revealed no significant differences with organoleptic intensity scores for all visits during both phases (P> 0.05). During Phase I, the mean changes in organoleptic scores for the test group were significantly different from the baseline at each visit: Weeks 1 to 3 (P< 0.05). After crossover, significant differences were found for the last two visits: Weeks 7 and 8 (P< 0.05). No adverse effects to oral tissues were observed or reported. This product is safe to use for up to 3 weeks and resulted in a decrease in oral malodor. (Am J Dent 2021;34:195-200).

 

 

 

Mail: Dr. Montry Suprono, Center for Dental Research, Loma Linda University, School of Dentistry, Chan Shun Pavilion, 11175 Campus Street, Loma Linda, CA 92350, USA. E-mail: msuprono@llu.edu

 

 

 

 

Influence of light irradiation for in-office tooth whitening: A randomized clinical study

 

Akimasa Tsujimoto, Bds, DDD,  Carlos A. Jurado, dds, ms,  Mohammed E. Sayed, bds, mds, phd, Nicholas G. Fischer, PHD,  Toshiki Takamizawa, dds, phd,  Mark A. Latta, dds, ms,  Masashi Miyazaki, dds, phd  &  Franklin Garcia-Godoy, dds, ms, phd, phd

 

Abstract: Purpose: To evaluate the influence of light irradiation on the clinical efficiency of an in-office whitening agent. Methods: The in-office whitening agent (Opalescence Boost 35%) was used in this study. Two whitening regimens were evaluated on maxillary anterior teeth: (1) with light irradiation; and (2) without light irradiation. The ΔE*, changes of L*, a*, b*, and the best shade match on the central incisor before, immediately after, and 6 months after whitening procedures were evaluated using a dental spectrophotometer. Results: The ΔE and shade had no significant differences with or without light irradiation. In addition, the ΔE, changes of L*, a*, b*, and shade did not change over 6 months after bleaching at a level detectable to the naked eye. The results suggested that the in-office whitening agent using 35% hydrogen peroxide without photocatalysts can improve tooth color with or without light irradiation for 6 months after whitening. (Am J Dent 2021;34:201-204).

 

 

 

 

Mail: Dr. Akimasa Tsujimoto, 801 Newton Rd, Iowa City, Iowa 52242, USA.  E-mail: akimasa-tsujimoto@uiowa.edu

 

 

In vitro rehardening and staining effects of silver diamine fluoride with and without mucin on early enamel caries lesions

 

Parand Sorkhdini, dvm, phd, Yasmi O. Crystal, dmd, msc, Qing Tang, ms  &  Frank Lippert, phd

 

Abstract: Purpose: To evaluate the rehardening ability of SDF and its individual components, silver, and fluoride ions, on early enamel caries lesions using artificial saliva with and without mucin. Methods: Early caries lesions were created in human permanent enamel specimens. The specimens (n=36 per group) were then treated with a single application of: SDF (38%), SDF followed by application of potassium iodide (SDF+KI), potassium fluoride (KF); fluoride control, 44,800 ppm (F), silver nitrate (AgNO₃); silver control, 253,900 ppm (Ag), or deionized water (DIW). Immediately, the specimens were subjected to 4 days of continuous remineralization with or without mucin (n=18 per subgroup). Changes in Vickers surface microhardness from lesion baseline (∆VHN) were calculated. Data were analyzed using two-way (intervention vs. rehardening models) ANOVA. Results: In both rehardening models (with or without mucin), SDF (∆VHN data; mean ± standard deviation; with/without mucin: 26± 19/3± 11) was significantly less effective in rehardening promotion than SDF+KI (37± 12/39± 16) and KF (40± 17/41± 29; P≤ 0.0332). Compared to AgNO₃ (9± 9/18± 15) and DIW (3± 7/12± 9), SDF was more effective in the presence of mucin (P≤ 0.001) but not in its absence, similar to DIW (P= 0.1117); less effective vs. AgNO₃ (P= 0.0061). The presence of mucin significantly increased the rehardening ability of SDF (P< 0.0001). However, mucin did not affect the extent of rehardening in the other groups (P≥ 0.082). SDF+KI and KF were superior in their ability in rehardening promotion than AgNO₃ and DIW in both rehardening models (P< 0.0001). In both rehardening models, ΔL* values from baseline to post-rehardening show that applying KI after SDF significantly lessened the dark staining caused by SDF (P< 0.0001). Under the present in vitro conditions, SDF does not appear to enhance surface rehardening of early enamel caries lesions. The co-presence of mucin during rehardening enhanced the efficacy of SDF which warrants further investigation. (Am J Dent 2021;34:205-210).

 

 

 

 

Mail: Dr. Parand Sorkhdini, Department of Cariology, Operative Dentistry and Dental Public Health, Oral Health Research Institute, School of Dentistry, Indiana University, 415 Lansing Street, Indianapolis, IN 46202, USA. E-mail: Parsorkh@iu.edu

 

 

 

Prevalence of periapical abscesses in patients with rheumatoid arthritis. A cross sectional study     

 

Ilan Rotstein, dds  &  Joseph Katz, dmd

 

Abstract: Purpose: To assess the prevalence of periapical abscesses in patients with rheumatoid arthritis, and to evaluate the effect of commonly used antirheumatic medications on such prevalence. Methods: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for rheumatoid arthritis and periapical abscess was retrieved by searching the appropriate query in the database. The odd ratio (OR) of periapical abscesses, its association with rheumatoid arthritis and intake of three commonly prescribed antirheumatic medications were calculated and analyzed statistically. Results: The prevalence of periapical abscesses in patients with rheumatoid arthritis was 1.53% as compared to 0.51% in the general patient population of the hospital. The OR was 2.60 and the difference was statistically significant (P< 0.0001). In patients treated with either Methotrexate, Sulfasalazine, or Etanercept, the ORs were 2.88, 3.1, and 1.07, respectively. The differences between Methotrexate and Sulfasalazine were statistically significant (P< 0.0001). The OR for prevalence of periapical abscesses in patients treated with Etanercept was significantly lower than that of patients treated with either Methotrexate or Sulfasalazine (P< 0.005). (Am J Dent 2021;34:211-214).

 

 

 

 

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

 

 

 

Effect of a hydrogen peroxide bleaching agent with calcium and phosphorus-containing salts on enamel surface hardness and roughness

 

Adrielle Caroline Moreira Andrade, dds, ms,  Livia Maria Andaló Tenuta, dds, ms, phd, Alessandra Bühler Borges, dds, ms, phd  &  Carlos Rocha Gomes Torres, dds, phd

 

Abstract: Purpose: To evaluate whether adding calcium and phosphorus-containing salts to 35% hydrogen peroxide at saturation concentrations with respect to hydroxyapatite would reduce its deleterious effects on bleached enamel or affect bleaching efficacy. Methods: The saturation concentrations of elemental calcium and phosphorus in a 35% hydrogen peroxide solution were determined after equilibration with powdered enamel. The solubility limit of the salts in 35% hydrogen peroxide was then experimentally determined. Polished bovine enamel-dentin specimens (n=120) with known baseline enamel Knoop microhardness (KHN), surface roughness (Ra), and color were bleached with hydrogen peroxide containing different concentrations of calcium and phosphorus-containing salts as follows: Negative Control - water without any addition; Positive Control - 35% hydrogen peroxide without any addition; 50% of Ca and P - hydrogen peroxide with calcium and phosphorus-containing salt additions of 50% of the saturation concentration; 100% of Ca and P - hydrogen peroxide with calcium and phosphorus-containing salt additions of 100% of the saturation concentration; Ca limit - hydrogen peroxide with addition of calcium-containing salt at the solubility limit, and P limit - hydrogen peroxide with addition of phosphate-containing salt at the solubility limit. The prepared bleaching solutions were applied on the surface of the specimens for 60 minutes. The microhardness and surface roughness were measured immediately after bleaching, and the color change (ΔE*00) was evaluated after 7 days. Results: One-way ANOVA showed significant differences among the groups for all evaluations (P< 0.05). The groups saturated with elemental calcium and/or phosphorus with respect to hydroxyapatite did not show significant changes in microhardness and roughness in relation to the negative control, while the positive control without mineral supplementation and the 50% saturated group showed reduced microhardness and increased roughness. The addition of calcium and/or phosphorus-containing salts in sufficient concentrations to create a saturated hydrogen peroxide solution with respect to hydroxyapatite was able to completely prevent surface changes without affecting the bleaching effect. (Am J Dent 2021;34:215-221).

 

 

 

 

 

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

 

 

A randomized, controlled comparison of a stannous-containing dentifrice for reducing gingival bleeding and balancing the oral microbiome relative to a positive control

 

Tao He, dds, phd, Shi Huang, phd, Feng Yue, phd, Lijiang Wang, phd, Jiquan Liu, phd  &  Jian Xu, phd

 

Abstract: Purpose: To evaluate the effect of a stannous-containing fluoride dentifrice on gingival health and on the composition of the oral microbiome versus a positive control dentifrice over 2 weeks, in a population of healthy adults with self-reported sub-optimal oral health at baseline. Methods: This was a randomized, controlled, double-blind clinical study. 87 subjects with self-reported sub-optimal oral health at enrollment were randomized to brush twice daily with either an experimental dentifrice (n= 43) or a marketed positive control dentifrice (n= 43), both containing stannous chloride and 0.321% sodium fluoride. All subjects used a soft, manual toothbrush that was provided. The Mazza modification of gingival papillary bleeding Index (Mazza GI) was used to assess gingivitis at baseline and at Week 2. Supragingival plaque was collected for microbiome composition analyses at baseline, Week 1, and Week 2. Results: 83 subjects completed the study. Baseline means were balanced between the treatment groups (P> 0.34). At Week 2, the positive control dentifrice demonstrated a 63.8% statistically significant (P< 0.0001) reduction relative to baseline for Mazza number of gingival bleeding sites. The experimental stannous containing dentifrice provided a comparable 63.5% gingival bleeding reduction versus baseline. There was no significant (P= 0.96) difference between the two dentifrices for either Mazza GI score or number of bleeding sites measured. The microbiome composition analysis at Week 1 found that 28 gingivitis-associated bacterial genera, including Porphyromonas, Tannerella, and Fusobacterium, were significantly inhibited in both dentifrice groups when compared to baseline, while the relative abundance of genera associated with oral health, such as Rothia, Streptococcus, Haemophilus, and Lautropia, was significantly elevated after treatment. These improvements in the oral ecosystem were sustained at Week 2. (Am J Dent 2021;34:222-227).

 

 

 

 

 

 

Mail: Dr. Tao He, The Procter & Gamble Company, Mason Business Center, 8700 Mason-Montgomery Road, Mason, OH 45040, USA. E-mail: he.t@pg.com

 

 

Evaluation of the antimicrobial effect of silver ion tubing on dental unit waterlines

 

Lanxin Cheng, Tianshu Liu, Shimin Liang, Yuhua Dai, Zhuoli Zhu, dds, ms, phd, phd

 

Abstract: Purpose: To assess the antimicrobial effects of silver ion tubing (ST) on dental unit waterlines (DUWLs) and their sustainability over time. Methods: Six dental chair units (DCUs) equipped with ST and four with common tubing (CT) were included in the study. Repeated flushing with phosphate-buffered saline (PBS) was conducted to dislodge biofilms. Then, genetic analysis of the PBS was performed. The tubing was also detached and scanned under a scanning electron microscope (SEM) to observe the adherent biofilm on the lumen walls. Results: Low bacterial levels were noted in both the CT and ST groups, but biofilm attachment was only observed in the CT group. (Am J Dent 2021;34:228-232).

 

 

 

Mail: Dr. Zhuoli Zhu, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, No. 14, 3rd Sec. Renmin Nan Rd, Chengdu 610041, Sichuan, PR China.  E-mail: zzl7507@126.com