^{October 2023 Abstracts}

Effects of the multi-channeled oral irrigation (MCOI) unit in preventing dental plaque formation and gingivitis: A randomized controlled trial

 

Julie Y. Kim, dds, mph, Eun-Bin Bae, msd, phd, Eric C. Sung, dds, Thomas Lee, dds Paulo Camargo, dds, ms. mba, Ki-Hyuk Shin, phd, Hyun Jeong Kim, md, mph, phd, Woong-Beom Pyun, phd & Reuben H. Kim, dds, phd

 

Abstract: Purpose: To evaluate the efficacy of COMORAL a new multi-channeled oral irrigation (MCOI) unit with pulsating water jet, in plaque score reduction and gingivitis. Methods: This was a single-blinded clinical randomized controlled trial (NCT05031260). Forty-two healthy subjects between 18 to 35 years old were initially recruited, and the control group (n = 20) and the intervention group (n = 17) were randomly assigned. Both groups were asked to brush their teeth one or two times a day without any supplementary oral hygiene products while the intervention group used COMORAL 3 times a day, 5 days a week. Clinical indices including gingival index (GI), plaque index (PI), bleeding on probing (BOP), pocket depth (PD), gingival recession (GR), and clinical attachment loss (CAL) were obtained at the baseline (D0), day 14 (D14), and day 28 (D28). Saliva was collected to examine the presence of periodontal pathogens. The repeated measures analysis of variance or generalized estimating equation was used to compare the interaction between groups and time points. The independent t-test or Mann-Whitney test were used for intergroup differences at each time point. Results: At V0, PI, GI, BOP, and PD scores showed no differences between the two groups. At V1 and V2, these scores showed significant difference between two groups (P < 0.05) such that the intervention group showed gradual decreases while the control group showed no change. There were no differences in GR, CAL, and periodontal pathogens between the two groups. COMORAL showed improvement in reducing gingival inflammation and dental plaque formation adjuvant to routine toothbrushing in healthy adults (Am J Dent 2023;36:215-221).

 

 

 

 

Mail: Dr. Reuben H. Kim, UCLA School of Dentistry, Center for the Health Sciences, Room 43-091, 10833 Le Conte Ave, Los Angeles, CA  90095, USA.  E-mail: rkim@dentistry.ucla.edu

 

 

 

 

Titanium abutment background masking using highly opaque cements for implant prosthetics

 

Sabrina Elise Moecke, dds, ms, Ana Laura Honorato Diniz, dds, Alessandra Bühler Borges, dds, msc phd &  Carlos Rocha Gomes Torres, dds, phd

 

Abstract: Purpose: To evaluate the capacity of highly opaque cements on masking titanium abutment background. Methods: Dentin and titanium specimens were used to simulate respectively, a natural dental background and an implant abutment. To simulate the full-crowns, Y-TZP zirconia (ZC), lithium disilicate (LD), and resin composite (RC) blocks were used. The titanium specimens were divided into six cementation groups (n=10): two regular cements (BQM and RX); three opaque cements (MHA; VA and BHA); and a clear liquid (CL). The masking capacity of each cement was calculated as the color difference between the color of the crowns over dentin with clear liquid (reference) and the color of the crowns over the titanium with the different cements (DEab). Data were statistically analyzed using two-way ANOVA and Tukey test (α= 0.05). Results: Significant differences (P= 0.0001) were observed for both factors, cement and crown, and for the interactions between them. The results of Tukey test for cement were: BHA-2.25(0.98), MHA-2.94 (1.03), VA-3.45 (1.67), BQM-9.55 (2.77), RX-9.88 (3.12), CL-10.41 (3.47). The cements BHA, MHA and VA showed significantly smaller means than BQM, RX and CL. The results for crown were: ZC-3.66 (2.37), LD-7.50 (4.08), RC-8.08 (4.67). The means for all crown materials were significantly different. Highly opaque cements were more efficient on background masking than regular cements. Zirconia promoted the higher color masking while the resin composite the lowest. (Am J Dent 2023;36:222-226).

 

 

 

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

 

 

 

Staining- and aging-dependent changes in color and translucency of 3D-printed resin-modified ceramics

 

Natalie Pereira Sanchez, dds, ms, Maria D. Gonzalez, dds, ms, Donald M. Belles, dds, ms, Gary N. Frey, dds &  Rade D. Paravina, dds, ms, phd

 

Abstract: Purpose: To evaluate staining- and aging-dependent changes in the color and translucency of 3D-printed resin-modified ceramics (RMC). Methods: Specimens (n= 5 per condition and material) were fabricated from test materials: Permanent Crown Resin (PCR), Crowntec (CT), Vita Enamic (VE) and Tetric CAD (TC). Specimens were stained in wine, coffee, tea, and water (control) and exposed to artificial accelerated aging (AAA). Color measurements were obtained using a spectrophotometer at baseline (T0) and at 3.5 (T1) and 7 (T2) days after immersion. For AAA, measurements were obtained at baseline (T0) and after exposure to controlled irradiance of 150 kJ/m² (T1) and 300 kJ/m² (T2). Mean and standard deviations were calculated on CIEDE2000 color differences (∆E₀₀), translucency parameter (TP₀₀) and treatment-dependent changes in the translucency parameter (∆TP₀₀). Differences between materials and test conditions were tested by one-way ANOVA (α= 0.05). Results were additionally interpreted using visual color difference thresholds in dentistry ΔE₀₀= 0.8 for the 50:50 perceptibility threshold (PT) and ΔE₀₀= 1.8 for the 50:50 acceptability threshold (AT). ∆TP₀₀ values were interpreted using 50:50 TPT₀₀= 0.6 and 50:50% TAT₀₀= 2.6. Results: Statistically significant differences were found among the materials when exposed to the different test conditions. At the T0-T1 time interval, the highest color difference was found with wine (0.1-2.2) on all materials except CT, which showed the highest ∆E₀₀ with AAA (2.5). The second highest color differences were obtained upon exposure to AAA (0.2-2.5) and tea (0.5-1.1). The TP₀₀ at baseline ranged from 5.1 to 9.8. Significant differences in ∆TP₀₀ were found among the tested materials and staining/aging conditions, but no significant differences were found among the staining/aging intervals (T0-T1, T0-T2 and T1-T2). (Am J Dent 2023;36:227-232).

 

 

Mail: Dr. Natalie Pereira Sanchez, The University of Texas School of Dentistry at Houston, 7500 Cambridge St., Suite 5350, Houston, TX 77054, USA. E-mail: Natalie.A.PereiraSanchez@uth.tmc.edu

 

 

 

Effect of a calcium phosphate-containing desensitizing agent on postoperative sensitivity: A split-mouth, randomized controlled study

 

Leyla Kerimova-Köse, dds, Ayfer Ezgi Yilmaz, phd, Kıvanc Yamanel, dds, phd  &  Neslihan Arhun, dds, phd

 

Abstract: Purpose: To evaluate the effectiveness of a calcium phosphate-containing-desensitizer (Teethmate Desensitizer - TD), caries type, subject age, and preoperative hypersensitivity on postoperative sensitivity (POS) after composite restorations on deep or extremely deep lesions. Methods: 50 subjects, having two teeth with deep or extremely deep caries, participated in this study. TD was applied randomly to one tooth of each participant, and all teeth were restored with composite resin (Filtek Z250). After 1 week, POS was evaluated according to NRS (numerical rating scale) and VAS (visual analogue scale) by using participant diaries. At 6 weeks, POS was assessed considering subjects’ reports. The normality of data was analyzed with Shapiro-Wilk test. For analyses, Pearson’s chi-squared test, Mann-Whitney U and the Wilcoxon Signed-Rank test were used, and the effect sizes (ES) were calculated (α= 0.05). Results: 47 of the participants completed the 6-week study. There was a small effect size noted for TD for NRS and VAS (P> 0.05, ES < 0.30). Also, there was no statistically significant difference between POS and subject age (P= 0.294, ES= 0.161), type of caries (P= 0.680, ES= 0.042) and preoperative sensitivity (P= 1.000, ES= 0.138) after the first week. (Am J Dent 2023;36:233-238).

 

 

Mail: Dr. Leyla Kerimova-Köse, Department of Restorative Dentistry, School of Dentistry, Baskent University, Yukarı Bahçelievler, 82. Sk. No. 26, 06490 Çankaya/Ankara, Turkey.  E-mail: leylakerim38@gmail.com, lkerimova@baskent.edu.tr

 

 

 

Shear bond strength of permanent 3D-printed resin and milled zirconia to primary teeth using different luting agents

 

Nazli Aydin, dds, ms  &  Hacer Nida Uguz, dds, ms

 

Abstract: Purpose: To evaluate the shear bond strengths (SBS) of permanent 3D-printed resin (PR) to primary dentin using different luting agents. Methods: 90 primary teeth were prepared. 45 cylinders (3 × 3 mm) were printed using PR, and 45 cylinders were milled using a Z block (to control). The cylinders were bonded to primary dentin by using three types of luting agent [glass-ionomer cement (GIC), resin-modified glass-ionomer cement (RMGIC), and self-adhesive resin cement (SRC)]. The SBS values of the specimens were calculated, and the fracture modes were examined. Results: There was a statistically significant difference between the three different luting agents that were used to lute the PR to primary dentin (P< 0.001). Changing the material (PR or Z) did not affect the SBS values of the luting agents (P> 0.05). The adhesive failure between cement and dentin in the PR-SRC group was significantly higher than the other groups (P< 0.001). The SBS values of the newly developed PR to primary dentin with RMGIC and SRC were similar, but GIC showed lower values than the others. (Am J Dent 2023;36:239-245).

 

 

Mail: Dr. Nazli Aydin, Department of Prosthodontics, Faculty of Dentistry, Cukurova University, 01250, Saricam Adana, Turkey.  E-mail: nazli.yesilyurt.aydin@gmail.com

 

 

 

Comparison of accuracy and reliability of CBCT and 3D laser scanner in the volumetric assessment of the root canal space

 

Anchu Rachel Thomas, mds, Htoo Htoo Kyaw Soe, phd, Christine Shenali Silva, bds, Harpeven Kaur, bds, Loshanii Devi Ganendrah, bds & Lynette Maria Gomez, bds

 

Abstract: Purpose: To compare the accuracy and reliability of cone-beam computed tomography (CBCT) and laser scanner in measuring minor volume changes such as the root canal space. Methods: 35 maxillary incisors were endodontically prepared. A dimensionally stable silicone material was injected into the root canal space and scanned with CBCT. The root canal volume was measured using Romexis 3.0.1 R software. Replicas were carefully removed from the teeth and scanned using an extraoral laser scanner. These images were exported to the Rhinoceros software for volume measurement. The volume of each replica was also assessed using the gravimetric method. To determine the accuracy, the volume obtained from both devices was compared with the gravimetric method. Statistical analysis was done using a paired t-test. The reliability was assessed using the intraclass correlation coefficient. Results: There was no statistically significant difference between the mean volume of CBCT 27.04 ± 7.25 mm³ and the mean volume of the gravimetric method 27.87 ± 7.17 mm³ (P> 0.05). A statistically significant difference was seen with the laser scanner at 25.31 ± 6.89 mm³ and the gravimetric method at 27.87 ± 7.17 mm³ (P< 0.05). CBCT showed a good degree of agreement (ICC 0.899), while the laser scanner showed a moderate degree of agreement (ICC 0.644) with the gravimetric method. CBCT proved accurate and reliable in measuring minor volumes like the root canal space, ideally in the range of 20-25 mm³. The laser scanner presented acceptable reliability. (Am J Dent 2023;36:246-250).

 

 

 

 

Mail: Dr. Anchu Rachel Thomas, Department of Conservative Dentistry and Endodontics, Faculty of Dentistry. Manipal University College Malaysia, Jalan Batu Hamper, Bukit Baru, Melaka 75150, Malaysia. E-mail: anchurachel@gmail.com

 

 

 

Effect of cold atmospheric plasma versus conventional surface treatments on the bond strength between CAD-CAM zirconia and resin cement

 

Gülay Kamiş, dds, phd  &  Bekir Eser, dds, phd

 

Abstract: Purpose: To evaluate the shear bond strength of two different resin cements to zirconia after treatment with cold atmospheric pressure plasma (CAPP) and other surface modification methods. Methods: 189 specimens fabricated from Vita YZ-HT zirconia discs were divided into nine surface treatment groups: (1) Untreated (U), (2) Sandblasting (S), (3) Laser (L), (4) Plasma (P), (5) Primer (PR), (6) Sandblasting + Primer (SPR), (7) Laser + Primer (LPR), (8) Plasma + Primer (PPR), (9) Laser + Plasma + Primer (LPPR). Surface roughness (Ra) and contact angles were measured (n= 10 each), and scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses were performed (n= 1 each). Specimens were cemented with RelyX Ultimate Clicker adhesive resin cement or Theracem self-adhesive resin cement. The specimens were subjected to shear bond strength (SBS) test. Modes of failure were examined under a stereomicroscope and visualized by SEM. Results: The S, PR, SPR, PPR and LPPR groups showed significantly greater Ra values than the U group. Significantly lower contact angles were observed in the S, P and L groups versus the U group. The SBS values of SPR, PPR and LPPR groups were significantly greater than those of the U group. CAPP can improve zirconia-resin cement bond strength by increasing the wettability of zirconia surfaces pretreated with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) primer. (Am J Dent 2023;36:251-259).

 

 

 

Mail: Dr. Gülay Kamiş, Department of Prosthodontics, Faculty of Dentistry, Firat University, 23200 Eläziğ, Turkey. E-mail: dtgulaykamis@gmail.com

 

 

Microhardness of different thicknesses of bulk fill composites

 

Ashton E. Reno, bs,  Hoda S. Ismail, bds, msd, phd,  Brian R. Morrow, ms,  Anne E. Hill, dds &  Franklin Garcia-Godoy, dds, ms, phd, phd

 

Abstract: Purpose: To compare the microhardness values and bottom/top hardness ratios of different composites after being cured in 2 or 4 mm increments. Methods: Two bulk fill composites, methacrylate-based and ormocer-based, and one conventional composite were tested. 36 cylindrical discs were prepared (n=12/composite, with six for 2 mm, and six for 4 mm thickness) by pressing each composite into a mold between two glass slides covered by Mylar strips. The top and bottom surfaces of each sample were evaluated using a Buehler hardness tester for Knoop microhardness, with a 50 g static load applied for 10 seconds at three different locations of the central part of each sample. The bottom/top hardness ratio was calculated for each sample. The Knoop microhardness data and bottom/top ratio percentages were analyzed using two-way repeated measures ANOVA and Holm-Sidak post hoc test, with significance at P< 0.05. Results: The tested methacrylate-based bulk fill had the highest overall microhardness among the three tested composites. All three composite types showed a significant difference in microhardness between the top and bottom of the 4 mm discs. The bottom/top ratio percentages differed significantly for both tested bulk fill composites across different thicknesses. Both tested bulk fill materials had a bottom/top ratio of ≥ 80% at the deepest level of a 4 mm increment. (Am J Dent 2023;36:260-264).

 

 

Mail: Dr. Hoda S. Ismail, Department of Conservative Dentistry, Faculty of Dentistry, Mansoura University, Algomhoria Street, PO Box 35516, Mansoura, Egypt.  E-mail: hoda_saleh@mans.edu.eg