^{August 2024 Abstracts}

Influence of coffee characteristics on tooth discoloration

 

Soyeon Kim, ba,  Ji-Soo Song, dds, phd,  Jihyun Yoon, phd,  Franklin Garcia-Godoy, dds, ms, phd, &  Young-Seok Park, dds, msD, phd

 

Abstract: Purpose: To evaluate the impact of coffee attributes on tooth discoloration, emphasizing the importance of potential factors such as serving temperature, bean variety, and chlorogenic acid (CGA) content. Methods: Coffee preparation involved the extraction of espresso from four types of roasted beans (Vietnam Robusta, Uganda Robusta, Ethiopia Yirgacheffe Arabica, and Colombia Supremo Arabica), followed by chlorogenic content analysis using high-performance liquid chromatography. Bovine tooth enamel specimens were carefully prepared and stained with coffee (hot and iced), with a color assessment conducted at different time intervals (3, 9, 24, 48, and 72 hours). The Vickers hardness tester was employed to ensure specimen quality, while spectrophotometry aided in color analysis using the CIEDE2000 formula. Results: The results revealed varying effects of serving temperature, bean type, and CGA content on tooth discoloration. It was demonstrated that perceptible color differences occur after a 3-hour immersion in coffee, with hot coffee showing higher staining potential compared to iced variations. Furthermore, chlorogenic acid content and bean type significantly affected tooth discoloration, with higher chlorogenic acid levels associated with increased staining. Notably, Robusta coffee showed less discoloration compared to Arabica, potentially due to differences in pH levels. (Am J Dent 2024;37:171-176).

 

 

 

 

 

 

Mail:  Prof. Dr. Young-Seok Park, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.  E-mail:  ayoayo7@snu.ac.kr

 

 

 

Evaluation of tissue conditioner-assisted complete denture restoration: A randomized controlled clinical trial

 

Hui Gu, msc, Xin-Chen Zhu, msc, Na-Na Fan, msc, Ai-Ling Cao, msc, Qiang Xue, msc  &  Li-Qin Gong, msc

 

Abstract: Purpose: To evaluate the clinical effect of three impression methods, conventional, closed-mouth, and tissue conditioner, on complete denture fabrication. Methods: 60 subjects (edentulous with severely resorbed alveolar ridges - Atwood classification III or IV) who visited the Prosthodontic Department of Wuxi Stomatology Hospital, China, between January 2022 and June 2023, were selected for this study. The subjects were randomly divided into three groups of 20: a conventional impression group (CI group), a closed-mouth impression group (CM group), and a tissue conditioner group (TC group). Three months after denture restoration was completed, denture quality was assessed by clinicians in terms of marginal extension, retention, and stability. In addition, patients completed the oral health impact profile-edentulous (OHIP-EDENT) questionnaire to provide subjective satisfaction evaluations of the final denture restoration outcomes. Results: The comprehensive denture quality evaluation results showed that the TC group had the lowest score, which was significantly lower than that of the CM (P= 0.014) and CI (P< 0.001) groups. The average score of the CM group was also significantly lower than that of the CI group (P= 0.004), indicating that tissue conditioner restoration was the most effective method. The OHIP-EDENT scores gradually decreased across the groups from CI to CM to TC (P= 0.001), indicating patients' oral health was significantly improved using tissue conditioner. (Am J Dent 2024;37:177-182).

 

 

Mail:  Li-Qin Gong, Department of Prosthodontics, Wuxi Stomatology Hospital No. 6 of Jian Kang Road, Liang Xi District, WuXi 214000, China.  E-mail:  liqingong_g61@163.com

 

 

 

Influence of provisional cementation on the stability of adhesively bonded resin-based composite crowns

 

Michael Benno Schmidt, dr med dent, Angelika Rauch, pd dr med dent, Laura Haas, dr med dent &  Martin Rosentritt, prof dr dipl ing

 

Abstract: Purpose: To investigate the influence of temporary cementation and subsequent bonding on the durability during in-vitro aging-simulation and fracture force of resin-based composite crowns. Methods: Identical molar crowns (n=48, n=8 per group) were milled from resin-based composites and temporarily cemented and finally bonded to human molars. To simulate temporary application, crowns were cemented either with zinc-oxide-eugenol-cement (Tempbond) or with eugenol free zinc-oxide-cement (Tempbond NE). For a first simulation of a long-term provisional clinical application, thermal cycling, and mechanical loading (TCML 2 × 600 × 5°C-55°C, 2 minutes each cycle, distilled water, 240,000 cycles at 50N) was performed. After TCML all crowns were removed, cleaned, and luted either by using etch-and-rinse technique (Vococid, Futurabond U, Bifix QM) or a self-adhesive (Bifix SE) cementation system. A second thermal cycling and mechanical loading (TCML 2 ×3,000 × 5°C/55°C, 2 minutes each cycle, distilled water, 1.2 × 10⁶ at 50N) was accomplished to simulate 5 years of clinical application. To assess the survival of the crowns, the failure rates during TCML were documented. As controls, crowns were included without prior provisional cementation. After TCML all crowns were loaded to failure. Failure was categorized as fracture of the crown and partial loosening of the crown. Results: All crowns survived both TCML procedures without any failures. The fracture values after TCML varied between 3,538.0 ± 1,041.2 N and 4,612.0 ± 801.5 N without significant (P= 0.146) differences between the individual groups. No correlation was found between fracture force and type of provisional cementation (zinc-oxide-eugenol vs. zinc-oxide: Pearson: -0.063/P= 0.672) or type of bonding (adhesive vs. self-adhesive: Pearson: -0.151/ P= 0.307). No different failure pattern was observed between the tested systems. (Am J Dent 2024;37:183-186).

 

 

 

 

 

Mail: Dr. med. dent. Michael Benno Schmidt, Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93053 Regensburg, Germany.  E-mail:  Michael3.Schmidt@klinik.uni-regensburg.de

 

 

A comparison of the radiopacities of CAD-CAM restoratives: Effect of thickness

 

Dilan Kopuz, dds,  Zeynep Betül Arslan, dds,  Özlem Erçin, dds,  Nevin Kaptan Akar, dds, phd &  Neslihan Tekçe, dds, phd

 

Abstract: Purpose: To evaluate the radiopacities of CAD-CAM materials using digital techniques. Methods: Five different CAD-CAM materials were used (Cerasmart, LAVA Ultimate, Cerec Blocs C, Tetric CAD, and IPS e.max CAD) in this study (n= 5). For each group, samples with thicknesses of 1 and 2 mm were prepared. As a control, tooth slices with 1 and 2 mm thicknesses and a 99.5% pure aluminum step wedge were used. The samples, tooth slices, and step wedges were placed on a photostimulable phosphor plate. Radiographs were taken at 30 cm distance with 7 mA, 70 kVp, and 0.32 ms exposure time. The images were analyzed using the ImageJ software to measure the mean gray values. Data were analyzed with Kruskal-Wallis H test and the Mann-Whitney U test (P< 0.05). Results: In the comparison of CAD-CAM materials with 1 and 2-mm thicknesses, the highest radiopacity value was seen in LAVA Ultimate samples (2.67 ± 0.05 for 1 mm samples: 5.74 ± 0.13 for 2 mm samples). The lowest value in 1 mm samples was seen in IPS e.max (0.59 ± 0.07), and in 2 mm samples, in Cerec Blocs C samples (1.49 ± 0.11). The results showed that the radiopacity values of the samples were associated with increased thicknesses. The 2 mm samples’ radiopacity values were statistically significantly higher compared with the 1 mm samples. All samples except IPS e.max CAD and Cerec Blocs C had higher radiopacity than dentin (P< 0.05). (Am J Dent 2024;37:187-190).

 

 

Mail:  Dr. Dilan Kopuz, Department of Restorative Dentistry, Faculty of Dentistry, Istanbul Kent University, Istanbul, Turkey.  E-mail:  dilan.kopuz@kent.edu.tr

 

 

Microhardness, diametral tensile strength and color stability of heated resin composites used for luting ceramic veneers

 

Leandro Castro Lima, dds, msc,  Juliana Aldarvis, dds, msc,  Flávia Lucisano Botelho do Amaral, dds, msc, phd, Waldemir Francisco Vieira-Junior, dds, msc, phd,  Cecilia Pedroso Turssi, dds, msc, phd, Roberta Tarkany Basting, dds, msc, phd,  Adriano Lima, dds, msc, phd,  Leonardo Santos Barros, dds, msc &  Fabiana Mantovani Gomes França, dds, msc, phd

 

Abstract: Purpose: To evaluate color change in ceramic veneers luted to enamel with light-cured, dual-cured resin luting agents, or heated resin composites, as well as to evaluate microhardness and diametral tensile strength of these luting agents. Methods: For color analysis, 0.5 mm-thick leucite-reinforced glass ceramic veneers (IPS Empress CAD) were cemented onto 40 bovine dental blocks (n= 10) using RelyX Ultimate (RU) or RelyX Veneer (RV) resin-based luting agents, or Gradia Direct (GD) and Palfique Lx5 (P) heated resin composites. After luting, the specimens were subjected to thermocycling (10,000 cycles). Color analysis was performed before and after thermocycling (L*, a*, b*, ∆E_ab, ∆E₀₀). For the microhardness (Knoop) and diametral tensile strength tests, specimens (Ø 6 × 2 mm) were made (RU, RV, GD, and P). The specimens were subdivided into eight groups (n=10) and light-cured through different ceramic sheets (thicknesses of 0.5 mm or 1.5 mm). Knoop microhardness was performed on the top surface in a microhardness tester, and diametral tensile strength on a universal testing machine. Data were submitted to statistical analysis, using two-way ANOVA, Tukey, and Kruskal-Wallis tests (α= 0.05). Results: For the general color alteration, there was no statistically significant difference between the luting materials (∆E_ab, P= 0.57; ∆E₀₀, P= 0.50). There was no interaction between luting agent and thermocycling, for L* (P= 0.87), a* (P= 0.97) and b* (P= 0.95) values. Thermocycling significantly affected only the L* values (P= 0.047), which increased after the cycles. For microhardness, there was a statistically significant difference considering luting agents and ceramic thickness (P< 0.001). GD heated resin composite presented significantly lower microhardness values than all other materials, at both ceramic thicknesses. At a thickness of 1.5 mm, RU cement had higher microhardness values than RV and P materials. Diametral tensile strength was significantly influenced by luting agent (P= 0.01), but not by ceramic thickness (P= 0.55). Diametral tensile strength of GD resin composite was higher than that of the RU, but neither of these two materials differed from RV and P. (Am J Dent 2024;37:191-196).

 

 

 

 

Mail:  Dr. Fabiana Mantovani Gomes França, Research Institute São Leopoldo Mandic, Faculty São Leopoldo Mandic, Rua José Rocha Junqueira, 13 Swift Campinas – SP,  CEP: 13045-755, Brazil.  E-mail:  biagomes@yahoo.com

 

 

 

Acute periapical abscesses and obese patients

 

Joseph Katz, dmd  &  Ilan Rotstein, dds

 

Abstract: Purpose: To evaluate the prevalence of acute periapical abscesses (PAs) in obese patients. Methods: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for obesity and PAs was retrieved by identifying the appropriate ICD 10 codes in the database. Results: Out of 1,874,214 hospital patients studied, 147,195 patients were classified as obese, of which 3,349 had acute PAs. The difference in prevalence of PAs between obese and average-weight patients was statistically significant (OR 4.22, 95%CI: 4.05-4.39, P< 0.0001). Adjustment for diabetes comorbidity reduced the OR to 2.55; however, the difference remained statistically significant (95%CI: 2.43-2.68, P< 0.0001). Adjustment for smoking reduced the OR to 2.63; however, the difference remained statistically significant (95%CI: 2.51- 2.87, P< 0.0001). Adjustment for periodontal disease comorbidity reduced the OR to 3.85; however, the difference remained statistically significant (95%CI: 3.70-4.01, P< 0.0001). Females were more affected than males; adults were more affected than children; and African Americans were more affected than Whites. (Am J Dent 2024;37:197-200).

 

 

 

Mail:  Dr. Ilan Rotstein, University of Southern California, DEN 310, Los Angeles, CA 90089, USA. E-mail:  ilan@usc.edu

 

Staining- and aging-dependent changes in color, translucency, and gloss of cloud-shade and one-shade resin composites

 

Hamid Nurrohman, dds, phd,  Yonca Korkmaz-Ceyhan, dds, phd,  Pinar Cevik, dds, phd &  Rade D. Paravina, dds, ms, phd

 

Abstract: Purpose: To compare staining and artificial accelerating aging-dependent changes in color, translucency, and gloss of cloud-shade and one-shade resin composite. Methods: The “cloud-shade” composites were Filtek Easy Match Universal Restorative (FU) and SimpliShade (SS): three shades each (light, medium and dark), while the “one shade” composites were Admira Fusion x-tra (AD) and Venus Diamond One (VE). Polymerized composite specimens (10 mm in diameter, 2 mm-thick) were polished using PoGo disks for 40 seconds. Color, translucency, and gloss measurements were performed before and after exposure to 3.8-day staining in coffee or wine (equivalent to a year of service with a 15-minute exposure per day), or exposure to 150 kJ/m² of accelerated aging (n= 5 per condition × three conditions, for a total of 15 specimens per shade). Color and translucency were measured using a benchtop spectrophotometer, and CIEDE2000 color differences (ΔE₀₀) and translucency parameter (TP₀₀) were calculated. Gloss (gloss units, GU) was measured using a small-area gloss meter. Gloss retention percentages after staining and aging were calculated. A two-way ANOVA was used to compare the effect of material and procedure, while a Tukey’s post hoc multiple comparison test was used to assess differences among levels within each variable (α= 0.05). Results: The AD exhibited the best color stability upon staining, while VE was the most stable when exposed to artificial aging. Statistically significant differences were recorded among materials and procedures (P< 0.001), and their interactions (P< 0.01). AD also exhibited the highest TP stability upon staining, while the TP of FU was the most stable when exposed to artificial aging. Statistically significant differences were recorded among materials and procedures (P< 0.001), and their interactions (P< 0.01). Gloss retention upon staining and aging was greater than 90% for all tested materials. Statistically significant differences were recorded among materials (P< 0.001), procedures (P< 0.05), and their interactions (P< 0.01). (Am J Dent 2024;37:201-205).

 

 

 

 

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

 

 

Antibacterial effect of Softsoap used to disinfect dentures

 

Katherine Ashley DelPriore, bs,  Jegdish Babu, phd,  Brian R. Morrow, ms,  David Umsted, dds &  Franklin Garcia-Godoy, dds, ms, phd, phd

 

 

 

 

 

 

 

Abstract: Purpose: To evaluate the in vitro antibacterial effect of Softsoap and Efferdent used as solutions to disinfect Lucitone 199 poly(methyl methacrylate) (PMMA) resin used for dentures. Methods: S. mutans and plaque bacteria were grown for 24 hours, and suspended to a concentration of 1x10⁶ cells/ml. Bacterial suspensions (0.2 mL) were added to the decontaminated PMMA discs placed in a 48-well culture plate and incubated for 3 days at 37°C. The discs were rinsed to remove the unbound bacterial cells and then incubated for 60 minutes with 5% and 1% dilutions (triplicates) of each of the detergent solutions (0.3 ml). Discs were rinsed and then MTT reagent (0.2 ml) was added and incubated for 2 hours, then overnight with a solubilizing agent. An aliquot from each well (0.1 ml) was transferred to a 96-well flat bottom plate and absorbance was measured to OD @ 595 nm (MTT) of four samples for each data point. Normalized data was compared and statistically analyzed using a three-way ANOVA with Student-Newman-Keuls on Rank data with P< 0.05 for significance. Additionally, data were double-checked with the Holm-Sidak test. Results: There was no statistically significant difference between testing media for C. albicans and mixed plaque (P= 0.078) or testing duration in time at 24 hours and 21 days (P= 0.07). Statistically significant differences were found between all treatment solutions group combinations (P< 0.001) except for 30% Softsoap versus Efferdent (P= 0.056). (Am J Dent 2024;37:206-209).

 

 

 

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

 

 

Reduced staining from a chlorhexidine mouthwash: A randomized clinical trial

 

Saide Tang, phd,  Rabab Ahmed, ms,  Carlo Amorin Daep, phd,  Michael A. Stranick, phd,   Sarita V. Mello, phd,  Betty Won, phd,  Paloma Pimenta, phd, Yun-Po Zhang, phd, dds(hon),   Prem K. Sreenivasan, phd,  Deborah Tischio-Bereski, rdh, bs, Dipty Godboley, bds, ms  &  Daniel Fine, dmd

 

Abstract: Purpose: To investigate the stain preventing ability of a new chlorhexidine mouthwash while maintaining efficacy using a randomized clinical trial design. Methods: 98 subjects were enrolled and completed a 4-week clinical study that evaluated the effectiveness of the new mouthwash on plaque, gingivitis, and staining as compared to a commercially available chlorhexidine mouthwash. A subset of 62 subjects was evaluated for the effectiveness of the mouthwashes against plaque bacteria. Results: After 4 weeks of use, the new chlorhexidine mouthwash reduced staining by 42.6% (P< 0.05) as compared to the commercially available mouthwash. The two mouthwashes were equivalent with regards to their effect on gingivitis, plaque, and plaque bacteria. (Am J Dent 2024;37:000-000).

 

 

Mail:  Dr. Paloma Pimenta, Colgate-Palmolive Company, 909 River Road, Piscataway NJ 08854, USA. E-mail:    paloma_pimenta@colpal.com

 

 

A randomized crossover trial assessing denture adhesive for prevention of food infiltration among partial denture wearers

 

Julie Grender, phd,  Malgorzata Klukowska, dds, phd,  Kimberly Milleman, rdh, phd &  Jeffery Milleman, dds, mpa

 

Abstract: Purpose: This two-treatment, four-period, double-blind, randomized controlled crossover trial assessed the ability of two denture adhesives, both applied with a thin nozzle in a continuous application pattern, to prevent food infiltration beneath partial dentures. Methods: Participants with mandibular partial dentures and a history of food particle infiltration were enrolled. All participants used both an optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (PVM/MA) denture adhesive and a calcium/sodium partial salt of PVM/MA test denture adhesive, twice each, throughout four study periods, according to a randomly assigned sequence. At each visit, participants underwent two assessments: once with no denture adhesive (baseline) and once with denture adhesive, 1 hour after adhesive application. For each assessment, participants ate one-half of the top of a poppy seed muffin, and a dental professional counted the seeds retained on the denture and mucosa, which was the primary variable. The change-from-baseline comparison was made for each treatment separately using a paired t-test or Wilcoxon Signed Rank test depending on the normality of the data. A between-treatment comparison for the change from baseline was performed using a crossover ANCOVA with treatment and period as fixed effects and participant as a random effect. The baseline poppy seed count was used as a covariate. Results: 30 participants were enrolled; 29 completed the trial. Both denture adhesives achieved statistically significantly fewer retained seeds versus baseline (P< 0.001). The calcium/zinc adhesive reduced the seed count from baseline by 85.9% (6.18 vs 0.86), and the calcium/sodium adhesive reduced seed count by 76.6% (6.04 vs 1.43). Comparing the two denture adhesives, the reduction in seed count from baseline was statistically significantly greater for the calcium/zinc adhesive versus the calcium/sodium formulation (P= 0.008). (Am J Dent 2024;37:216-220).

 

 

 

 

 

 

Mail:  Dr. Julie Grender, The Procter & Gamble Company, 8700 Mason-Montgomery Road, Mason, OH 45040, USA. E-mail:  grender.jm@pg.com