^{October 2016 Abstracts}

NaF rinse and dentifrice concentrations on enamel lesion demineralization

 

Zachary S. Goettsche, ba, dds, Ronald L. Ettinger, bds, mds, ddsc, ddsc(hc), Mary M. Hogan, ba, Jeffrey D. Harless, bs, ms   &  Fang Qian, phd

 

Abstract: Purpose: To compare the in vitro effectiveness of two mouthrinses containing different concentrations of NaF to reduce enamel lesion demineralization. Methods: Nine extracted caries-free molars were selected and cleaned. The teeth were painted with acid resistant varnish, leaving a 1 mm × 4 mm window exposed. The teeth were cycled in a demineralizing solution at pH 4.5 for a total for 96 hours. The teeth were sectioned longitudinally through the unpainted window using a hard-tissue microtome, producing 96 sections. The sections were measured and photographed under polarized light microscopy using water and Thoulet’s 1.47 as imbibing mediums. Six treatment groups were randomly created: (A) water control group, (B) 0.05% rinse group once a day (C) 0.02% rinse group twice a day, (D) 1,500 ppm paste group used twice a day, (E) combination group containing 0.05% rinse once a day, and 1,500 ppm paste twice a day, and (F) combination group containing 0.02% rinse and 1,500 ppm paste twice a day. A 10-day cycling protocol was carried out. All sections were then re-measured and re-photographed. A statistical analysis was performed to detect any differences between pre- and post-treatment groups. Results: There was a statistically significant difference in lesion depth between the water control group and the 1,500 ppm paste group as well as the 0.05% rinse in combination with 1,500 ppm paste group (P= 0.0184). No statistically significant differences were found between the control group and any other groups. A statistically significant difference was found in lesion area between the two rinse groups alone and the 1,500 ppm paste group, as well as the 0.05% rinse in combination with the 1,500 ppm paste group (P= 0.0002). An analysis of the results suggested that both rinse concentrations performed equally well in reducing lesion demineralization when used alone. However, only the 0.05% rinse used in combination with 1,500 ppm paste decreased lesion demineralization as compared to the water control group, and was equally as effective as the 1,500 ppm paste alone. (Am J Dent 2016; 29:243-247).

 

 

Mail: Dr. Ronald L. Ettinger, Department of Prosthodontics and Dows Institute of Dental Research, College of Dentistry and Dental Clinics, University of Iowa, Iowa City, IA 52242, USA. E-mail: ronald-ettinger@uiowa.edu

 

 

Silver diamine fluoride, potassium iodide, and esthetic perception: An in vitro pilot study.

 

Michael B. Miller, dds, Laura A. Lopez, ba  &  Ryan L. Quock, dds

 

Abstract: Purpose: To assess if there was a perceptible difference in staining of restorations in silver diamine fluoride (SDF)-treated teeth, with or without the subsequent application of potassium iodide (KI). Methods: 20 extracted teeth with frank cavitated carious lesions were prepared with a spoon excavator to remove superficial soft carious dentin and then randomly divided into two groups of 10. The control group was treated with 38% SDF and then restored with glass-ionomer. The experimental group received similar treatment, with the additional step of KI applied before restoration. All teeth were subjected to 500 thermocycles between 5°C and 55°C, followed by storage in artificial saliva at 37°C for 30 days. Three blinded examiners evaluated all 20 teeth for intensity of staining on a scale from 0-5. Wilcoxon rank sum test compared average staining intensity between control and experimental groups of teeth as perceived by each examiner. Results: No significant differences were found (P values: 0.93, 0.67, and 0.97). An aggregate comparison of staining perception between control and experimental groups by repeated measure analysis was done treating the outcome as Poisson distribution also finding no significant difference (P= 0.82). (Am J Dent 2016;29:248-250).

 

 

 

 

Mail: Dr. Michael Miller, Department of General Practice & Dental Public Health, University of Texas School of Dentistry, 7500 Cambridge, Houston, TX 77054, USA.  E-mail: Michael.B.Miller@uth.tmc.edu

 

 

 

Comparison of dental bleaching effects of ozone and hydrogen peroxide: An ex vivo study

 

Mahmoud K. Al-Omiri, bds, phd, fds rcs (england), Ra’ed S. Abul Hassan, bds, msc, Bader K. AlZarea, bds, msc &  Edward Lynch, bds, ma, phd fds rcs (england)

 

Abstract: Purpose: To compare the efficacy of using ozone versus hydrogen peroxide (H₂O₂) for tooth bleaching. Methods: 90 extracted teeth were allocated into two groups. Teeth in Group 1 (n= 45) were exposed to ozone for 60 seconds; ozone was produced by healOzone X4 machine (healOzone X4), and was applied to teeth through special disposable silicone cups. The silicone cups allowed total seal and avoided gas escape as the machine is devised to work only if the cup guarantees perfect seal and thus secure the safety of the machine for human use. Teeth in Group 2 (n= 45) were treated with 38% H₂O₂ for 20 minutes. The shade of teeth was recorded for both groups at base line, after application of ozone in Group 1, and after application of H₂O₂ in Group 2. The reading for L* a* b* values and Vita Classic shades were recorded using the Colorimeter Konica-Minolta CR-400. The statistically significant differences were set at P≤ 0.05. Results: The teeth in both groups acquired lighter shades after bleaching (P< 0.001). In addition, baseline L* shade values were increased and b* shade values were decreased (means lighter shades) after bleaching in both groups (P< 0.01). However, baseline a* shade values were not significantly changed after bleaching with ozone in Group 1 (P= 0.682). In contrast, a* shade values were significantly decreased after bleaching with H₂O₂ in Group 2 (P= 0.005). Furthermore, final shades achieved after bleaching were not significantly different between groups (P> 0.05). In conclusion, application of ozone for 60 seconds or application of 38% of H₂O₂ for 20 minutes resulted in teeth with lighter shades. Bleaching by application of ozone for 60 seconds would result in similar outcomes to bleaching with 38% H₂O₂. (Am J Dent 2016;29:251-254).

 

 

Mail: Prof Mahmoud K. AL-Omiri, Faculty of Dentistry, The University of Jordan, Amman 11942, Jordan. E-mail: alomirim@yahoo.co.uk

 

 

 

Effect of resin cement, aging process, and root level on the bond strength of fiber-posts: An in vitro study

 

Khalid S. Almulhim, bds, mscd, Luana Oliveira-Haas, dds, ms, phd  &  Amir Farhangpour, dds

 

Abstract: Purpose: To compare the push-out bond strength (POBS) of two resin cement systems (total-etch versus self-etch) for cementing FRC (fiber-reinforced composite) posts in three different thermocycling aging periods (40,000; 20,000; and none) using thermocycling and three root levels (apical, middle, and coronal). Methods: 60 bicuspid single rooted natural teeth were endodontically treated and post spaces were prepared to receive a fiber-post (RelyX FiberPost) cemented with either total-etch (RelyX Ultimate) or self-etch (RelyX Unicem) cement. Teeth were randomly allocated into six groups (n= 10): G1: Control (Ultimate without thermocycling); G2: Ultimate (20,000 cycles); G3: Ultimate (40,000 cycles); G4: Unicem without thermocycling; G5: Unicem (20,000 cycles); and G6: Unicem (40,000 cycles). POBS was determined by using a push-out test on a universal testing machine. Additionally, failure mode of each specimen was observed under a stereomicroscope at ×40 magnification and scanning electron microscope (SEM) examination of selected samples. A nested general linear model was created for statistical significance P< 0.05. Post-hoc tests were carried out using pair-wise comparisons with a Bonferroni adjustment. Results: No significant differences were found on the bond strengths between the resin cements (P= 0.856). Regarding aging effect, bond strengths of the 40,000 cycle groups (G3/G6) were significantly lower than 20,000 cycle groups (G2/G5). In addition, the POBS of the specimens collected from the coronal third of the roots were significantly lower than specimens from the apical third regardless of the type of cement used. Regarding types of failures, adhesive failure (post/cement) was significantly higher in total-etch groups (G1-G3) than the self-etch groups (G4-G6). Adhesive failure (dentin/cement) was significantly higher in self-etch groups than the total-etch groups. (Am J Dent 2016;29:255-260).

 

 

Mail: Dr. Khalid S. Almulhim, 16 Quarry Lane, Apt. #4303, Malden, MA 02148, USA. E-mail: khalid415@hotmail.com

 

 

 

 

Salivary IL-6 and IL-10 levels in subjects with obesity and gingivitis

 

Gülnihal Emrem Doğan, dds, phd,  Ayşe Toraman, phd,  Saime Özbek Şebin, phd,  Çetin Doğan, phd, Adem Güngör, phd,  Hülya Aksoy, phd   &   Hilal Asutay, dds

 

Abstract: Purpose: To evaluate the association between cytokines IL-6 and IL-10 in saliva, obesity and periodontal disease. Methods: The study was carried out in 40 subjects: 20 obese subjects with gingivitis and 20 non-obese subjects with gingivitis (controls). Periodontal parameters such as gingival index (GI) and plaque index (PI) of subjects were recorded. Saliva samples were used for measuring IL-6 and IL-10 levels by ELISA method. Results: Saliva IL-6 levels were significantly higher in obese subjects than those of non-obese subjects (P= 0.002). When total groups were evaluated, negative significant correlation between GI and salivary IL-10 levels (r= -0.452, P= 0.003) and positive correlations between salivary IL-6 level and body mass index (BMI) (r= 0.369, P= 0.019) were found. There was a negative correlation between the GI and salivary IL-10 levels in obese subjects (r= -0.548, P= 0.012). Also there was a positive correlation between the salivary level of IL-6 and IL-10 in obese subjects (r= 0.594, P= 0.006). (Am J Dent 2016;29:261-265).

 

 

Mail: Dr. Gülnihal Emrem Doğan, Department of Periodontology, Faculty of Dentistry, Atatürk University, 25240 Erzurum, Turkey. E-mail: gulnihalemrem@hotmail.com

 

 

The effects of overhang amalgam restorations on levels of cytokines, gingival crevicular fluid volume and some periodontal parameters

 

 

 

 

 

 

 

 

Nurcan Ozakar Ilday, dds, Neslihan Celik, dds, Alparslan Dilsiz, dds, Hamit Hakan Alp, phd, Tuba Aydın, dds, Nilgun Seven, dds  & Ahmet Kızıltunç, phd

 

Abstract: Purpose: To evaluate clinical periodontal findings and GCF levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and interleukin 8 (IL-8) in patients with overhang amalgam restorations before and after overhang restoration removal. Methods: 22 volunteer subjects (age range: 22-42 years old) with 22 overhang Class II amalgam restorations were selected. GCF samples were obtained from adjacent and contralateral teeth for IL-6, IL-8 and TNF-α measurements and analyzed using enzyme-linked immunosorbent assay (ELISA) kits. The amalgam overhangs were removed and the readings were repeated at the end of 1 week. Clinical periodontal assessments, including gingival index (GI) and plaque index (PI) were performed at baseline and after 1 week. Data were analyzed using the paired t test and independent sample t-test at a significance level of 0.05. Correlations were investigated using Pearson correlation analysis. Results: A significant reduction in GI and PI was observed after removal of the overhanging restoration on Day 7. (P< 0.05) However, there was no significant difference between IL-6 (P= 0.857), IL-8 (P= 0.579) and TNF-α (P= 0.958) levels before and after overhang restoration removal. There were no significant correlations between laboratory findings and clinical parameters. (Am J Dent 2016;29:266-270).

 

 

Mail:  Dr. Neslihan Celik, Department of Restorative Dentistry, Faculty of Dentistry, Ataturk University, 25240/Erzurum-Turkey.  E-mail: dtnesli@gmail.com

 

 

Dentin hypersensitivity reduction using an arginine-based approach after non-surgical periodontal treatment

 

Isabela Lima França-Grohmann, dds, ms,  João Paulo Menck Sangiorgio, dds, ms, Renato Corrêa Viana Casarin, dds, phd, Márcio Zaffalon Casati, dds, phd, Antonio Wilson Sallum, dds, phd &  Enilson Antonio Sallum, dds, phd

 

Abstract: Purpose: To determine the efficacy of two oral hygiene regimens in the reduction of dentin hypersensitivity (DH) on subjects undergoing non-surgical periodontal treatment (NST), over a period of 8 weeks. Methods: 60 subjects that were randomly assigned to: Test group - NST followed in-office application of an arginine-based professional paste and toothbrushing with arginine-based toothpaste at home (n= 30) and Control group - NST followed in-office application of a fluoride-free prophylaxis paste and toothbrushing with a toothpaste based on sodium monofluorophosphate 0.76%, at home (n= 30). Air blast sensitivity assessments were made using the Schiff scale. The sensitivity parameters were measured at baseline, 1, 4 and 8 weeks. Results: After 1 week, DH reduction was statistically significant for the test group (63.6%) compared to baseline, while no significant reduction was observed for the Control group (4.8%). After 4-8 weeks, the reductions were 81.6%/86.3% for the test group and 9.5%/14.2% for the Control group. When comparing the two groups, the test group showed a superior DH reduction in all evaluation periods (P< 0.05). Within the limits of the present study, it was concluded that the test oral hygiene regimen can effectively reduce dentin hypersensitivity during the most critical period after non-surgical periodontal treatment (up to 8 weeks). (Am J Dent 2016;29:271-276).

 

 

 

 

 

Mail:  Dr. Enilson Antonio Sallum, Avenida Limeira, 901, Areão, Piracicaba, P.O Box 52, São Paulo CEP: 13414-903, Brazil.  E-mail:  easallum@fop.unicamp.br

 

 

 

Analysis of the biofilm formed on the surface of a glass-ionomer cement associated with different concentrations of chlorhexidine diacetate

 

Ana Carolina de Oliveira Becci, dds, ms,  Luana Mafra Marti, dds, ms, Angela Cristina Cilense Zuanon, dds, ms, phd,  Fernanda Lourenção Brighenti, dds, ms, phd, Denise Madalena Palomari Spolidório, bs, ms, phd  &  Elisa Maria Aparecida Giro, dds, ms, phd

 

Abstract: Purpose: This cross-over in situ experiment evaluated the microbial composition and quantified the total polysaccharides in the biofilm formed on the surface of a high viscosity glass-ionomer cement (GIC) mixed with chlorhexidine diacetate (CHX) in concentrations of 0.5%, 1% and 2%. GIC without CHX was used as control. Methods: The volunteers (n= 8) tested each material for a 7-day period, by using a palatal acrylic device containing four round specimens, all fabricated with the same material. An increasing order of CHX concentration and a 15-day washout period between each concentration was adopted. The biofilm formed was collected and inoculated in specific culture media and thereafter, the total microorganisms, total streptococci, Streptococcus mutans and Lactobacillus spp were counted. Total polysaccharides were quantified by using a phenol-sulfuric method. Microbiologic data were analyzed by ANOVA for repeated measures and Tukey tests, and the total polysaccharide content by Friedman and Dunn's tests. Significance level was set at 5%. Results: Microorganism counts showed statistically significant differences among groups only for Lactobacillus (P< 0.05), that were significantly higher for group GIC+CHX 2% compared with GIC and GIC+CHX 0.5%. However, the concentration of total polysaccharides in the biofilm was lower for groups containing 1% and 2% of CHX. (Am J Dent 2016;29:277-281).

 

 

Mail:  Dr. Elisa Maria Aparecida Giro, Department of Pediatric Dentistry, Araraquara School of Dentistry – UNESP, Rua Humaitá nº 1680, Araraquara, SP, CEP: 14801-903, Brazil.  E-mail:  egiro@foar.unesp.br

 

 

The influence of two different curing regimens on light energy transmission through bulk-fill resin composites and Vickers hardness

 

Mohammed Saeed Aldossary, bds, mclindent  &  Ario Santini, md, bds, dds, phd

 

Abstract: Purpose: To compare the total light energy transmission (J/cm²) through bulk-fill composite materials (BFMs) and Vickers hardness (VH) using a single-peak light curing unit (LCU) using two curing regimens. Methods: Samples (n= 5) of viscous BFMs, Tetric EvoCeram Bulk Fill (TBF), X-tra fil (XF), and flowable BFMs, SureFil SDR (SDR), and X-tra base (XB) were prepared in 4 mm deep rings. The control was Tetric EvoCeram (TEC), a conventional composite. Using MARC-RC, the irradiance delivered to the top surface of the samples was adjusted to either 800 mW/cm² for 20 seconds (16 J/cm²) or 1,600 mW/cm² for 10 seconds (16 J/cm²). Samples were stored post-irradiation at 22 ± 2°C for 24 hours. Top and bottom-surface VH were measured and Bottom/Top (B/T) VH ratios were calculated. Data were analyzed using one-way ANOVA (α= 0.05). Results: Total energy transmission for all materials ranged from 1.0 J/cm² (6.1%) to 2.7 J/cm² (16.9%). There was a statistically significant difference for total energy transmission to the bottom surface, more being transmitted at 800 mW/cm² × 20 (P< 0.001). XB and TEC were significantly different, with higher B/T VH ratio when cured at 800 mW/cm² × 20 seconds (P< 0.001). There was no statistically significant difference for TBF, XF and SDR (P> 0.05) with either curing regimen. (Am J Dent 2016;29:282-288).

 

 

 

 

 

 

Mail: Dr. Mohammed Saeed Aldossary, P.O.Box 13743 Riyadh 11414, Saudi Arabia. E-mail: msfd99@hotmail.com

 

 

Influence of de/remineralization of enamel on the tensile bond strength of etch-and-rinse and self-etching adhesives

 

Ana Julia Farias de Lacerda, dds, ms,  Rayssa Ferreira Zanatta, dds, ms,  Bruna Crispim, dds, Alessandra Bühler Borges, dds, phd,  Carlos Rocha Gomes Torres, dds, phd,  Franklin R. Tay, bdsc, phd &  Cesar Rogério Pucci , dds, ms, phd

 

Abstract: Purpose: To evaluate the bonding behavior of resin composite and different adhesives applied to demineralized or remineralized enamel. Methods: Bovine tooth crowns were polished to prepare a 5 mm² enamel bonding area, and divided into five groups (n= 48) according to the surface treatment: CONT (sound enamel control), DEM (demineralized with acid to create white spot lesions), REMS (DEM remineralized with artificial saliva), REMF (DEM remineralized with sodium fluoride) and INF (DEM infiltrated with Icon resin infiltrant). The surface-treated teeth were divided into two subgroups (n= 24) according to adhesive type: ER (etch-and-rinse; Single Bond Universal) and SE (self-etching; Clearfill S3 Bond), and further subdivided into two categories (n= 12) according to aging process: Thermo (thermocycling) and NA (no aging). Composite blocks were made over bonded enamel and sectioned for microtensile bond strength (MTBS) testing. Data were analyzed with three-way ANOVA and post-hoc Tukey’s test (α= 0.05). Results: Significant differences were observed for enamel surface treatment (P< 0.0001), adhesive type (P< 0.0001) and aging (P< 0.0001). CONT and INF groups had higher MTBS than the other groups; Single Bond Universal had higher MTBS than Clearfil S3 Bond; thermo-aging resulted in lower MTBS irrespective of adhesive type and surface treatment condition. The predominant failure mode was mixed for all groups. Enamel surface infiltrated with Icon does not interfere with adhesive resin bonding procedures. (Am J Dent 2016;29:289-293).

 

 

Mail: Dr. César Rogério Pucci, Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, SP, 12245-000, Brazil.  E-mail: cesar@fosjc.unesp.br

 

 

 

Effect of finishing technique on the occurrence and length of microcracks in resin-based materials

 

Adalberto B. de Vasconcellos, dds, ms, phd,  Alex Delgado, dds, ms,  Ronaldo Hirata, dds, ms, phd, Richard Blackmon, bs, phd,  Edward J. Swift, Jr., dmd, ms,  Harald O. Heymann, dds, med, Amy L. Oldenburg, ms, phd  &  André V. Ritter, dds, ms, mba

 

Abstract: Purpose: To evaluate the presence and length of microcracks in resin-based materials finished with different techniques, using optical coherence tomography (OCT). Methods: Standardized Class V preparations (3×2×2mm) were made in the facial and lingual surfaces of 20 recently-extracted human third molars. 20 preparations were restored with a resin-based composite material (RBC; Filtek Supreme Ultra) and the other 20 with a resin-modified glass-ionomer material (RMGI; Ketac Nano). After final polymerization, specimens were further stratified by finishing system: aluminum oxide discs (Sof-Lex) or spiral fluted carbide bur series (H48L). By random allocation, each extracted tooth therefore received one RBC and one RMGI restoration, and equal numbers of restorations from each material were finished using each finishing system (n= 10). After 24 hours of storage in 100% humidity at room temperature, the specimens were evaluated at ×20 to ×600 under environmental SEM. Cross-sectional occlusal-cervical B-mode images were obtained in increments of 25 mm from the mesial margin to the distal margin of the restoration using a spectral-domain (SD) OCT system and analyzed using Image J software to identify and measure microcrack penetration into each restoration. The total length (mm) at the point of the deepest microcrack penetration in each specimen was recorded. Data were statistically analyzed using a t-test. Results: No microcracks were observed in the RBC samples. However, microcrack presence was identified in all of the RMGI specimens. The t-test showed a statistically significant difference (P< 0.05) in mean microcrack length values based on the finishing technique used for the RMGI samples. [SofLex: 0.67 (± 0.28) mm; carbide: 1.26 (± 0.30)] mm. Two-way ANOVA showed significant differences in the factors “finishing technique” and “restorative material” (P< 0.001). The interaction of these two factors was also statistically significant (P< 0.001). For the tested RMGI, Tukey post-hoc test revealed that the finishing with aluminum oxide groups resulted in statistically significant lower mean microcrack length when compared to spiral fluted carbide burs (P< 0.001). (Am J Dent 2016;29:294-300).

 

 

 

 

Mail: Dr. A. Bastos de Vasconcellos, rua Doutor Sylvio Henrique Brauma 22, Centro, Nova Friburgo, RJ, Brazil.  E-mail: adalbertovasconcellos@id.uff.br; prof.vasconcellos@hotmail.com