^{June 2015 Abstracts}

Effect of polymer-based desensitizer with sodium fluoride on prevention of root dentin demineralization

 

Megumi  Oshima, dds,  Hidenori  Hamba, dds, phd,  Alireza Sadr, dds, phd,  Toru  Nikaido, dds, phd &  Junji  Tagami, dds, phd

 

Abstract: Purpose: To evaluate the effect of a fluoride-containing polymer-based desensitizer on prevention of root demineralization using micro-computed tomography (micro-CT). Methods: Bovine root dentin blocks were divided into four groups; no treatment (Control);  1% oxalic acid (OA); MS Coat One containing methacrylate-co-p-styrene sulfonic acid (MS polymer) and 1% oxalic acid (MSO); and MS Coat F containing MS polymer, 1% oxalic acid and 3,000 ppm sodium fluoride (MSF). A window of the dentin surface was treated with each solution. The blocks were scanned using micro-CT after demineralization (pH 4.5, 5 hours). The dentin surfaces before and after demineralization were examined by scanning electron microscopy (SEM). Fluoride ion release was measured using a fluoride ion-specific electrode. The data were statistically analyzed using one-way ANOVA and Tukey’s test (α= 0.05). Results: MSF showed the lowest mineral loss (80.4±10.6 vol%.µm), which was significantly different from Control (99.4±13.0 vol%.µm), OA (91.1±10.9 vol%.µm) and MSO (89.1±9.2 vol%.µm). Under the SEM observations, the dentin tubules appeared to be blocked after all desensitizer treatments. After demineralization, the exposure of dentin tubules was clearer in OA and MSO compared to MSF which showed sealed dentin tubules after demineralization. Fluoride ion release was detected only in the MSF group. (Am J Dent 2015;28:123-127).

 

 

 

Mail: Dr. Toru Nikaido, Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University (TMDU), Tokyo, Japan. E-mail: nikaido.ope@tmd.ac.jp

 

 

The dentin tubule occlusion effects of desensitizing agents and the stability against acids and brushing challenges

 

Zhejun Wang, dds,phd,  Xiao Ma, dds, phd, Tao Jiang, dds, phd, Yining Wang, dds, phd, YunzhiFeng, dds, phd, &  Rong Li, dds, phd

 

Abstract: Purpose: To investigate the effects of desensitizing agents on dentin tubule occlusion, acid and tooth brushing challenge, and microhardness change of human dentin. Methods: Partially demineralized dentin slabs were divided into four groups (n= 30): (1) Control, (2) Non-desensitizing toothpaste, (3) Pro-Argin toothpaste, (4) CPP-ACP paste. The specimens were treated with these dentifrices for 2 minutes/day and soaked in artificial saliva (AS) for 24-hour remineralization. Then the dentin discs were divided into three subgroups for removal resistance tests: acid challenge, mechanical brushing challenge and blank control. Changes in dentin morphology were observed using scanning electron microscopy (SEM). Vickers microhardness measurements were performed at baseline and after 24-hour remineralization for all groups. Results: A surface layer and intra-tubular crystals were observed in SEM imaging of Pro-Argin toothpaste and CPP-ACP paste groups, which occluded most of the dentin tubules for those specimens. But the dentin tubules were opened after the acid challenge again. Moreover, the dentin microhardness showed a slight increase after 24-hour AS immersion. The percentage microhardness gain (PMG) values of these two groups were 5.4% and 5.1% respectively, which were significantly higher than the other groups (P< 0.05). (Am J Dent 2015;28:128-132).

 

 

Mail: Dr. Rong Li, Department of Stomatology, the Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan,410011, PR China. E-mail:  hnlirongg@126.com

 

 

Serum lipid levels in patients with minor recurrent aphthous ulcers

 

Erim  GÜlcan, md

 

Abstract: Purpose: To evaluate the possible association between minor recurrent aphthous ulcers (RAUs) and plasma lipid levels. Methods: 85 patients (50 ♀, 35 ♂) with minor RAUs and another 80 patients (52 ♀, 28 ♂) without minor RAUs were included in the study. Body mass index (BMI), hemoglobin (HB), white blood cells (WBCs), platelets (PLT), glucose (GL), total cholesterol (TCH), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine (CR), alanine transaminase (ALT), and aspartate transaminase (AST) levels, as well as the gender and age of the patients in the groups were compared. Results: Cumulative evaluation showed that HDL was statistically higher in the control group (P< 0.05). Except for WBCs, PLT, TG, and ALT, all parameters were significantly higher in the study group (P< 0.05). Correlations between minor RAUs and investigated parameters were observed with age, BMI, HB, GL, CR, TCH, HDL, LDL, and AST (P< 0.05). If gender was considered and the groups were compared, the greatest differences were seen between the female study group and the female control group (age, BMI, HB, GL, CR, TCH, TG, LDL, ALT; P< 0.05). Correlations were mostly observed between minor RAUs and parameters within the female group (P< 0.05). (Am J Dent 2015;28:133-136).

 

 

Mail: Dr. Erim Gülcan, Dumlupinar University, Faculty of Medicine, Department of Internal Medicine, Central Campus, Tavsanlı Yolu 10 Km, Kutahya, Turkey.  E-mail: drerimgulcan@gmail.com

 

 

Clinical and microbiological efficacy of systemic roxithromycin as an adjunct to non-surgical periodontal therapy in treatment of chronic periodontitis. A randomized, double-blinded, placebo-controlled clinical trial

 

Santosh S. Martande, mds,  Avani R. Pradeep, mds,  Minal Kumari, mdS,  Ningappa Priyanka, mds, Sonender P. Singh, mds,  Savitha B. Naik, mds,  Swati Pradeep Patel, mds  &  Paulami Bagchi, mds

 

Abstract: Purpose: The objective of this randomized clinical trial was to evaluate the clinical and microbiological effects of systemic administration of roxithromycin (RXM) as an adjunct to non-surgical periodontal therapy (NSPT) in the treatment of individuals with moderate to severe chronic periodontitis (CP). Methods: 70 individuals (38 males and 32 females, aged 25 to 60 years) with moderate to severe CP were randomly allocated into two groups. 35 individuals were allocated to full mouth SRP+RXM while 35 individuals were allocated to SRP+ Placebo group. The clinical parameters evaluated were probing depth (PD), clinical attachment level (CAL), gingival index (GI), plaque index (PI) and % bleeding on probing sites (%BOP) at baseline (B/L), 1-, 3- and 6-month intervals while microbiologic parameters included percentage of sites positive for periodontopathic bacteria A. actinomycetemcomitans, P. gingivalis and T. forsythia at B/L, 3 and 6 months using polymerase chain reaction. Results: Both groups showed improved clinical and microbiologic parameters over 6 months. RXM group showed a statistically significant reduction in mean PD and CAL gain as compared to the placebo group (P< 0.0001). There was reduction in percentage of sites positive for periodontopathic bacteria over the duration of the study in both groups and a statistically significant reduction in the number of sites positive for A. actinomycetemcomitans in RXM group (P< 0.001). (Am J Dent 2015;28:137-142).

 

 

Mail: Dr. Avani R. Pradeep, Department of Periodontics, Government Dental College and Research Institute, Bangalore-560002, Karnataka, India. E-mail: periodonticsgdcri@gmail.com

 

 

Strengthening effect of horizontally placed fiberglass posts in endodontically-treated teeth restored with direct resin composite

 

Fernando JosÉ Favero, dds, ms, Tiago André Fontoura de Melo, dds, ms, Deborah Stona, dds, ms, Eduardo GonÇalves Mota, dds, ms, phd, Ana Maria Spohr, dds, ms, phd  &  Luiz Henrique Burnett Jr., dds, ms, phd

 

Abstract: Purpose: To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters. Methods: 84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic  treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP). Results: The data were subjected to ANOVA and Tukey’s test (P< 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor. (Am J Dent 2015;28:143-149).

 

 

 

 

Mail:  Prof. Dr. Luiz Henrique Burnett Jr, PUCRS, Av. Ipiranga 6681, prédio 6, Faculdade de Odontologia, Porto Alegre, RS, Brazil, 90619-900.  E-mail: burnett@pucrs.br

 

Effects of short-term immersion and brushing with different denture cleansers on the roughness, hardness, and color of two types of acrylic resin

 

Beatriz  Helena  Dias  Panariello, dds, msc,  Fernanda  Emiko  Izumida, dds, msc, Eduardo  Buozi  Moffa, dds, msc, Ana  Claudia  Pavarina, dds, msc, phd, Janaina  Habib  Jorge, dds,,msc, phd &  Eunice  Teresinha  Giampaolo, dds, msc, phd

 

Abstract: Purpose: To investigate the cumulative effects of brushing (B) or immersion (I), using different cleansing agents, on the surface roughness, hardness and color stability of a heat-polymerized denture resin, Lucitone 550 (L), and a hard chairside reline resin, Tokuyama Rebase Fast II (T). Methods: A total of 316 specimens (10 x 2 mm) were fabricated. The specimens (n= 9) were divided into brushing or immersion groups according to the following agents: dentifrice/distilled water (D), 1% sodium hypochlorite (NaOCl), Corega Tabs (Pb), 1% chlorhexidine gluconate (Chx), and 0.2% peracetic acid (Ac). Brushing and immersion were tested independently. Assays were performed after 1, 3, 21, 45 and 90 brushing cycles or immersion of 10 seconds each. Data were evaluated statistically by repeated measures ANOVA. Tukey’s honestly significant difference (HSD) post-hoc test was used to determine differences between means (α= 0.05). Results: For L there was no statistically significant difference in roughness, except a significant decrease in roughness by brushing with D. T showed a significant effect on the roughness after 90 immersions with Ac. Hardness values decreased for L when specimens were immersed or brushed in NaOCl and Pb. The hardness of T decreased with increases in the repetitions (immersion or brushing), regardless of the cleaning method. Values of color stability for L resin showed significant color change after brushing with and immersion in Ac and Pb. Brushing with D exhibited a higher incidence of color change. For T there were no significant differences between cleaning agents and repetitions in immersion. A color change was noted after three brushings with the Ac, Chx, and D. Brushing with dentifrice decreased roughness of L. Immersion in or brushing with NaOCl and Pb decreased the hardness of L. For T, hardness decreased with increases in immersions or brushing. Color changes after the immersion in or brushing with cleaning agents were clinically acceptable according to National Bureau of Standards parameters for both resins. (Am J Dent 2015;28:150-156).

 

 

Mail: Dr. Janaina Habib Jorge, Rua Humaitá, 1680, Centro, Araraquara, SP, Brazil. E-mail: janainahj@foar.unesp.br

 

 

Class I restoration margin quality in direct resin composites: A double-blind randomized controlled clinical trial

 

Felice Femiano, md, phd, Luigi Femiano, dds, Rossella Femiano, dds, Alessandro Lanza, dds, Michele Lanza, md, Rosario Rullo, md  &  Letizia Perillo, md

 

Abstract: Purpose: To evaluate the margin quality of direct resin composite restorations comparing the enamel-dentin adhesive standard procedure with additional use of adhesive layer at the external outline. Methods: A total of 648 teeth with Class I occlusal lesions in molars and premolars were randomly selected and distributed into two groups of 324 each in order to compare the margin quality with two restoration strategies. Lesions were sealed with the standard adhesion procedure for direct resin composite restorations (Group 1) and with an additional procedure of enamel adhesive on the outer boundary of the finished restoration (Group 2). Evaluation of marginal quality at 6, 12, 24, 36 and 48 months was performed and described as good marginal adaption or as poor quality defined as Inadequacy A (IA): overhanging resin or change of color; Inadequacy B (IB): the presence of a gap at the enamel-composite interface that retained the probe tip; or Inadequacy C (IC) presence of gap at the enamel-composite interface with explorer tip penetration of more than 1 mm. Results: Data showed a higher number of Inadequacy A for restorations with the additional technique for marginal seal (Group 2): 16 of 24 total (57%) at 6 months; 28 of 37 total (76%) at 12 months; 36 of 44 total (82%) at 18 months; 22 of 33 total (67%) at 24 months; 14 of 21 total (70%) at 36 months and 16 of 25 total (64%) at 48 months. The Inadequacy B and C of marginal seal were more prevalent for restorations without the additional marginal seal (Group 1): 18 of 28 total (64%) at 12 months with inadequacy B; 19 of 25 total (76%) with inadequacy B and 16 total (100%) with inadequacy C at 18 months; 9 of 17 total (53%) with Inadequacy B and 13 total (100%) with Inadequacy C at 24 months; 12 of 17 total (70%) with Inadequacy B and 9 of 13 total (73%) with Inadequacy C at 36 months; 14 of 24 total (58%) with Inadequacy B and 7 of 11 total (63%) with Inadequacy C at 48 months. (Am J Dent 28;2015:157-160).

 

 

Mail: Dr. Felice Femiano, Via Francesco Girardi 2, S. Antimo (NA) 80029, Italy. E-mail: femiano@libero.it

 

 

Mechanical properties and ultrastructural characteristics of a glass fiber-reinforced composite

 

Álvaro Enrique GarcÍa Barbero, md, dds, phd, Vicente Vera GonzÁlez, md, dds, phd, Ernesto GarcÍa Barbero, md, dds, phd  &  Ignacio Aliaga Vera, dds

 

Abstract: Purpose: To examine the ultrastructural characteristics of a fiber-reinforced composite (FRC) and its behavior in vitro as a framework for fixed partial dentures (FPDs). Methods: A total of 40 specimens were prepared using extracted teeth fixed in methacrylate blocks as supports for the FPD, then the specimens were divided into four groups depending on whether a retaining box was used to fix the FPD to the support teeth, and on whether a composite pontic was assembled on top of the fibers. Fracture testing was performed in a universal testing machine (1 mm/minute). Fracture strength values and failure types were statistically compared for each group. Results: Using retaining boxes did not improve the mechanical behavior of the restorative system. The weakest element of the system was the composite tooth constructed on top of the FRC. (Am J Dent 2015;28:161-166).

 

 

Mail: Dr. Álvaro Enrique García Barbero, Department of Conservative Dentistry, School of Dentistry, Complutense  University of Madrid, 28040 Madrid, Spain. E-mail: aegarcia@.ucm.es

 

 

In situ antimicrobial activity and inhibition of secondary caries of self-etching adhesives containing an antibacterial agent and/or fluoride

 

Cristiane Franco Pinto, dds, ms, phd, Sandrine Bittencourt Berger, dds, ms, phd, Vanessa Cavalli, dds, ms, phd, SÉrgio  Eduardo  Braga da  Cruz, dds, ms, phd,  Reginaldo  Bruno  GonÇalves, dds, ms, phd, GlaÚcia Maria Bovi Ambrosano, dds, ms, phd  &  Marcelo Giannini, dds, ms, phd

 

Abstract: Purpose: To evaluate the in situ effect of fluoride and MDPB-containing adhesives on antibacterial activity around restorations in conditions of high caries risk. Methods: Bovine enamel and dentin blocks were restored with a fluoride-containing (One-up Bond F Plus - OP) or a MDPB and fluoride-containing adhesive (Clearfil Protect Bond - PB). Volunteers (n=17) wore an intra-oral appliance containing three enamel and three dentin blocks, aligned side-by-side and restored with OP or PB and one enamel and dentin block (controls). The cariogenic challenge was carried out in two phases of 14 days each. The counts of total streptococci (TM), mutans streptococci (MS) and lactobacilli (LB) were analyzed in the biofilm formed. Cross-sectional microhardness (CSM) and polarized light microscopy (PLM) evaluated caries lesions around the restorations and the demineralization extension. Data obtained by CSM testing was analyzed by Split-Split Plot ANOVA (P< 0.05). PLM and microbiota results were analyzed by Wilcoxon test (P< 0.05). Results: TM and MS counts were highest for the OP enamel restorations, and these presented higher lesion depths than PB in both the enamel and dentin. The CSM in dentin was the lowest at 60 µm from the restoration wall. None of the adhesives prevented demineralization and bacteria growth, but PB reduced the amount of oral pathogens in enamel and demineralization around restorations in enamel and dentin. (Am J Dent 2015;28:167-173).

 

 

Mail: Dr. Marcelo Giannini, Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 - PO Box 52, Piracicaba, 13414-903  SP, Brazil. E-mail: giannini@fop.unicamp.br

 

 

Surface degradation of lithium disilicate ceramic after immersion in acid and fluoride solutions

 

Aljomar JosÉ Vechiato-Filho, dds, msc, Daniela Micheline dos Santos, dds, msc, phd, Marcelo Coelho Goiato, dds, msc, phd, AmÁlia Moreno, dds, msc, phd, Rodrigo Antonio de Medeiros, dds, msc, Sidney Kina, dds, msc, phd, Elidiane Cipriano Rangel, phd  &  Nilson Cristino da Cruz, phd

 

Abstract: Purpose: To analyze whether immersion in sodium fluoride (NaF) solutions and/or common acidic beverages (test solutions) would affect the surface roughness or topography of lithium disilicate ceramic. Methods: 220 ceramic discs were divided into four groups, each of which was subdivided into five subgroups (n = 11). Control group discs were immersed in one of four test beverages for 4 hours daily or in artificial saliva for 21 days. Discs in the experimental groups were continuously immersed in 0.05% NaF, 0.2% NaF, or 1.23% acidulated phosphate fluoride (APF) gel for 12, 73, and 48 hours, respectively, followed by immersion in one of the four test beverages or artificial saliva. Vickers microhardness, surface roughness, scanning electron microscopy (SEM) associated with energy dispersive spectroscopy, and atomic force microscopy (AFM) assessments were made. Data were analyzed by nested analysis of variance (ANOVA) and Tukey’s test (α = 0.05). Results: Immersion in the test solutions diminished the microhardness and increased the surface roughness of the discs. The test beverages promoted a significant reduction in the Vickers microhardness in the 0.05% and 0.2% NaF groups. The highest surface roughness results were observed in the 0.2% NaF and 1.23% APF groups, with similar findings by SEM and AFM. Acidic beverages affected the surface topography of lithium disilicate ceramic. Fluoride treatments may render the ceramic surface more susceptible to the chelating effect of acidic solutions. (Am J Dent 2015;28:174-180).

 

 

Mail: Dr. Daniela Micheline dos Santos, Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ. Estadual Paulista – UNESP, Jose Bonifacio St., 1153, Vila Mendonca, Aracatuba, Sao Paulo, 16015-050  Brazil. E-mail: danielamicheline@foa.unesp.br