^{June 2017Abstracts}

 

 

 

 

Prognosis test by visualization of demineralized dentin under restorations to prevent initial wall-lesions initiated by lactic acid

 

Morakot Piemjai, dds, mdsc, phd,  Pareewan Chantarawej, dds,  Nobuo Nakabayashi, ms, phd

&   Franklin Garcia-Godoy, dds, ms, phd, phd

 

Abstract: Purpose: To visualize the complete protection of restored dentin in the acidic environment by the complete impregnation of resin into demineralized dentin. Methods: Class V cavities prepared in extracted human molars composed of enamel, cementum and dentin surfaces were sealed using either 4-META/MMA-TBB resin with conditioning periods of 10, 30, 60 seconds with 10% citric acid and 3% ferric chloride mixed aqueous solution (10-3) or Single-Bond 2 adhesives prior to restoration with light-cured resin-composite. Specimens were either immersed in artificial saliva or 0.1 mol/L buffered lactic acid solutions at 37°C for 14 days. After immersion in 0.5% basic fuchsin dye for 24 hours, the extent of dye penetration at the margin was measured. SEM micrography was used to investigate the quality of hybridized dentin when immersed in HCl followed by NaOCl solutions. Results: After lactic acid exposure, dye penetration into the adjacent demineralized cementum/dentin was found to be significantly lower than the leakage distance under 30 and 60 seconds and Single-Bond 2 specimens. Leakage-free margins were found in 10-second conditioning period specimens for both control and after soaking in buffered lactic solution with the stable hybridized dentin after chemical challenge. (Am J Dent 2017:30:119-124).

 

 

Mail: Dr. Morakot Piemjai, Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Henri-Dunant Road, Patumwon, Bangkok 10330, Thailand.  E-mail: tmorakot@chula.ac.th

 

 

Porosity of flowable resin composites is not influenced by applicator tip diameter

 

Rémy Balthazard, dds, phd, Stéphanie Jager, dds, phd, Olivier Ferry, eng, Abdessellam Dahoun, phd

&  Eric Mortier, dds, phd

 

Abstract: Purpose: To assess the influence of applicator tip diameter on the inclusion of porosities in three different flowable resin composites. Methods: The initial porosity of three syringes [Filtek Supreme XTE Flowable (XTE), Grandio Flow (GRF), Gradia Direct Flo (GDF)] was determined by 3D tomography. 25 samples per syringe, i.e. 75 samples in total, were prepared using five applicator tips of different diameters (n= 5). The porosity of the 75 samples was assessed by 3D tomography. Results: For each of the materials, the applicator tips, irrespective of type, all generated an increase in the average porosity percentage compared to the initial porosity of the syringes. For XTE and GRF, the applicator tips, irrespective of type, all generated a decrease in the average porosity volume compared to the initial average porosity volume in their respective syringes. Conversely, for GDF the average porosity volume of the samples was increased. Furthermore, for each of the materials, varying the diameter of the applicator tips had no significant influence on the porosity percentage and volume. Using the present study conditions, the applicator tip generated a variation in the initial porosity of the materials; however, the diameter of the tip had no influence on said variation. (Am J Dent 2017:30:125-130).

 

 

Mail: Dr. Eric Mortier, Department of Conservative Dentistry, Faculty of Dentistry, University of Lorraine, 96 Avenue de Lattre de Tassigny, 54000 Nancy, France. E-mail: eric.mortier@gmx.fr

 

 

 

Clinical and radiographic evaluation of white MTA versus formocresol

pulpotomy: A 48-month follow-up study

 

María Biedma Perea, dds, phd, Beatriz Solano Mendoza, dds, mds, Franklin Garcia-Godoy, dds, ms, phd, phd,

Asunción Mendoza Mendoza, mds, phd  &  Alejandro Iglesias-Linares, dds, ms, phd

 

Abstract: Purpose: To determine whether there were differences between formocresol (FC) and white mineral trioxide aggregate (MTA) pulpotomy in terms of clinical and radiographic signs or effects upon the permanent successor over a long term. Methods: A total of 212 molars (74 treated with FC and 138 with white MTA) corresponding to 129 subjects [66 females (51.1%) and 63 males (48.8%)] were evaluated. The coronal pulp was carefully amputated up to the entrance of the root canals using a sharp spoon excavator. Post-amputation bleeding was confirmed to be bright red and was seen to subside after applying 2-3 minutes of gentle pressure with a sterile cotton pellet. One group was treated with a 1:5 dilution of formocresol (20% Buckley’s formocresol solution), while a second group was treated using white MTA powder (ProRoot). Results: There were no significant differences in clinical success rate between the two groups (89.9% in the white MTA group versus 82.5% if the FC group). However, the radiographic success rate was significantly greater for white MTA versus FC. The radiographic failure rate in the molars treated with MTA was 7.9% versus 18.9% with FC. Regarding alterations in the timing of eruption, early and delayed eruption were respectively recorded in 7.24% and 8.69% of the cases in the MTA group, versus 9.45% and 4.05% of the cases in the FC group. Thus, neither group showed relevant alterations in the timing of eruption. (Am J Dent 2017;30:131-136).

 

 

 

 

 

Mail: Dr. María Biedma Perea, Manuel Siurot, 52 – 2ª Planta - 41013 Sevilla, Spain. *-mail: Coinsol@clinicadentalcoinsol.com

 

 

Magnesium hydroxide-based dentifrice as an anti-erosive agent

in an in situ intrinsic erosion model

 

Vanara  Florêncio  Passos, dds, msc, phd,  Lidiany  Karla Azevedo Rodrigues  Gerage, dds, msc, phd

&  Sérgio  Lima  Santiago, dds, msc, phd

 

Abstract: Purpose: To evaluate in situ a magnesium hydroxide-[Mg(OH)₂] based dentifrice on enamel erosion. Methods: Human dental enamel slabs were selected by surface microhardness and randomly assigned to one out of the following three groups (n=18): non-fluoride (control); NaF (1,450 ppm F); and Mg(OH)₂ dentifrices. 18 volunteers were enrolled in a randomized, crossover and double-blind study, with three phases in 5 days. They wore acrylic palatal appliances containing two human enamel slabs, which were treated with one of the three dentifrices. During each experimental phase, the specimens were subjected to erosion by immersion in 0.01 M HCl for 60 seconds, 4x/day, followed by a 1-minute treatment with the correspondent slurry (saliva/dentifrice). Enamel changes were determined by the percentage of surface hardness loss (%SHL) and mechanical profilometry analysis. Data were analyzed by ANOVA, followed by Tukey's test (P< 0.05). Results: The means (SD) for %SHL and surface wear (µm) were, respectively, as follows: control [50.67(17.48); 2.70(1.24)]; NaF [45.45(15.44); 1.95(0.70)]; and Mg(OH)₂ [(53.94(19.48); 1.95(0.67)]. There was no statistically significant difference among the treated and control groups for %SHL (P= 0.349); however, for wear rates, a statistically significant difference was found between the groups treated with NaF and Mg(OH)₂ and the control group (P= 0.04). (Am J Dent 2017;30:137-141).

 

 

mail: Dr. Sérgio Lima Santiago, Cap. Francisco Pedro St., CEP: 60430-170 - Fortaleza, CE Brazil. E-mail: sergiosantiago@ufc.br; sergiosantiago@yahoo.com

 

 

The abrasive effect of commercial whitening toothpastes on eroded enamel

 

Victor Mosquim, dds, Beatriz Martines Souza, dds, ms, Gerson Aparecido Foratori Junior, dds,

Linda Wang, dds, ms, phd  & Ana Carolina Magalhães, dds, ms, phd

 

Abstract: Purpose: To evaluate the in vitro abrasive effect of commercial whitening toothpastes on eroded bovine enamel samples in respect to erosive tooth wear. Methods: 72 bovine crowns were embedded, polished and subjected to the baseline profile analysis. The samples were then protected in 2/3 of the enamel surface and were randomly assigned to six groups (n= 12/group): G1: Oral-B 3D White; G2: Close-up Diamond Attraction Power White; G3: Sorriso Xtreme White 4D; G4: Colgate Luminous White; G5: Crest (conventional toothpaste); G6: erosion only (control). All samples were submitted to an erosive pH cycling (4 × 90 seconds in 0.1% citric acid, pH 2.5, per day) and abrasive challenges (2 × 15 seconds, per day) for 7 days. After the first and the last daily cycles, the samples were subjected to abrasive challenges, using a toothbrushing machine, soft toothbrushes and slurry of the tested toothpastes (1.5 N). Between the challenges, the samples were immersed in artificial saliva. The final profile was obtained and overlaid to the baseline profile for the calculation of the erosive tooth wear (µm). The data were subjected to Kruskal-Wallis/Dunn tests (P< 0.05). Results: G1 promoted the highest enamel wear (3.68±1.06 µm), similarly to G3 (3.17± 0.80 µm) and G4 (3.44± 1.29 µm). G3 and G4 performed similarly between them and compared with G5 (2.35± 1.44 µm). G2 (1.51± 0.95 µm) and G6 (0.85± 0.36 µm) showed the lowest enamel wear, which did not differ between them and from G5. Oral-B 3D White showed the highest abrasive potential while Close-up Diamond Attraction Power White showed the lowest abrasive potential on eroded enamel in vitro. (Am J Dent 2017;30:142-146).

 

 

 

Mail: Dr. Ana Carolina Magalhães, Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75. Bauru-SP, Brazil. E-mail: acm@usp.br

 

 

Clinical evaluation of a toothpaste containing lysozyme for removal

of extrinsic stains on the tooth surface: An 8-week, double-blind, randomized study

 

Yanxiong  Shao, mmed,  Jiaojiao Xue, mmed,  Canbang  Peng, mmed,  Chenxi  Li, mmed,  Shiyun  Zhang, mmed

&  Haiwen  Zhou, dds

 

Abstract: Purpose: To assess the efficacy and safety of application of a toothpaste containing lysozyme to remove extrinsic stains on the tooth surface in an 8-week trial. Methods: 70 adult participants with extrinsic staining of the tooth surface were recruited to this randomized, parallel-controlled, double-blind clinical trial. Participants were allocated randomly to the test group or the control group and the study procedure and correct usage of the toothpaste were explained to them. Staining, measured by the Lobene stain index, and any side effects, were recorded over the course of the 8 weeks. All data were analyzed using SAS software version 8.0. Results: 69 participants completed the study. The value of the Lobene stain index was significantly reduced (P< 0.05) in the treatment group compared with the control group after both 4 and 8 weeks. No obvious side effects were observed. (Am J Dent 2017;30:147-150).

 

 

Mail: Dr. Haiwen Zhou, Department of Oral Mucosal Diseases, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 500 Qu-xi Road, Shanghai, 200011, PR China. E-mail: haiwen39@126.com

 

 

Long-term outcomes of pulpotomy in permanent teeth with irreversible

pulpitis: A multi-center randomized controlled trial

 

Saeed Asgary, dds, msc,  Mohammad Jafar Eghbal, dds, msc  &  Alireza Akbarzadeh Bagheban, phd

 

Abstract: Purpose: To compare success rates of full pulpotomy (FP) with two endodontic biomaterials on symptomatic vital teeth with closed apices in the presence of apical periodontitis. Methods: In this multicenter controlled clinical trial, 412 volunteers met the inclusion criteria; they were all randomly allocated to either FP/ProRoot mineral trioxide aggregate (MTA) or FP/calcium enriched mixture (CEM) group. The subjects were followed up for 2- and 5-years to evaluate and compare the treatment outcomes. Data were analyzed using Chi square test and the multiple binary logistic regression model. Results: Data for a total number of 344 and 304 subjects were available for 2- and 5-year follow-ups. In terms of clinical outcomes, 2- and 5-year success rates of both groups were ≥ 98%, without significant differences. In terms of radiographic outcomes, the 2-year result of FP/MTA was significantly superior to FP/CEM (P= 0.005); however, the 5-year success rates were similar (P= 0.413). Age and preoperative periapical status did not affect the treatment outcomes. (Am J Dent 2017;30:151-155).

 

 

 

 

 

 

Mail: Prof. Saeed Asgary, Iranian Center for Endodontic Research, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Evin, Postal Code:1983963113, Tehran, Iran. E-mail: saasgary@yahoo.com

 

Influence of different cavity preparation designs on fracture resistance

of onlay and overlay restorations using different CAD/CAM materials

 

Gizem  Ön  Salman, DClinDent, İbrahim  Halil  Tacír, PhD,  Zelal  Seyfioğlu  Polat, PhD  &  Afşin  Salman, DClinDent

 

Abstract: Purpose: To evaluate fracture strength of different preparation designed onlay and overlay restorations produced by Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) and three different new ceramic-polymer blocks. Methods: Ninety-one extracted human mandibular molars were used in this study. Preparations were made as (1) Only functional cusps reduction, (2) Only functional cusps reduction+rounded shoulder finish line, (3) All cusps reduction, or (4) All cusps reduction+rounded shoulder finish line. Then these four cavity types were restored with three different materials: VITA Enamic, GC Cerasmart, Lava Ultimate. Thirteen groups were created by added control group (n= 7). Adhesive cementation was achieved by using a dual cured composite resin adhesive cement RelyX Ultimate. All samples were subjected to thermocycling for 5,000 cycles in water baths between 50°C and 55°C. The fracture resistance of specimens was determined under compressive loads along the long axis of the restored teeth at 0.5 mm/minute crosshead speed until fracture with a universal test machine. Fracture types of restored groups were evaluated. For fracture resistance data, one-way ANOVA; for correlation between material type and preparation design, two-way ANOVA were used. Percentage table and Kruskal-Wallis test were performed for analysis of fracture types. Results: There was no significant difference between all the groups (one-way ANOVA, P> 0.05). Group 4 showed statistically higher fracture strength values than Group 1 and no significant difference was found among other preparation designs by two-way ANOVA that compared all types of preparation designs regardless of material difference (P< 0.05). (Am J Dent 2017;30:165-170).

 

 

 

 

Mail: Dr. Gizem Ön Salman, Department of Prosthodontics, Faculty of Dentistry, Dicle University, Diyarbakır, 21280, Kıtılbil, Bağlar, Turkey.  E-mail: gizem_on@hotmail.com

 

 

Initial microbial colonization of enamel in children with different levels of

caries activity: An in situ study

 

Susann Hertel, dr med dent, Alexandra Wolf, dr med dent, Sabine Basche, Gabriele Viergutz, dr med,

Stefan Rupf, dr med dent, Matthias Hannig, dr med dent  &  Christian Hannig, dr med dent

 

Abstract: Purpose: To investigate patterns of overnight in situ microbial colonization of enamel in children. Methods: Overall, 29 children (aged 5–9 years) participated in the study. Nine were caries-free with no decayed, missing, or filled teeth (DMFT), 11 were caries-rehabilitated (DMFT ≥ 2, no active carious lesions), and nine were caries-active (DMFT ≥ 2, at least two carious lesions). Bovine enamel samples were fixed on individual upper jaw splints stored overnight in situ. 4´,6-diamidino-2-phenylindole (DAPI) combined with Concanavalin A staining was applied for fluorescence microscopic visualization of total adherent bacteria and glucans. Fluorescence in situ hybridization (FISH) was used for distinction of eubacteria, streptococci, and Candida albicans. Salivary samples were investigated for Streptococcus mutans (S. mutans) by using CRT bacteria test and yeasts with Calcofluor white (CFW) staining. Results: With all fluorescence methods, bacteria but not Candida albicans were detected on enamel samples. No statistically significant differences were observed in distribution patterns of the adherent bacteria between the groups. CFW staining indicated fungal structures in saliva samples of all participants. Based on CRT test results, the lowest amount of S. mutans were observed in caries-free children. Thus, initial microbial colonization patterns of enamel in children are not influenced by caries activity. (Am J Dent 2017;30:171-176).

 

 

 

 

 

 

Mail: Dr. Susann Hertel, Clinic of Operative and Pediatric Dentistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, D-01307 Dresden, Germany. E-mail: susann.hertel@uniklinikum-dresden.de

 

 

Adverse effects of salivary contamination for adhesives in restorative

dentistry. A literature review

 

Pooja Nair, bds, Reinhard Hickel, dds, phd  &  Nicoleta Ilie, dipl-eng, phd

 

Abstract: Purpose: To review and critically analyze the literature concerning the influence of salivary contamination on the bond quality of adhesives used in restorative materials by comparing and contrasting the different adhesive materials. Methods: A detailed search on PUBMED, Cochrane Library, Google Scholar and Web of Science was carried out to identify publications on salivary contamination and dental adhesive materials, from 1990-2017 (March) which resulted in a total of 6,202 web-identified publications. After screening titles/abstracts and de-duplicating, 54 publications were selected that matched the requirements for this review. The condition for selection was English literature concerning the effect of salivary contamination on the adhesives used in restorative dentistry. The obtained articles were systematically evaluated. Results: Salivary contamination of adhesives during restorative procedures statistically (64.6%) showed an adverse effect on adhesives, occurring either at one or many stages of restoration. Methodological dissimilarities impeded the direct comparison of the selected studies. Nevertheless, the 2-step etch and rinse adhesives were relatively less vulnerable to salivary contamination than the others. 65% of the evaluated studies for decontamination achieved improved bonding when the contaminated surface was subjected to some kind of decontamination procedure. However, the duration and other specificities were not standard in all the evaluations and need further research to assess the course of action. It is necessary to do long term studies to evaluate the effectiveness of contaminated adhesive over time. (Am J Dent 2017;30:156-164).

 

 

Mail: Pooja Nair, Department of Operative Dentistry and Periodontology, Ludwig Maximilians University Munich, Goethestraße 70, 80336 Munich, Germany. E-mail: poojanair8888@gmail.com