^{June 2016 Abstracts}

Prevention of caries with probiotic bacteria during early childhood. Promising but inconsistent findings

 

Mette  Rose  Jørgensen, dds,  Gina  Castiblanco, dds,  Svante Twetman, dds, phd, odont dr &  Mette  Kirstine  Keller, dds, phd

 

Abstract: Purpose: This review summarized the available literature on the prevention of childhood caries through biofilm engineering with probiotic bacteria in early childhood. Methods: Three databases (PubMed, Cochrane Library and Trip) were searched through January, 2016 for randomized controlled trials published in English. Out of 144 abstracts, seven studies fulfilled the predetermined inclusion criteria and were quality assessed with respect to risk of bias independently by two examiners. Due to the paucity and heterogeneity, a narrative synthesis was performed. The effect size was estimated from the caries prevalence and expressed as prevented fraction and number needed to treat. Results: Probiotic supplements were better than placebo in preventing early childhood caries in all seven studies although the difference was statistically significant in only four of them. The prevented fraction ranged from 11% to 61% with a median of 48%. However, the quality of the evidence was low or very low and further translational research is needed to investigate this preventive approach in the clinic. (Am J Dent 2016;29:127-131).

 

 

 

Mail: Dr. Mette Kirstine Keller, Department of Odontology, Faculty of Health and Medical Sciences, University of

Copenhagen, Nørre Allé 20, 2200 Copenhagen N, Denmark. E-mail: mke@sund.ku.dk

 

 

 

Health concerns of heterotrophic plate count (HPC) bacteria in dental equipment water lines

 

Martin J. Allen, phd  &  Stephen C. Edberg, phd

 

Abstract: There is an unsubstantiated concern as to the health relevance of HPC (heterotrophic plate count) bacteria in dental equipment waterlines. The American Dental Association (ADA) web site includes guidelines for controlling HPC populations and implies that HPC populations >500 CFU/mL as a “health” benchmark. The world-wide published literature including the United Nations fully examined this situation and concluded that HPC bacteria are not a health risk, but merely a general water quality parameter for all waters including dental water lines. This review provides documentation that the standard measurement of HPC bacteria in waters alone do not pose a health risk and the ADA already provides appropriate practices to minimize HPC bacteria in dental equipment water. (Am J Dent 2016;29:137-138).

 

 

Mail: Dr. Martin J. Allen, 5303 E. Lake Place, Centennial, CO, 80121, USA. E-mail: mjallen3012@gmail.com

 

 

A spectroscopic and surface microhardness study of enamel exposed to beverages supplemented with ferrous fumarate and ferrous sulfate. A randomized in vitro trial

 

Arun M. Xavier, bds, mds, Kavita Rai, bds, mds, Amitha M. Hegde, bds, mds  &  Suchetha Shetty, bsc, msc, phd

 

Abstract: Purpose: To compare the efficacy between supplementing ferrous fumarate and ferrous sulfate to carbonated beverages by recording the in vitro mineral loss and surface microhardness (SMH) changes in human enamel. Methods: 120 enamel blocks each (from primary and permanent teeth) were uniformly prepared and the initial SMH was recorded. These enamel specimens were equally divided (n= 60) for their respective beverage treatment in Group 1 (2 mmol/L ferrous sulfate) and Group 2 (2 mmol/L ferrous fumarate). Each group was further divided into three subgroups as Coca-Cola, Sprite and mineral water (n= 10). The specimens were subjected to three repetitive cycles of respective treatment for a 5-minute incubation period, equally interspaced by 5-minute storage in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH recorded. Results: The results were tested using student’s t-test, one-way ANOVA and Wilcoxon signed rank test (P< 0.05). The spectrophotometric assessment of calcium and phosphate withdrawal found more loss with the supplementation of 2 mmol/L ferrous sulfate than ferrous fumarate (P< 0.005). Similarly, the mean surface microhardness reduction was less with the supplementation of 2 mmol/L ferrous fumarate than with ferrous sulfate (P< 0.005). Statistical comparisons revealed the maximum surface microhardness and mineral loss with primary enamel and the maximum loss produced in all groups by Coca-Cola (P< 0.005). (Am J Dent 2016;29:132-136).

 

 

Mail: Dr. Arun M. Xavier, Department of Pediatric Dentistry, Amrita School of Dentistry, Amrita Vishwa Vidyapeetham, Cochin - 41, Kerala, India. E-mail: arunmamachan@yahoo.co.in

 

 

Potential of desensitizing toothpastes to reduce the hydrogen peroxide diffusion in teeth with cervical lesions

 

Andrés Dávila-Sánchez, dds, ms, Andrés Fernando Montenegro, dds,ms, Luis Alfonso Arana-Gordillo, dds,ms, phd, Paulo Vitor Farago, ms, phd, Alessandro D. Loguercio, dds, ms, phd  &  Alessandra Reis, dds, phd

 

Abstract: Purpose: To evaluate the occlusive potential of four toothpastes by atomic force microscopy (AFM) before and after bleaching and quantify the hydrogen peroxide (HP) diffusion into the pulp chamber after application of desensitizing toothpastes in teeth with cervical lesions. Methods: In 52 human extracted premolars, 2-mm deep artificial cervical lesions (ACL) were prepared and rinsed with EDTA for 10 seconds. Then teeth were adapted in a brushing machine and brushed with one of the following toothpastes [Regular toothpaste with no occlusive compounds Colgate Cavity Protection (CP), Oral-B Pro Health (OB), Colgate ProRelief (PR) and Sensodyne Rapid Relief (RR)] under constant loading (250 g; 4.5 cycles/seconds; 3 minutes). In 13 teeth (control group), no artificial cervical lesion was prepared. After that, the teeth were bleached with 35% HP with three 15-minute applications. The HP diffusion was measured spectrophotometrically as a stable red product based on HP reaction with 4-aminoanthipyrine and phenol in presence of peroxidase, at a wavelength of 510 nm and the dentin surfaces of ACL were evaluated before and after bleaching by AFM. Data was statistically analyzed by one-way ANOVA and Tukey´s test (α = 0.05). Results: In the AFM images, some modifications of the dentin surface were observed after application of OB and RR. However, only for RR the formation of a surface deposit was produced, which occluded the majority of the dentin tubules. Also, only for RR, this deposit was not modified/removed by bleaching. Despite this, all groups with ACL showed higher HP penetration than sound teeth, regardless of the toothpaste used (P< 0.001). (Am J Dent 2016;29:139-144).

 

 

 

Mail: Prof. Alessandro D. Loguercio, Postgraduate Dental Education, State University of Ponta Grossa, Rua Carlos Cavalcanti, 4748 – Bloco M, Sala 64A – Uvaranas, Ponta Grossa, Paraná, Brazil. E-mail: aloguercio@hotmail.com

 

 

 

Consumption of baked nuts or seeds reduces dental plaque acidogenicity after sucrose challenge

 

Xiaoling  Wang, dds, msd,  Chuoyue  Cheng, Chunling  Ge, dds, phd, Bing  Wang  &  Ye-Hua  Gan, dds, phd

 

Abstract: Purpose: To assess the acidogenic potential of eight different types of baked nuts or seeds eaten alone and after a sucrose challenge using in-dwelling electrode telemetry. Methods: Six participants wearing a mandibular partial prosthesis incorporated with a miniature glass pH electrode were enrolled. The plaque pH was measured after 5 or 6 days of plaque accumulation. To establish a control, the subjects were instructed to rinse with sucrose, without any subsequent treatment, at the first visit. At each subsequent test visit, the subjects were asked to chew sugar free xylitol gum or consume 10 g of baked (180°C, 5 minutes) peanuts, walnuts, pistachios, cashews, almonds, sunflower seeds, pumpkin seeds, or watermelon seeds alone and 10 minutes after a sucrose rinse. The minimum plaque pH value and area of plaque pH curve under 5.7 (AUC_5.7) during and after nut/seed consumption or gum chewing alone, the plaque pH value at 10 minutes after the sucrose rinse, the time required for the pH to return to >5.7 and AUC_5.7 after the sucrose rinse with or without nut/seed consumption or gum chewing were calculated from the telemetric curves. Results: The sucrose rinse induced a rapid decrease in the plaque pH to 4.32 ± 0.17 at 10 minutes; this value remained below 5.7 for the measurement period. The AUC_5.7 values were 34.58 ± 7.27 and 63.55 ± 15.17 for 40 and 60 minutes after the sucrose challenge, respectively. With the exception of cashews and pumpkin seeds (minimum pH, 5.42 and 5.63 respectively), the nuts or seeds did not decrease the plaque pH to below 5.7 when consumed alone, with the AUC_5.7 values during and after consumption (total 40 minutes) ranging from 0.24 to 2.5 (8.44 for cashews), which were significantly lower than those after the sucrose challenge. Furthermore, nut/seed consumption or gum chewing after the sucrose challenge significantly reversed the sucrose-induced decrease in the plaque pH, and the time required for the pH to return to >5.7 and the AUC_5.7 values for 60 minutes after the sucrose challenge were much less than that of the sucrose challenge without subsequent interference. (Am J Dent 2016; 29:145-148).

 

 

 

 

Mail: Dr. Ye-Hua Gan, Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Nandajie, Haidian District, Beijing 100081, China. E-mail: kqyehuagan@bjmu.edu.cn

 

 

 

Antimicrobial efficacy of complete denture cleansers

 

Flávia Cristina Targa Coimbra, msc, Marcela Moreira Salles, msc, Viviane Cássia de Oliveira, msc, Ana Paula Macedo, dds, msc, Cláudia Helena Lovato da Silva, dds, msc, phd, Valéria Oliveira Pagnano, dds, msc, phd  &  Helena de Freitas Oliveira Paranhos, dds, msc, phd

 

Abstract: Purpose: To evaluate the in vitro antimicrobial efficacy of alkaline peroxides against microbial biofilms on acrylic resin surfaces. Methods: Denture base acrylic resin (Lucitone 550; n= 360) circular specimens (15 × 3 mm) were obtained from a circular metal matrix and sterilized with microwave irradiation (650 W, 6 minutes). The specimens were then contaminated with suspensions [10⁶ colony-forming units (CFU)/mL] of Candida albicans (Ca), Candida glabrata (Cg), Staphylococcus aureus (Sa), Streptococcus mutans (Sm), Bacillus subtilis (Bs), Enterococcus faecalis (Ef), Escherichia coli (Ec), and Pseudomonas aeruginosa (Pa). After contamination, the specimens were incubated at 37°C for 48 hours and then placed in a stainless steel basket, which was immersed in a beaker with one of the following solutions prepared and used according to the manufacturers’ instructions (n= 10 per group): Group PC (positive control), phosphate-buffered saline (PBS) solution; Group MI, NitrAdine, Medical Interporous; Group EF, Efferdent Plus; Group CT, Corega Tabs; and Group NC (negative control; n= 5), no contamination and immersed in PBS. After incubation (37°C, 24 hours), the number of colonies with characteristic morphology was counted, and CFU/mL values were calculated. The data were processed following the transformation into the formula log¹⁰ (CFU + 1) and statistically analyzed by the Kruskal-Wallis and Dunn’s tests (α= 0.05). Results: There were significant differences between the groups for the evaluated microorganisms with a significant reduction in the CFU/mL. MI was effective for Ca, Cg, Sa, Sm, Ef, Ec and Pa; EF was effective for Cg, Sm, Ef, Ec and Pa; and CT was effective for Sa, Bs and Ec, when compared with the PC group. (Am J Dent 2016;29:149-153).

 

 

Mail: Dr. Helena de Freitas Oliveira Paranhos, Department of Dental Materials and Prosthetics, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café S/N, Ribeirão Preto-SP, CEP: 14040-904, Brazil. E-mail: helenpar@forp.usp.br

 

 

Effect of mechanical toothbrushing combined with different denture cleansers in reducing the viability of a multispecies biofilm on acrylic resins

 

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

 

Abstract: Purpose: To investigate the efficacy of immersion and brushing with different cleansing agents in reducing the viability of multispecies biofilm on acrylic resins. Methods: Lucitone 550 (L) and Tokuyama Rebase Fast II (T) specimens (10 × 2 mm) were prepared, sterilized, and inoculated with a suspension of Candida albicans, Candida glabrata, and Streptococcus mutans. Specimens were incubated for 48 hours at 37°C for biofilm formation. Then, they were divided into groups (n= 12) and subjected to brushing or immersion for 10 seconds in distilled water (W), 0.2% peracetic acid - Sterilife (Ac), 1% chlorhexidine digluconate (CHX), 1:1 water/dentifrice solution (D), 1% sodium hypochlorite (NaOCl), and sodium perborate/Corega Tabs (Pb). Viable microorganisms were evaluated by the XTT assay and colony counts (cfu/mL). Data were performed by ANOVA and Tukey test with 5% significance level. Results: The multispecies biofilm on L and T were killed by brushing or immersion in Ac, CHX, and NaOCl for only 10 seconds. (Am J Dent 2016;29:154-160).

 

 

Mail: Dr. Beatriz Helena Dias Panariello, Department of Dental Materials and Prosthodontics, Araraquara Dental School, Univ. Estadual Paulista, UNESP, São Paulo, Brazil, Rua Humaitá, 1740, apto 37, Araraquara, SP, Brazil. E-mail: beatriz@dipanariello.com.br

 

 

Headache and jaw locking comorbidity with daytime sleepiness

 

Steven R. Olmos, dds,  Franklin Garcia-Godoy, dds, ms, phd, phd,  Timothy L. Hottel, dds, ms, mba

&  Nhu Quynh T. Tran, phd

 

ABSTRACT: Purpose: To investigate the relationship between craniofacial pain symptoms (painful conditions present in the cranium and face, including jaw joint-related pathology and primary headache conditions) and daytime sleepiness, determined by the Epworth sleepiness scale (ESS), to correlate comorbidity as well as potential predictive factors. Methods: 1,171 patients seeking care for chronic pain and/or sleep-related breathing disorders (SRBDs) at 11 international treatment centers were included in the study. Patients completed the ESS and identified their primary craniofacial pain and sleep pathology symptoms. Descriptive statistics and regression analysis were performed to determine comorbidities between craniofacial pain symptoms and daytime sleepiness, and factors predictive of higher ESS scores. Results: There was high comorbidity of some craniofacial pain symptoms and high ESS scores, including headaches. In addition, for the first time to our knowledge, orthopedic craniofacial dysfunction (i.e., jaw locking) was correlated with, and predictive of, high ESS scores. (Am J Dent 2016;29:161-165).

 

 

 

 

 

 

Mail: Dr. Steven Olmos, TMJ & Sleep Therapy Centre, 7879 El Cajon Blvd., La Mesa, CA 91942, USA. E-mail: steven@tmjtherapycentre.com

 

 

An ion extract obtained from mineral trioxide aggregate induced dentin remineralization and dentin tubule occlusion in artificially demineralized bovine dentin

 

Linlin Han, dds, phd  &  Takashi Okiji, dds, phd

 

Abstract: Purpose: To investigate the ability of a mineral trioxide aggregate (MTA) extract mixed with a phosphate buffered saline (PBS) system to induce remineralization and dentin tubule occlusion in artificially demineralized bovine dentin. Methods: The MTA extract solution was prepared by mixing white ProRoot MTA with distilled water (1:2) for 48 hours, before subjecting it to centrifugation. The elemental composition of the MTA extract solution was analyzed with inductively coupled plasma atomic emission spectrometry. The deposits produced by the MTA extract-PBS mixture were chemically analyzed using electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The effects of the two-step application of the mixture (MTA extract solution followed by PBS) to bovine dentin samples that had been artificially demineralized with phosphoric acid (10%, 10 seconds) were investigated with scanning electron microscopy and EPMA after the specimens had been stored in PBS for 1 or 7 days. Results: The MTA extract solution contained calcium, silicone, and aluminum (Ca>Si>Al), and the deposits produced by the MTA extract-PBS mixture contained calcium, phosphorous, sodium, silicone, and aluminum (Ca>P>Na>Si>Al) as major mineral elements. XRD also revealed that the deposits contained hydroxyapatite. The two-step application process resulted in the formation of a 2-3 µm-thick "mineral infiltration layer", together with mineral tag-like structures in the dentin tubules. The MTA extract-treated specimens exhibited a significantly higher dentin tubule occlusion rate than the untreated specimens (P< 0.05). (Am J Dent 2016;29:166-170).

 

 

Mail: Dr. Linlin Han, Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, 5274 Gakkocho-dori 2-bancho, Chuo-ku, Niigata 951-8514, Japan. E-mail: han@dent.niigata-u.ac.jp

 

 

Wear of an enhanced resin-modified glass-ionomer restorative material

 

Ritika Bansal, bds, ms,  John O. Burgess, dds, ms   &   Nathaniel C. Lawson, dmd, phd

 

Abstract: Purpose: To compare the wear of an enhanced resin-modified glass-ionomer (RMGI) restorative material (ACTIVA BioACTIVE Restorative) to a resin composite (Filtek Supreme Ultra), RMGI (Fuji II LC), and glass-ionomer (GI) (Fuji IX) material. Methods: Specimens of each material (n= 8) were prepared in a silicone mold. All specimens other than the GI material were light polymerized for 40 seconds. After 24-hour storage (H₂O, 37°C), the specimens were loaded into the modified Alabama wear testing device. Freshly extracted cusps of human premolars were prepared as antagonists. Specimens were loaded with 20N for 100,000 cycles at 1 Hz. A 33% glycerin lubricant was cycled throughout testing. Specimens and enamel antagonists were scanned before and after wear testing with a non-contact optical profilometer and volumetric wear was measured with superimposition software. Representative specimens were examined with scanning electron microscopy. Data were analyzed with a 1-way ANOVA and Tukey post-hoc analysis (alpha= 0.05). Results: Significant differences were found between materials. Materials ranked in order of increasing wear: Filtek Supreme Ultra and ACTIVA BioACTIVE Restorative < Fuji II LC < Fuji IX. Micrographs revealed that Filtek Supreme Ultra and ACTIVA BioACTIVE Restorative underwent abrasive wear whereas Fuji II LC and Fuji IX underwent fatigue wear. (Am J Dent 2016;29:171-174).

 

 

 

 

 

Mail: Dr. Nathaniel C. Lawson, SDB Box 49, 1720 2nd Ave S, Birmingham AL 35294-0007, USA.  E-mail: nlawson@uab.edu

 

 

 

Bond strength of resin cements to dentin using universal bonding agents

 

Christopher J. Raimondi, dds, ms, Jeffrey P. Jessup, dds, Deborah Ashcraft-Olmscheid, dds, ms &  Kraig S. Vandewalle, dds, ms

 

Abstract: Purpose: To determine the effect of new universal bonding agents on the bond strength of dual-cure resin cements to dentin. Methods: 140 extracted human third molars were mounted in dental stone and sectioned with a saw to remove coronal tooth structure. The teeth were randomly divided into seven groups of 20, based on the use of five universal bonding agents (All-Bond Universal; FuturaBond U; Prime&Bond Elect; Scotchbond Universal; Clearfil Universal) compared to two self-etch bonding agents (Clearfil SE Bond and Clearfil SE Bond 2). Each group was further divided into two equal subgroups of 10 specimens each with each subgroup tested with either self- or light-cure activation of the dual-cure resin cement (Calibra). The bonding agent was applied per manufacturers’ instructions to the dentin surface of each specimen. The specimens were placed into a jig and resin cement was inserted into the mold to a height of 3-4 mm and light cured. Specimens were stored for 24 hours in 37°C distilled water and tested in shear in a universal testing machine. A mean shear bond strength value (MPa) and standard deviation was determined per group. Results: Except for Clearfil Universal, the new simplified universal bonding agents resulted in significantly lower shear bond strength of the resin cement to dentin than the two-step, self-etching bonding agents Clearfil SE Bond or Clearfil SE Bond 2. (Am J Dent 2016;29:175-179)

 

 

Mail: Dr. Kraig S. Vandewalle, Director of Dental Research, 1615 Truemper St., Joint Base San Antonio - Lackland, TX 78236, USA. E-mail: kraig.vandewalle.3@us.af.mil

 

 

Intratubular penetration in post cementing: A comparative study between a total etching system and a self-etching cement

 

María García-Gallart, dds, Carmen Llena, md, dds, phd, Leopoldo Forner, md, dds, phd &  Marco Ferrari, md, dds, phd

 

Abstract: Purpose: To analyze the penetration depth and percentage perimeter with penetration of two fiber post cementing systems using confocal laser scanning microscopy (CLSM). Methods: 20 maxillary incisors were shaped with the Mtwo system and filled using lateral condensation and TopSeal mixed with fluorescein. Fiber posts were cemented. The samples were divided into two groups of 10 teeth each, according to the post cementing technique used: Prime&Bond NT combined with Rebilda DC using a total dentin etching technique (Group 1); or BisCem a self-adhesive cement (Group 2). Rhodamine B was incorporated in the adhesive systems. Cross-sections were prepared, with the selection of three sections (coronal, middle and apical thirds). CLSM was used to measure the percentage perimeter of the root canal showing penetration of the endodontic cement and of the adhesive system in the dentin tubules, together with the maximum penetration depth. The nonparametric Mann-Whitney U-test was used to compare the data referred to each of the three tooth sections between the two study groups. The Friedman test was used to compare the variables by coronal, middle and apical thirds within each group. Results: Greater penetration was recorded with the BisCem system in all thirds, with statistically significant differences in the case of the middle and apical thirds (P= 0.001). The percentage perimeter with penetration was also greater in all thirds with the BisCem system, though without significant differences between the two groups. Penetration depth and percentage were found to decrease in the coronal to apical direction in both groups. (Am J Dent 2016;29:180-184).

 

 

Mail:  Prof. Leopoldo Forner, Department of Stomatology, University of Valencia, C. Gascó Oliag, 1, 46010 Valencia, Spain.  E-mail:  forner@uv.es