Subscribe: pubmed: 0894-8275
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pubmed: 0894-8275



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Effect of radiotherapy, adhesive systems and doxycycline on the bond strength of the dentin-composite interface.
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Effect of radiotherapy, adhesive systems and doxycycline on the bond strength of the dentin-composite interface.

Am J Dent. 2016 Dec;29(6):352-356

Authors: Freitas Soares E, Zago Naves L, Bertolazzo Correr A, Costa AR, Consani S, Soares CJ, Garcia-Godoy F, Correr-Sobrinho L

Abstract
PURPOSE: To investigate the effect of radiotherapy, doxycycline and adhesive systems on the microtensile bond strength (μTBS) of the dentin-composite interface.
METHODS: 60 human third molars were sectioned to expose middle dentin surface and distributed according to: (1) adhesive system (Adper Scotchbond MP and Clearfil SE Bond) applied, (2) application or not of doxycycline, and (3) submission to 60 Gy total radiation (2 Gy daily doses, 5 days/week for 6 weeks) before restoration procedure (RtRes); after restoration procedure (ResRt) or not submitted to radiotherapy (Control group). Specimens were tested for μTBS and mode of failure were evaluated under optical microscopy. The bonding interface was evaluated with a scanning electron microscope (SEM). Data was submitted to three-way ANOVA and Tukey's test (α= 0.05).
RESULTS: There was no significant difference between the μTBS (MPa) of Adper Scotchbond MP (25.5±11.1) and Clearfil SE (27.6±9.1). Control (30.5±10.9) and ResRt (29.2±10.4) presented μTBS significantly higher than RtRes (23.1±7.2). Doxycycline (21.7±7.6) significantly reduced μTBS compared to groups without doxycycline application (33.6±8.6). Dentin cohesive failure mode was predominant for RtRes and mixed failure mode for ResRt. Mixed and adhesive failures were frequently observed in control groups. SEM showed adhesive penetration in dentin tubules in all groups, regardless of the radiotherapy and the application of doxycycline. The radiotherapy before composite restoration procedure decreased the μTBS. No statistical difference was observed between the adhesive systems. The doxycycline reduced μTBS regardless of the other conditions.
CLINICAL SIGNIFICANCE: Composite restoration procedure should be done before radiotherapy, regardless of the adhesive system used.

PMID: 29178724 [PubMed - indexed for MEDLINE]




Effects of desensitizing toothpastes on the permeability of dentin after different brushing times: An in vitro study.
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Effects of desensitizing toothpastes on the permeability of dentin after different brushing times: An in vitro study.

Am J Dent. 2016 Dec;29(6):345-351

Authors: Yang M, Lin H, Jiang R, Zheng G

Abstract
PURPOSE: To investigate the effects of three commercially available desensitizing toothpastes on dentin permeability, and compare the efficacy of each product for reducing dentin permeability in the short term according to the frequency and duration of usage.
METHODS: 100 dentin discs with no caries were prepared from freshly extracted human third molar teeth. The dentin discs were brushed with three desensitizing toothpastes or with a non-desensitizing toothpaste and distilled water, which served as control. The 100 dentin slices were randomly divided into two groups (n= 50): one group underwent continuous brushing (brushed for 3 minutes continuously), and the other group underwent discontinuous brushing (brushed three times, each time for 1 minute). Then, the two groups were divided into five subgroups (n = 10) for the five brushing applications. Dentin permeability was measured with a hydraulic permeability system before and after brushing.
RESULTS: All desensitizing toothpastes reduced dentin permeability significantly after treatment. Sensodyne Repair and Protect (calcium sodium phosphosilicate) and discontinuous brushing reduced dentin permeability significantly compared with continuous brushing. Dentin permeability values showed no significant difference between the three toothpastes after 3 minutes of continuous brushing. When comparing the three toothpastes under discontinuous brushing conditions after 3 minutes, Sensodyne Repair and Protect (calcium sodium phosphosilicate) reduced dentin permeability significantly.
CLINICAL SIGNIFICANCE: Sensodyne Repair and Protect (calcium sodium phosphosilicate) and discontinuous brushing reduced dentin permeability significantly compared with continuous brushing. Moreover, brushing with Sensodyne Repair and Protect (calcium sodium phosphosilicate) resulted in the lowest dentin permeability compared with those of the other two toothpastes. These results indicated that Sensodyne Repair and Protect may relieve dentin hypersensitivity.

PMID: 29178723 [PubMed - indexed for MEDLINE]




Case-specific finite element analysis of dental CAD/CAM prostheses to identify design flaws prior to manufacture.
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Case-specific finite element analysis of dental CAD/CAM prostheses to identify design flaws prior to manufacture.

Am J Dent. 2016 Dec;29(6):339-344

Authors: Apicella D, Joda T, Bonadeo G, Sorrentino R, Ferrari M

Abstract
PURPOSE: To apply a design optimization strategy to dental prostheses machining to verify whether this approach can detect flaws occurring in the CAD process and to estimate the influence of the type of material on the occurrence of fractures in restorations.
METHODS: The stereo lithography interface format of a 4-unit (from canine to first molar) fixed dental prosthesis designed by a conventional dental CAD process was converted into a Finite Element Analysis (FEA) model. This basic model was coupled to the mechanical properties of feldspathic ceramic, lithium disilicate ceramic (LS2) and zirconia (ZrO2) to create three FEA models with different mechanical properties. The models were constrained along the abutment housing surfaces of the canine and the first molar, respectively. Finally, a simulated load of 50 N was applied vertically to the occlusal surface of the first premolar.
RESULTS: The FEA showed a stress peak concentration between the second connectors and the second premolar. The stress peak overcame the ultimate tensile stresses of feldspathic and lithium disilicate ceramics; conversely, the ultimate tensile stress of zirconia was not overcome. A geometrical flaw was identified in the 4-unit fixed dental prosthesis. The flaw was sensitive to tensional stress and could lead to failure of the component.
CLINICAL SIGNIFICANCE: The results of the present investigation showed the importance and future impact of the application of FEA in the daily practice of prosthodontics. A FEA-implemented CAD process would allow proper prosthetic volumes with correct dimensions of the framework, in order to withstand occlusal loads and consequently reduce mechanical failures. FEA is a useful tool to simplify the design of prosthetic frameworks and select esthetic ceramic materials with strength enough to withstand occlusal stress.

PMID: 29178722 [PubMed - indexed for MEDLINE]




The new generation of conventional and bulk-fill composites do not reduce the shrinkage stress in endodontically-treated molars.
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The new generation of conventional and bulk-fill composites do not reduce the shrinkage stress in endodontically-treated molars.

Am J Dent. 2016 Dec;29(6):333-338

Authors: Oliveira Schliebe LRS, Lourenço Braga SS, da Silva Pereira RA, Bicalho AA, Veríssimo C, Novais VR, Versluis A, Soares CJ

Abstract
PURPOSE: To compare flowable and regular paste bulk-fill resin composites with old and new generation conventional composites that use incremental filling techniques for direct restoration of endodontically-treated teeth.
METHODS: Four resin composites produced by the same company (3M-ESPE) were used: two conventional resin composites (old formulation, Z100, and new nanofilled formulation, Filtek Supreme XT); and two bulk-fill resin composites (flowable composite, Filtek Bulk-fill Flowable associated with Filtek Supreme, and regular paste, Filtek Bulk-fill Posterior). Elastic modulus (E), Vickers hardness (VH), post-gel shrinkage (Shr), diametral tensile strength (DTS) and compressive strength (CS) were determined (n= 10) and statistically analyzed using ANOVA and Tukey's test (α=0.05). Shrinkage stresses were analyzed using non-linear finite element analysis.
RESULTS: Filtek Bulk-fill flowable and Filtek Supreme XT had higher CS than Z100 and Filtek Bulk-fill Posterior. Z100 and Filtek Supreme XT had higher DTS than Filtek Bulk-fill Posterior. Filtek Bulk-fill flowable had the lowest values and Z100 the highest E and Shr. Z100 resulted in higher stresses in the enamel and in root dentin close to the pulp chamber than the other filling techniques. Filtek Bulk-fill Flowable resulted in lower stress than other resin composites.
CLINICAL SIGNIFICANCE: Using bulk-fill composites, especially flowable resin composite, created lower stresses in restored endodontically-treated teeth. Clinicians, when deciding for direct restoration of endodontically-treated teeth, may choose the bulk-fill composite to decrease undesirable effects of direct restoration while simplifying filling procedure.

PMID: 29178721 [PubMed - indexed for MEDLINE]




Lipopolysaccharide and lipoteichoic acid binding by antimicrobials used in oral care formulations.
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Lipopolysaccharide and lipoteichoic acid binding by antimicrobials used in oral care formulations.

Am J Dent. 2016 Dec;29(6):328-332

Authors: Haught JC, Xie S, Circello B, Tansky CS, Khambe D, Sun Y, Lin Y, Sreekrishna K, Klukowska M, Huggins T, White DJ

Abstract
PURPOSE: To study the reactivity of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) with the cationically charged agents cetylpyridinium chloride, stannous fluoride, and the non-cationic agent triclosan. We also assessed the effect of these agents to inhibit LPS and LTA binding to cellular Toll-like Receptors (TLRs) in vitro.
METHODS: The ability of these antimicrobials to bind with LPS and/or LTA was assessed in both the Limulus amebocyte lysate and BODIPY-TR-cadaverine dye assays. Mass spectroscopy was then used to confirm that stannous fluoride directly binds with LPS and to determine stoichiometry. Lastly, we looked for possible inhibitory effects of these antimicrobial agents on the ability of fluorescently conjugated LPS to bind to TLR4 expressed on HEK 293 cells.
RESULTS: Cetylpyridinium chloride (CPC) and stannous salts including stannous fluoride interfered with LPS and LTA reactivity in both dye assays, while triclosan had no effect. Mass spectroscopy revealed direct binding of stannous fluoride with E. Coli LPS at 1:1 stoichiometric ratios. In the cellular assay, cetylpyridinium chloride and stannous fluoride, but not triclosan, inhibited LPS binding to TLR4.
CLINICAL SIGNIFICANCE: These results support a potential mechanism of action for stannous fluoride and CPC formulated in oral products in which these ingredients bind bacterial toxins and potentially render them less toxic to the host. These results may influence home care recommendations for patients at risk for plaque-related diseases.

PMID: 29178720 [PubMed - indexed for MEDLINE]




Quantitation of endotoxin and lipoteichoic acid virulence using toll receptor reporter gene.
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Quantitation of endotoxin and lipoteichoic acid virulence using toll receptor reporter gene.

Am J Dent. 2016 Dec;29(6):321-327

Authors: Huggins T, Haught JC, Xie S, Tansky CS, Klukowska M, Miner MC, White DJ

Abstract
PURPOSE: To apply quantitative Toll-like receptors (TLR) cell assays to compare lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs) from different oral bacterial strains for potential pathogenicity in vitro.
METHODS: The potency of LPS and LTA from different bacteria on activation of TLR reporter genes in HEK-tlr cell lines was examined. P. gingivalis LPS mix, P. gingivalis 1690 LPS, P. gingivalis 1435/50 LPS, E. coli LPS (E. coli K12), B. subtilis LTA, S. aureus LTA, E. hirae LTA and S. pyogenes LTA were examined in both TLR2 and TLR4 HEK cell line reporter assays. Solutions of LPS and LTA from selected bacteria were applied in a dose response fashion to the TLR reporter cells under standard culture conditions for mammalian cells. Reporter gene secreted-embryonic-alkaline-phosphatase (SEAP) was measured, and half maximal effective concentration (EC50) was determined for each sample. Concentration dependent TLR activation was compared to similar responses to LPS and LTA for commercial BODIPY-TR-Cadaverine and LAL biochemical (non cell based) assays.
RESULTS: All LPS from P. gingivalis activated both TLR2 and TLR4 responses. E. coli LPS is a strong activator for TLR4 but not for TLR2 responses. In contrast, both B. subtilis and S. aureus LTA provoked responses only in TLR2, but not in the TLR4 assay. Interestingly, E. hirae LTA and S. pyogenes LTA did not stimulate strong TLR2 responses. Instead, both E. hirae LTA and S. pyogenes LTA mounted a reasonable response in TLR4 reporter gene assay. Both LPS and LTA showed deactivation of fluorescence in BODIPY-TR-Cadaverine while only LPS was active in LAL. As with biochemical assays, an EC50 could be determined for LPS and LTA from various bacterial strains. The EC50 is defined as a concentration of LPS or LTA that provokes a response halfway between the baseline and maximum responses. Lower EC50 means higher potency in promoting TLR responses, and in principle indicates greater toxicity to the host.
CLINICAL SIGNIFICANCE: InvivoGen TLR2 and TLR4 assays distinguish specific types of microbial products, such as LPS and LTA from different bacteria. Application of EC50 determinations creates a means for quantitative and comparisons of LPS and LTA virulence in a cellular-based assay and combinations of TLR reporter cell assays along with biochemical evaluation of LPS#47;LTA in BODIPY-TR-Cadaverine and LPS in LAL assays provides a means to quantitate virulence of plaque samples with respect to both LPS and LTA. These learnings have long-term implications for patient care in that understanding the virulence of patients' plaque provides important information to assess risk of oral diseases.

PMID: 29178719 [PubMed - indexed for MEDLINE]




Antimicrobial and antibiofilm activity of silver, titanium dioxide and iron nano particles.
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Antimicrobial and antibiofilm activity of silver, titanium dioxide and iron nano particles.

Am J Dent. 2016 Dec;29(6):315-320

Authors: Lavaee F, Faez K, Faez K, Hadi N, Modaresi F

Abstract
PURPOSE: To compare the antimicrobial effects of chlorhexidine, penicillin, erythromycin, clindamycin, tetracycline and vancomycin with silver, titanium dioxide and iron nanoparticles and also to consider the synergistic antibacterial and antibiofilm effects of nanoparticles in clinical and standard strains of Streptococcus mutans and Streptococcus sanguinis.
METHODS: The specimens collected from 66 3-5 year-old children with detected S. mutans and S. sanguinis by PCR were then exposed to the antimicrobial activity of chlorhexidine, penicillin, erythromycin, clindamycin, tetracycline and vancomycin with silver, titanium dioxide and iron nanoparticles measured by microdilution and disc diffusion tests and the colony counted after 1 to 5 minutes. The antibiofilm activity was examined by microtiter test.
RESULTS: Use of nanoparticles alone showed higher minimum inhibitory concentration (MIC) than using them synergistically. The most effective synergistic solution was the one containing TiO2, Ag and Fe3O4 showing 0.019 μg#47;ml in S. mutans and S. sanguinis. Furthermore, this solution had the lowest biofilm inhibitory concentration (BIC) and colony forming units than the other antibiotics and chlorhexidine.
CLINICAL SIGNIFICANCE: The solution containing TiO2, Ag and Fe33O4 showed the lowest inhibitory and antibiofilm concentration against S. mutans and S. sanguinis compared to those of other nanoparticle containing solutions, antibiotics and chlorhexidine, thus it may be used for treating dental caries, dental plaque and oral infections.

PMID: 29178718 [PubMed - indexed for MEDLINE]




The influence of the utilization time of brush heads from different types of power toothbrushes on oral hygiene assessed over a 6-month observation period: A randomized clinical trial.
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The influence of the utilization time of brush heads from different types of power toothbrushes on oral hygiene assessed over a 6-month observation period: A randomized clinical trial.

Am J Dent. 2016 Dec;29(6):307-314

Authors: Schmickler J, Wurbs S, Wurbs S, Kramer K, Rinke S, Hornecker E, Mausberg RF, Ziebolz D

Abstract
PURPOSE: This randomized clinical trial investigated the influence of the utilization time of brush heads from different types of power toothbrushes [oscillating rotating (OR) and sonic action (SA)93; on oral hygiene (plaque accumulation and gingival inflammation) over a 6-month observation period.
METHODS: 49 participants were randomly allocated into two groups: use of the same brush head over 6 months (NR: non-replacement) or replacement of brush head every 4 weeks over 6 months (R: replacement). Each group was subdivided into two subgroups according to kind of toothbrush (TB) used (OR and SA). Modified Quigley-Hein plaque index (QHI), papilla bleeding index (PBI), and gingival index (GI) were recorded at baseline and 2, 8, 12, 16, and 24 weeks after baseline. After 24 weeks, participants of both groups (R and NR) received a new brush head. At week 26, final QHI, PBI, and GI were recorded.
RESULTS: QHI decreased between baseline and follow-up visits in R groups (P< 0.05), with the exception of week 12 (P= 0.26). In NR groups, no significant decrease was detected (P> 0.05). There was no significant effect of time on PBI or GI in any of R subgroups (P> 0.05). In NR oscillating/rotating TB: significant increase in PBI and GI was detected 24 weeks after baseline (PBI: P= 0.02, GI: P= 0.03); sonic action TBs showed significant decrease in PBI at every follow-up visit (P< 0.05), except at 24 weeks after baseline (P= 0.73). GI was significantly decreased at 2 weeks after baseline only (P< 0.01).
CLINICAL SIGNIFICANCE: Six-month use of the same brush head reduced effectiveness in removing plaque, and gingival inflammation appeared to increase after a utilization time of over 4 months. Replacing brush heads is advised after 4 months.

PMID: 29178717 [PubMed - indexed for MEDLINE]




Clinical evaluation of a toothpaste containing lysozyme for the treatment of recurrent aphthous stomatitis: A 3-month, double-blind, randomized study.
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Clinical evaluation of a toothpaste containing lysozyme for the treatment of recurrent aphthous stomatitis: A 3-month, double-blind, randomized study.

Am J Dent. 2016 Dec;29(6):303-306

Authors: Shao Y, Zhou H

Abstract
PURPOSE: To assess the efficacy and safety of a toothpaste containing lysozyme for the treatment of minor recurrent aphthous stomatitis (MiRAS) in a 3-month clinical trial.
METHODS: 71 participants with MiRAS were recruited to this randomized, parallel-controlled, double-blind clinical trial. Participants were allocated randomly to the test group or the control group. Demographic data and pain score (visual analogue scale, VAS) were recorded at baseline. Healing time of MiRAS, recurrence frequency and side effects were recorded at the 1-, 2- and 3-month follow-up visits. All data were analyzed using SAS software version 8.0.
RESULTS: There was no significant difference (P>0.05) in pain score between the treatment group (3.00 ± 1.66) and the control group (2.66 ± 1.51). The average healing time was significantly reduced (P< 0.01) in the treatment group (5.66 ± 2.02) compared with the control group (7.46 ± 2.69), while the recurrence frequency also showed a significant reduction from 4.40 ± 2.89 in the control group to 3.06 ± 1.48 in the treatment group (P< 0.05). No obvious side effects were observed.
CLINICAL SIGNIFICANCE: The results of this clinical study supported the conclusion that a toothpaste containing lysozyme was effective in promoting healing and reducing recurrence frequency without significant side effects in the treatment of minor recurrent aphthous stomatitis.

PMID: 29178716 [PubMed - indexed for MEDLINE]




Heat generated during light-curing of restorative composites: Effect of curing light, exotherm, and experiment substrate.
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Heat generated during light-curing of restorative composites: Effect of curing light, exotherm, and experiment substrate.

Am J Dent. 2016 Aug;29(4):234-2240

Authors: Balestrino A, Veríssimo C, Tantbirojn D, Garcia-Godoy F, Soares CJ, Versluis A

Abstract
PURPOSE: To investigate temperature rise, separating heat caused by irradiation and exotherm for three composites polymerized with three curing lights. The effect of substrate on temperature measurements was also determined.
METHODS: Composite samples (n= 5) (Filtek Supreme Ultra, Filtek LS, and EsthetX HD) were placed on a thermocouple tip inside three substrates (aluminum, Delrin, and tooth). The composites were photoactivated using three curing lights (Elipar 2500 QTH, SmartLite Max LED, DemiUltra LED) at 1 mm distance. Irradiance was 798, 980, and 1,135 mW/cm2, respectively. Exotherm was determined by subtracting post-cure from the polymerization temperature curves. ANOVA and Student-Newman-Keuls post-hoc tests were used to analyze differences among peak temperatures and exotherms (significance level 0.05).
RESULTS: SmartLite LED curing light resulted in higher peak temperatures and exotherms compared to the DemiUltra LED and QTH for all tested composites (16.9-20.4°C vs 12.3-14.7°C vs 8.9-9.7°C). Thus, the LEDs produced higher temperature rises than the QTH, and the LED with lower irradiance caused higher temperature rise than the LED with higher irradiance. The silorane-based Filtek LS generated significantly higher exotherm than the methacrylate-based EsthetX HD and Filtek Supreme Ultra (6.2-7.6°C vs 3.6-4.5°C vs 2.7-3.6°C). Substrate affected temperatures significantly. Temperature profiles found in Delrin substrate were comparable to tooth substrate, while aluminum substrate reduced temperatures 10-20 degrees.
CLINICAL SIGNIFICANCE: Curing of restorative composites raises the temperature under a restoration due to irradiation and exothermic reaction; how much the temperature increases depends on curing light design, type of composite, and surrounding substrate. The silorane-based Filtek LS generated significantly higher exotherm than the methacrylate-based EsthetX HD and Filtek Supreme Ultra.

PMID: 29178754 [PubMed - indexed for MEDLINE]




Detection of occlusal caries with impedance spectroscopy and laser fluorescence before and after placement of fissure sealants: An in vitro study.
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Detection of occlusal caries with impedance spectroscopy and laser fluorescence before and after placement of fissure sealants: An in vitro study.

Am J Dent. 2016 08;29(4):229-233

Authors: Mortensen D, Ekstrand KR, Twetman S

Abstract
PURPOSE: To (1) investigate the influence of fissure sealants on impedance spectroscopy (ACIS) and laser fluorescence (LF) readings, (2) compare the performance of the ACIS device with the LF technique and visual inspection (ICDAS) in permanent molars with various degrees of occlusal caries, and (3) validate all methods against radiographs and histological hemi-sectioning.
METHODS: 102 permanent molars were randomly selected to represent different stages of occlusal caries, from clinically sound to minor cavities. The teeth were examined by one trained examiner and scored with CarieScan PRO, the DIAGNOdent pen and ICDAS at baseline, after bleaching, etching and placement of a clear fissure sealant. A digital radiograph was exposed at baseline. After the assessments, the actual lesion depth was histologically determined.
RESULTS: Bleaching did not affect the readings but significantly higher ACIS and LF-pen values were recorded after acid etching (P< 0.05). The placement of a fissure sealant increased the LF-pen readings significantly (P< 0.05) while no values could be obtained with the ACIS device. Both the baseline ACIS and LF-pen values were significantly associated (P< 0.05) with the lesion depth but visual inspection displayed the best correlation with radiographs and histology. The ACIS technology displayed high sensitivity and specificity for detecting extensive occlusal lesions.
CLINICAL SIGNIFICANCE: The findings demonstrated that placement of a fissure sealant had a significant impact on the ACIS and LF-pen readings. Both methods mirrored the actual histological and radiographic lesion depth to various extents but could not match the performance of visual inspection.

PMID: 29178753 [PubMed - indexed for MEDLINE]




Fiber optics reflectance spectroscopy (45°x: 45°) for color analysis of dental composite.
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Fiber optics reflectance spectroscopy (45°x: 45°) for color analysis of dental composite.

Am J Dent. 2016 Aug;29(4):223-228

Authors: Gargano M, Ludwig N, Federighi V, Sykes R, Lodi G, Sardella A, Carrassi A, Varoni EM

Abstract
PURPOSE: To evaluate the application of a fiber optic reflectance spectroscopy (FORS) prototype probe for 45°x: 45° FORS for determining color of dental materials. A portable spectrophotometer with a highly manageable fiber optics co-axial probe was used to apply 45°x: 45° FORS for color matching in restorative dentistry.
METHODS: The color coordinates in CIELAB space of two dental shade guides and of the corresponding photopolymerized composites were collected and compared. The 45°x: 45° FORS with the co-axial probe (test system), the integrating sphere spectroscopy (reference system) and a commercial dental colorimeter (comparator system) were used to collect data and calculate color differences (ΔE and ΔE00).
RESULTS: FORS system displayed high repeatability, reproducibility and accuracy. ΔE and ΔE00 values between the shade-guide, each other, and the corresponding composites resulted above the clinically acceptable limit. The 45°x: 45° FORS test system demonstrated suitable in vitro performance for dental composite color evaluation.
CLINICAL SIGNIFICANCE: 45°x: 45° fiber optic reflectance spectroscopy allows reliable color analysis of small surfaces of dental composites, favoring the color matching of material with the closely surrounding dental tissue, and confirming significant color differences between shade guide tabs and photo-polymerized composites.

PMID: 29178752 [PubMed - indexed for MEDLINE]




Cytogenetic damage in exfoliated oral buccal cells by dental composites.
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Cytogenetic damage in exfoliated oral buccal cells by dental composites.

Am J Dent. 2016 Aug;29(4):219-222

Authors: Tadin A, Galic N, Marovic D, Gavic L, Klaric E, Pejda S, Ugrin K, Zeljzic D

Abstract
PURPOSE: To evaluate the possible geno/cytotoxic effects of dental composite materials by assessing the frequency of micronuclei formation and other nuclear abnormalities in the exfoliated buccal epithelium.
METHODS: Swabs were taken from the buccal mucosa of 85 young healthy subjects. All participants had healthy dentition or dentition restored only with composite materials. Genotoxicity and cytotoxicity was assessed by micronucleus assay.
RESULTS: The results indicated no significant difference in number of oral mucosa cells with micronuclei in subjects with different numbers of composite restored tooth surfaces (P= 0.476). Also, the number of restored surfaces had no effect on nuclear alterations closely related to cytotoxicity, such as karyolysis (P= 0.572), karyorrehexis (P= 0.573) and picnosis (P= 0.765).
CLINICAL SIGNIFICANCE: Despite doubts about the safe clinical use of resin composites, this study found no evidence that composite materials trigger long-term cytogenetic damage in the epithelial cells of buccal mucosa in humans. There is no objective and quantifiable evidence of genotoxicity induced by composite restorative materials in clinical practice.

PMID: 29178751 [PubMed - indexed for MEDLINE]




Efficacy of a new filler-containing root coating material for dentin remineralization.
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Efficacy of a new filler-containing root coating material for dentin remineralization.

Am J Dent. 2016 Aug;29(4):213-218

Authors: Okuyama K, Kadowaki Y, Matsuda Y, Hashimoto N, Oki S, Yamamoto H, Tamaki Y, Sano H

Abstract
PURPOSE: To evaluate a new root coating material containing surface pre-reacted glass-ionomer (S-PRG) filler for remineralization of demineralized dentin.
METHODS: The dentin was exposed on root surfaces of human third molars and demineralized by immersion in demineralization solution for 4 days. The demineralized dentin surface was divided into three areas. The center area was left untreated. The area on one side of the center area was coated with protective wax. The area on the other side was coated with one of four test materials: fluoride-containing S-PRG filler (PRG Barrier Coat: PR), fluoride-containing bonding agent (Bond Force: BF), fluoride-containing glass-ionomer cement as a positive control (Fuji IX EXTRA: EX), or non-fluoride-containing bonding agent as a negative control (Clearfil MegaBond: MB). The samples were stored in remineralization solution for 7 days, and then cut into two slices. The mineral changes, defined as variation in mineral loss between wax-coated area and the central untreated area, were measured in one slice by transversal microradiography. The fluoride concentration was measured in the other slice by µ-particle-induced gamma/X-ray emission. Seven thin specimens (0.25-mm thickness) of each test material were used to determine fluoride ion release from the materials over 21 days.
RESULTS: The mineral changes were greatest for EX, followed by PR, with no difference between BF and MB (P> 0.05). Regarding the fluoride concentrations in dentin, there was no difference between EX and PR (P> 0.05). MB had the lowest value (P< 0.01). Fluoride release from EX was largest, followed by PR, with BF showing low fluoride release (P< 0.05). MB had no fluoride release.
CLINICAL SIGNIFICANCE: A new coating material with S-PRG filler can be applied in a thin layer on root dentin, which could be especially useful for hard-to-access lesions. This material remineralized demineralized root dentin and had fluoride diffusion characteristics similar to those of glass-ionomer cement in vitro.

PMID: 29178750 [PubMed - indexed for MEDLINE]




Effects of carbodiimide dentin surface treatment on resin-dentin bonding.
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Effects of carbodiimide dentin surface treatment on resin-dentin bonding.

Am J Dent. 2016 Aug;29(4):208-212

Authors: Haught YZ, Tang L, Liu Y, Zhou Y, Chung KH, Chan DCN

Abstract
PURPOSE: To assess the effects of ethanol-based 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide (EDC) dentin surface treatment on resin-dentin bonding and dentin collagen fibril biodegradation.
METHODS: Acid-etched dentin surfaces were pretreated with different concentrations of ethanol-based EDC solutions (0.01-2M) for 60 seconds, followed by two-step etch-and-rinse dentin adhesive application and resin composite bonding. Dentin surfaces pretreated with either ethanol alone or no pretreatment were used as controls. The specimens were subjected to microtensile bond strength testing after storage in 0.9% NaCl solution at 37°C for either 24 hours or 90 days. Furthermore, demineralized dentin slabs with and without ethanol-based EDC pretreatment were exposed to a collagenase solution for 24 hours, and subsequent hydroxyproline release was measured using ELISA. Data were analyzed with ANOVA and multiple comparison tests at α= 0.05.
RESULTS: The bond strength values were significantly lower for dentin surfaces pretreated with 1 and 2 M ethanol-based EDC than for the control surfaces (P< 0.05). The 0.01, 0.1, and 0.3 M ethanol-based EDC pretreated groups obtained significantly higher bond strength values at 90 days compared to controls. Hydroxyproline release measurements revealed that there were significantly lower levels released in the 0.3 and 1 M ethanol-based EDC pretreated specimens than for controls (P< 0.05).
CLINICAL SIGNIFICANCE: Pretreatment of dentin surfaces with ethanol-based EDC solution ≤ 0.3M before resin composite bonding can improve the stability of the resin-dentin bond and prevent dentin collagen fibril biodegradation.

PMID: 29178749 [PubMed - indexed for MEDLINE]




Direct pulp capping versus root canal treatment in young permanent vital teeth with pulp exposure due to caries. A systematic review.
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Direct pulp capping versus root canal treatment in young permanent vital teeth with pulp exposure due to caries. A systematic review.

Am J Dent. 2016 Aug;29(4):201-207

Authors: Brodén J, Heimdal H, Josephsson O, Fransson H

Abstract
PURPOSE: To evaluate the available evidence on pulp capping procedures and root canal treatment in young permanent teeth with vital pulps exposed by caries.
METHODS: The study was conducted as a systematic review of the literature. Three databases, PubMed, Web of Knowledge, and The Cochrane Library were searched. Reference lists of relevant articles were hand searched. The quality of all relevant publications was rated.
RESULTS: Ten original scientific studies were included in the review. The quality was rated as low in all studies. The search failed to disclose any article directly comparing pulp capping and root canal treatment. The level of evidence was insufficient to draw any conclusions regarding the effectiveness of the two treatment concepts. High success rates are reported for pulp capping procedures in exposure due to caries, though it is not possible to compare them to success rates of root canal treatment. The review confirms the lack of high quality studies on the treatment of young permanent teeth with cariously exposed pulps.
CLINICAL SIGNIFICANCE: For the treatment of young permanent teeth with pulp exposure due to caries there is currently no evidence to support the assumption on pulp capping being more beneficial than root canal treatment in achieving a symptom free tooth with normal periapical conditions.

PMID: 29178748 [PubMed - indexed for MEDLINE]




Correlation among periodontal health status, maternal age and pre-term low birth weight.
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Correlation among periodontal health status, maternal age and pre-term low birth weight.

Am J Dent. 2016 Aug;29(4):197-200

Authors: Capasso F, Vozza I, Capuccio V, Vestri AR, Polimeni A, Ottolenghi L

Abstract
PURPOSE: To assess correlations between periodontal status, maternal age and adverse pregnancy outcomes, such as pre-term and low birth weight in a sample of pregnant women.
METHODS: Study population was represented by outpatient pregnant women, gestational age > 26 weeks. Medical history questionnaires were administered to all participants who underwent clinical evaluation; clinical obstetric outcome records were collected after delivery. A questionnaire was administered regarding personal information, socio-economic status, oral hygiene habits, and oral health conditions. A clinical oral examination was performed to collect Simplified Oral Hygiene Index (OHI-S) and Community Periodontal Index (CPI). Pregnancy outcome records included: delivery week, kind and causes of delivery, any relevant complications, and birth weight. Descriptive statistics were used to depict the data from the questionnaire while the relationship between delivery week, birth weight, maternal age and periodontal status was evaluated through multivariate tests of significance.
RESULTS: 88 pregnant women were enrolled in the study. The results showed a statistically significant correlation (P< 0.001) among participants older than 40 years of age, between periodontal disease and adverse pregnancy outcomes. No statistical correlation was found among pre-term and low birth weight, smoking, ethnicity and educational level of mothers. The results highlight the importance of including a routine oral and periodontal health examination in pregnant women older than 40 years of age.
CLINICAL SIGNIFICANCE: The correlation between periodontal status and adverse pregnancy outcomes in older mothers indicates the need for routine oral health examination and periodontal status assessment and care in pregnant women older than 40 years of age.

PMID: 29178747 [PubMed - indexed for MEDLINE]




A randomized 3-month clinical comparison of a power toothbrush to a manual toothbrush in the reduction of gingivitis.
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A randomized 3-month clinical comparison of a power toothbrush to a manual toothbrush in the reduction of gingivitis.

Am J Dent. 2016 Aug;29(4):193-196

Authors: Li Z, He T, Li C, Sun L, Chang J, He Y, Zhao J, Ji N

Abstract
PURPOSE: To compare the anti-gingivitis effect of a power toothbrush relative to a manual toothbrush control.
METHODS: This was a 3-month, randomized and controlled, single-center, parallel group, examiner-blinded clinical study. 123 Chinese adults in good general health and with at least 15 gingival bleeding sites, as measured by the Gingival Bleeding Index, were enrolled into the study. At baseline, pre-treatment gingivitis levels were assessed using the Mazza Bleeding Index. Subjects were then randomly assigned to receive either an oscillating-rotating power toothbrush [Oral-B Professional Care 7000 (D17u/EB17)] or a flat-trim manual toothbrush with tapered filaments (Lion Dentor Systema). Subjects brushed at home twice-daily with their assigned toothbrush and a marketed sodium fluoride dentifrice (Crest Cavity Protection dentifrice), and were reevaluated at Months 1, 2, and 3.
RESULTS: 113 evaluable subjects completed the study. Both groups showed significant reductions in gingivitis from baseline for all time points measured (P< 0.001). At Months 1, 2 and 3, the power toothbrush demonstrated significantly greater gingivitis reductions of 7.11%, 9.20% and 8.47%, respectively, than the manual toothbrush (P< 0.01), and significantly fewer bleeding sites (17.3%, 23.9% and 24.3%, respectively, P< 0.05). No adverse events were reported or observed for either brush during the study.
CLINICAL SIGNIFICANCE: The power brush provided statistically significantly greater reductions in gingivitis compared with a manual toothbrush at Months 1, 2 and 3.

PMID: 29178746 [PubMed - indexed for MEDLINE]




Clinical performance of bonded ceramic inlays/onlays: A 5- to 18-year retrospective longitudinal study.
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Clinical performance of bonded ceramic inlays/onlays: A 5- to 18-year retrospective longitudinal study.

Am J Dent. 2016 Aug;29(4):187-192

Authors: Borgia Botto E, Baró R, Borgia Botto JL

Abstract
PURPOSE: This retrospective longitudinal study evaluated the clinical performance of bonded ceramic inlays/onlays, placed by the first author in his private practice, in a 5 to 18-year period.
METHODS: The patients evaluated had been treated in the office for at least 7 years and were still in the practice up to year 2013. 130 randomly selected patients agreed to participate in the study. 93 bonded ceramic inlays/onlays (BCRs), were placed on posterior teeth in 47 subjects. Gender, age, tooth preparation, number, type, extent, location, quality and survival of the restorations, ceramic materials, luting resins cements, parafunctional habits, secondary caries and maintenance therapy were the variables evaluated. Cohen 's Kappa coefficient, on the quality analysis of the restorations, ranged from 0.78 to 1. Fisher 's exact test, Chi Square test, Kruskal-Wallis test and Mann-Whitney non-parametric test were indicated to analyze significant differences.
RESULTS: At the initial examination, 87 (93.5%) restorations were in function and six failed (6.5%). 81 (93%) were rated as clinical successes. The observed mean survival time of those that remained functional was 11 years. The standard deviation was 4 years, with a 95% CI for the overall observed mean survival time (10 years-11 years, 9 months). 87 of 93 BCRs had a functional success of 93.5%, with an observed mean survival of 11 years. The clinical performance of bonded ceramic onlays was very acceptable.
CLINICAL SIGNIFICANCE: Bonded ceramic onlays showed a predictable, esthetic, and functional treatment, with acceptable longevity.

PMID: 29178745 [PubMed - indexed for MEDLINE]