^{February 2016 Abstracts}

Comparing different enamel pretreatment options for resin-infiltration of natural non-cavitated carious lesions

 

Marwa  Abdelaziz, dmd, Adele  Lodi  Rizzini, dmd,  Tissiana  Bortolotto, pd, dmd, phd, Giovanni Tomasso Rocca, dmd, Albert  J.  Feilzer, dds, phd, Franklin  Garcia-Godoy, dds, ms, phd, phd &  Ivo  Krejci, dmd, phd

 

Abstract: Purpose: To compare two different enamel pretreatments and their effect on the efficiency of penetration of a one-component adhesive into natural carious lesions. Methods: Eight extracted human molars and premolars with non-cavitated interproximal lesions were selected. ICDAS code 1-2 was assessed by visual, microscopic, X-ray and Diagnocam record analysis. Samples were cut vertically across the demineralization to obtain two symmetrical lesions, (n=16). After isolating the cut surfaces with nail varnish, paired lesion halves’ surfaces were pretreated with two different techniques: Group 1: surfaces were firstly abraded with fine diamond-coated metallic strips (Steelcarbo) and then etched with 37% H₃PO₄ acid (Omni-etch, 120 seconds); Group 2: lesion surfaces were etched with 15% HCl acid (Icon-etch, 120 seconds). All teeth were stained with rhodamine isothiocyanate (RITC) solution (12 hours) and subsequently stored in dry chamber (3 hours). All samples were penetrated with a one-component adhesive (Scotchbond Universal) for 180 seconds and coated with a thin layer of flowable composite (Tetric Flow). After light curing, un-encapsulated dye was bleached by immersion in 30% hydogen peroxide for 12 hours at 37°C. Remaining lesion pores were stained with sodium fluorescein solution. Thin cuts of the teeth were observed with confocal microscopy and computer image analysis was performed (ImageJ). The percentage of penetration (area of resin penetration/area of total demineralization ×100) was calculated. Results: Pretreatment with fine aluminum oxide-coated metallic strip followed by 37% H₃PO₄ acid showed a larger infiltration area (51.7% ± 12.2) in almost all samples compared to pretreatment with 15% HCl acid alone (22.1% ± 13.2). Statistical analysis using t-test showed a significant difference between the two groups (P= 0.011). (Am J Dent 2016;29:3-9).

 

 

 

 

 

 

Mail:  Dr. Marwa Abdelaziz, Division of Cariology and Endodontology, University of Geneva, Rue Barthélemy-Menn 19, CH-1205 Geneva, Switzerland.  E-mail:  marwa.abdel@unige.ch

 

Cardiovascular effects of combined hyaluronidase and mepivacaine in dental anesthesia: A randomized clinical trial

 

Maurício  José  Tornelli, phd, Renata  Martins  Silva  Prado, phd, Helena  Regina  Tornelli, msc, Gustavo  Faibischew  Prado, phd, Patricia  Verónica  Aulestia  Viera, msc, Rodney  Garcia  Rocha, phd &  Maria  Aparecida  Borsatti, phd

 

Abstract: Purpose: To evaluate the effects of combined administration of mepivacaine with epinephrine and the diffusion agent hyaluronidase on hemodynamic and electrocardiographic parameters in healthy individuals undergoing dental surgery. Methods: In a double-blind, split-mouth, randomized clinical trial, the cardiovascular effects induced by 2.7 mL of 2% mepivacaine with 1:100,000 epinephrine injected concomitantly with 1 mL of 75 TRU/mL hyaluronidase or placebo for inferior alveolar nerve block was evaluated in systemically healthy subjects that underwent bilateral third molar extraction in two separate sessions. Systolic and diastolic blood pressure and heart rate were monitored using oscillometric and photoplethysmographic methods in 10 clinical stages, while electrocardiographic records of 12 leads were obtained in four stages. Results: Hyaluronidase injected concomitantly with local anesthetic did not induce changes in blood pressure and heart rate compared to placebo. There were no instances of ST segment depression or elevation, or wide or narrow QRS complex extrasystoles in ECG. The use of mepivacaine injected concomitantly with 75 TRU/mL hyaluronidase was safe, from a cardiovascular standpoint.(Am J Dent 2016;29:10-14)

 

 

 

 

 

 

 

Mail: Dr. Maria Aparecida Borsatti, Av. Professor Lineu Prestes, 2227, CEP: 05508-000 Cidade Universitária, São Paulo, SP, Brazil.  E-mail: maborsat@usp.br

 

 

Effectiveness of chemical disinfection on biofilms of relined dentures: A randomized clinical trial

 

Eduardo B. Moffa, dds, msc, phd, Fernanda E. Izumida, dds, msc, phd, Janaina H. Jorge, dds, msc, phd, Maria C.M. Mussi, dds, msc, phd, Walter L. Siqueira, dds, phd  &  Eunice T. Giampaolo, dds, msc, phd

 

Abstract: Purpose: To evaluate the effect of disinfection with sodium perborate or chlorhexidine (when combined with brushing) on the removal of biofilm in relined dentures. Methods: Swabs were collected 48 hours after the relining procedure and at the follow-up time intervals of 7, 15, 30, 90, and 180 days. The dentures’ surface roughness was measured at the same times. 45 subjects were randomly divided into three groups of 15 subjects each. The control group brushed with coconut soap and a soft toothbrush. The sodium perborate group followed the same procedure and also disinfected with sodium perborate solution for 5 minutes per day. The chlorhexidine group followed the control group procedure and disinfected with 2% chlorhexidine digluconate solution for 5 minutes per day. The number of colony forming units and the surface roughness were evaluated statistically by 2-way repeated-measure ANOVA (α = 0.05). Results: The control group dentures exhibited similar levels of microbial cells throughout the experiment. However, after 15 days, no microbial growth was observed on the dentures for which either disinfection agent was used. There were no statistically significant differences in superficial roughness between the groups (P= 0.298). The disinfection agents used, combined with brushing, were able to remove the relined dentures’ biofilm after 15 days of disinfection. Roughness was not a predominant factor in CFU reduction. (Am J Dent 2016;29:15-19).

 

 

 

 

Mail: Dr. Eduardo Buozi Moffa, Department of Dental Materials and Prosthodontics, Araraquara Dental School - UNESP - Univ Estadual Paulista, R. Humaitá, n° 1680, Araraquara, SP, Brazil, CEP: 14801 – 903. E-mail:  du_moffa@yahoo.com.br

 

 

 

 

Stain removal efficacy of two manual toothbrushes

 

Lynn Roosa Friesen, dds, ms, Svetlana Farrell, dds, phd, Julie M. Grender, phd, Jill Underwood, ba, Pam Cunningham,  Renzo A. Ccahuana-Vásquez, dds, phd

 

Abstract: Purpose: To evaluate the dental stain removal efficacy of two commercially-available manual toothbrushes. Methods: This was a randomized, examiner-blind, parallel-group, two treatment clinical trial of 2 weeks duration. Subjects qualifying for the study had a mean Modified Lobene Stain Index of ≥ 1.5 on at least two anterior teeth. Subjects were randomly allocated to one of two groups, receiving a test manual toothbrush (Oral-B 3D White Radiant) or a positive control (PC) manual brush to be used for 1 minute, twice daily for 2 weeks with a standard, anti-cavity fluoride dentifrice. Subjects were given written and verbal instructions, and the first use was supervised at the baseline visit. Stain was measured at baseline and after 2 weeks of product use. Stain measurements were conducted using the Modified Lobene Stain Index (MLSI) and the Interproximal Modified Lobene Stain Index (IMLSI). Results: Use of the two manual brushes resulted in statistically significant reductions of surface stain relative to baseline after 2 weeks of use. The mean MLSI composite stain reductions versus baseline were 1.37 for White Radiant and 0.87 for PC (P< 0.001 for both). Using the IMLSI, the mean stain reductions for composite, gingival and interproximal regions were 1.68, 1.20 and 1.68 for White Radiant (P< 0.001) and 1.25, 0.97 and 1.43 for PC (P≤ 0.002). ANCOVA yielded statistically significant between group differences, with greater composite stain removal observed for White Radiant using both indices (P< 0.025). (Am J Dent 2016;29:20-24).

 

 

 

 

 

Mail: Dr. Renzo A. Ccahuana-Vásquez, Procter & Gamble, GIC, Frankfurter Straβe 145,  61476 Kronberg, Germany. E-mail: vasquez.r.15@pg.com

 

 

Three randomized clinical trials to assess the short-term efficacy of anhydrous 0.454% w/w stannous fluoride dentifrices for the relief of dentin hypersensitivity

 

Charles R. Parkinson, phd,  Nathan Hughes, bsc,  Claire Hall, msc,  Helen Whelton, bds, mdph, phd, John Gallob, dmd  &  Stephen Mason, phd

 

Abstract: Purpose: To assess the short-term efficacy of dentifrices containing 0.454% weight/weight (w/w) stannous fluoride applied using a focused brushing methodology for the relief of dentin hypersensitivity (DH). Methods: Three randomized, examiner blind, controlled, two treatment arm, parallel group studies were conducted utilizing a novel application method in which, prior to brushing the whole mouth, the stannous fluoride dentifrice was applied to two sensitive teeth by focused brushing. DH was assessed with an evaporative (air) stimulus (with the Schiff Sensitivity Scale and a Visual Analogue Scale [VAS, Studies 1 and 3 only]) and a tactile stimulus (using a Yeaple Probe). Clinical assessments were made at baseline, immediately after first use of study dentifrice and after 3 and 14 days of twice daily brushing. Study 1 compared a marketed 0.454% w/w stannous fluoride dentifrice indicated for short-term DH relief to a marketed standard fluoride dentifrice (negative control). Studies 2 and 3 compared a novel anhydrous 0.454% w/w stannous fluoride dentifrice to the same negative control. Results: For Studies 1, 2 and 3, 118, 113 and 120 subjects respectively were randomized to treatment and included in the intent-to-treat populations. Study 1 showed significant DH improvements in all measures for the test dentifrice compared to the negative control at Day 14. Study 2 showed significant differences in favor of the test dentifrice for all measures at all time points (Immediate, Days 3 and 14). In Study 3, treatment with both test and control dentifrices resulted in significant improvements over baseline, but there were no significant between-treatment differences. While these studies provide evidence for relief of DH with 0.454% w/w stannous fluoride dentifrices after short-term use (14 days) using a novel focused brushing methodology, the evidence, especially at the earliest time points, is inconclusive and further testing is needed. Study dentifrices were well tolerated. ClinicalTrials.gov trial registration numbers: Study 1 NCT01494649; Study 2: NCT01592851; Study 3: NCT01724008; funded by GSK Consumer Healthcare. (Am J Dent 2016;29:25-32).

 

 

Mail: Dr. Charles Parkinson, GSK Consumer Healthcare, St Georges Avenue, Weybridge, KT13 0DE, United Kingdom. E-mail: charles.x.parkinson@gsk.com

 

 

Influence of operator experience on non-carious cervical lesion restorations: Clinical evaluation with different adhesive systems

 

Nicola Scotti, dds phd, Allegra Comba, dds,  Alberto Gambino, dds, Elena Manzon, dds, Lorenzo  Breschi, dds phd, Davide  Paolino, phd,  Damiano  Pasqualini, dds  &  Elio Berutti, md

 

Abstract: Purpose: To evaluate the influence of operator experience on adhesive technique and to assess the clinical performances of two different adhesive systems. Methods: 90 cervical lesions in 42 subjects, with a mean age of 52.4 years (range between 32-63) were selected. Lesions were divided into two groups according to operator experience (n= 42 restorations performed by a skilled operator, n= 48 restorations performed by five unexperienced operators) and further divided into two subgroups according to the adhesive system used: three-step etch-and-rinse (Optibond FL) or one step self-etch (G-Bond). Adhesives were applied according to manufacturers’ instructions. Subjects underwent follow-up at 12, 24, and 36 months and restoration retention, enamel and dentin marginal integrity, marginal discoloration, caries occurrence, post-operative sensitivity, and preservation of tooth vitality were evaluated according to USPSH criteria. ANOVA test was performed to evaluate the influence of the adhesive system, the operator experience, and aging on restorations. Results: Operator experience (expert vs. inexperienced), aging time (12, 24, or 36 months), and the adhesive system (self-etch vs. etch-and-rinse) all affected the results statistically, as did the interaction between the adhesive system and operator experience. (Am J Dent 2016;29:33-38).

 

 

 

Mail: Dr. Nicola Scotti, Via Nizza 230, 10100, Turin, Italy. E-mail: nicola.scotti@unito.it

 

 

Surface roughness and maintenance of surface sealants for resin composites after toothbrushing

 

Fernanda  Bonato, dds, ms, Ana  Maria  Spohr, dds, ms, phd, Eduardo  Gonçalves  Mota, dds, ms, phd, Sinval  Adalberto  Rodrigues-Junior, dds, ms, phd  &  Luiz  Henrique  Burnett Jr, dds, ms, phd

 

Abstract: Purposes: (1) To evaluate in vitro the surface roughness of a resin composite covered with three surface sealants and submitted to simulated toothbrushing for different periods; (2) Verify, through scanning electron microscopy (SEM), the presence of surface sealants after simulated toothbrushing; and (3) To evaluate whether the type of dentifrice influences the maintenance of the surface sealant. The study hypothesis was that neither variable would influence the surface roughness of the composite and the maintenance of the surface sealant. Methods: 108 specimens were prepared with the resin Amelogen Plus, and divided into six groups (n = 18) according to the type of surface sealant [Fortify (F), BisCover LV (B) and Permaseal (P)] and toothpaste [Total 12 Clean Mint (CT) and Colgate Total 12 Professional Whitening (PW)]. The samples were subjected to brushing cycles, simulating periods of 6, 12, 18, and 24 months. After each period, the surface roughness of the samples was measured. An additional group of 48 samples was prepared for SEM analysis. The results were analyzed by ANOVA with three fixed variables (sealants, time and toothpaste) and by Tukey's test (α = 0.05). Results: BisCover had the lowest mean surface roughness (0.06 µm) compared with the sealants Fortify (0.09 µm) and Permaseal (0.08 µm), which were not statistically different. Fortify, at 12 months of brushing, had the highest mean roughness (0.13 µm). The mean roughness for the dentifrice CT was lower (0.07 µm) when compared with PW (0.08 µm) and was statistically different. Roughness increased up to 12 months of simulated brushing (0.04 µm, 0.08 µm and 0.11 µm), decreasing from the 18th month (0.08 µm) to the 24th month of brushing (0.07 µm). None of the sealants was observed (with SEM) to be completely removed from the resin at 24 months of brushing. (Am J Dent 2016;29:39-45).

 

 

Mail: Dr. Luiz Henrique Burnett Junior, School of Dentistry, Building 6, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga 6681, Porto Alegre, Brazil. E-mail: burnett@pucrs.br

 

 

Effect of adhesive materials on shear bond strength of a mineral trioxide aggregate

 

Ahmed Ali, bds, msc,  Avijit Banerjee, bds, msc, phd, fds  &  Francesco Mannocci, md, dds, phd

 

Abstract: Purpose: To compare the shear bond strength (SBS) and fractography between mineral trioxide aggregate (MTA) and glass-ionomer cement (GIC) or resin composite (RC) after varying MTA setting time intervals. Methods: MTA was mixed and packed into standardized cavities (4 mm diameter × 3 mm depth) in acrylic blocks. RC with 37% H₃PO₄ and type 2 (etch and rinse) adhesive, or conventional GIC was bonded to the exposed MTA sample surfaces after 10-minute, 24-hour, 72-hour and 30-day MTA setting intervals (n=10/group, eight groups). Samples were stored (37°C, 24 hours, 100% humidity) before SBS testing and statistical analysis (ANOVA, Tukey LSD, P< 0.05). Fractography was undertaken using stereomicroscopy for all samples and three random samples/group by using SEM. Results: Significant differences between all groups were found (P= 0.002). SBS of RC:MTA (Max 5.09±1.79 MPa) was higher than the SBS of GIC:MTA (Max 3.74 ± 0.70 MPa) in 24-hour, 72-hour and 30-day groups except in the 10-minute MTA setting time groups, where SBS of GIC:MTA was higher. There was a significant effect of time on SBS of RC: MTA (P= 0.008) and no effect on SBS of GIC:MTA (P= 3.00). Fractography revealed mixed (adhesive/cohesive) failures in all groups; in RC:MTA groups there was a decrease in adhesive failure with time in contrast to the GIC:MTA groups. (Am J Dent 2016;29:46-50).

 

 

Mail: Dr. Francesco Mannocci, King’s College London, Guy’s Hospital/ Dental Institute, Tower wing-Floor 25, London, SE1 9RT  United Kingdom.  E-mail: francesco.mannocci@kcl.ac.uk

 

 

Depth and distribution of the cure in a resin-based composite cured in a simulated Class II cavity

 

Robert L. Erickson, phd, dds  &  Wayne W. Barkmeier, dds, ms

 

Abstract: Purpose: To examine the effect that a stainless steel (SS) matrix band has on the depth and distribution of cure of a resin-based composite (RBC) in a simulated Class II cavity. Methods: RBC was cured for 20 seconds in a simulated Class II cavity with and without a SS matrix band, and after 24 hours the specimens were scraped back and ground to expose a vertical central plane where Knoop micro-hardness (KHN) mapping was conducted from 0.05 - 1.5 mm from the band and in 0.5 mm intervals from the top of the specimens. The effect of different angles of the light guide on the distribution of hardness was also examined. Results: KHN values near the SS matrix band were significantly lower (P< 0.05) than within the bulk of the specimen and were lower than those found without the matrix band. Angles of incidence for the curing light-guide produced changes in the distribution of KHN within the specimens, but particularly near the matrix band, and with a 35° angle of incidence, the depth of cure was significantly different from that of normal incidence of the light. (Am J Dent 2016;29:51-57).

 

 

 

 

 

Mail: Dr. Wayne W. Barkmeier, Creighton University School of Dentistry, 2500 California Plaza, Omaha, Nebraska, 68178, USA. E-mail: wbark@creighton.edu

 

 

A randomized clinical trial in subjects with dry mouth evaluating subjective perceptions of an experimental oral gel, an oral rinse and a mouth spray compared to water

 

Anto Jose, phd, Muhammad Siddiqi, phd, Matthew Cronin, dmd, Thomas S. DiLauro, dmd & Mary Lynn Bosma, dds

 

Abstract: Purpose: This multicenter, randomized, parallel group study analyzed the effectiveness of an experimental oral gel, a commercially available oral rinse and a commercially available mouth spray versus water alone at relieving self-reported symptoms of dry mouth over a 28-day home use treatment period. The effects of the study treatments on dry mouth-related quality of life (QoL) were also investigated. Methods: Eligible subjects were stratified by dry mouth severity (mild, moderate or severe) and randomized to receive one of the study treatments. Prior to first use they completed a questionnaire designed to assess their baseline dry mouth-related QoL. Following first use and on Day 8 (2 hours post-treatment only) and Day 29, subjects completed the modified Product Performance and Attributes Questionnaire (PPAQ) I at 0.5, 1, 2 and 4 hours post-treatment. Subjects further assessed treatment performance using the PPAQ II questionnaire on Days 8 and 29 and the dry mouth-related QoL questionnaire on Day 29. Results: In 396 randomized subjects almost all comparisons of responses to PPAQ I, including those for the primary endpoint (response to PPAQ I Question 1 ‘Relieving the discomfort of dry mouth’ after 2 hours on Day 29), were statistically significant in favor of active treatment groups versus water (P< 0.05). All comparisons of responses to PPAQ II on Days 8 and 29 were statistically significant in favor of active treatments versus water (P< 0.05). Moreover, nearly all comparisons for dry mouth-related QoL scores on Day 29 were statistically significant in favor of the active treatments versus water. All the dry mouth management strategies in this trial were well tolerated. (Am J Dent 2016;29:58-64).

 

 

Mail: Dr. Anto Jose, GSK Consumer Healthcare, St George’s Ave., Weybridge KT13 0DE, UK. E-mail: anto.x.jose@gsk.com