Computerized technology for restorative dentistry

 

Dennis J. Fasbinder, dds

 

Abstract: Computers have had a meaningful impact on the dental office and dental practice leading to significant changes in communication, financial accounting, and administrative functions. Computerized systems have more recently generated increasing diversity of application for the delivery of patient treatment. Digital impression systems and chairside CAD/CAM systems offer opportunities to integrate digital impressions and full contour restorations in the dental office. Systems rely on single image and video cameras to record the digital file that is the foundation for an accurate outcome. This article presents key aspects of computerized technology using the CAD/CAM process. (Am J Dent 2013;21:115-120).

 

 

Mail: Dr. Dennis J. Fasbinder, University of Michigan School of Dentistry, 1011 N University, Ann Arbor, MI 48109-1078, USA. E-mail: djfas@umich.edu

Influence of dentin pretreatment with titanium tetrafluoride and self-etching adhesive systems on microtensile bond strength

 

Enrico  Coser  Bridi, dds,  FlÁvia  Lucisano  Botelho  Amaral, dds, ms, phd, Fabiana  Mantovani  Gomes FranÇa, dds, ms, phd, Cecília  Pedroso  Turssi, dds, ms, phd &  Roberta  Tarkany  Basting, dds, ms, phd

 

Abstract: Purpose: To evaluate the effect of dentin pretreatment with 2.5% titanium tetrafluoride (TiF₄) on microtensile bond strength (µTBS) of one- or two-step self-etching adhesive systems. Methods: 24 human sound third molars were used. A flat dentin surface of each tooth was exposed. After planing, teeth were divided into groups so that dentin would be left untreated or treated with a 2.5% TiF₄ solution for 1 minute. Specimens were then subdivided into two groups to receive one of the following adhesive systems: one-step self-etching Adper Easy One (ADP) or two-step self-etching adhesive Clearfil SE Bond (CLEAR). A block of composite measuring 5.0 mm high and 5.0 mm wide was made incrementally on the tooth. Specimens were taken to a metallographic cutter to fabricate sticks with a bond area of approximately 1 mm². After 24 hours, specimens were submitted to µTBS testing and the failure mode was recorded by examining specimens under stereomicroscopy. Scanning electron microscope (SEM) photomicrographs were obtained of the tooth/restoration interface. Results: Two-way ANOVA and Tukey’s test demonstrated that pretreatment of dentin with a TiF₄ solution did not affect the µTBS values of either of the adhesive systems (P= 0.675). CLEAR provided higher bond strength than ADP, regardless of whether dentin was or was not pretreated with the TiF₄ solution. Failure mode showed mostly adhesive failures in all groups, except when only ADP was used, causing mostly cohesive fractures in resin. (Am J Dent 2013;26:121-126).

 

 

 

 

Mail: Prof. Dr. Roberta Tarkany Basting, Department of Restorative Dentistry-Operative, Faculty of Dentistry and Research Institute São Leopoldo Mandic, Rua José Rocha Junqueira, 13. Bairro Swift, Campinas – SP CEP: 13045-755, Brazil.  E-mail:  rbasting@yahoo.com

 

Effect of different bonding strategies on the marginal adaptation of class 1 silorane restorations

 

Ladislav Gregor, dr med dent, Tissiana Bortolotto, phd, dr med dent, Albert J. Feilzer, prof, phd, dds  &  Ivo Krejci, prof, dr med dent

 

Abstract: Purpose: To evaluate the quality of marginal and internal adaptation of Filtek Silorane composite in standardized class 1 cavities before and after thermo-mechanical loading using different application protocols of the Silorane System Adhesive (SSA). Methods: Five groups (n=10) of class 1 cavities were restored with Filtek Silorane using different SSA applications. Total bonding (TB): Group A (SSA), Group B (SSA without primer polymerization), Group C (enamel etching + SSA), Group D (enamel etching + SSA without primer polymerization) and Selective bonding (SB): Group E. Marginal adaptation was assessed on replicas in the SEM at x200 magnification before and after thermo-mechanical loading (3,000 × 5-55°C, 1.2.10⁶ × 49N; 1.7Hz) under simulated dentin fluid. After loading, the samples were sectioned and the internal adaptation was evaluated as well. Results: The lowest scores of %CM (Continuous Margin) before/after thermo-mechanical loading being 80.8 (±8.2) / 32.1 (±8.3) were observed in the control group A. Enamel phosphoric acid etching prior to the application of the SSA resulted in significantly higher %CM before and after loading in comparison with the “non-etched” groups (P> 0.05). When enamel etching was performed before the application of the adhesive system, no statistically significant differences (P> 0.05) were observed regardless of how the SSA was applied (total vs. selective bonding). Internal adaptation was negatively influenced by omitting the SSA-primer polymerization (P> 0.05). (Am J Dent 2013;26:127-131).

 

 

Mail: Dr. Ladislav Gregor, Division of Cariology and Endodontology, School of Dentistry, University of Geneva, Rue Barthélemy-Menn 19, CH-1205 Geneva, Switzerland. E-mail: ladislav.gregor@unige.ch

 

 

Recovery percentage of remineralization according to severity of early caries

 

Hee  Eun  Kim, rdh, phd,  Ho  Keun  Kwon, dds, phd  &  Baek  Il Kim, dds, phd

 

Abstract: Purpose: To analyze the cutoff severity of early lesions according to recovery rate after fluoride treatment. Methods: 100 specimens were demineralized over 3 to 40 days. Specimens were immersed in 2% sodium fluoride solution for 4 minutes, and then in artificial saliva for the rest of the total 24 hours. After 10-time repetition of this cycle, the ΔF recovery rates (R_ΔF, %) were calculated from the ΔF values before (ΔF_base, %) and after (ΔF_tx, %) remineralization using the QLF-D system. For the discrimination of R_ΔF based on ΔF_base, the sensitivities versus 1-specificities were analyzed in receiver operating characteristic (ROC) curves, the 95% confidence interval (CI) as well as the significance of differences. The histological features of lesions were observed and lesion depths were digitally measured by polarized light microscopy (PLM). A paired t-test was also performed to assess the differences in ΔF and lesion depth before and after applying fluoride. Results: For a threshold recovery percentage of 40%, the suggested ΔF_base cutoff value was -19.15%, whereas for a threshold recovery percentage of 50%, the suggested cutoff value was -14.60% (P< 0.0001). According to the QLF-D system and PLM analysis, recovery percentage was greater for shallower lesions. Based on fluoride treated recovery percentages, the findings suggested that it is possible for early caries lesions to make more than 50% recovery when the ΔF_base value was greater than -14.60%. Visually and numerically, the relative recovery percentages were highest during the earlier stages of caries. (Am J Dent 2013;26:132-136).

 

 

Mail: Dr. Baek Il Kim, Department of Preventive Dentistry & Public Oral Health, College of Dentistry, Yonsei University 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea. E-mail: drkbi@yuhs.ac

 

Effect of a functional desensitizing paste containing 8% arginine and calcium carbonate on the microtensile bond strength of etch-and-rinse adhesives to human dentin

 

Hongye  Yang, mds,  Dandan  Pei, phd,  Siying  Liu, mds,  Yake  Wang, phd,  Liqun  Zhou, mds,  Donglai  Deng, mds &  Cui  Huang, ms, mds, phd

 

Abstract: Purposes: To evaluate (1) the effect of a desensitizing paste containing 8% arginine and calcium carbonate on the microtensile bond strength between dentin and etch-and-rinse adhesive systems; and (2) to examine the dentin tubules occlusion quantitatively. Methods: 48 freshly extracted intact human mandibular third molars were divided randomly into three groups. The mid-coronal dentin of each tooth was exposed and treated. Group A: no treatment; Group B: specimens were polished with a desensitizing paste containing 8% arginine and calcium carbonate using a rotary cup operating at a low speed for 3 seconds, followed by an additional duration of 3 seconds (total operation time of 6 seconds), according to the manufacturer's instructions; Group C: specimens were handled in the same way with the exception of an increased operation time of 9 seconds, twice (total operation time of 18 seconds). Each group was randomly divided into two subgroups in order to evaluate the effectiveness of two different adhesive agents. A two-step etch-and-rinse adhesive agent (Adper SingleBond 2) and a three-step etch-and-rinse adhesive agent (Adper ScotchBond Multi-purpose) were applied to dentin surfaces. Then, microtensile bond strengths of the six subgroups were tested. Dentin surfaces were analyzed using field-emission scanning electron microscopy (FESEM) and laser scanning confocal microscopy (LSCM). Results: There was no significant difference in microtensile bond strength between the control group and the experimental groups treated with the 8% arginine and calcium carbonate desensitizing paste during the application of etch-and-rinse adhesives. Both FESEM and LSCM showed that the desensitizing paste occluded dentin tubules effectively. (Am J Dent 2013;26:137-142).

 

 

 

Mail:  Dr. Cui Huang, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory for Oral Biomedical Ministry of Education, School  &  Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.  E-mail:  huangcui@yahoo.com

 

 

Clinical evaluation of the efficacy of fluoride adhesive tape (F-PVA) in reducing dentin hypersensitivity

 

Sang-Ho  Lee, dds, phd,  Nan-Young  Lee, dds, phd  &  In-Hwa  Lee, phd

 

Abstract: Purpose: To evaluate the in vivo effectiveness of an experimental 2.26% fluoride polyvinyl alcohol (F-PVA) tape in reducing dentin hypersensitivity. Methods: 30 healthy men and women (total of 79 teeth) in their third decade of life with dentin hypersensitivity were enrolled in this study. The subjects were divided into four groups: three experimental groups were treated with fluoride agents (F-PVA tape, Vanish varnish, and ClinPro XT varnish), and a control group was treated with gelatin as a placebo. Each fluoride agent was applied according to the manufacturer’s instructions. Stimulation was applied to the subjects’ teeth using compressed air and ice sticks before applying the agent, as well as at 3 days and 4, 8, and 12 weeks after applying the agent. The degree of pain was measured using a visual analogue scale (VAS). Results: The VAS scores were significantly (P< 0.05) decreased at 3 days and at 4, 8, and 12 weeks from baseline in both the air stream and ice stick tests. The reduction in the VAS scores for the three fluoride agents was decreased 8 weeks after their application. The F-PVA tape was found to be more effective for dentin hypersensitivity than the Vanish varnish and ClinPro XT varnish at 4 and 8 weeks of the examination period. (Am J Dent 2013;26:143-148).

 

 

Mail: Dr. Sang-Ho Lee, Department of Pediatric Dentistry, School of Dentistry, Chosun University, 375 Seosuk-Dong, Dong-Gu, Gwangju, 501-759 South Korea. E-mail: shclee@chosun.ac.kr

 

Long-term management of plaque and gingivitis using an alcohol-free

essential oil containing mouthrinse: A 6-month randomized clinical trial

 

Sheila  Cavalca  Cortelli, dds, ms, phd,  JosÉ  Roberto  Cortelli, dds, ms, phd,  Hongyan  Shang, ms, James  A.  McGuire, ms  &  Christine  A.  Charles, rdh, bs

 

 

Abstract: Purpose: This 6-month, examiner-blind, single center, randomized, parallel group, controlled clinical trial compared the antiplaque/antigingivitis effects of an alcohol-free EO mouthrinse (Listerine Zero) to a negative control (5% flavored, colored hydroalcohol) and to an alcohol-free CPC-containing mouthrinse (Colgate Plax). Methods: 337 gingivitis subjects were clinically examined to determine Modified Gingival Index (MGI) and Plaque Index (PI) at baseline, 3 and 6 months. The primary efficacy variables were mean MGI and mean PI at 6 months (statistically analyzed by ANCOVA). After professional dental prophylaxis, subjects were randomly assigned to 6-month twice daily unsupervised use of alcohol-free EO, alcohol-free CPC or a negative control rinse, in conjunction with normal brushing and flossing. Safety was monitored throughout the study. Results: 311 subjects completed the study. After 6 months of use, EO significantly reduced plaque (31.6%) and gingivitis (24.0%) compared to negative control. At 6 months, CPC also significantly reduced plaque (6.4%) and gingivitis (4.4%) compared to negative control. EO provided a 26.9% decrease in plaque and a 20.5% decrease in gingivitis compared to CPC (P< 0.001). All rinses were well tolerated. The alcohol-free EO mouthrinse demonstrated superior efficacy in reducing plaque and gingivitis over 6 months compared to both negative control and alcohol-free CPC mouthrinse. (Am J Dent 2013;26:149-155).

 

 

 

 

 

Mail: Christine Charles, Global Consumer Healthcare Research, Development and Engineering, Johnson & Johnson Consumer and Personal Products Worldwide, 185 Tabor Road, Morris Plains, NJ 07950, USA. E-mail: ccharles@its.jnj.com

 

Effects of two essential oil mouthrinses on 4-day supragingival plaque

regrowth: A randomized cross-over study

 

Giuseppe Pizzo, dds,  Domenico Compilato, dds, phd,  Biagio Di Liberto, rdh,  Ignazio Pizzo, dds, phd &  Giuseppina Campisi, dds, msc

 

Abstract: Purpose: To investigate the plaque inhibiting effects of two commercially available mouthrinses containing essential oils (EO). Both products contained the same concentration of EO, but one of them did not contain ethanol. Methods: The study was an observer-masked, randomized, 4 × 4 Latin square cross-over design, balanced for carryover effects, involving 12 participants in a 4-day plaque regrowth model. A 0.12% chlorhexidine (CHX) rinse and a saline solution served as positive and negative controls, respectively. On Day 1, subjects received professional prophylaxis, suspended oral hygiene measures, and commenced rinsing with their allocated rinses. On Day 5, subjects were scored for disclosed plaque. Results: Differences among treatments were highly significant (P< 0.0001), with greater plaque inhibition by CHX compared to EO rinse containing ethanol (P= 0.012), which, in turn, was significantly more effective than the rinse without ethanol and the saline (P< 0.001). The reduction in plaque regrowth seen with the EO rinse without ethanol was quite similar to that elicited by saline (P> 0.05). (Am J Dent 2013;26:156-160).

 

 

 

 

Mail: Dr. Giuseppe Pizzo, Section of Oral Sciences, University of Palermo, Via del Vespro 129, 90127 Palermo, Italy. E-mail: giuseppe.pizzo@unipa.it

 

How to re-seal previously sealed dentin

 

Florian  J.  Wegehaupt, dr med dent,  Tobias  T.  Tauböck, dr med dent  &  Thomas  Attin, dr med dent

 

Abstract: Purpose: To test different kinds of mechanical and chemical pre-treatments of previously sealed dentin before re-sealing. Methods: 75 bovine dentin samples were precycled for 3 days (per day: 6×1 minute erosion (HCl; pH 2.3), and kept in artificial saliva in dwell time and overnight. Group 1 samples (n=15) remained untreated (control). Remaining samples were sealed with Seal&Protect (S&P). After thermo-mechanical loading (5,000 cycles, 50/5°C, 11,000 brushing strokes) a first measurement was performed to evaluate permeability of the sealant. Permeability was tested by storing the samples in HCl (pH 2.3; 24 hours) and measuring the calcium release into the acid by atomic absorption spectroscopy. Based on these calcium release values, the previously sealed samples were allocated to four groups (2-5) according to a stratified randomization. Samples of Groups 2-5 were re-sealed with S&P after either being treated with ethanol (Group 3), silane-coupling-agent (Group 4) or sandblasting (Group 5). After re-sealing, all samples had a second measurement of permeability. After another thermo-mechanical loading, a third evaluation of permeability was conducted. Results: At all measurements, calcium release was significantly higher in the untreated control group than in the sealed Groups 2-5 with no significant differences among the sealed groups. Within Groups 2–5, calcium release at the first and third measurement was higher compared with that at the second measurement (P< 0.05). (Am J Dent 2013;26:161-165).

 

 

Mail: Dr. Florian J. Wegehaupt, Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zürich, Plattenstrasse 11, CH-8032 Zürich, Switzerland. E-mail: florian.wegehaupt@zzm.uzh.ch

 

Fluoride uptake by human tooth enamel: Topical application versus combined dielectrophoresis and AC electroosmosis

 

Chris  S.  Ivanoff, dds,  Bashir  I.  Morshed, ms, phd,  Timothy  L. Hottel, dds, ms, mba

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

 

Abstract: Purpose: To compare fluoride uptake by enamel after applying 1.23% acidulated phosphate fluoride gel to human tooth enamel topically (n=12) or with combined dielectrophoresis and AC electroosmosis (DEP/ACE) at frequencies of 10, 400 and 5,000 Hz (n=12) for 20 minutes. Methods: DEP/ACE induced nonuniform electrical fields with three alternating current frequencies to polarize, orient, and motivate fluoride particles. Fluoride concentrations were measured at various enamel depths using wavelength dispersive spectrometry. Data were analyzed by ANOVA/Student-Newman-Keuls post hoc tests (P≤ 0.05). Results:Fluoride concentrations in the diffusion group were significantly higher than baseline readings at 10, 20 and 50 μm depths. Fluoride concentrations in DEP/ACE-treated teeth were significantly higher than the diffusion group at 10, 20, 50, 100, 200 and 300 μm (ANOVA/Student-Newman-Keuls post hoc, P< 0.05). Fluoride uptake with DEP/ACE was substantially higher than diffusion at 10, 20, 50, 100, 200 and 300 μm depths (paired t test, P< 0.05). DEP/ACE transported fluoride up to 300 μm deep, whereas conventional fluoride application was comparatively ineffective beyond 20 μm depth (P< 0.05). Compared to passive diffusion, fluoride uptake in enamel was significantly higher in the DEP/ACE group at 10, 20, 50, 100, 200 and 300 μm depths (P< 0.05). DEP/ACE drove fluoride substantially deeper into human enamel with a difference in uptake 1,575 ppm higher than diffusion at 100 μm depth; 6 times higher at 50 μm depth; 5 times higher at 20 μm depth; and 7 times higher at 10 μm depth. Fluoride levels at 100 μm were equivalent to long-term prophylactic exposure. (Am J Dent 2013;26:166-172).

 

 

 

 

 

 

 

 

 

 

Mail: Dr. Chris S. Ivanoff, Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, 875 Union Avenue, Memphis, TN 38163, USA. E-mail: civanoff@uthsc.edu