Amir Reza Rokn, DDS, MSc
Mohammad-Sadegh Ahmad-Akhoundi, DDS, MSc.
Shahroo Etemad-Moghadam, DDS, MSc.
Abbas Mirzaei, PhD
Vol 15, No 4 (2018)
Objectives: Enterococcus faecalis (E. faecalis), an infecting microorganism of the root canals, is difficult to eliminate during endodontic therapy. In this study, the effect of root canal disinfection with sodium hypochlorite (NaOCl) and chlorhexidine (CHX) was evaluated on planktonic and biofilm forms of E. faecalis in comparison with antimicrobial photodynamic therapy (aPDT) as an alternative strategy for root canal disinfection.
Materials and Methods: In this study, E. faecalis (ATCC 29212) was used. The experimental procedures included aPDT with curcumin (CUR) and indocyanine green (ICG) as photosensitizers, irrigation with 5.25% NaOCl, 0.2% and 2.0% CHX solutions as traditional endodontic irrigating solutions, and the control group. The antibacterial and anti-biofilm potentials were assessed by counting the colony forming units and also using the crystal violet assay, respectively.
Results: According to the results, E. faecalis biofilm was disrupted by 65.3%, 81.0% and 92.6% using 0.2% CHX, 2.0% CHX, and 5.25% NaOCl, respectively (P<0.05). In addition, CUR- and ICG-mediated aPDT displayed a significant reduction in E. faecalis count (90.2% and 82.5%, respectively) and its biofilm (83.6% and 75.2%, respectively) in comparison to the control group (P<0.05).
Conclusions: APDT has a high potential for elimination of E. faecalis and is almost equivalent to NaOCl and CHX. It can be used as an adjucnt to conventional endodontic irrigating solutions.
Objectives: Resin composites, glass ionomers (GIs), or a combination of these materials have gradually replaced silver amalgam in pediatric dentistry. The purpose of this study was to compare the microleakage of Class II (box only) cavity restorations with ACTIVA Bioactive Restorative Glass, resin-modified GI (RMGI), and composite in primary molars.
Materials and Methods: A total of 65 primary molars with at least one intact proximal surface were selected in this in-vitro study. After debridement of each tooth, Class II (box only) cavities were prepared. Based on the type of the restorative material and the application of etching and bonding adhesives, the samples were categorized into five groups: (1) composite; (2) RMGI (Fuji II LC)+conditioner; (3) RMGI (Fuji II LC); (4) enhanced RMGI (ACTIVA Bioactive Restorative Glass)+etching/bonding; and (5) ACTIVA Bioactive Restorative Glass. The restored teeth were thermocycled for 2000 cycles. After embedding in an acrylic resin, the degree of dye penetration at axial and gingival walls was assessed using a stereomicroscope. The data were statistically analyzed by analysis of variance (ANOVA) and Tukey’s test.
Results: Resin-based composite (RBC) Z250 showed the least microleakage, while RMGI showed maximum microleakage at axial walls. The mean degree of microleakage at gingival margins was the lowest in RBC Z250 and ACTIVA+etching/bonding groups and the highest in RMGI+conditioner and RMGI groups.
Conclusions: The microleakage of ACTIVA Bioactive Restorative material in the absence or presence of etching and bonding could be comparable to the microleakage of composites
Objectives: The aim of this study was to compare the microleakage in normal and caries-affected dentin (CAD) and to investigate the effect of three hemostatic agents on the microleakage of Class V composite resin restorations in CAD.
Materials and Methods: Ninety-six Class V non-beveled cavities were prepared in 48 third molars at 1 mm below the cementoenamel junction (CEJ) in the cervical margin with the occlusogingival size of 2 mm, mesiodistal dimension of 3 mm, and a depth of 1.5 mm. Next, the teeth were divided into 8 groups (n=12): G1-4 included normal dentin (N) substrate, while G5-8 were exposed to mineralization/demineralization cycles to produce CAD substrate. Groups 1 and 5 were the controls. ViscoStat was used in groups 2 and 6, ViscoStat Clear was used in groups 3 and 7, while trichloroacetic acid (TCA) was used in groups 4 and 8. The cavities were restored with composite resin. The samples were sectioned after thermocycling and immersion in 2% fuchsin for 24 hours. The degree of dye penetration was evaluated under a stereomicroscope at 40× magnification. Data were evaluated using Kruskal-Wallis and Mann-U-Whitney tests in SPSS 15 software (α=0.05).
Results: Significant differences were recorded on the mean microleakage of different groups (P=0.047). There was a significant difference in the mean dentinal microleakage between N and CAD groups (P=0.014). The dentinal microleakage in group 3 was significantly higher than that in groups 4 to 8.
Conclusions: According to the results, CAD showed less microleakage in comparison with intact dentin. ViscoStat Clear caused a greater microleakage than did ViscoStat or TCA.
Objectives: The aim was to investigate the effect of intracanal irrigants and agents on the bond strength of intraradicular fiber posts to dentin.
Materials and Methods: Root canals of 72 decoronated single-rooted premolars were cleaned, shaped, and obturated with gutta-percha and AH26. The specimens were incubated at 37oC and 100% humidity for seven days. Next, the coronal 10 mm of the canals were prepared to receive size 2 D.T. Light fiber post, and the specimens were randomly allocated into six groups according to the irrigants used after post space preparation: normal saline (control group), 5.25% sodium hypochlorite (NaOCl)/15 seconds, 17% ethylenediaminetetraacetic acid (EDTA)/60 seconds, 2% chlorhexidine (CHX)/5 minutes, MTAD/5 minutes, and acid-etching/15 seconds. All canals were rinsed with normal saline and dried. Fiber posts were cemented using Panavia F2.0. After 24 hours, two mid-root slices of 1mm thickness were obtained from each specimen. Push-out bond strength test was performed in a universal testing machine at 0.5mm/minute. The maximum applied load was recorded, and the bond strength was calculated in megapascal (MPa). Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's test.
Results: The mean shear bond strengths of etched (53.21±12.11 MPa), MTAD (52.47±14.75 MPa) and EDTA (49.08±10.19 MPa) groups were significantly higher than that of the control group (39.82±10.04 MPa). The difference was marginally significant for CHX group (49.8±13.57 MPa) and not significant for NaOCl group (47.15±17.64 MPa).
Conclusions: Etching or irrigating the root canals with MTAD or EDTA after post space preparation increases the bond strength of Panavia F2.0 to dentin.
Objectives: Finding predictable approaches for root surface biomodification is an important challenge in the treatment of gingival recession. This study sought to assess the root coverage percentage by subepithelial connective tissue graft (SCTG) following root surface conditioning with erbium, chromium: yttrium scandium gallium garnet (Er,Cr:YSGG) laser.
Materials and Methods: In this split-mouth, randomized clinical trial, 30 teeth with Miller’s Class I and II gingival recession were treated with SCTG (the Langer and Langer technique) with (case group) or without (control group) root surface conditioning with Er,Cr:YSGG laser (wavelength=2780 nm, power=0.75 W, H mode, repetition rate=20 Hz). Recession depth (RD), recession width (RW), clinical attachment level (CAL), and probing depth (PD) were assessed at the baseline (one week before surgery) and at 2 and 6 months postoperatively. The amount of root coverage was quantified in the two groups. Data were analyzed using Friedman test and Wilcoxon signed-rank test.
Results: No significant difference was noted between the case and control groups in any parameter (P>0.05). Significant improvement occurred in all the measured parameters in the two groups after surgery (P<0.05). The mean root coverage at the end of the study period was 87% and 80% in the case and control groups, respectively (P=0.244), and complete root coverage was achieved in 66% and 60% of the samples in the case and control groups, respectively.
Conclusions: Root surface conditioning by Er,Cr:YSGG laser improved the mean root coverage and the percentage of complete root coverage. However, these changes were not statistically significant.
Objectives:The aim of this study was to evaluate enamel and dentinal microleakage in Class II cavities restored with silorane- and methacrylate-based resin composites using specific and nonspecific adhesives.
Materials and Methods: Thirty-six caries-free human premolars were used. Two Class II cavities were prepared on each tooth. The gingival floor was set at 1 mm above (on the mesial surface) and at 1 mm below (on the distal surface) the cementoenamel junction (CEJ). The samples were randomly divided into four groups, and the cavities were restored with a methacrylate-based composite (Filtek™ P60) and a silorane-based composite (Filtek™ P90) with specific and nonspecific adhesives. Microleakage was tested using a standardized dye penetration method. All samples were examined under a stereomicroscope, and microleakage scores were statistically analyzed using Kruskal-Wallis and Mann-Whitney-U tests. One sample from each group was examined under a scanning electron microscope (SEM) to determine the bonding area.
Results: No significant difference was found between the groups in terms of the enamel microleakage (P=0.086). There was a significant difference between the groups with regard to dentinal microleakage (P=0.003). No significant reduction in microleakage was observed in groups restored with Filtek™ P90 composite using its specific adhesive compared to those restored with Filtek™ P60 composite using its specific adhesive (P=0.626).
Conclusions: The results indicated that the application of methacrylate- and silorane-based composites with specific or nonspecific adhesives had no impact on enamel microleakage, but it affected dentinal microleakage, and specific adhesives showed less microleakage. It seems that a phosphate-methacrylate-based intermediate resin is required to bond dimethacrylate adhesive to silorane-based composites.
Objectives: Studies on modeling a pre-exposure technique for the prevention of anxiety in children are rare, and there is no study on interactive modeling using computer games. We assessed the effect of playing a dental simulation game before operation on pain and anxiety in 4- to 7-year-old children during their first dental treatment session.
Materials and Methods: In this double-blind randomized clinical trial, 50 children needing unilateral pulpotomy and placement of stainless-steel crowns (SSC) on mandibular primary first molars were enrolled and randomly divided into experimental (a simulation game) and control (no intervention) groups. The experimental group played the game twice a day for two weeks before the scheduled visit. At the dental session, their pre- and post-operative pains were recorded using the Wong-Baker Facial Rating Scale (W-BFRS). Also, heart rate (HR; as an indicator of anxiety) was measured using a finger pulse oximeter at six treatment stages: (1) baseline (at the initial session, two weeks before treatment) and (2-6) during different stages of treatment. Effects of playing the simulation on pain and HR were analyzed using t-test and repeated-measures two-way analysis of covariance (ANCOVA).
Results: Game playing significantly reduced the HR (P=0.031). The interaction of playing with the treatment period was also significant (P=0.004). When the groups were compared in each of the six time points, the experimental group showed reduced HR during anesthetic injection and cavity preparation using a high-speed handpiece (P<0.003).
Conclusions: Based on the results, playing certain dental simulation games before the first dental visit might reduce the anxiety felt during anesthetic injections and drilling.
Typically, full arch reconstruction of edentulous ridges requires five to 10 dental implants; however, some patients demanding fixed implant-supported prostheses are not able to medically or economically afford complex bone grafts and/or a greater number of implants. These situations could pivot the treatment plan toward the All-on-4 protocol. Nevertheless, due to less implant support in this treatment option, mechanical and biological complications might arise. This article describes the treatment of a fully edentulous patient with two types of fixed implant-supported prostheses on four dental implants along with the following complications
Amir Reza Rokn, DDS, MSc
Mohammad-Sadegh Ahmad-Akhoundi, DDS, MSc.
Shahroo Etemad-Moghadam, DDS, MSc.
Abbas Mirzaei, PhD
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