Marginal Sealing Durability of Two Contemporary Self-Etch Adhesives

Introduction. Sealing abilities of two self-etch adhesives were evaluated after two aging processes: storage in water and thermocycling. Materials and Methods. Cl V cavities were prepared on the buccal and lingual aspects of 48 human premolars, with cervical margins 1 mm below the CEJ. Clearfil Protect Bond (CPB) and BeautiBond (BB) (two-step and one-step self-etch adhesives, resp.) were applied, each to half of the cavities and restored with composite resin. Each group was randomly subdivided into 4 subgroups (n = 12) and evaluated for dye penetration after 24 hours, after 3000 thermocycling rounds, after a 6-month water storage, and after 3000 thermocycling rounds plus 6-month water storage, respectively. Data was analyzed using SPSS 11.5 and Kruskal-Wallis and Mann-Whitney U tests (α = 0.05). Results. There were no significant differences in enamel and dentin microleakage between the adhesives (P = 0.683; P = 0.154). Furthermore, no significant differences were observed in enamel microleakage of each one of CPB and BB (P = 0.061 and P = 0.318, resp.). However, significant decrease was observed in subgroups 3 and 4 (P = 0.001) for CPB dentinal margins. Conclusion. In this study, limited aging procedures had no influence on marginal integrity of composite resin restorations bonded with self-etch adhesives of CPB and BB. Furthermore, CPB dentinal sealing improved after aging

Effect of postbleaching application of an antioxidant on enamel bond strength of three different adhesives

Objectives: The aim of this study was to compare the shear bond strength (sbs) of three different adhesives on bleached enamel immmmediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent. Study Design: The enamel surfaces of 144 freshly extracted incisors without any caries and restorations were flattened and divided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step etch rinse), Optibond Solo Plus (OSP) (two-step etch rinse), Optibond All-in-One (OA) (one-step self-etch), (Kerr, Orange, USASA). Unbleached enamel groups were prepared as negative controls. The remainder surfaces were bleached with 20% Opalescent PF (Ultradent, USASA) 6 h/d for 5 consecutive days. Specimens were bonded immmmediately after bleaching, after 1 week or after using 10% sodium ascorbate gel for 6 hours. After 500 rounds of thermocycling, sbs was measured and data was analyzed with Kruskall-Wallis and Mann-Whitney U-tests (? = 0.05). Results: The sbs decreased for the adhesives after bleaching except for OFL. The effect of applying sodium ascorbate subsequent to bleaching was not equal for the studied adhesives. While for OFL, sbs of the sodium ascorbate group was significantly higher than the unbleached control group, for OSP, the sodium ascorbate group had no statistically significant difference with the unbleached control group and for OA, sbs was significantly lower than the unbleached control group. Conclusions: Different adhesives demonstrate different degrees of reversed bond strength subsequent to applying antioxidant. It seems the method of application and the chemical composition of the adhesives could affect the antioxidant as a reducing agent. © Medicina Oral S. L

Marginal integrity of low-shrinkage and methacrylate-based composite resins: Effect of three different hemostatic agents

Background: Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents. Material and Methods: Standardized Class V cavities were prepared on the buccal and lingual surfaces of 48 premolars with cervical margins 1 mm apical to the cementoenamel junction (CEJ). The samples were randomly divided into 8 groups. In groups 1 to 4, an etch-and-rinse adhesive (Adper Single Bond) was applied as the bonding system, followed by exposure to different hemostatic agent: group 1: no hemostatic agent (control); group 2: ViscoStat; group 3: ViscoStat Clear; and group 4: trichloracetic acid, as hemostatic agents. The cavities were restored with Z-250 composite resin. In group 5 to 8 Silorane System Adhesive (Filtek P90 Adhesive) was applied as a bonding agent, followed by exposure to different hemostatic agents in a manner similar to that in groups 1to 4. The cavities were restored with Filtek P90, a low-shrinkage composite resin. The samples in each group were evaluated for dye penetration under a stereomicroscope at ×36 after 24 hours and a 500-round thermocycling procedure at enamel and dentin margins. Statistical analysis was carried out using Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: Z-250 composite resin exhibited significantly higher dentin microleakage scores compared to Filtek P90 (P = 0.004). Trichloracetic acid increased dentin microleakage with Filtek P90 (P=0.033). Conclusions: Under the limitations of this in vitro study, application of hemostatic agents did not affect microleakage of the two tested composite resins except for trichloracetic acid that increased marginal microleakage when used with Filtek P90. © Medicina Oral

Bond Strength of Composite Resin to Bleached Dentin: Effect of Using Antioxidant Versus Buffering Agent

Objective: Application of sodium ascorbate as an antioxidant and calcium hydroxide as a buffering agent following intracoronal bleaching has been recommended. The aim of this study was to investigate the effect of using the mentioned materials onshear bond strength of composite resin to the bleached dentin.Materials and Methods: In this in vitro investigation, sixty human sound premolars were divided randomly into five groups (n=12). Occlusal dentin surfaces were exposed.The negative control (NC) group was not bleached and the other groups were bleached with 35% hydrogen peroxide gel for 5 days. Afterwards, compositecylinders were built up in the positive control (PC) group immediately after bleaching,in the delay bonding (DB) group after one week, in the sodium ascorbate (SA)and calcium hydroxide (CH) groups after 40 hours of treatment with the materials.Then, the samples were stored in 37°C for 24 hours. The specimens were thermocycled (5-55°C, 500 cycles), subjected to shear bond testing by universal machine.The data were analyzed by One-Way ANOVA and Duncan tests (a =0.05).Results: There was a significant difference between PC and CH groups in comparison with the other groups (p<0.05), but the difference among other groups was not significant (p>0.05).Conclusion: Application of sodium ascorbate could significantly increase the bond strength of composite resin to bleached dentin, while the use of calcium hydroxide did not affect bond strength

Marginal integrity of low-shrinkage and methacrylate-based composite resins: effect of three different hemostatic agents

Background: Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents. Material and Methods: Standardized Class V cavities were prepared on the buccal and lingual surfaces of 48 premolars with cervical margins 1 mm apical to the cementoenamel junction (CEJ). The samples were randomly divided into 8 groups. In groups 1 to 4, an etch-and-rinse adhesive (Adper Single Bond) was applied as the bonding system, followed by exposure to different hemostatic agent: group 1: no hemostatic agent (control); group 2: ViscoStat; group 3: ViscoStat Clear; and group 4: trichloracetic acid, as hemostatic agents. The cavities were restored with Z-250 composite resin. In group 5 to 8 Silorane System Adhesive (Filtek P90 Adhesive) was applied as a bonding agent, followed by exposure to different hemostatic agents in a manner similar to that in groups 1to 4. The cavities were restored with Filtek P90, a low-shrinkage composite resin. The samples in each group were evaluated for dye penetration under a stereomicroscope at ×36 after 24 hours and a 500-round thermocycling procedure at enamel and dentin margins. Statistical analysis was carried out using Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: Z-250 composite resin exhibited significantly higher dentin microleakage scores compared to Filtek P90 ( P = 0.004). Trichloracetic acid increased dentin microleakage with Filtek P90 ( P =0.033). Conclusions: Under the limitations of this in vitro study, application of hemostatic agents did not affect microleakage of the two tested composite resins except for trichloracetic acid that increased marginal microleakage when used with Filtek P90

Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

Background: Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitro study, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods: Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). Results: There were significant differences in the mean bond strength values between the three bond strength tests (P<0.001). Rinsing protocol and cement type resulted in similar variations in the mean bond strength in all tests (P>0.05). Conclusions: Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results

Interfacial fracture toughness of universal adhesive systems treated with an antioxidant

Background: Secondary caries, degradation of the dentin-resin interface and fracture of the restoration are the most common forms of failure. The aim of this study was to assess the interfacial fracture toughness of three different adhesive approaches and to compare their fracture toughness after surface treatment with antioxidant. Material and Methods: Seventy two dentin blocks with 3×4mm dimension and 3mm thickness were prepared and attached to precured 3×4×12mm composite blocks from both sides. Six adhesive groups (N=12), All-bond universal, Scotchbond universal and Clearfil SE bond with or without antioxidant treatment (Sodium Ascorbate 10% )were applied to dentin surfaces, a 160? polyethylene paper formed the chevron in adhesive-dentin interfaces. Chevron-notched beam fracture toughness was measured following a modified ISO 24370 standard. The uniform composite-dentin-composite block was subjected to a 4-point test in universal machine. Data were analyzed by Kruskal-Wallis, Wilcoxon signed-rank and Mann-Whitney tests (? =0.05). Results: Different adhesive approaches yielded different significant in fracture toughness rates. A significant increase of fracture toughness was observed between adhesive groups after antioxidant surface treatment. The difference in fracture toughness between Scotchbond universal and All-bond universal were significant. Conclusions: The highest value of fracture toughness was reported for Clearfil SE bond and the lowest value was found for All-bond universal. Sodium ascorbate as antioxidant surface treatment had a significant effect in increasing the fracture toughness

A review of CAD/CAM use in dentistry (part II): Comparison of intraoral digital scanners used in restorative dentistry

Introduction: Intraoral imaging technology has become one of the most exciting new fields in dentistry. Three-dimensional scanning of the oral cavity is used in many dental procedures such as restorative dentistry and orthodontics. To date, a number of intraoral scanners have been developed for restorative dentistry throughout the world, and many researchers and manufacturers seek the design and development of new digital devices. Only some of these devices are currently available on the market and some others are being clinically tested. All existing intraoral scanners try to overcome the drawbacks of traditional impression processes. The aim of the present article is to provide an extensive evaluation of intraoral scanners in restorative dentistry, with special attention to their assessment principles, characteristics and performance. Review report: This review article was prepared by scientific searching in electronic sources of Pubmed and ISI Web of Science in connection with articles published in English until 2014, and with these key words: intraoral scanners and digital impression. Conclusion: Over the years there have been major advances in digital scanning systems, and a variety of digital systems have been introduced that enable the dentist to select different intraoral reconstruction methods in the extraoral environment. The ultimate goal of dentists is to provide accurate and efficient dental restorations for the patient, while maintaining patient comfort during the impression process. High-resolution dental optical scanners will enable the operator to provide high-quality restorations. With digital impression techniques, the number of operators and material variables will decrease, making restoration fabrication processes more predictable and easier

Review of Predisposing Factors of Cervical Ectopic Pregnancy; an Update

Cervical ectopic pregnancies (CEPs) are rare, comprising less than 1% of ectopic pregnancies. On one hand, the abundant blood supply of the cervix and its incompatibility to keep the pregnancy in progress increases the potential for bleeding following CEP, mortality, complications, and infertility in affected women. CEPs are more difficult to diagnose and get identified at later gestational ages. CEP is one of the rarest forms of ectopic pregnancies and most commonly are a consequence of assisted reproductive technology (ART); while definitive risk factors are not fully known. Possible risk factors include cervical and uterine anomalies, previous curettages or cesarean sections, smoking, tubal factor infertility, or in vitro fertilization (IVF) treatment. Our analysis of literature in 200 patient restricted to retrospective case series , showed that a history of previous C-section, uterine curettage or D&C procedures, and a history of using assisted reproductive technology might be some of the potential risk factors. The increasing application of Hegar dilators was hypothesized as the cause of the rise in CEPs. Dilation and curettage (D&C) might also make the subject vulnerable to CEP development in the future. Previous D&C history could be a potential predisposing factor that is common among CEP patients.  In this review, we critically reviewed these potential risk factors. In conclusion, the risk factors of CEP and their effect on fertility are also not studied properly. The rarity of these cases makes it difficult to predict as well if the risk of their recurrence is elevated