Papers by Saied Mostafa Moazzami
Progress in orthodontics, Nov 21, 2013
Background: Although using light-cured composites for bonding orthodontic brackets has become inc... more Background: Although using light-cured composites for bonding orthodontic brackets has become increasingly popular, curing light cannot penetrate the metallic bulk of brackets and polymerization of composites is limited to the edges. Limited access and poor direct sight may be a problem in the posterior teeth. Meanwhile, effectiveness of the trans-illumination technique is questionable due to increased bucco-lingual thickness of the posterior teeth. Light-emitting diode (LED) light-curing units cause less temperature rise and lower risk to the pulpal tissue. The purpose of this study was to evaluate the clinical effectiveness of trans-illumination technique in bonding metallic brackets to premolars, using different light intensities and curing times of an LED light-curing unit. Methods: Sixty premolars were randomly divided into six groups. Bonding of brackets was done with 40-and 80-s light curing from the buccal or lingual aspect with different intensities. Shear bond strengths of brackets were measured using a universal testing machine. Data were analyzed by one-way analysis of variance test and Duncan's post hoc test. Results: The highest shear bond belonged to group 2 (high intensity, 40 s, buccal) and the lowest belonged to group 3 (low intensity, 40 s, lingual). Bond strength means in control groups were significantly higher than those in experimental groups. Conclusions: In all experimental groups except group 6 (80 s, high intensity, lingual), shear bond strength was below the clinically accepted values. In clinical limitations where light curing from the same side of the bracket is not possible, doubling the curing time and increasing the light intensity during trans-illumination are recommended for achieving acceptable bond strengths.
Operative Dentistry, 2013
SUMMARY Objective: Durability is still a major challenge in adhesive dentistry. One of the bigges... more SUMMARY Objective: Durability is still a major challenge in adhesive dentistry. One of the biggest areas of development has been to simplify the bonding process by using all-in-one adhesives. The aim of this study was to compare the shear bond strength (SBS) to dentin and enamel of nine dental bonding agents (DBAs) from three generations after simulated aging. Methods and Materials: For this study, 108 sound extracted human molars were randomly assigned to nine groups (n=12). The sample teeth were mounted in self-cure acrylic resin sectioned to provide paired enamel and dentin samples. All samples were polished with 240 and 600-grit silicon carbide sandpaper and randomly grouped according to the product and substrates (enamel or dentin). Herculite Ultra resin composite cylinders were bonded on each test surface, stored in 100% humidity at 37°C for 24 hours, and then thermocyled for 1,000 cycles at 5°C and 55°C. SBS testing was performed using an Ultratester at a crosshead speed of 0...
International Endodontic Journal, 2017
Aim To examine the effect of reduction in MTA particle size on dento-alveolar and osseous healing... more Aim To examine the effect of reduction in MTA particle size on dento-alveolar and osseous healing in dogs. Methodology Root canals of 24 mandibular premolars in four 2-year-old beagles were prepared and filled with gutta-percha and sealer. Two to four weeks later, during periapical surgery, the root-end cavity preparations in these teeth were filled with either grey ProRoot MTA or modified (reduced particle sizes with faster setting time) MTA. The animals were sacrificed 4 months later. Degrees of inflammation, type of inflammatory cells, fibrous connective tissue adjacent to the root-end filling materials, cementum formation over the resected roots and root-end filling materials and bone healing were examined. Data were analysed using the McNemar test. Results No significant differences in healing of periapical tissues were found when comparing ProRoot MTA to a modified MTA containing reduced particle sizes. Conclusion Reducing the particle sizes of MTA did not impact its biological properties.
Journal of Dentistry, Shiraz University of Medical Sciences, 2011
Statement of Problem: Free surface energy of substrate is an important factor for adhesion. High ... more Statement of Problem: Free surface energy of substrate is an important factor for adhesion. High free surface energy results in increased wetness and better adhesion. Purpose: The aim of the present study was to evaluate the effect of different rinsing times after cutting with a suggested coolant on the free surface energy of the dentin. Methods and Material: In this in-vitro experimental study, 75 intact human premolar were randomly assigned into 5 groups: 1) Cut with water coolant, 5 seconds of rinse with water. 2) Cut with water coolant, 5 seconds of rinse with water, etch, rinse. 3) Cut with a suggested coolant (0.5 surfactant/HLB=7), 5 seconds of rinse with water. 4) Cut with a suggested coolant, 10 seconds of rinse with water, and 5) Cut with suggested coolant, 15 seconds of rinse with water. Free surface energy was measured by estimating the contact angle. The statistical analyses were performed using one-way ANOVA and Tukey tests. Results: The surface energy means (dyne...
Journal of Dentistry Indonesia, 2019
Objectives: To evaluate the effect of additional light curing on microhardness and microleakage a... more Objectives: To evaluate the effect of additional light curing on microhardness and microleakage at cervical third of class II silorane-based composite restorations. Methods: Class II cavities were prepared on the proximal surfaces of 20 human premolars. The premolars were randomly and equally divided in two groups. In both the groups, class II cavities were restored incrementally with silorane-based composite and cured. Samples were immersed in 0.5% fuchsine. Dye penetration was recorded at four regions of the gingival floor. Vickers hardness test was performed 1 mm above the gingival margin. Data were statistically analyzed using ANOVA, post-evaluation of normal data distribution with Kolmogorov-Smirnov test at a significance level of 0.05. Results: The two photoactivation methods affected hardness and microleakage. Additional light curing increased Vickers hardness compared with occlusal curing. Comparison of microleakage in various areas of the first and second groups showed no significant difference with the first, but a significant difference with the second group. Additional light curing decreased dye penetration at all depths. The curing technique affected the results only in H3 and M3 regions. Conclusion: Additional light curing could lead to better hardness and lower microleakage. Therefore, we recommend this technique following initial occlusal curing.
The Journal of Contemporary Dental Practice, 2010
Aim Core buildup composite resins with prefabricated posts are commonly used to restore endodonti... more Aim Core buildup composite resins with prefabricated posts are commonly used to restore endodontically treated teeth. This study compared the sealing ability of Core Max II and Panavia F2.0 cement with total-etch and self-etch adhesive systems. Methods and Materials Sixty recently extracted human second premolar teeth were chosen and their crowns were cut 3 mm above the CEJ. After preparing proximal boxes (4±1 mm buccolingually and 3 mm occlusogingivally dimensions) and finishing root canal therapy, the teeth were randomly divided into four groups (n=15): groups 1 and 2, Core Max II without and with total-etch adhesive; groups 3 and 4, Clearfil photocore composite, A2 shade, and Panavia F2.0 cement without and with self-etch adhesive respectively. The Dentatus posts (# 2 Long) were used in canals approximately 8 mm depth. According to manufacturer guidelines, pins were cemented and cores were restored. After keeping the specimens for 24 hours at 37°C and 100% humidity, they were the...
The Journal of Contemporary Dental Practice, 2017
Aim The aim of this prospective cohort study was to evaluate the postinsertion posterior single-i... more Aim The aim of this prospective cohort study was to evaluate the postinsertion posterior single-implant occlusion changes at 3- and 6-month intervals using T-Scan computerized occlusal analysis. Materials and methods A total of 21 patients received single implant, opposed by natural dentition, in posterior regions of the maxilla or mandible (13 premolar, 8 molar) and were finally restored with cemented-retained metal–ceramic crowns. The occlusal contacts were equilibrated according to the implantprotective occlusion concept to develop light contact with heavy occlusion and no contact with light occlusion in maximum intercuspation. The percentage of force applied to the implant crowns (POFI) and contralateral teeth (POFT) was evaluated using T-Scan computerized occlusal analysis at prosthesis insertion, 3- and 6-month follow-up appointments. The data were statistically analyzed using Friedman test and Wilcoxon post hoc test (α = 0.05). Results The POFI values at the 6- and 3-month fo...
Operative Dentistry, 2014
SUMMARY Objectives The aim of the present study was to evaluate the effect of four different sand... more SUMMARY Objectives The aim of the present study was to evaluate the effect of four different sandwich techniques on gingival microleakage of Class II direct composite resin restorations. Materials and Methods Fifty sound human premolars were selected and randomly divided into five groups (n=10). Class II box only cavities were prepared in one of the proximal surfaces of each tooth with a gingival margin located approximately 0.5 mm below the cemento-enamel junction. Group A (control) was restored incrementally with composite resin (Tetric Ceram). Groups B, C, D, and E were restored with the sandwich technique using a compomer (Compoglass F), flowable composite resin (Tetric Flow), self-cure composite resin (Degufill SC), or resin modified glass ionomer (Fuji II LC), respectively. After thermal-load cycling, the specimens were immersed in 0.5% basic fuschin for 24 hours. Dye penetration (10−1 mm) was detected using a sectioning technique. Data were analyzed with repeated measurements...
ABSTRACT The aim of this study was to assess bonding of orthodontic metal brackets to porcelain s... more ABSTRACT The aim of this study was to assess bonding of orthodontic metal brackets to porcelain surfaces using various surface treatment methods. Etching the porcelain with 9.6 percent HF followed by a bonding agent or silane application provided high and acceptable shear bond strengths.
Journal of Dental Materials and Techniques, 2015
Making a conservative bridge using a natural tooth pontic with mobile teeth is complicated, time-... more Making a conservative bridge using a natural tooth pontic with mobile teeth is complicated, time-consuming and sometimes impossible with the current techniques and materials. The aim of this paper is` to describe a new method using Special Rigid Tray Technique (SRTT) to deal with such difficult clinical cases.
Journal of dentistry (Shiraz, Iran), 2016
Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it tak... more Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap in the early hours after setting by means of Electro-Chemical Tests (ECTs). Thirty cylindrical cavities of 4.5mm x 4.7mm were prepared on intact bicuspids. The samples were divided into five main groups of application of Adhesive Resin (AR)/ liner/ None (No), on the cavity floor. The first main group was left without an AR/ liner (No). In the other main groups, the types of AR/ liner used were I-Bond (IB), Clearfil S(3) (S(3)), Single Bond (SB) and Varnish (V). Each main group (n=6) was divided into two subgroups (n=3) according to ...
Journal of dental biomaterials, 2016
Bioglasses are a series of biocompatible dental materials, which are considered as light conducti... more Bioglasses are a series of biocompatible dental materials, which are considered as light conducting inserts in resin composite restorations. Consequently, their chemical stability is more essential when they are used in conjunction with resin composite. The aim of this study was to evaluate and compare the chemical stability of Bioglass with dental porcelain and resin composite by determining the amount of released K+, Na+, Ca2+ ions and silicone elements from these materials as a result of exposure to tested solutions with different pH levels including: Sodium Bicarbonate [SB, (pH=9.2)], Sodium Buffer Lactate [SBL, (pH=2.4)], Acetic Acid [AA, (pH=2.4)], and Distilled Water [DW, (pH=6.2)]. In this experimental study, forty 2.0 × 4.0 cylindrical rods for each tested material group (Dental porcelain, Resin composite and Bioglass) were prepared. They were divided into four subgroups of 10 rods each, which immersed in one of the four testing solutions in a designated container. The cont...
Journal of Dental Materials and Techniques, 2012
Introduction: Application of light transmitting posts to restore greatly damaged endodontically t... more Introduction: Application of light transmitting posts to restore greatly damaged endodontically treated teeth has been increased. It is suspected that light intensity decreases as it passes throughout different materials. This can reduce the degree of conversion required for adequate bond strength throughout the length of these posts. The objective of this study was to evaluate the amount of light intensity reduction after passing through different depths of FRC posts. Methods: Four groups of five extracted human central incisors were prepared to cement four types of FRC posts with Panavia F 2 resin cement. The apical end of the posts were exposed by sectioning with a diamond disk and then polished. The light intensity measurement was performed using a micro-voltmeter in 8 points or depths with 2mm intervals beginning from the apical depth of 16mm up to a coronal depth of 6mm. Two different output light intensities [HIP (High Intensity Program) and LOP (Low Intensity Program)] were ...
Progress in Orthodontics, 2013
Background: Although using light-cured composites for bonding orthodontic brackets has become inc... more Background: Although using light-cured composites for bonding orthodontic brackets has become increasingly popular, curing light cannot penetrate the metallic bulk of brackets and polymerization of composites is limited to the edges. Limited access and poor direct sight may be a problem in the posterior teeth. Meanwhile, effectiveness of the trans-illumination technique is questionable due to increased bucco-lingual thickness of the posterior teeth. Light-emitting diode (LED) light-curing units cause less temperature rise and lower risk to the pulpal tissue. The purpose of this study was to evaluate the clinical effectiveness of trans-illumination technique in bonding metallic brackets to premolars, using different light intensities and curing times of an LED light-curing unit. Methods: Sixty premolars were randomly divided into six groups. Bonding of brackets was done with 40-and 80-s light curing from the buccal or lingual aspect with different intensities. Shear bond strengths of brackets were measured using a universal testing machine. Data were analyzed by one-way analysis of variance test and Duncan's post hoc test.
Australian orthodontic journal, 2011
Fibre reinforced composite bars (FRC) have applications as bonded retainers, space maintainers an... more Fibre reinforced composite bars (FRC) have applications as bonded retainers, space maintainers and anchorage/movement units. However, the bond strength of attachments to FRC anchorage bars is unknown. To compare the shear bond strengths of brackets bonded immediately to FRCs with different orthodontic adhesive systems and bonded with the same adhesives after a 48-hour delay, abraded with a diamond bur and etched with phosphoric acid. One hundred and five recently extracted upper premolars were randomly assigned to seven groups (N = 15 teeth per group). FRCs were bonded to the buccal surfaces of the teeth and stainless steel orthodontic brackets were bonded to the FRCs with the following adhesive systems: Group 0 (Tetric Flow); Groups 1, 2 and 3 (Immediate bonding with chemically cured, no-mix and light cured composites, respectively, the bars covered with Tetric Flow); Groups 4, 5 and 6 (Bonding to FRCs delayed 48 hours, then bonded with chemically cured, no-mix and light cured comp...
European Journal of Dentistry, 2016
The aim of this study was to evaluate the effect of increased exposure time and light intensity o... more The aim of this study was to evaluate the effect of increased exposure time and light intensity on microhardness of cured composite through different thicknesses of tooth structure in primary teeth. One hundred and seventy cylindrical resin composite specimens were prepared. All specimens were divided into 17 experimental and control groups. "Light-emitting diode" light curing unit (LCU) applied directly or through 1, 2, and 3 mm thicknesses tooth slices for experimental groups. The irradiation protocols were 25 and 50 s at 650 mW/cm(2) and 15 and 30 s at 1100 mW/cm(2). The "quartz-tungsten-halogen" LCU (400 mW/cm(2)) for 40 s was used in control group. Microhardness was measured by the Vickers hardness test. Indirectly cured specimens and those cured through a 1 mm thick tooth structure, an increase in intensity caused hardness drop. In the specimens cured through 2 and 3 mm thick tooth structures, increased intensity and/or exposure time did not show any appropriate changes on microhardness. Irradiation through a 1.0 mm thick tooth slice resulted in reduced microhardness although it was still within the clinically acceptable level. The hardness values of the specimens cured through 2 or 3 mm thick tooth slices fell below the clinically acceptable level even after doubling the exposure time and/or light intensity.
Journal of Dental Materials and Techniques, Jun 1, 2014
Journal of Dental Research Dental Clinics Dental Prospects, Mar 18, 2011
Adhesive permeability is hindered by application of an additional layer of hydrophobic resin, whi... more Adhesive permeability is hindered by application of an additional layer of hydrophobic resin, which increases its concentration within the hydrophilic layer, reduces its affinity to water, and enhances its physical properties. The aim of the present study was to evaluate the effect of a hydrophobic layer on the microleakage of class V composite restorations using different adhesives.
Journal of Dental Materials and Techniques, Sep 1, 2014
Journal of Dental Materials and Techniques, Jun 1, 2015
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Papers by Saied Mostafa Moazzami