Dental erosion in patients with gastroesophageal reflux disease [GERD] in a sample of patients referred to the Motahari clinic, Shiraz, Iran

Statement of Problem: Systematic reviews of the literature show that the dental erosion is associated with the gastroesophageal reflux disease [GERD]. The prevalence of the problem may not be exclusively similar in different countries

Purpose: The purpose of this study was to investigate the association of gastro-oesophageal reflux disease [GERD] with dental erosion in a sample of Iranian population regarding the standing difference in the Iranian oral hygiene and diet

Materials and Method: 140 patients with the average age of 30 to 50 years old comprised the study group. The participants were already eligible for the endoscopy examination, diagnosed by their gastroenterologist. All patients completed a detailed questionnaire regarding the medical and dental situations. After completing the questionnaire and before endoscopy, dental examination was performed by two blinded dentists. The endoscopy was then performed by a gastroenterologist and the patients were divided into three groups of healthy, suspected to GERD, and positive GERD. Data were collected and analysed by Chi- Square test. The cross tabulation test was performed to compare the qualitative variants and discover the correlations. The statistical significance was adopted as p < 0.05

Results: The prevalence of dental erosion in GERD patients [22.6%] was found to be higher than the suspected [5.3%] and the healthy [7%] individuals

Conclusion: This study declared the GERD patients are at higher risk of developing dental erosion compared to the healthy individuals in a sample of Iranian population

Direct esthetic rehabilitation of teeth with severe fluorosis: a case report

This article describes an esthetic rehabilitation of a case of severe fluorosis associated with tooth mobility and gingival recession. Direct composite technique was applied to improve the color, shape and alignment of the teeth using direct composite veneering and replacement of the missing tooth by fiber-reinforced composite bridge. One year follow up have displayed acceptable outcomes and esthetic appearance

Flexural strength of glass and polyethylene fiber combined with three different composites

Statement of Problem: The flexure of the fiber- reinforced composites [FRC] which can be generally used instead of fixed metal- framework prostheses have been more advocated due to the enormous demands for the conservative and esthetic restoration. The flexure of the fiber should be well-fitted to its covering composite. No study has been reported the comparison of the combination of glass and polyethylene fiber with particulate filled composite and fiber reinforced composite yet

Purpose: This study compared the flexural strength of two types of fibers combined with three types of composites

Materials and Method: Sixty-six specimens were prepared in a split mold [25x2x2 mm]. The specimens were divided into six groups according to the type of resin and the fiber [N = 11]: group 1: Z250 composite + Polyethylene fiber; group 2: Build It composite + Polyethylene fiber; group 3: Nulite F composite+ Polyethylene fiber; group 4: glass fiber + Z250 composite; group 5: glass fiber + Build-It composite and group 6: glass fiber + Nulite F. The mean flexural strengths [MPa] values were determined in a 3-point bending test at a crosshead speed of 1 mm/min by a universal testing machine [Zwick/Roell Z020, Germany]. The results were statistically analyzed, using one and two- way ANOVA and LSD post-hoc tests [p< 0.05]

Results: The highest flexural strength was registered for glass fiber in combination with Z250 composite [500 MPa] and the lowest for polyethylene fiber in combination with Build-It composite [188 MPa]. One-way ANOVA test revealed that there was no statistically significant difference between polyethylene fiber combinations [p= 0.62] but there was a significant difference between glass fiber combinations [p= 0.0001]. Two way ANOVA revealed that the fiber type had a significant effect on flexural strength [p= 0.0001]

Conclusion: The choice of fiber and composite type was shown to have a significant positive influence on the flexural properties of the fiber-reinforced composite. Glass fiber has a significant influence on the flexural properties of directly- made specimens

[ effect of different light curing units and composite thicknesses on the shear bond strength]

Development of new composite resins is one of the most important technological advances in the field of cosmetic dentistry. The aim of this study was to investigate the effectiveness of different light curing units and composite thicknesses on the shear bond strength composite to dentin. In this experimental in-vitro study, the test groups were composed of 80 dentinal samples, prepared on occlusal surfaces of 80 maxillary premolar teeth and routinely divided into 8 groups of 10. Two cylindrical molds [2×2 and 2×5 mm] were filled in bulk using P60 and Ceram X composites and light cured with LED and QTH light curing units .After curing and 3 months aging in 37 degree water, shear bond strength of all samples were obtained using a universal testing machine with 1mm/min crosshead speed. One- and three-way ANOVA were used for statistical analysis using SPSS software. The highest mean of shear bond strength [31.75 MPa] was in group [P60, QTH, 2] and the lowest [15.34 MPa] was recorded in [Ceram X, LED, 5]. Type and thickness of composites had significant effects on the value of shear bond strength and no significant differences were obtained between two light curing units. The shear bond strengths of P60 and CeramX composites tested were much lower when cured in a 5-mm than in a 2-mm increment. The two types of light curing units tested did not show any significant differences in the amount of shear bond strengths

[Shear bond strength of MTA to composite resin in comparison with glass ionomer]

Nowadays, MTA has numerous clinical applications because of desirable properties. Many teeth which are treated by MTA need final composite restorations. In this situation, the bonding between composite and MTA has the main role in retention, durability and seal of the restoration. Evaluation of the bond strength between MTA and composite resin and its comparison with Resin Modified Glass Ionmoer [RMGI]. Sixty specimens were prepared for three experimental groups of white MTSA, gray MTA, and glass ionomer Fuji II LC. Ten specimens in each group were etched with 37% phosphoric acid for evaluation of the etching effect while ten speicments were not etched. All specimens were then bonded to the composite and shear bond strength test was performed, using Instron testing machine. In addition, the fractured surfaces of the samples were checked with stereomicroscope [x10]. Data were analyzed by ANOVA and Tukey HSD test. The highest shear bond strength value was seen in unetched glass ionomer subgroup and there were significant differences in shear bond strength of the composite to unetched glass ionomer in comparison with the other groups [p<0.001]. There were no significant differences in shear bond strength of the composite to etched and unetched white MTA, etched and unetched gray MTA, and etched glass ionomer [p > 0.05]. Shear bond strengthe between MTA and the composite is comparable with etched glass ionomer. The etching of the RMGI surface causes as significant decrease of bond strength to the composite but it has no effect on the bond strength of MTA to Composite

Effect of composite elasticity and filler concentration on shear bond strength of composite to dentin

Resin composites are one of the most popular tooth colored restorative materials. Their enamel and dentin bonding ability are based on many factors, including elasticity and filler concentration. This study was undertaken to evaluate the effect of volumetric filler percentage and modulus of elasticity of six composites by measuring shear bond strength to dentin of the bovine teeth as experimental bonding substrate. Eighty bovine incisors were prepared and divided into eight groups. Tetric Ceram, Tetric Flow, Compo glass F, Helimolar RO, Definite, and Degufill Mineral were applied respectively. A fifth generation of dentin bonding system [Single Bond [3M, USA]] was used for all the groups. The volumetric filler percentage of each composite was obtained from their specification data. The modulus of elasticity was determined, using the formula presented by Bream et al [1986]. Then, in last two groups Heliomolar RO and Definite were bonded using their own bonding systems, Syntac Multicomponent, and Definite Multibond. The shear bond strength was measured according to the ISO/TR 11405. Pearson's correlation test was used to compare the result with groups 4 and 5. The results indicated that the relationship between both the filler percentage and the modulus of elasticity with the shear strength was 16% [P < 0.005]. There was a significant difference between groups 4 and 7, but no significant difference was observed between groups 5 and 8. Using composites with a higher filler content and modulus of elasticity resulted in higher shear bond strength in dentin bonding system. Our results showed that the corresponding dentin bonding system of composites had better results

[ effect of the light activation mode on incompatibility between one-bottle adhesives and light-cured composites: an in-vitro shear bond strength study]

Adverse surface interactions between one-bottle adhesives and self-cured composites may occur similarly with light-cured composites during the use of different modes of light activation. The study examined the effect of different light activation modes of light-cured composite on the shear bond strength of 2 one-bottle adhesives with different acidity to the dentin. The experimental study was performed on 110 extracted sound molars. Then, the teeth were randomly divided into 10 equal groups [n=11]. One-Step plus [OS] and Prime and Board NT [P and B NT] were [SSI]. Soft- Start II [SSII], Pulse-Delay I [PDI], Pulse- Delay II [PDII]. Then, shear bond strength [SBS] test was performed, using an Instron at 1mm/min. The SBS was recorded in MPa. Statistical analysis included two way ANOVA with a significance level of 0.05. The highest SBS [MPa] was shown in OS conventional group [19.62] and the lowest in P and B NT, PDII [5.43]. In each group of 5 curing mode, mean SBS in P and B NT was significantly lower than that in OS as follows: In conventional; P and B NT [17.27] vs OS [19.82] in SSI; P and B NT [10.89] vs OS [13.09] in SSII; P and B NT [14.48] vs. OS [18.79] in PDI; P and B NT [5.93] vs OS [11.97] and in PDII; P and B NT [11.82] vs OS [16], [p<0.001]. In each of 2 adhesives, ranking of SBS from minimum to maximum was as follows: PDI

[ effect of different tooth surface preparation methods on microshear bond strength]

Evaluation of new adhesives efficacy in bonding orthodontic brackets to enamel has led to different results. The new measuring method, micro-shear bond strength, is preferred as an accurate method due to its ability to reduce confounding factors.The purpose of this study was to evaluate and compare the micro-shear bond strength of three different adhesive systems for enamel surface preparation before bracket bonding.In this experimental study, 90 extracted premolars were randomly divided into three groups of 30. Transbond XT was bonded to enamel after enamel surface preparation with acid etch in the first [control] group, Transbond plus self-etch primer in second group, and Adper prompt L-pop self-etch adhesive in third group. Then each group was randomly divided into two subgroups of 15. Micro-shear bond test was performed after 24 hours [T1] and 3-months [T2]. Bond failure mode was also evaluated according to Adhesive Remnant Index [ARI]. Two way ANOVA and Tukey tests were used for bond strength evaluation in groups, and mode of bond failure was analyzed with Kruskall Wallis and Mann Whitney tests.The highest bond strength was found in acid etch group [29.17 MPa]. Difference of bond strength at two intervals was statistically significant in all groups [p <0.001]. Bond strength difference between T1 and T2 was also significant in three groups [p <0.001]. However changes over time in three groups did not reveal any significant differences [p = 0.091]. Bond failure analysis demonstrated significant differences in ARI between groups.Bond strength of acid etch group was the highest and self etch primer showed higher bond strength than self etch adhesive group. Less adhesive remnant was found in self etch group

[Effect of fiber orientation and position on fracture resistance and failure mode of cuspal coverage composite restorations]

Position and orientation of fiber may lead to increase load bearing capacity and prevent undesirable fractures in cuspal coverage composite restorations. The aim was to evaluate the effect of fiber position and orientation on fracture resistance and failure mode of composite cusp capping restorations. In this experimental study, MOD cavities with 2.5mm cuspal reduction were prepared in 50 human maxillary premolars. The teeth were divided into five groups [n=10] and all teeth were restored with packable composite resin [P60]. In the first group no fibers were applied. In the second group one strip of fiber was inserted into resin composite in buccal to palatal direction. In the third group two strips of fiber were inserted in buccal to palatal and mesial to distal direction by crossing in central part of cavity. In the forth group, one strip was directed from mesiobuccal to distopalatal and the other from distobuccal to mesiopalatal line angle. In the fifth group, two strips of fiber were inserted in buccal to palatal direction with 1.5 mm distance. The teeth were stored in water for 7 days in room temperature and then thermocycled 500 times between 6 +/- 2 and 60 +/- 2 centigrade degrees. The specimens were subjected to compressive loading perpendicular to the occlusal surface. The necessary fracture loads were recorded in [KN] and the results were statistically analyzed by Mann-Whitney and ANOVA tests. Mode of fracture was analyzed by using Fisher test. Statistical analysis showed a significant increase of fracture load from control to the other four groups [p<0.05]. There were statistically significant differences between second and third groups [p=0.034] as well as second and fifth groups [p=0.041]. No significant differences were found between other pairs of groups. Also significant differences were observed in failure mode between composite restorations with and without fiber, except for second group [p<0.005]. Fiber reinforced composites improve fracture resistance and failure mode of restorations with cusp capping. With increase use of fiber strips in special directions, fracture resistance will be rised

Pulmonary metastases: results of surgical resection in 60 cases: treatment modalities other than surgery are needed

Pulmonary metastases occur in 30% of all oncology patients. Surgical resection of lung metastases is a widely accepted procedure but long-term results are disappointing with a 5-year survival rate of 20-40% and the results vary with the histologic type of the primary tumor. Due to unavailability of any study regarding pulmonary metastasectomy in Iran and emergence of new treatment modalities, reassessment of our current practices is essential. We performed a retrospective study of 60 cases of pulmonary metastasectomy during a 5-year period in one of the major thoracic surgery centers in Tehran [Imam Khomeini Hospital]. Bilateral metastases were present in 23% of cases, number of metastases in each patient ranged from 1-12. Average disease-free interval was 12 months, pneumonectomy rate was 21.7% mostly as a second or third attempt and finally, recurrence or death following initial metastasectomy occurred in 12-18 months in most patients. These results confirm that surgery remains unsuccessful in obtaining long-term survival or cure in most patients with pulmonary metastases and treatment strategies other than surgery, such as radiofrequency ablation are needed to avoid performing multiple operations in these patients and improving their quality of life

Evaluation of Possibility of Using Core Max II in Bonding Orthodontic Brackets to Teeth

Different adhesives have been used for bonding orthodontic brackets to teeth. The aim of this study was to evaluate the possibility of using Core Max II in bracket bonding by comparing it's shear bond strength with the two commonly used orthodontic adhesives; Transbond XT and Unite. In this interventional study, 105 human premolars were divided into 3 groups of 35 each. After etching with 37% phosphoric acid, Dyna-Lock stainless steel brackets [3M Unitek, Monrovia, CA] with the average base surface area of 12.09 mm2 were bonded with three different adhesives; Core Max II [Sankin, Tokyo, Japan] Transbond XT [3M Unitek] and Unite [3M Unitek]. The shear bond strength of 3 groups were measured by a universal testing machine [Instron 3401, Canton, Mass] with cross- head speed of 0.5 mm/min. Adhesive Remnant Index [ARI] was determined under 10[X] magnification. For data analysis, SPSS statistical package was used. Mean shear bond strength of Core Max II [17.24 +/- 3.2 MPa] was significantly higher than Transbond XT [15.44 +/- 2.2 MPa] [P=0.009] but had not statistically difference with Unite [17.16 +/- 3.7 MPa] [P=0.93]. Evaluation of ARI indicated that 83% of Core Max II samples had score 0 or 1 and 17% had score 2 or 3. These percentages were 66% and 34% for Transbond XT and 77% and 23% for Unite, respectively. In this study, it was concluded that: 1] Core Max II had a shear bond strength higher that Transbond XT and equal to Unite. 2] ARI of Core Max II showed a higher frequency of score 0 and 1, which indicated that after debonding, most of the adhesive remains on the bracket base. 3] Core Max II has the potential of being a good orthodontic adhesive

[ in vitro comparison of 3 selfetch adhesives in dry and wet condition on dentin]

The goal of adhesive dentistry is creation of perfect seal along resin-dentin interface. However, small ions and molecules can permeate the hybrid layer even in the absence of detectable interfacial gap formation. This phenomen is called "Nanoleakage". The aim of this in vitro study was to compare the nanoleakage of 3 selfetch adhesive systems in dry and wet conditions on human dentin. Seventy-seven intact human premolars were selected and flat occlusal surfaces were prepared. Teeth were divided into 7 groups of 11 teeth and each group was treated according to the following protocol: group 1: clearfil SE Bond in dry condition, group 2: clearfil SE Bond in wet condition, group 3: I Bond SE Bond in dry condition, group 4: I Bond SE Bond in wet condition, group 5: prompt L-pop in dry condition, group 6: propmpt L-pop in wet condition and group 7: scoth Bond Multipurpose [control]. In dry condition, the dentin surfaces were air-dried for 10 seconds and in wet condition, dentin surfaces were blot dried. Adhesives and composite resins were bonded to dentin surfaces. After 24 hours, all teeth were stored in 50% AgNo3 solution in darkness for 24 hours. Then the teeth were rinsed and stored in photodeveloper solution under flouresceut for 8 hours. The prepared teeth were embedded in epoxy resin and sectioned as 1 mm diameter. All slabs were polished, gold coated and analyzed by SEM. The mean nanoleakage of the 3 self etch adhesives in dry condition was significantly higher than the wet condition. The mean nanoleakage of 3 self etch adhesives had no significant difference in wet condition. In dry condition, PLP was better than CSEB and IB. Based on this study, it is recommended to dry the dentin, before application of self etch adhesives. The water content of these bonding systems is enough for the release of H + which is necessary for the activation of acidic monomer

[Evaluation of fracture resistance of teeth restored with three types of tooth colored onlay]

Regarding to esthetic needs of the patients and the demand for tooth colored restoration, this study evaluated the compressive fracture resistance of cuspal coverage of the maxillary premoalrs with tow types of indirect composites [Tetric Ceram HB, Targis] and one type of porcelain [IPS Empress]. 32 extracted maxillary premolars were collected and were allocated in to four groups of eight teeth. The MOD cavities were prepared with following dimensions; Buccolingual width: 2/3 of cuspal tips distance, pulpal depth: 2.5mm, axial depth: 2mm, gingival floor 1mm above CEJ and 2mm reduction of cusp. One group were kept sound as control. The prepared teeth were restored with the above mentioned materials according to the manufacture's instruction, and then they were stored in normal saline for 7-10 days. All teeth were loaded occlusally using universal-testing machine to the point of fracture. Data were anulysed by ANOVA test. Also the types fracture of teeth were compared. The fracture resistance values for all of the groups were equivalent to those obtained for the unresorted control teeth, and according to the ANOVA test, no difference were detected between fracture resistances of resorted groups [P=0.7]. The mode of fracture of teeth resorted with composite onlays when subjected to compressive loading were less catastrophic than that of teeth resorted with porcelain onlays. Cuspal coverage of extensively weakened teeth with composites or ceramics onlays can improve fracture resistance comparable to intact teeth