[In Vitro Assessment of Antibucteriul Activie of Pomegranate Vinegur ilnd Rose Water Compared with Persicu Mouthwush on Oral Bacteriu]

Backgroand and Aim: Mutans streptococci are the main cause of tooth decay. Application of natural materials as mouthwash has been effective in reducing the bacterial count. This study aimed to assess the antimicrobial effebts of rose water and pomegranate vinegar in comparison with Persica mouthwash on two oral bacteria gesponsible for tooth decay.

Materials and Methods: Strongly adherent strains of Streptococcus mutans and Streptococcus sobrinus were selected for this in vitro study. Antimicrobial effects of pomegranate vinegar and rose water on microbial count in the biofilm and adhesion potential of bacteria was evaluated by microtiter plate method. Also, the well-plate technique was used to assess the effect of rose water and pomegranate vinegar in comparison with Persica mouthwash on bacterial growth and proliferation. The obtained resulted were analyzed by one-way ANOVA and Tukey's post hoc test using Graph Pad Prism version 5 software. Level of significance was set at P:0.05 withglo/o confidence interval.

Results: Pomegranate vinegar, rose water and Persica decreased plaque formation by S. mutans by 93%, 80% and 680%, respectively. These values for the S. sobrinus were 92%, 57% and 48%, respectively [all Ps<0.001]- Pomegranate vinegar was more effective than the other fwo materials [p<0.001]. However, none of these materials eliminated the biofilm. Pomegranate vinegar and Persica mouthwash had a negative effect on growth of the aforementioned bacteria.

Conclusion: Within the limitations of this study, it seems that pomegranate vinegar and rose water have the potential to prevent or control the proliferation of S. mutans and S. sobrinus.

[Shear bond strength of two self-etch adhesives to permanent and deciduous dental enamels: effect of acid preconditioning]

There are some studies that strongly recommend acid-conditioning before applying the self-etch adhesives. The aim of this in vitro study was to compare the shear bond strength [SBS] of two self-etch adhesives to the enamel of primary and permanent teeth with acid preconditioning. The buccal surfaces of 48 permanent molars and 48 primary molar teeth were prepared for bonding of the adhesives to the enamel. Then the samples were randomly divided into eight groups, each containing 12. According to the manufacturers' instructions, Clearfil SE Bond [CSEB] and ACE All Bond SE [ABSE] self-etch adhesives were applied on the enamel and the etched enamel of both permanent and primary teeth and bonded with composite resin. After 24 hours of storage in 37°C and 500 rounds of thermocycling, the specimens were tested in a shear at a crosshead speed of 1.0 mm/min. The results were statistically analysed using SPSS 11.5 with Kruskal-Wallis and t-test at a significance level of 0.05. The mean +/- SD in permanent enamels using CSEB and ABSE were 16.10 +/- 7.6 and 8.49 +/- 2.34 Mpa, respectively. The same data for the deciduous enamels were 16.08 +/- 3.91 and 9.23 +/- 3.20 Mpa, respectively. After acid etching, SBS for permanent enamel using CSEB and ABSE were 32.05 +/- 7.13 and 31.39 +/- 6.51 Mpa, respectively. The same data for deciduous enamels were 24.73 +/- 10.74 and 21.70 +/- 6.18 Mpa, respectively. The bond strength of CSEB was significantly higher than ABSE adhesive in both primary and permanent teeth. In addition, acid etching leads to increase in the enamel bond strength of both studied adhesives

[Shear bond strength of two self-etch adhesives to permanent and deciduous dentin: Effect of acid preconditioning]

Statement of Problems: Enamel preconditioning using phosphoric acid has been recommended prior to applying self-etch adhesives. Meanwhile, there is the possibility for etching of the dentin

Purpose: The aim of this study was to evaluate the shear bond strength [SBS] of two self-etch adhesives to the dentin of the primary and permanent teeth in case of phosphoric acid preconditioning

Methods and Materials: In this experimental study, the buccal surfaces of 48 permanent molars and 48 primary molar teeth were prepared for bonding of two self-etch adhesives including Clearfil SE Bond [CSEB] and ACE All Bond SE [ABSE], to the dentin. Each of the permanent and primary teeth was randomly divided into 4 groups [n=12]. According to the manufacturers' instructions, CSEB and ABSE were applied on the dentin or etched dentin of both permanent and primary teeth, then, they were bonded with composite resin. The specimens were stored in water at 37[degree sign]c for 24 hours and then were thermocycled for 500 cycles. SBS was performed at a crosshead speed of 1.0 mm/min using DARTEC universal machine. The results were statistically analyzed in SPSS 11.5 using Kruskal- Wallis and T-Test

Results: The bond strength of CSEB was significantly higher than ABSE adhesive in both primary and permanent teeth [p =0.001]. Acid preconditioning significantly increased the dentin bond strengths of ABSE adhesive in the primary and permanent dentin [p =0.001], and CSEB adhesive in primary dentin

Conclusion: Bond strength of the studied adhesives was significantly different. While acid phosphoric preconditioning improved the bond strength of the both adhesives in primary teeth, it did not influence the bond strength of the studied two-step self-etch adhesive in the permanent dentin

[Tensile strength analysis of three different restoring techniques in canine primary teeth]

Extensive caries in the primary anterior teeth is one of the highly prevalent dental issues in primary dentition. On the other hand, special considerations for restoring these teeth are a challenge for the dental practitioner. The aim of this in vitro study was to compare the tensile bond strength of a new method of Reverse Metal Post Technique [RMPT] with two conventional methods. Eighty-four extracted primary canines were assigned to three equal groups. The crowns were cut-off 1 mm coronal to CEJ and the root canals were prepared for the next stage. The teeth were restored according to the groups they were assigned to; Group 1 with composite posts; Group 2 with alpha-shaped orthodontic wires; and Group 3 with the RMPT. The specimens were then subjected to tensile force by a mechanical testing machine. Data were analyzed using ANOVA, tukey post hoc, Chi-square and student t test [alpha =0.05]. The mean tensile bond strength for groups 1, 2 and 3 were 6.26 +/- 2.40, 7.35 +/- 1.60 and 9.88 +/- 2.60MPa, respectively. A significant difference was observed between group 3 and the two other groups [p<0.001]. However, the difference between groups 1 and 2 was not statistically significant [p>0.05]. The tensile bond strength was significantly higher in RMPT than the two conventional methods used for restoring severely destroyed primary anterior teeth

Effect of CPP-ACP on shear bond strength of composite-resin to bleached enamel

Tooth sensitivity is common after vital tooth bleaching. Desensitizers are available as a component of bleaching agents or separated materials. The aim of this invitro study was to evaluate the effect of [GC tooth Mousse [GCTM]] on bond strength of composite resin to bleached enamel. This experimental study was conducted on 48 freshly extracted sound molars. Samples were divided in 4 groups [n=12]. In group 1 [negative control] composite resin was bonded on the buccal enamel surfaces. Specimens in groups 2 and 3 were bleached for 6 hrs/d for 5 consecutive days [Daywhite ACP]. Group 2 specimens were immediately bonded with composite resin. In group 3, GCTM was used for 30 min in 5 consecutive days and then rinsed after each procedure. On the 5[th] day the specimens were bonded using composite resin. In group 4, the specimens only received GCTM and then composite resin cylinders were bonded. After 500 rounds of thermocycling, shear bond strength of the samples were measured and the findings were analyzed by Two-way ANOVA and Tukey-Keramer tests, [a = 0.05] Variance analysis showed significant differences between groups [P = 0.0]. The highest and the lowest bond strengths were found in groups 1 and 2 respectively. The Tukey-Keramer analysis showed that using GCTM after bleaching had significant effect on composite shear bonding strength. [P < 0.05]. Within limitations of this invitro study, using the GCTM as a desensitizer agent either alone or during bleaching affected the composite resin bond strength to enamel. More investigation is recommended

[Effect of sodium ascorbate gel on class V composite resin restoration microleakage]

Composite restoration microleakage has been reported following bleaching treatment. The purpose of this study was to assess the in-vitro effect of sodium ascorbate gel on microleakage of class V restorations on bleached teeth. Forty-eight premolar teeth were randomly divided into 4 equal groups. Class V cavities were prepared on the buccal surfaces of group 1 teeth [negative control] and they were restored. In groups 2-4, bleaching was applied by using 9.5% hydrogen peroxide gel. In group 2 [positive control] and group 3, [delayed bonding] teeth were restored immediately and one week later, respectively. In group 4, 10% sodium ascorbate gel was applied, rinsed and restored. After thermocycling, samples were immersed in fushin and then, sectioned. Leakage was assessed and penetration of dye was scored. Data were analyzed using Kruskal-Wallis and Dunn's tests. There were significant differences in terms of microleakage between group 2 and other groups [P<0.05]. Groups 1, 3 and 4 exhibited similar leakage patterns, and all groups demonstrated less leakage values than group 2. Regarding marginal microleakage, there were significant differences between enamel and dentinal margins. Applying sodium ascorbate gel or 7-day delay following bleaching technique may improve the marginal integrity of composite class V restorations

[Effect of sodium ascorbate and calcium hydroxide on shear bond strength of composite resin to bleached enamel]

Application of sodium ascorbate as an antioxidant and calcium hydroxide as a buffering agent has been recommended after bleaching .The aim of this study was to investigate the effect of these two materials on shear bond strength of composite resin attached to bleached enamel. This in-vitro investigation used 60 human sound premolars. They were randomly divided into five groups [n=12]. Buccal enamel surfaces were flattened by using a trimmer machine and silicon carbide paper. The samples in negative control [NC] group were not bleached, while all others were bleached with 35% hydrogen peroxide gel for 5 days. Composite cylinders were bonded in positive control [PC] group immediately after bleaching; in delayed bonding [DB] group after one week; in sodium ascorbate [SA] and calcium hydroxide [CH] groups after 40 hours of treatment with these two materials, respectively. The specimens were thermocycled [5-55°C, 500 cycles] 24 hours after bonding and they were subjected to shear bond testing by using universal machine. Statistical analyses were carried out to identify group differences and Kruskal-Wallis and Mann-Whitney tests were used to detect the significance level. Group differences revealed that, the lowst mean of bond strength belonged to the calcium hydroxide group the difference of which was significant compared with the other groups [P<0.006]. The positive control group had lower bond strength in comparison with the negative control, sodium ascorbate and delay bonding groups [p<0/001] .But the difference among other groups was not significant. Both one week delay and using sodium ascorbate treatment could significantly increase the bond strength of composite resin to bleached enamel, while the use of calcium hydroxide had an adverse effect on composite resin bond strength

[Effect of thermocycling on the shear bond strength of composite-resin to supercast alloy]

lntraoral repairs often involve bonding composite to fractured PFM crowns, Newer adhesive systems currently referred to as multipurpose systems are capable of bonding to enamel, dentin, metal and porcelain. The Adper Scotchbond Multipurpose Plus system [ASMP] is as one of the systems using in repair procedures. Most studies observed significant differences between early and late bond-strength results. This study evaluated the effect of thermal stresses on shear bond strength of composite resin to Supercast alloy by using different surface treatments including etching, sandblasting and combination. In this invitro experimental study composite cylinders were bonded with ASMP to the 60 surfaces of alloy that were treated with etching [groups 184], sandblasting [groups 285] or combination of both [groups 386] following the manufacturer instructions. In each group, groups 4, 5 and 6 were thermocycled intermittently in 5 and 55 C°. Groups 1, 2 and 3 were stored in 37 C° distilled water. Shear bond strengths were measured and compared by loading each specimen in shear to failure in an Instron testing machine. Data were analyzed using two-way ANOVA and Duncan tests. The mean shear bond strengths in groups 1 to 6 were respectively: 1.84 +/- 0.49, 4.77 +/- 0.77, 17.97 +/- 3.59, 1.08 +/- 0.62, 1.98 +/- 0.81, 12.77 +/- 2.38 [MPa]. There were significant differences between the study groups [p<0.001]. Thermocycling significantly reduced the bond strength of composite resin and Supercast alloy. The bond strength of composite resin increased when the combination of sandblasting and etching used fur surface treatment

[Effect of different shades of flow able composite on micro leakage of posterior restorations]

Due to perfect adaptability, the flow able composite has been recommended to be used as the first layer of restoration in the gingival floor of the proximal cavities restored with composite filling materials. The objective of this in-vitro study was to evaluate the effect of using different shades of flow able composite as gingival increment on the micro leakage of posterior composite restorations. Total of thirty-six freshly extracted human sound premolar teeth were used in this laboratory investigation. Standard class II box-shaped cavities were prepared with proportional size and shape [3mm width, 2mm depth] with 1mm apical extension to CEJ. The teeth were randomly divided into 6 groups. Five shades of flow able composite resin A[1], A[2], A[3.5], C[2], D[3], [Aeliteflow, Bisco, USA] were used as the first layer in the gingival portion of groups 2-6 respectively. All the rest of cavities were restored with hybrid composite A[3] [Aelite, Bisco, USA], incrementally, and light cured through the proximal surface. After 24 hours of immersion in distilled water, the specimens were thermocycled [500 cycles, at 5-55°C, with 30 seconds dwell time], sealed with nail varnish and immersed in 2% basic fushin solution for 24 hours. The restorations were sectioned longitudinally parallel to mesiodistal tooth dimension. Micro leakage status was evaluated using a 0-3 scoring scale. Data analysis was conducted using Kruskal-Wallis test at 0.05 significance level. No statistically significant differences were observed between the study groups [p>0.05] under investigation. The least and the most micro leakage values were related to group 1 and 6 respectively. All specimens restored with A[1] demonstrated zero score for dye penetration. The use of flow able composite with A[1] shade as gingival increment may decrease the gingival micro leakage compared with control group. It may be advisable to use flow able composite with lower chroma in posterior composite restorations

Shear bond strength of Composite / Amalgam restorations: Effect of using, adhesive cement

The aim of this study was to evaluate the shear bond strength [SBS] of composite/amalgam restorations when adhesive resin cement was used. 60 Acrylic cylinders were prepared using special Teflon molds. A square-shaped cavity was made at the center of each cylinder. The samples were divided into four groups [n = 15]. After amalgam condensation and burnishing in the first group, a two parts Teflon die with a cylindrical hole at the center was placed on the amalgam surface. These holes were filled with composite-resin. Single bond and Rely X-ARC were applied on amalgam surfaces respectively, prior to curing the composite-resins in the second group. In groups 3 and 4, the prepared amalgam samples were kept in 37 C for 24 hours. Then they were identically roughened using burs. In group 3, composite was bonded immediately and in group 4, first single bond, and then Rely-X ARC were applied before curing the composite. The SBS was determined by DARTEC testing machine. The mean SBS for the study groups were 9 +/- 2.77, 8.74 +/- 6.42, 6.13 +/- 2.35 and 8.25 +/- 1.43 respectively. The maximum value was related to group 1 and the minimum value belonged to group 3. However, there were no significant differences between the study groups. Application of Rely X-ARC in amalgam/composite interface did not cause any significant difference

Saliva contaminated and re-etched All-in-one adhesive influence on bond strength

In this study, we have investigated the effect of using phosphoric acid on bonding efficacy of an all-in-one adhesive system, after salivary Contamination of dentin. Eighty-four extracted human molars were prepared for their superficial dentins to be exposed. The molars separated into 7 groups. Group 1 specimens were not contaminated. In groups 2-4, samples were contaminated with fresh human saliva after applying and before curing the adhesive [in group 2, adhesive was rinsed, in group 3, adhesive was not rinsed, and in group 4, after rinsing the adhesive, phosphoric acid was applied, and then rinsed]. In groups 5-7, contamination was done after adhesive curing [in group 5, only rinsing, in group 6, rinsing, and adhesive reapplication, and in group 7, rinsing, using phosphoric acid, rinsing and adhesive reapplication. Shear bond strength was measured and analyzed. There were statistically significant differences between group means, except groups 3 and 5. Groups 1 and 4 demonstrated higher bond strength than other groups. Using phosphoric acid may be effective, provided that the contamination occurs prior to curing of the adhesive

Fracture resistance of endodontically - treated premolars restored with pins and adhesive resin cement

This in vitro study compared the ability of horizontal pins and an adhesive resin cement to reinforce the facial cusp of endodontically treated maxillary premolars. Seventy-two maxillary premolars were divided into six groups and mounted in acrylic blocks [n=12]. In all of groups standardized endodontic treatment were completed. In groups 2-6 the palatal cusp were reduced, leaving the buccal cusp intact. In group 1 access cavity was filled with amalgam simply. The facial cusps of the teeth in other groups received one of the following reinforcements: Group 2- no reinforcement; Group 3- amalgam build up; Group 4- two horizontal dentinal pins; Group 5- Adhesive resin cement. Teeth in Group 6 were prepared for and restored with amalgam using two horizontal dentinal pins and adhesive resin cement. Then the lingual slope of the facial cusp of each specimen was loaded to failure using a compressive force. The mean fracture strengths for all groups were analyzed using statistical analysis. [a= 0.05]. Fracture patterns and modes of failure were also evaluated. The mean fracture values for groups were 1429.58; 701.80, 1242.50, 1298.63, 1289.25, 1311.83 kgf respectively. With the exception of group 1 [positive control group], group 6 were more fracture resistant than all other groups, and there were not significant difference between that group with groups 1 and 3-5. The buccal cusp of endodontically treated maxillary premolars whether reinforced with a horizontal pins or adhesive resin cement were not significantly weaker than conservatively restored teeth

[Evaluation of blood mercury concentration in two groups of students of Isfahan Dental School]

Dental amalgam has been one of the most widely used restorative dental material for over 150 years. Mercury is one of the main elements in dental amalgam composition. Absorption of mercury in human body can cause serious problems such as insomnia, loss of memory, mental depression and inability to concentrate. Widespread use of dental amalgam in dental schools make a lot of mercury vapour, So, evaluation of blood mercury in dental students during their practical courses may be useful. In this study, two groups of dental students were selected. The first group included 25 clinical dental students and the second 25 preclinical dental students. All selected students were non-smokers, non-alcoholics, and neither group hadn't had new amalgam restoration nor had see food for at least a week. Blood samples were prepared from each group. In each sample 4 ml of blood was drawn and mixed with 0.5 ml, 1% EDTA as anticoagulant. The concentration of mercury was determined by cold vapor atomic absorption spectrometry with amalgamation.. The results showed significant differences between total mercury and nonorganic mercury in two mentioned groups but organic mercury had no significant difference. However means were less than 4ng/ml. According to the result of this study working with amalgam in dental school and operative department can increase blood mercury however no toxicity and serious problem for dental students could be observed. Therefore, it seems making a good air conditioned environment for exiting mercury vapor is necessary, especially in operative department. In addition special attention to control of blood mercury is necessary for assistants, staff and professors of dental school because of their permanent presence in environment containing mercury uapour