Effect of sodium hypochlorite on microleakage of three-step total etch bonding systems with different solvents

some recent research have reported increased stability in mechanisms of adhesion to dentin in remove of collagen fiber of the dentin surface.The aim of this study was to evaluate the effect of sodium hypochlorite in microleakage of three step total etch dental adhesives with different solvents. this experimental study on 80 intact bovine incisor teeth, were prepared class V cavities on buccal surface of teeth, box shap and all walls on enamel. Then the specimens were randomly divided into eight groups [n=10]. NaOCl+etching+ SBMP [waterbase], NaOCl+etching+ All Bond[2] [Acetonebase], etching+ NaOCl+ SBMP, etching+ NaOCl+ All Bond[2], NaOCl+ SBMP, NaOCl+ All Bond[2], etching+ SBMP, etching+ All Bond[2]. Then the cavities were restored using Z[250] [3M] composite and Coltolux 75 light curing unit [350 mw/cm2]. The specimens were thermo cycled for 1000 times on water baths of 5 and 55[Oc]. After thermocycling, the specimens were immersed in a 2% aqueous solutions of basic fuchsin for 24 hours, then longitudinal section of each restoration was obtained and examined with a stereomicroscope for evaluation of micro leakage. The data were analyzed using kruskal-walls test and the mean of micro leakage of samples were compared by two- way ANOVA test. The findings showed that the higher rate of micro leakage was detected in hypo+Acid and lower rate of micro leakage was detected in Acid+hypo in different treatment method. The finding was different in hypo+Acid procedure, the higher rate of micro leakage was in SBMP. In hypo groups, the microleakage with ALL Bond 2 was higher than SBMP. In control groups, the microleakage with SBMP was higher than ALL Bond 2. Application of Naoci before dentin etching for removal organic materials increase the rate of microleakage of All Bondz, SBMP to that of control group

[Microleakage evaluation of silorane-based composites versus low shirinkage methacrylate-based composites]

Determining the best restorative material to decrease microleakage in class V restorations is of great importance in operative dentistry. The aim of this in-vitro study was to evaluate the microleakage of silorane-based composites compared to low shrinkage methacrylate-based composites in class V restorations. In this in vitro study, class V cavities were prepared on the buccal and lingual surfaces of 24 human premolars and molars [48 cavities]. The specimens were divided into four groups of 6[12 cavities] as follows: group 1 [LS System Adhesive, Primer and Bond + Filtek P90], group 2 [Kalore-GC+ Clearfil SE bond], group 3 [Clearfil SE bond + Grandio] and group4 [Clearfil SE bond + Aelite LS Posterior]. All the specimens were thermocycled for 2000 cycles [5-50°C]. The teeth were then immersed in 0.5% basic fuchsin dye for 24 hours at 37°C, sectioned and observed under stereomicroscope. Data were analyzed using Kruskal-Wallis and Wilcoxon tests at a P<0.05 level of significance. There were no significant differences in microleakage among the four groups at the occlusal margin [P>0.05]. But, there were statistically significant differences in microleakage between Silorane and Aelite at the gingival margin [P<0.05]. Statistically significant differences were also found in microleakage between occlusal and gingival margins [except for Kalore and Silorane] [P>0.05] Silorane was not superior to the conventional low shrinkage methacrylate-based composites except for Aelite in terms of microleakage

[Effect of trenched zirconia bar on flexural strength of ips-empress 2 ceramic]

In the recent years, inlay-retained fixed partial dentures [FPDs] have gained attention due to the preservation of tooth structure and their conservative tooth preparation. The wettability of IPS2 ceramic surfaces can be increased by acid etching enhancing their bond to resin cement. High-strength ceramics cannot be etched due to the high resistance of alumina and zirconia. Inadequate bond between the zirconia and resin cement in zirconia-based FPDs leads to unequal stress distribution on the surface and consequent debonding and failure of the inlay-retainer. This study aimed to evaluate the effect of a trenched zirconia bar on the flexural strength of IPS-Empress 2 ceramic core. In this experimental study, 21 ceramic specimens measuring 3x4x25 mm were divided into three groups: Group 1 was the control group and fabricated from In-Ceram alumina ceramic Group 2 specimens were fabricated from IPS-Empress 2 ceramic Group 3 specimens were fabricated from IPS-Empress 2 and had an embedded trenched zirconia bar at the bottom Specimens were subjected to three point flexural test with 15 mm support span at a cross head speed of 0.5 mm/min. The fracture forces were recorded and data were statistically analyzed using ANOVA and Tukey's test. The fracture surfaces were evaluated with an electron microscope. The flexural strength of specimens was 302.66 in group 1, 187.25 in group 2 and 247.89 MPa in group 3. Flexural strength of In-Ceram specimens was significantly higher than that of IPS2 [P<0.019] but no difference existed between In-Ceram and IPS2 with an embedded trenched zirconia bar. Therefore, use of trenched zirconia bar at the bottom of specimens had limited effects on increasing their flexural strength]. Flexural strength of IPS-Empress 2 specimens with an embedded trenched zirconia bar was equal to that of the other two groups. Although the flexural strength value of the mentioned group was higher than that of IPS-Empress 2 specimens without the bar and lower than that of In-Ceram alumina specimens, these differences were not statistically significant

[ effect of different bonding agent curing times on microleakage of composite restorations in enamel and dentin margins using two curing systems]

Lack of appropriate seal is one of the major problems in composite restorations. Properties of the bonding system can play a crucial role in sealing ability of these restorations. The aim of this study was to evaluate the microleakage of composite restorations with varying irradiation time for curing dentin bonding agents with two different curing devices in class V cavities. In this experimental study, 60 intact extracted human molars and premolars were subjected to standard class V cavity preparations. Cavities were divided to six groups. Following etching, Excite bonding agent was applied and light cured using QTH and LED systems for 20, 30 and 40 seconds and cavities were filled with composite. The filled cavities were subjected to 3000 thermal cycles with 5-55 degree temperatures. Teeth were immersed into 0.5% basic fushin dye and sectioned occlusogingivally from the restoration middle area and the microleakage was determined using stereomicroscope by a 5-scaled rankings. Data were analyzed by Mann-Whitney and Kruskal-Wallis tests with p<.0.05 as the level of significance. No leakage was found in enamel margins. The type of light curing device did not have any significant effect on dentin margins microleakage [p>0.05]. Furthermore, no significant reduction in microleakage scores were observed in the restorations irradiated with different curing times [p>0.05]. QTH and LED curing units in 20, 30, and 40 s curing time did not have any significant effect on microleakage of class V composite restoration margins

[Effect of mechanical load cycling on class V glass- ionomer and composite restorations; a microleakage and scanning electron microscopic evaluation]

Microleakage is an important problem with direct restorations and familiarity with its contributing factors is of utmost importance. The aim of this study was scanning electron microscopic evaluation of marginal integrity in three types of class V tooth-colored restorations and the effect of load cycling on their microleakage. In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 30 bovine incisors [60 cavities]. The specimens were divided into three groups [n=10 each or 20 cavities] and restored as follows: group 1: with Filtek Z350[nanocomposite], group 2: Fuji IX/G Coat Plus[CGIC], and group 3: Fuji II LC[RMGI]. All specimens were finished and polished immediately and were thermocycled [_2000,5-50 °C]. In each group, half of the teeth were load cycled .Epoxy resin replicas of 12 specimens were evaluated under FE-SEM and interfacial gaps were measured. Finally the teeth were immersed in 0.5% basic fuchsine dye for 24 hours at room temperature, sectioned and observed under stereomicroscope. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests and a comparison between incisal and cervical microleakage was made with Wilcoxon test. It was shown that the mechanical load cycling caused a statistically significant increase in cervical microleakage of Fuji IX and Fuji II LC and in incisal microleakage of Fuji II LC. Microleakage in Z350 with load-cycling and Fuji IX with and without load-cycling was significantly higher in cervical compared with incisal area. Both incisal and cervical microleakage were significantly different among these materials under load-cycling.[Fuji II LC>Fuji IX>Z350]. It was concluded that the marginal sealing ability of Fuji IX under loadcycling was better than that of Fuji II LC. Z350 showed better marginal integrity while being load-cycled than both Fuji II LC and Fuji IX

[Laboratory assessment of fracture resistance of endodontically treated teeth restored with three different post and core systems]

Prefabricated posts are advantageous in restoring endodontically treated teeth because of their lower cost and operation time. Since selecting a suitable restoration is important in the survival of these teeth, in this study fracture resistance and the mode of failure of endodontically treated teeth restored with three different post and core systems were evaluated. In this in vitro study, 36 human premolars were divided into three groups; namely, group 1, non precious cast post and core; group 2, prefabricated metal post with amalgam core; group 3, FRC post and composite core. All groups received crowning. Specimens were thermocycled and loaded until definite failure. The fracture resistance and failure modes were analyzed with one way ANOVA and Fisher Exact tests. The mean failure load for the three groups was 794, 647 and 724 N, respectively. Statistical analysis did not show any significant differences between the fracture resistance of the three experimental groups [P=0.0579]. All failures in group 1, eight in group 2 and three in group 3, were unrestorable. Fisher's Exact test showed significant difference between group 3 and the two other groups [P<0.05]. If there is a 2-mm ferrule, the type of post and core does not have a significant effect on the fracture resistance, but it has a significant effect on the failure mode

[In vitro evaluation of Fuji IX glass ionomer to microleakage after exposure to hydrogen peroxide 35% in class V restoration]

Fuji IX packable glass ionomer has anti-carious properties by adhesion to tooth structure. It seems to provide adequate seal between tooth structure and restoration due to the development of ionic crosslinks. Furthermore, bleaching may affect the marginal seal of restorations, subsequently increasing the leakage of oral fluids and bacteria into the restored structure. The aim was to evaluate the effect of packable glass ionomer [Fuji IX] on the microleakage of Class V restoration exposed with and without H2O2 35%. Forty sound human molars and premolars were selected and class V standard cavities were prepared on each tooth. The specimens were assigned in two case and control groups while cases were exposed to H2O2 35% for the subsequent 5 days [30 minutes each day thrice] and the controls were stored in serum physiology. The specimens were thermocycled, stained with fushin and sectioned longitudinally. The microleakage scores were determined and subjected to Mann-Whitney U and Friedman tests in both groups. The mean and median of leakage scores in four regions of control specimens were 1.588 and 1.625 while the ratios were 1.913 and 2.25 for the teeth exposed to H2O2. The teeth exposed to H2O2 35% leaked higher than control specimens in the mesial region [p<0.04], while no significant differences were observed between two groups in the other areas. The use of Fuji IX glass ionomer cements in the restoration of class V cavities is an acceptable treatment modality for the restoration of bleached teeth

[SEM evaluation and comparison of marginal integrity of glass-ionomer and composite restorations with immediate or delayed polishing]

Marginal seal in class V cavities and determining the best restorative material to decrease microleakage is of great importance in operative dentistry. The aim of this study was to evaluate the effect of polishing time on the microleakage of three types of tooth-colored restorative materials in class V cavity preparations and to assess the marginal integrity of these materials using scanning electron microscope [SEM]. In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 30 bovine incisors [60 cavities]. The specimens were divided into three groups each containing 10 teeth [20 cavities]: group 1, Filtek Z 350 [nanocomposite]; group 2, Fjui IX/G Coat Plus [CGIC]; and group 3, Fuji II LC [RMGI]. In each group, half of the specimens [n=20] were finished/polished immediately and the rest of them were finished/polished after 24 hours. All the specimens were thermocycled for 2000 cycles [5-50 [degree sign] C]. epoxy resin replicas of 12 specimens [2 restorations in each subgroup] were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at room temperature, sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between incisal and cervical microleakage was made with Wilcoxon test. Incisal and cervical microleakage were not affected by polishing time in none of the three restorative materials [P>0.05]. Cervical microleakage only in Fuji IX with immediate polishing was significantly higher than incisal microleakage [P<0.05]. Incisal and cervical microleakage with immediate or delayed polishing were not significantly different in Fuji IX, Fuji II LC, and Z350 [P>0.05]. Immediate polishing is recommended in tooth-colored class V restorations

Influence of surface treatment on microtensile bond strength of self-adhesive resin cement to zirconia

Different alternative surface treatments, which have not been fully investigated, have been suggested to improve bonding to zirconia. The aim of this study was to compare microtensile bond strength of self-adhesive resin luting cements to zirconia following different surface treatments., Three blocks of zirconia [Cercon, Degussa, Germany] and three composite blocks [Z100, 3M, ESPE, USA] with 11x11x5 mm dimension were made. The blocks were divided into three groups. The ceramic blocks were cemented to the composite blocks using G-Cem [GC, Japan] according to the manufacturer's specifications. All samples were stored in 37°C distilled water for 24 hours and later sectioned in two axes using diamond disk to obtain bar shape specimens with a cross-sectional area of approximately 1mm[2] and 10mm long [n=12]. Specimens were stored in 37°C distilled water for 72 hours and thermocycled for 2000 cycles [5°C/55°C]. Each specimen was then attached to a microtensile test device. Bond strength was measured with crosshead speed of Imm/min. Failure modes were examined under stereomicroscope [x40]. Representative specimens were observed by scanning electron microscopy [SEM]. Bond strength data were analyzed with one way ANOVA and Tukey tests [a-0.05]. Alloy Primer subgroup [49.64 +/- 7.02] had a significantly higher bond strength than silane [42.12 +/- 4.2] and silicoating with silanopen [21.78 +/- 4.7] [p<0.0001]. Silanopen had the lowest bond strength in this group. SEM observation indicate that ceramic surface in silanopen group had fewer irregularities. Primers containing MDP functional monomer like Alloy Primer affect the durability of self adhesive resin cement [G-Cem] bond strength to zirconia

[In vitro evaluation of antibacterial activity of extract of Salvia officinalis and Carum copticum against cariogenic microorganisms]

Based on the attraction of the world society to traditional treatment and the importance of drug extraction of natural material and plants, in this in vitro study the effect of hydroalcoholic extract of Salvia officinalis and Carum copticum which are very useful in the traditional treatment of mouth and teeth disease have been determined against cariogenic bacteria. In this experimental study, hydroalcoholic extracts have been prepared after sterilization of the extracts by special filter from Salvia officinalis and Carum copticum using the maceration method [serial dilution of the sample by the method]. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated by the broth macrodilution method. Results have been analyzed with Mann-Whitney test. MIC [Minimum Inhibitory Concentration] of Salvia officinalis and Carum copticum for Streptococcus mutans were 6.25 and 12.5 micro gram per milliliter, respectively, These figures were 1.56 and 6.25 micro gram per milliliter for Lactobacillus rhamnosus and 12.5 and 25 micro gram per milliliter for Actinomyces viscosus. Both extracts had inhibitory effects on growth in all three bacterial species. Salvia officinalis had a greater effect on inhibition of growth in all three bacterial species. Salvia officinalis also had a bactericidal effect in the range of concentration

Effect of the thermal and mechanical load cycling on microleakage of packable composite resin

Some studies have reported packable composite has good mechanical properties including less stress, polymerization shrinkage and lower coefficient in thermal expansion, but it's adaptation to cavity walls is not so good. This study evaluated the thermal cycling and Mechanical loading on microleakage of packable composite using in-vitro method. Forty eight bovine incisors were selected; Cl II cavity preparations were performed. The teeth were etched with 37% phosphoric acid. After etching, the teeth were rinsed with distilled water and dried with cotton pellet. Single bond [3M] adhesive system was applied next according to the manufacturer's instructions. The surface was light-cured [Intensity 520 MW/cm[2] and the cavities were filled with P 60 composite [3M]. The teeth were randomly divided into two groups and two subgroups [n=12]. Each group was treated with different thermal and mechanical load cycling. The entire surface of each tooth was coated with three layers of Nail polish, except for the 1- mm width around the cervical margin. The teeth were immersed in 2% fushin solution for two hours and then embedded in acrylic resin. Then they were hemi-sectioned longitudinally in a mesio-distal direction through the center of the restoration. The half tooth specimens were evaluated according to the amount of dye microleakage by means of a 40xmagnification. Statistical analysis was conducted using SPSS software, and Kruskal-Wallis test. No significant difference was detected between the four groups [P>0.05]. According to the results of this study, thermo cycling and mechanical loading showed no effect on microleakage

[Effect of curing time and application of one bottle bonding on shear bond strength of composite to dentin]

Bonding type and curing time may affect shear bond strength of composite to dentin. This study was conducted to evaluate the effect of these factors on composite to dentin bond strength. The buccal dentin of seventy-two intact extracted premolar and molar teeth were etched with phosphoric acid 37% for 5 seconds [S] and washed with water, for 15S and dried for 2-3S. The teeth were randomly assigned to six groups. Group 1: Dentin Bonding [DB] was applied once and not cured; Group 2: DB was applied once and cured for 10S; Group 3: DB was applied once and cured for 20S; Group 4: DB was applied twice and not cured; Group 5: DB was applied twice and each layer cured for 10S; Group 6: DB was applied twice and each layer was cured for 20S. Then composite blocks were placed on bonded surfaces and cured for 40S. The specimens were thermo-cycled and the shear bond strength was measured using Instron testing machine. The data were analyzed with two-way ANOVA and Tukey HSD tests. Mean shear bond strengths of the groups in MPa were as follows: Group 1: 15.57; Group 2: 16.22; Group 3: 16.68; Group 4: 17.39; Group 5: 18.18 and Group 6: 20.02. [P<0.001] Additionally the mean bond strength of groups cured 20S was significantly higher than other groups [P<0.05]. Adequate polymerization time and increased adhesive layer thickness could improve bond strength of composite to dentin

[Evaluation of monomer elution from two dentin bonding agents cured with halogen and LED lights]

Polymerization of resin-based dental materials is not complete; and the release of unreacted monomers has undesirable effects on biocompatibility and integrity of material. The aim of this study was to evaluate the type and effect of dentin bonding agents, type of light curing unit, the distance between the tip of curing unit and surface of bonding agents on monomer leaching. This experimental study used 40 sound extracted teeth, with prepared cavities about 3x3x2 and 3x3x4 mm on the smooth surfaces. A self-etch bonding [Clearfil SE Bond Curary, Japan] and one etch and rinse [Scotch Bond multipurpose, USA] were applied on cavities according to the manufacturer's instruction. The bonding agents were cured with halogen [Optilux 501, Colten] and LED [Ultalume 2, Vivadent] lights. The samples were saved in pure methanol with 37°C for 24h. Liquids were studied with gas chromatography [GC] for detection of different monomers. Data were analyzed using 3-Way ANOVA and Independent T-tests. The type of bonding agent had significant effect on monomer release. Scotch Bond released more monomer than Clearfil SE Bond [P=0.001]. The effect of light curing unit on monomer leaching was not significant, but the samples of Scotch Bond with more distance released more monomer. Only HEMA monomer was detected from dentin bonding agents in this study. Scotch Bond released more HEMA than Clearfil SE Bond. Halogen and LED lights had no significant effect on monomer leaching. More distance between the tips of light causes less degree of polymerization

[ vitro evaluation of antibacterial activity of hydroalcoholic extract of Salvia officinalis and Menta longifolia against three cariogenic bacteria]

The microbial cause of dental caries has been proved among its multifactorial etiologies. The prevention and control of dental caries is very critical because of high prevalence and cost especially in high risk patient such as xerostomia. Based on the world attraction to traditional treatment and importance of drug extraction of natural material and plants, in this in vitro study effect of hydroalcoholic extract of Salvia officinalis and Menta longifolia which were very useful in traditional treatment of mouth and teeth disease has been determined against cariogenic bacteria. In this experimental study, hydroalcoholic extracts have been prepared from Salvia officinalis and Menta longifolia with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with broth macrodilution method. Results have been analyzed with Mann-Whitney test. Minimum inhibitory concentration for Salvia officinalis and Menta longifolia for streptococcus mutans were respectively 6.25 and 12.5 micro g/ml, for Lactobacillus rhamnosus 1.56 and 3.12 micro g/ml and for Actinomyces viscosus 12.5 and 100 micro g/ml. Both extracts had growth inhibitory effect on all three bacteria. Saliva officinalis had greater effect on inhibition of growth of all three bacteria [p<0.05]. Both extracts had bactericidal effect in the range of studied concentrations

[EDTA dentin conditioning and Micro-shear bond strength using SE and SEM]

The main objective of using adhesive material is the improvement of restorative materials bonding to dentin surface in clean environment. The aim of this study was to investigate the effect of EDTA on bond strength of composite resin to dentin surface when used at different times and concentrations prior to application of adhesive systems by employing Scanning Electronic Microscope [SEM]. A total of 100 dentin samples were prepared from 50 human premolars. These samples were divided into two groups according to bonding type [Clearfil SE Bond =group I, Futurbond NR=group II] and each one was classified 5 subgroups according to time and concentration of EDTA as follows: 1 - Control. 2- EDTA 15%, 30 seconds. 3 - EDTA 15%, 60 seconds. 4 - EDTA 24%, 30 seconds. 5 - EDTA 24%, 60 seconds. These samples were conditioned and composite cylinders were adhered to them. After 500 cycles of thermocycling, the testing for micro-shear bond strength was conducted on these samples. Another 10 samples were demineralized for 30 seconds with 6NHCL and deproteinized with 2.5% Naocl for 10 minutes, air dried with desiccators and viewed under SEM. Data were analyzed using one-way as well as three-way ANOVA and Tukey tests. The mean Micro-shear bond strength in group I [Clearfil SE bond] were: 31.88 [ +/- 13] for subgroup 1, 28.4 [ +/- 13] in subgroup 2, 29.8 [ +/- 9] in subgroup 3, 29.2 [ +/- 11] in subgroup 4, and 32.7 [ +/- 12] in subgroup 5. The mean Micro-shear bond strength in group 2 [Futurbond NR]: were: 22.6 [ +/- 10] for subgroup 1, 28.5 [ +/- 9] in subgroup 2, 27.3 [ +/- 10] subgroup 3, 32.4 [ +/- 15] in subgroup 4, and 31.1 [ +/- 14] in subgroup 5. There were no significant differences between the samples conditioned and the ones not conditioned with EDTA, time and the concentration of EDTA applied and also the two bonding types. EDTA conditioning prior to use of the two bonding agents under investigation in this study did not improve the bonding strength of the self etch systems, neither did the time and the concentration of EDTA applied

[Antiviral effects of different sterilization and disinfection methods on internal tubes of dental handpiece]

Dental handpieces are the most commonly used instruments in dentistry and their cross contamination is very high due to their direct contact with blood and saliva. The purpose of this study was to evaluate the antiviral effects of formalin tablets and autoclave on internal lumens of dental handpieces. This experimental study was designed in order to evaluate the effect of different materials and methods of sterilization and disinfection on virus elimination from internal spaces and interior chambers of dental turbines. Four study groups were composed of: 1] Vacuum autoclave, 2] Non vacuum autoclave, 3] Ten Para Formaldehyde tablets, and 4] Twenty Para Formaldehyde tablets. Nine turbines were tested in each group after preliminary washing, drying and autoclaving. The internal tubes and spaces were then contaminated with Polio and Herpes Simplex virus type I. Antiviral agents and devices were used according to the manufacturers' instructions. Two cell culture samples were obtained from each handpiece, after washing them with sterile distilled water and MEM [Minimum Essential Medium]. In each group one handpiece was designated as control. The culture results were recorded after one week. Autoclaving was perfectly effective on both Polio and Herpes Simplex virus type I in all groups [vacuumed, non-vacuumed, with or without lubricant]. Formalin tablets were 100% effective only on polio virus, and in the 20 tablet group turbines without lubricant. These tablets killed the Herpes Simplex virus in all groups. According to the results of this study, autoclaving is the best method of virus elimination in dental handpiece

[Antibacterial activity of hydroalcoholic extract of Salvia officinalis and Achillea millefolium against cariogenic microorganisms: an in vitro investigation]

There is an increasing global tendency to use traditional medicines and drug-extracts from natural plant materials. This in-vitro study was conducted in order to evaluate the cariostatic effect of hydroalcoholic extract of Salvia officinalis and Achillea millefolium. In this experimental study, hydroalcoholic extracts were prepared from Salvia officinalis and Achillea millefolium using maceration method. The antibacterial activity of these two extracts against Streptococcus mutans, Lactobacillus rhamnosus, and Actinomyces viscosus were evaluated through broth macrodilution method. Data was analyzed with Mann-Whitney test. The Minimum Inhibitory Concentration [MIC] of Salvia officinalis and Achillea millefolium for streptococcus mutans were 6.25 and 50 micro gram per milli liter, respectively. The corresponding figures for Lactobacillus rhamnosus were 1.56 and 12.5 micro gram per milli liter; and for Actinomyces viscosus the value were 12.5 and 50 micro gram per milli liter, respectively. The differences between the two extracts were statistically significant. Both extracts had growth inhibitory effect on all three bacteria. Salvia officinalis showed greater inhibitory effect on growth of all three bacteria. Both extracts had bactericidal effect in the considered concentration range

[Evaluation of disinifecting of 5% sodium hypochlorite solution diluted to 2:100 along with the use of disposable covers on HBV contaminated dental office surfaces and equipments]

The efficiency of disinfecting materials and procedures in removal of contamination from dental surfaces and equipments is essential. In authors' previous study, daily use of 2:100 dilution of 5% sodium hypochlorite in water and disposable covers were recommended since HBV contamination was found on semi-critical parts of the operative dentistry department. The aim of this study was to evaluate the HBV contamination following application of the recommended procedures. The study was conducted in two parts. In the first cross-sectional part, samples were collected from 17 sites of dental surfaces. In the second interventional part samples were collected from 10 sites of 9 dental and 3 sites of 2 light cure units, before and after disinfection with 5% sodium hypochlorite solution diluted to 2:100. Sterile cotton swabs moistened with sterile BSAS [Bovcine Serum Albumin in Sodium Chloride] solution were used for sampling. Samples were tested by PCR technique in Pasteur Institute, Iran. None of the samples collected in the first part of the study showed contamination. In the second part of the study, from 96 samples taken from various parts of dental and light cure units, before and after disinfecting, there was only on HBV contaminated site before disinfection which showed not contamination after disinfection. Based on the results of this study, disinfecting procedure with 5% sodium hypochlorite solution diluted to 2:100 along with using disposable covers is effective in preventing HB contamination

[Frequency of orthodontic malpractice cases and verdicts filed at the Iranian Medical Council during 1994-2004]

Recent studies have reported the increase in bonding stability when collagen was removed from the dentin surfaces. This study was designed to investigate the effect of collagen removal on the shear bond strength of three single bond dentin bonding systems with structural differences. This laboratory experiment was performed on 100 intact bovine incisors. Smooth surfaces of dentin on the buccal aspects of teeth were prepared. The samples were then classified, according to dentin conditioning and bonding types, into 4 main groups. A] The use of 3 adhesive systems, P and B NT, SB, and PLP, with no dentin treatment by sodium hypochlorite solution [control group]. B] The use of adhesive system P and B NT with dentine treatment by sodium hypochlorite solution for 1 min, before, after and without etching. C] The use of adhesive system SB with dentine treatment by sodium hypochlorite solution for 1 min before, after and without etching. D] The use of adhesive system PLP with dentine treatment by sodium hypochlorite solution for 1 min before bonding system. A cylinder of Z100 [3M] dental composite with a 2-mm diameter and 3-mm height was placed on the adhesive covered dentin surface of all groups and light-cured [900 mW/cm[2], for 40 sec]. The specimens were kept in distilled water at room temperature for one week and then thermo cycled for 500 times [5-556]. Shear bond strength of specimens was measured using a Zwick testing machine with cross-head speed of 0.5 mm/min and chisel from shearing blade. Data were analyzed by Two Way ANOVA, Tukey HSD and Dunnet T3 tests with P-value < 0.05 as the limit of significance. 1] Bonding type, dentin conditioning and their combined effects had statistically significant effects on the shear bond strength [P<0.05]. 2] The mean shear bond strength values were not the same in the PLP and P and B NT groups and were found to be higher in the PLP group [17.41 +/- 2.96 mpa-12.77 +/- 1.51mpa]. 3] In the P and B NT group, there were statistically significant differences in the mean shear bond strength among different dentin conditioning methods in all binary comparisons [except between control-H1]. 4] In the SB group, there were statistically significant differences in the mean comparisons [except between control-H1 and H1-H2]. 5] In the PLP group, statistically significant differences in the control-H1 groups in the mean shear bond strength values were found. Collagen removal from dentin surface caused a significant decrease in shear bond strength of alcohol, water and acetone-based bonding systems except when hypochlorite was used before etching in the acetone-based bonding system

Postoperative thermal sensitivity reduction after amalgam fillings; A clinical evaluation and presentation of a new method

Prepared cavities are usually treated with liners prior to amalgam placement. Light cured glass ionomer [RMGI] have been widely used for this purpose. The aim of this study was to compare the effect of RMGI on decreasing postoperative sensitivity with a new method of applying self etch bonding and glass ionomer simultaneously. In a blind randomized clinical trial study, A total of 36 patients with 2 deep caries in their posterior teeth [cavities with less than 2 mm distance from pulp in radiography] were included. Diagnostic tests [cold-heat, percussion, electric pulp test] were performed for each tooth prior to final restoration. After cavity preparation, one tooth was treated by light cured glass ionomer, the next one with SE bond and glass ionomer randomly, followed by amalgam restoration. Diagnostic tests were performed three days, thirty days and three months after amalgam restoration. The statistical analysis was performed using SPSS software version 11.5 as well as Friedman and Wilcoxon signed-rank tests. In second follow up, the sensitivity to cold was significantly less than the conventional method [P < 0.05] in our suggested compound method. However, there was no significant difference between the two groups when using the other vitality tests. Using SE bond and light cured glass ionomer simultaneously was an effective new method of decreasing the postoperative sensitivity in short term, [1 month] although, there was no difference between the two groups in the long term