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Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; suchmethods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasiveaction. This study was done to assess the effect of three polishing systems on surface texture of new anteriorcomposites after storage in artificial saliva.Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for onemonth and then samples were divided into four groups according to surface treatment:Group A (control group):10 specimens received no surface polish and were subdivided into A1 (Giomer) and A2(Tetric®N-Ceram). Group B: 10 specimens received polishing with Air polishing devise (APD) and were subdivided intoB1 (Giomer) and B2 (Tetric®N-Ceram). Group C: 10 specimens received polishing with pumice and brush and weresubdivided into C1 (Giomer) and C2 (Tetric®N-Ceram). Group D: 10 specimens were polished with pumice andrubber cup and were subdivided into D1 (Giomer) and D2 (Tetric®N-Ceram). Testing was done by means ofprofilometer and statistically analyzed using analysis of variance test (ANOVA), LSD and student t-test. Also sampleswere photographed by special orthoplane camera using light polarizing microscope.Results: The results showed a highly statistical significant difference in surface roughness among Giomer subgroupsP<0.05. Also there was a highly significant difference P<0.05 when comparing Tetric subgroups according to type ofsurface treatment. Furthermore there was non-significant difference P>0.05 between groups according to the typeof restorative material used.Conclusion: The use of prophylactic surface treatment significantly increased Giomer and Tetric ceram surfaceroughness and the use of rotating brush has shown the roughest surface among all other types of prophylacticprotocols also Giomer had shown more surface roughness than Tetric ceram although the difference was notsignificant.

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Aims: To evaluate the artificial saliva sorption for three different types of light activated composite resin. Materials and Method: A total of thirty six specimens (bars) (3x8x15)mm were prepared from three different types of light activated composite resin. (Tetric N-ceram, Iv o clar-vivadent-Liechtenstein. Arabesk – voco – Germany. Soltaire–2, Heraeus, kulzer, Germany). Twelve specimens were prepared from each type of composite resin. Complete fabrication of composite resin specimens, polished and kept in three different types of artificial saliva medium, three specimens from each type of composite resin as interactive specimens kept in type of artificial saliva and the last three specimens kept in Deionized water as control medium. The weight of each specimens was measured at an analytic balance before and after different time intervals of storage (1,2,7,21,35,60) days to measure the amount of absorption of artificial Saliva (gaining and loss of weight). The study showed a significant difference (P< 0.05) in artificial saliva sorption among the three different types of composite resin at different time intervals when kept in different artificial saliva medium. Tetric N-ceram (nano composite) has more affect with three different types of artificial saliva medium (gaining and loss weight) followed by Arabesk, Soltaire-2 composite resin for different types of artificial saliva at different time intervals. Conclusion: Dental composites are sensitive to artificial salive medium (gain and loss of weight) Tetric N ceram (nano – composite) interact actively followed by Arabesk and Soltaire-2 for three different artificial saliva medium at different time intervals

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Aims: To evaluate the effect of immersion periods in artificial saliva on the surface roughness of an arch wire. Materials and Methods: The roughness of three types of orthodontic arch wires: stainless steel (SS), titanium molybdenum alloy (TMA) and composite coated wire (CC) were first measured at dry condition then incubated in artificial saliva at 37 o C with saliva pH (7.25) for different immersion periods (1, 14 and 28 days). Then the surface roughness was measured by using Taylor Hobson Profi-lometer (Talysurf type 10). Results: There was a significant increase in surface roughness of the three types of wires during the first day of immersion but as the immersion periods increased, it showed a non significant difference in the roughness of SS and TMA. The roughness of CC however, increased. Conclusions: It was concluded that the surface roughness of SS and TMA wires increased during the first day of immersion, such increase is not significant after that, while in case of CC, as the immersion periods increase the surface roughness significantly increased.

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Aims: To evaluate the Absorbance and transmittance of the optical light for three different types of light activated dental composite resin stored in artificial saliva. Materials and Methods: 30 specimens were prepared from light activated composite resin and divided in to three groups, G1: 10 specimens prepared from Els, G2: 10 specimens prepared from Tetric n Ceram, G3: 10 specimens prepared from Solitaire2. Absorbance of the optical light measured using spectrophotometer. The specimens were evaluated after (zero,1,7,28) day immersion time in artificial saliva. Results: Statistical analysis shows significant difference at P ≤ 0.05 among tested groups at same immersion time, Solitaire 2 showed highest absorbance means compare to Tetric, Els specially after 1 day immersion in artificial saliva. No significant difference P> 0.05 in absorbance mean at various immersion time in artificial saliva for each group. Els shows low absorbance and highest transmittance percentage T% than Tetric and Solitaire composite resin. Conclusion: The Els extra composite resin has lowest absorbance and highest transmittance means for optical light, Solitaire2 showed more absorbance means with less amount of light transmittance through the composite resin compare to Tetric and Els. The performance of the experimented groups statistically not significant in terms of immersion time in artificial saliva.

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Background: The aim of this study was to evaluate the effect of thermo cycling and different pH of artificial saliva(neutral, acidic, basic) on impact and transverse strength of heat cure acrylic resin reinforced of with 5% silanatedZrO2 nano fillers.Materials and methods: 120 samples were prepared, 60 samples for impact strength test and another 60 samples fortransverse strength test, for each test, samples were divided into two major groups (before and after thermo cycling),then each of these major groups were further subdivided into 3 subgroups according to the pH of prepared artificialsaliva (neutral, acidic, basic). Charpy impact device was used for impact strength test and Flexural device was usedfor transverse strength test.Result: There was a non-significant difference between the two major groups (before and after thermo cycling). Alsoresults showed that there was a non-significant difference between the subgroups for each major group in referenceto pH of artificial saliva. These results were found in both impact and transverse strength.Conclusion Transverse strength and impact strength of heat cure acrylic resin reinforced with silanated ZrO2nanofillers was not affected by thermocycling and different PH of artificial saliva suggesting improvement in themechanical properties

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This work involves experimental study for corrosion of amalgam as filling material after different period time (0, 7, 14, 21, 35, 42 days) in artificial saliva by electrochemical method to estimate corrosion parameters such as corrosion potential Ecorr, corrosion current density icorr, and Tafel slopes bc & ba. The results of polarization resistance which calculated according to Stern- Geary equation indicates that the resistance of amalgam was increased during the experimental period due to stable phases which produced between mercury and other powders in amalgam such as Sn–Hg and Ag–Hg, in addition to Ag–Cu and Ag–Sn phases. Cyclic polarization test shows that the reverse scan curves meet the forward scan curve along the passive range.Numerical modeling was achieved to estimate the corrosion behavior of amalgam in artificial saliva through longer period time, the results of this modeling shows that values of polarization resistance for amalgam at long time of filling decreases with time, but after 2200 days of filling, i.e. after at least 6 years.

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Co-Cr-Mo alloy has been used for biomedical implant for a number of years. In this study, ASTM F-75 Cobalt-base substrate specimen was immersed in artificial saliva at 37 + 1 ºC to study the corrosion resistance properties. Surface of specimen before and after the immersion was analyzed by optical microscope and Scanning Electron Microscopy (SEM). X-Ray Diffraction (XRD) was used to study the phase structure present. The metallic ions in the artificial saliva were analyzed after the corrosion test by Absorption Spectrophotometer (AAS). Electrochemical Measurements by polarization experiments were performed to study the corrosion resistance, the main results obtained were expressed in terms of the corrosion potentials (Ecorr) and corrosion current density (icorr) in addition to measure the Tafel slops by Tafel extrapolation method, and also cyclic polarization are used in artificial saliva solution. The results of galvanic corrosion show that the Co-Cr-Mo alloy had localized corrosion in artificial saliva at 37+1ºC.

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In this research and for a first time we used an artificial saliva to ex-tract Salvadora persica (miswak) to obtain useful extract affecting on different pathogens isolated from oral cavity ,that associated in dental caries .Methods: Different types of pathogens isolated from dental car-ies , Salvadora persica extracted by using artificial saliva . Agar diffu-sion methods were used to determine inhibition zones of plant extract against different pathogens. Results: The results revealed different types of bacteria isolated from dental caries also isolated Candida albicans .The high concentration of plant extract (300 mg/ml) represented more effected of inhibit bacterial isolates depended on inhibition zones mea-sured except C.albicans which was not affected to any concentration of plant extract.

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The summery of this research is to determine the longest validity period of the orthodentic wires used in three corrosive media. The first was similar to human mouth such as corrosive medium (artificial saliva), human temperature, aeration and acidity (pH), in comparison with the second corrosive medium was Khelic acid solution (CH3COO) only at same temperature and aeration above. The final comparison with the third corrosive medium was mixture of artificial saliva with khelic acid solution at same human temperature and aeration too. This study was achieved by using corrosion system was locally designed and made according to modified American standard (ASTM G31) .The orthodentic wires in this research type (AISI 301). By using the Corrosion Penetration Rate formula (CPR), traditional mathematical methods after three corrosion tests mentioned for six months in sequent and by using microstructures of samples before and after those tests. It was found the longest validity period of orthodentic wires was in medium which similar to human mouth (65.324 yr.) then wires in khelic acid solution only at same human temperature and aeration (32.982 yr.), and shortest validity period of wires was in third medium (mixture of artificial saliva and khelic acid solution at same human temperature and aeration) (15.863 yr.).The longest validity period was in the first state because in which corrosion less (50%) than the second state and less (86%) than the third state.

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The heat treatment is necessary for 2205 duplex stainless steel to remove or dissolve intermetallic phases, removed segregation and to relieve any residual thermal stress in DSS which may be formed during production processes. In the present study, the corrosion resistance of a 2205 DSS in artificial saliva was studied by SEM, XRD, HV test and potentiodynamic measurements. The results indicated that the corrosion resistance mainly effected by ferrite /austenite ratio. The best result was obtained with the treatment at 900°C for 2 min. The austenite phase has corrosion resistance higher than ferrite.

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