Showing 16 results for Glass Ionomer
A. Kousari , J. Mahmoodian , A. Rashidian ,
Volume 13, Issue 3 (10-2000)
Abstract
The purpose of this study was to assess the fluoride release of three fluoride- containing materials exposed to fluoride solutions. This study compared the initial fluoride release and release following re-fluoridation (neutral or acidic 2% NaF) of three different filling materials, conventional glass ionomer cement (CG1C), resin- modified glass ionomer cement (RMGIC), polyacid- modified composite resin (PAMCR). Twenty discs of each material, measuring 2mm height and 6mm diameter, were suspended in separate vials of 2" laboratory artificial saliva. The amount of fluoride release was measured over two periods of 28 days each. Fluoride release was determined at 1,3,7,14 and 28 days of each period. Fluoride was measured with a fluoride ion- specific electrode and an ion analyzer previously calibrated with standard solution .T- test and ANOVA were used to evaluate the data. Fluoride release for all products at days 1 and 3 was significantly greater than the rest of the time intervals. Then, the fluoride release decreased significantly. CGIC released significantly more fluoride than the other products. This was followed by RMGIC, which exhibited significantly more fluoride release than PAMCR. In second period of experiment, the specimens were assigned to two subgroups often each. The samples exposed to two different solution of NaF (neutral or acidic). All groups showed the capacity of re-fluoridation and fluoride uptake. The specimens exposed to acidic NaF solution showed statistically more significant rechargeability than the neutral NaF solution. It may be concluded that glass ionomer cements act as a rechargeable slow fluoride release systems and as an effective caries preventive material in caries preventing programs for caries susceptible children.
E. Yasini , N Mohammadi ,
Volume 14, Issue 4 (1-2002)
Abstract
Posterior composite restorations, due to polymerization contraction, result in microleakage. Different methods have presented to reduce this phenomena. The aim of this study is to evaluate the effects of flowable and condensable composites to reduce microleakage. Seventy extracted human teeth were prepared with proximal class II cavities with gingival margin 1 mm below CEJ. The teeth randomly were divided into 7 groups. Groups I & II were restored with a dentin bonding (DB) agent plus a Prodigy condensable (Kerr Co.) composite, placing incremental or bulky, respectively.. In groups IK IV, V a dentin bonding agent was applied and then cavities were restored with Tetric flow composite resin as a base plus either a hybrid composite (Tetric ceram, Vivadent Co.) or a Prodigy condensable composite (Cond), placing bulky or incremental. Groups VI and VII were restored with a resin modified glass ionomer (GI) (Fuji II Lc Co.) as a base plus either Prodigy condensable or Tetric ceram. Restorations were polished, thermocycled, and immersed in 0.3% basic fushin. After that samples were sectioned and studied under a stereomicroscope to evaluate dye penetration. Results showed that all restorations showed some degree of microleakage and according to kruskall- wallis statistical analysis, there were not any significant differences between all groups (P-0.051). Then fore pair comparison, between groups. Mann-Whitney analysis was used and no statistical difference was observed. However. Gh DB- Tetric group showed the least microleakage and DB+ Cond (bulk) the most one. Due to lack of an" statistical difference among different materials methods, it is concluded that no method or restorative material have been able to eliminate microleakage in margins completely yet, and using a flowable composite resin, in place of resin modified glass ionomer or using a condensable composite, instead of conventional In brid composites, do not have any effect
A. Pahlavan , S. Banava ,
Volume 16, Issue 4 (1-2004)
Abstract
Statement of Problem: Composite reins have recently become popular for posterior teeth restorations. Gap formation and subsequent microleakage are of the complications resulting from such restorations. One of the techniques to overcome polymerization shrinkage of composite resins is sandwich technique (application of glass ionomer as a base beneath the composite resin). Since polymerization patterns in two types of composite resins (light cure and self cure) differ from each other, various effects on the bond strength between glass ionomer and dentin are expected.
Purpose: The aim of this in vitro study was to evaluate the effects of self- cure and light- cure composite resins in sandwich technique on the bond strength of light cure glass ionomer and dentin.
Materials and Methods: 40 extracted human premolars were selected and divided into four groups:Group 1: Light cure glass ionomer of 1mm thickness was placed on dentin.Group 2: 1mm thickness of light cure glass ionomer plus a mass of self cure composite resin of 2mm thickness were placed.Group 3: 1mm thickness of light cure glass ionomer plus light cure composite resin as two separate 1mm layer were placed.Group 4: 1mm thickness of light cure glass ionomer with 37% phosphoric acid etching followed by two separate layers of light cure composite resin of 1 mm thickness were placed.SEM was used to determine gap size ai Gl- dentin and Gi- composite interlaces. The findings were analyzed by ANOVA and t-student tests.
Results: Groups 1 and 2 showed no gap at Gl-dentm interface and also cracks were not observed in all these specimens. In group 3, there was gap between light cure GI and light cure composite resin and cracks were seen in GI, too. Group 4 showed gap at both interfaces and more cracks were seen in GI. Groups I and 2 showed the least gap formation and group 4 showed the most. Statistically significant difference was found between groups 3, 4 and group 1 (control), 2.
Conclusion: Base on this study, the application of self-cure composite resin on light cure GI showed no gap and crack formation on Gl-dentin and Gl-composite interfaces and GI itself. However, light cure composite resins and glass ionomer etching aggregated crack and gap formation.
F. Shafiee , Z. Borhan Haghighi ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: Because dental amalgam does not adhere to tooth structure, using adhesive cements in amalgam-bonded restorations have been increased.
Purpose: The goal of this in-vitro study was to compare the effects of three types of glass ionomer as adhesive liners as well as varnish liner in increasing fracture resistance of teeth restored with amalgam.
Materials and Methods: Seventy extracted human maxillary premolars were selected and MOD cavities were prepared on them excluding ten intact teeth as positive control group and ten cavity prepared teeth without restoration as negative control group. All the prepared teeth were then restored with spherical amalgam (gs.80) with one of the following liners silver alloy glass ionomer liner, conventional glass ionomer liner, varnish liner, resin-modified glass ionomer and resin-modified glass ionomer with delayed light curing. The teeth were stored in 37C distilled water for 7 days and were then loaded under compressive strength using an Instron testing machine. The force required to fracture teeth were recorded and the data were analyzed statistically using ANOVA and Tukey HSD tests.
Results: Statistically significant differences were observed in fracture resistance between restored and non-restored samples. Comparisons between groups attributed significant effects to resin-modified glass ionomer in increasing fracture resistance of amalgam restored teeth (P<0.05). In most specimens, one cusp was separated from tooth structure whereas amalgam remained bonded to the intact cusp. Conclusion: According to these findings, resin-modified glass ionomer put a statistically significant effect in fracture resistance of amalgam-restored teeth.
M. Mirzayi, M. Ghavam, Z. Emami Meibodi,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: Polymerization shrinkage of resin cements during setting leads to stress on teeth receiving indirect esthetic restorations. Some methods like blocking out undercuts during cavity preparation with glass Ionomer can reduce the mass of resin cement and therefore the amount of stress. The aim of this study was to evaluate the fracture resistance of molar teeth, receiving class I ceramic inlays with two different methods of blocking out undercut.
Materials and Methods: In this experimental study, thirty intact molar teeth were randomly divided into three groups of 10 each. One group was maintained intact as the control group. Similar class I cavities with identical undercuts were prepared on the other groups. In group 2 the undercut was filled with light cured glass Ionomer (vitremer 3M) before making impression, and in group 3 they were blocked out in the lab before preparation of the inlay. All the teeth in test groups were restored with indirect ceramic inlays.(vitadur - Alpha/ single bond / Rely X ARC). After thermocycling load causing fracture was assessed by universal testing machine. All the specimens were examined under a steriomicroscope (X40) to determine type of fracture. The results were analyzed by one way ANOVA and Tukey HSD tests. P< 0.05 was considered as the level of significance.
Results: The restored groups showed significantly less fracture resistance than the control group. The difference between two test groups was not significant. The fracture in group2 had less destruction.
Conclusion: According to the findings of this study, blocking out the undercut with two different methods (using glass ionomer/ or blocking it out on the die) made no diferrence in fracture resistance.
Z. Bahrololoomi, Aa. Soleymani, P. Namiranian,
Volume 24, Issue 2 (4-2011)
Abstract
Background and Aims: Use of glass ionomer cements in pediatric dentistry is increasing and limited information exists with regard to the effect of salivary contamination on the shear bond strength of glass-ionomer to dentin in primary teeth. The aim of this study was to evaluate the effect of salivary contamination on the shear bond strength of two types of glass ionomer cements to dentin in primary teeth.
Materials and Methods: A total of 36 human extracted primary molars were used in this study. The specimens were divided into two groups for each material and then further subdivided into three groups: group 1: uncontaminated, group 2: contaminated with saliva, group 3: contaminated, washed and air dried. The specimens in groups I, II, III were bonded to glass-ionomer and in groups IV, V, VI to resin modified glass-ionomer. Shear bond strength was measured using an Instron machine at 1 mm/min cross head speed. Data were analyzed with ANOVA and Tukey test.
Results: There were significant differences in the mean shear bond strength among groups IV, V (P=0.05). There were no significant difference among groups I & II (P=0.16), I & III (P= 0.93) and IV & VI (P=0.98).
Conclusion: Results showed that salivary contamination can decrease the mean shear bond strength of light- cured glass-ionomer to dentin in primary teeth.
Masumeh Hasani Tabatabaei, Sakine Arami, Ayob Pahlavan, Esmaeil Yasini, Mansoure Mirzae, Hamid Kermanshah, Farnaz Farahat,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: To evaluate the effect of polishing on surface roughness of silorane-based composite using profilometery and Scanning Election Microscopy (SEM) and compare it with that of a methylmethacrylate-based composite and a glass ionomer.
Materials and Methods: In this study, 3 groups (n=28) were tested: specimens of two composites (Filtek P90 and Filtek P60) and a glass ionomer (Fuji IX) which were prepared in polyethylene molds (4 mm diameter×10 mm height). Half of the specimens in each group were finished with 180-grit silicon carbide paper and the remaining were finished with 180-grit, and subsequently polished with 250, 400, 800, 1000, 2000, and 2500-grit silicon carbide papers. The surface roughness was evaluated using a contact profilometer and then mean (Ra) and maximum (Rmax) of surface roughness were recorded. Then, the surface of 4 specimens of each subgroup was observed under SEM. Statistical analysis was performed with T-test, ANOVA and Dunnett T3 tests.
Results: In all materials, Ra was different between polishing with 180 and 2500-grit silicon carbide papers. In 180-grit group, only Ra of Filtek P60 and Fuji IX showed significant difference (P=0.01). In 2500-grit group, there was no significant difference between the Ra of Filtek P60 and Filtek P90 (P=0.56).
Conclusion: Polishing is recommended for the glass ionomer and posterior composite restorations.
Abdolrahim Davari , Maryam Kashfi, Ebrahim Ataei, Danesh Kazemi Alireza ,
Volume 26, Issue 3 (8-2013)
Abstract
Background and Aims: Bleaching agents not only affect the tooth structure, but also may alter the properties of restorative materials. The aim of this in vitro study was to evaluate the effect of different bleaching regimens on the microhardness of four tooth-colored restorative materials.
Materials and Methods: Eighty specimens of four restorative materials (Microhybrid resin composite (Z250 (3M, ESPE), nanohybrid composite Z350 (3M, ESPE), packable composite P60 (3M, ESPE), and resin modified glass ionomer Vitremer (3M, ESPE)) were fabricated and were polished after 24 h with Soflex discs (3M,ESPE). Then the specimens were divided into two groups: In office bleach group, 40 specimens (10 of each restorative material) were bleached with hydrogen peroxide 37.5% for 30 min in two sessions with 7 days interval. In home bleaching group, 40 specimens were bleached with carbamid peroxide 22%, 6 h a day for 14 days. Vickers microhardness test were done before and after bleaching (baseline). Finally data were evaluated using analysis of Variance.
Results: Two bleaching regimens were significantly decreased the microhardness values. In Z250 resin composite, the microhardness values before and after bleaching were 95.30 and 92.67 kg/mm2, respectively. for office bleaching (P=0.011) and 95.38 and 92.39 kg/mm2 for home bleaching (P<0.001). In Z350 resin composite, the microhardness values before and after bleaching were 98.29 and 92.41 kg/mm2, for office bleaching (P<0.001) and 97.35 and 93.44 kg/mm2 for home bleaching (P<0.001) respectively. In P60 resin composite, the microhardness values before and after bleaching were 103.10 and 96.16 kg/mm2, respectively. for office bleaching (P=0.045) and 102.61 and 98.16 kg/mm2 for home bleaching (P=0.001). In resin modified glass ionomer (Vitremer), the microhardness values before and after bleaching were 56.79 and 49.41 kg/mm2, respectively. for office bleaching (P=0.004) and 54.17 and 46.50 kg/mm2 for home bleaching (P<0.001). There was no significant difference between two bleaching agents (P=0.365).
Conclusion: Dental bleaching agents decrease the microhardness of tooth-colored restorative materials.
Roza Haghgoo, Mohammad Bagher Rezvani, Somayeh Kameli,
Volume 26, Issue 3 (8-2013)
Abstract
Background and Aims: Metallic nano-particles show exclusive biological, chemical and physical characteristic. The purpose of this research was to evaluate the effect of various amounts of nanosilver incorporation (0 (as control), 20, 40, 80, 120, 200 ppm) on the mechanical Properties ( compressive and flexural strength) of resin modified Glass ionomer Cement.
Materials and Methods: Based on ISO 4049 and ISO 9971 for polyalkenoid cements, 90 cases in each group were prepared for the flexural and compressive strength. Specimens in 6 groups with different amounts of nanosilver (20, 40, 80, 120 and 200 ppm) and control (Fuji II LC improved), stored in distilled water at 37 ° C for 1 day and 30 days. Flexural strength, using a three-point bending method, Modulus of elasticity and the compressive strength were measured by universal testing machine (Zwick) with crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA and Tukey post HOC test.
Results: The flexural strength and modulus of various amounts of nanosilver incorporation of resin modified glass-ionomer cement were not significantly different (P>0.05). The compressive strength of incorporating of
20 ppm compared with control (P=0.01), 40 ppm (P=0.02) and 80 ppm compared with control (P<0.001) were increased. The flexural strength and compressive strength of Fuji II LC, containing nanosilver particles were increased after 1 day and 1 month significantly (P<0.001).
Conclusion: Incorporation of 20 to 80 ppm nanosilver into Fuji II LC had increased mechanical properties compared to the original cement.
Dastnaei Peimaneh Hosseini , Dastgurdi Maziar Ebrahimi ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: In case of nonsurgical endodontic re-treatment or replacing a restoration, one of the best methods for removing post from the canal is using an ultrasonic vibration. The aim of this study was to evaluate the effect of ultrasonic vibration time on the retention of post luted with zinc phosphate or glass ionmer cements.
Materials and Methods: 96 sound extracted lower premolars were selected. The coronal section of specimen was removed and the roots were endodontically treated. A 9-mm post space was prepared in each specimens and a stainless steel Parapost XP was cemented into the post space. Half of the specimens were cemented with the Zinc phosphate cement and the other by g lass ionomer cement. After 7 days of storage, both groups were equally divided into 4 subgroups of 12 teeth. Control group did not receive any treatment. The other subgroups subjected to ultrasonic vibration for 4, 8 or 12 minutes. The retention of all specimens was evaluated and data were analyzed using ANOVA and Tukey tests.
Results: In control (no ultrasonic) group and 4 minute ultrasonic group, the retention of posts luted with Zinc phosphate cement were not significantly differen t from those luted with g lass ionomer cement. (P=0.372). On the other hand , applying of ultrasonic vibration for 8 and 12 minutes in zinc phosphate and 12 minutes in g lass ionomer caused a significant reduction in the retention of posts (P=0.01).
Conclusion: Although, the initial retention of two cements was not different, the ultrasonic vibration had more catastrophic effect on zinc phosphate in comparison to glass ionomer.
Baharan Ranjbar Omidi, Ladan Madani, Aida Mirnejad Joybari, Ensyeh Rashvand, Sonia Oveisi,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: Microleakage is an important problem with direct restorations and familiarity with contributing factors is of utmost importance. The aim of this study was to evaluate the microleakage of three glass ionomer restorations in class V cavities.
Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual/ palatal surfaces of 30 human premolars (60 cavities). The specimens were divided into three group (n=10, 20 cavities). Restored as follows: group1: with Fuji IX (HVGI) ionomer/G coat plus, group 2: Ionofil molar (HVGI)/ G coat plus, and group 3: Fuji II LC (RMGI) / G coat plus. All specimens were finished and polished immediately and were thermocycled (2000 cycles, 5-50°C) . In each group half of the teeth were load cycled (50000 cycles). Finally, the teeth were immersed in 0.15% basic fushine dye for 24 hours at room temperature and then sectioned and observed under stereomicroscope. Data were analyzed using Kruskal-Wallis, Man- Whitney test and a comparison between incisal and gingival microleakage was made using Wilcoxon analysis.
Results: It was shown that the mechanical load cycling and filling material did not cause a statistically significant increase in the incisal and gingival microleakage in any of groups (P>0.05).
Conclusion: It was concluded that the extent microleakage of Fuji II LC was similar to that of the highly viscous glass ionomers (Ionofil molar, Fuji IX) and load cycling did not increase the microleakage.
Mansore Mirzaie, Esmaiel Yasini, Ladan Ranjbar Omrani, Morteza Rokni, Hojat Darvishpour ,
Volume 28, Issue 4 (1-2016)
Abstract
Background and Aims: Microleakage is a criterion proposed for assessing the success of any restorative material. Complete seal is difficult especially for dentin margins compared to enamel margins. The aim of this study was to assess the microleakage at the enamel and dentin margins of class V cavities restored by two GIs and two self-etch adhesive systems.
Materials and Methods: This study was done on forty third molars. Class V cavities (3×2×2mm) were prepared on the buccal and lingual surfaces of teeth using high speed handpiece with 0.8 mm diamond fissure burr. The occlusal margins of the cavities in the enamel and gingival margins were placed 1 mm below the CEJ. The teeth were divided into 4 groups and the bondings were cured for 20 sec and the teeth were restored. The specimens were kept in distilled water at the temperature of 37°C for 24 hrs. The teeth were thermo cycled and cut in buccolingual direction using diamond disc under water. The dye penetration was evaluated using a stereomicroscope and the leakage was scored. The scores were compared using Kruskal-Wallis test while the paired comparisons were done using Bonferroni correction. P≤0.05 was regarded as significant results.
Results: Microleakage scores were similar at the occlusal and gingival walls of all test groups. At the gingival walls, the least microleakage scores were observed. “Fuji IX + SE bond” group showed significant differences with the “Fuji IX + G bond” and “Nanoglass + G bond” groups (P≤0.05). At the occlusal walls, the least scores were observed in the “Fuji IX+SE bond” specimens which were significantly different from the other groups (P≤0.05).
Conclusion: Self-Cure glass ionomers yielded less microleakage scores compared to the different types of light-cures due to the less polymerization shrinkage.
Masumeh Hasani Tabatabaei, Sakineh Arami, Fatemeh Khajavi, Zohreh Moradi,
Volume 29, Issue 4 (1-2017)
Abstract
Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence.
Materials and Methods: In this experimental study, eighty human teeth were collected and stored in normal saline. The teeth were soft-tissue debrided and cleaned with water/pumice slurry and rubber cups in a low-speed handpiece. Speciments were randomly divided in two main groups. Cavities were prepared with diamond burs or Er:YAG laser (10 Hz, 300 mJ, 3W). Each group was divided into 4 sub-groups, and restored with a glass-ionomer cement (Fuji IX), resin modified glass-ionomer (Fuji II LC), total etch bonding + composite resin or self-etch bonding + composite resin. The specimens were submitted to pH cycling. Speciments were then sectioned, polished and Vickers microhardness measurements were performed on each specimen. Differences among the medians were analyzed using two way ANOVA test at a 95% confidence level and Tukey test.
Results: Statistical analysis showed significant difference in the type of substrate (enamel, dentin) in both main groups (P<0.0001) but no differences in the caries lesion development between the cavities restored with the same material and prepared with diamond burs or Er:YAG laser.
Conclusion: The Er:YAG laser used for cavity preparation and different types of restorative materials used did not show the ability to guarantee significantly more acid-resistance tooth structure against demineralization.
Dana Jafarpur, Rafaat Bagheri,
Volume 31, Issue 4 (1-2019)
Abstract
Background and Aims: Glass ionomer cements are among direct restorative materials which are used in an environment saturated with moisture. Therefore, having the ability to prevent water contamination is crucial. The aim of this study was to determine the water sorption and solubility of five glass ionomer restoratives with and without two nanofilled resin coating agents.
Materials and Methods: Five glass ionomer cements (Fuji BULK/GC, EQUIA Forte Fil/GC, Fuji II LC/GC, riva self cure/SDI, riva light cure/SDI) and two resin-based coating (G-COAT PLUS/GC and EQUIA Forte Coat/GC) were used in this study. Water sorption and solubility were measured in accordance with the ISO 4049's. For each material, 15 disc-shaped specimens were prepared using a polyethelyn mould. The specimens of each material were randomly divided into two groups: 10 coated and 5 uncoated. For the coated groups of each material, 5 specimens were coated with G-COAT PLUS, and 5 with EQUIA Forte Coat. Data were analyzed using SPSS software version 18 (SPSS Inc., Chicago, IL, USA). Two-way ANOVA was applied to investigate if there were any interactions between materials and coatings. One-way ANOVA was used to compare different variables between the materials, and post-hoc Tukey’s test was performed to show significant differences in subgroup comparisons.
Results: A significant interaction effect was obsevred between materials and coatings (P<0.05) using two-way ANOVA. The uncoated groups showed higher mean sorption and solubility values compared to the coated groups, and the groups coated by G-COAT PLUS showed less mean sorption and solubility values than that of EQUIA Forte Coat. In general, the lowest mean sorption and solubility values among glass ionomer cements belonged to Fuji BULK.
Conclusion: The water sorption and solubility values of glass ionomer cements could be reduced by the use of a protective coating.
Hoseinali Mahgoli, Rezvaneh Ghazanfari, Mahdi Mirmohammadi, Davoud Zare, Mahnaz Arshad,
Volume 32, Issue 3 (11-2019)
Abstract
Background and aims: Solubility is an important property of luting cements in determining clinical durability. The aim of this study was to compare the solubility of Panavia, Calibra and Maxcem resin cements with that of GC Fuji PLUS resin modified glass ionomer cement in three different pH values.
Materials and Methods: A total of 96 specimens were prepared (8mm diameter, 4mm thickness) according to manufacturer instructions. After setting, they were desiccated and weighed. The specimens were kept immersed in distilled water and lactic acid solution (pH values of 3 and 5) for 30 days and then removed and weighed again. Data were statistically analyzed by SPSS18 using two-way ANOVA with P≤0.05 set as the level of significance.
Results: The results of this study showed no significant difference between three pH values (P=0.08). The Calibra resin cement had the lowest value of solubility in distilled water and both pH of lactic acid. GC Fuji PLUS resin modified glass ionomer cement had the highest value of solubility in lactic acid and the Maxcem resin cement had the highest value of solubility in water.
Conclusion: The solubility characteristics of resin modified glass ionomer and three different resin cements were significantly affected by their composition and the storage condition.
Abdolrahim Davari, Farnaz Farahat, Mahnaz Mehranfar,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: Recently, the addition of nanoparticles into the restorative materials and tooth preparation by laser for improving the bond strength have been concidered by researchers. The aim of this study was to investigate the shear bond strength of the bioactive glass ionomer containing titanium particles and a conventional glass ionomer with two surface treatments by Er-YAG laser and conventional methods.
Materials and Methods: In this in-vitro study, 64 sound extracted premolars were collected. For conventional method, the specimens were prepared in such a way that dentin surfaces with a depth of 0.5 millimeter created at distance of 2 mm from the joint of CEJ at the root or crown. In the laser group, after preparing the teeth, the surface area was prepared by Er-YAG laser. Then, in the middle part of the buccal surface, a cylindrical mold with dimensions of 3.5 mm in diameter and 4 mm in height was placed and for each group was filled with its own glass ionomers. The specimens were divided into 8 groups by simple random sampling (n=8): A (laser, conventional glass ionomer, coronal dentin)/ B (laser, glass ionomer containing titanium nanoparticle, coronal dentin)/C (conventional, conventional glass ionomer, coronal dentin)/ D (conventional, glass ionomer containing titanium nanoparticle, coronal dentin)/ E (laser, conventional glass ionomer, root dentin)/ F (laser, glass ionomer containing titanium nanoparticle, root dentin)/ G (conventional, conventional glass ionomer, root dentin)/ H (conventional, glass ionomer containing titanium nanoparticle, coronal dentin). Finally, the shear bong strength by a universal testing machine was measured at a cross-head speed of 1 mm/min. For data analysis, Two-way ANOVA test was used to evaluate the effect of each variable and their interaction on the shear bond strength and Tukey test was used to compare the two groups.
Results: There was significant difference only between groups B with C (P=0.002), E (P=0.007), G (P=0.001) and H (P=0.01). The highest bond strength was found for group B (laser, glass ionomer containing titanium nanoparticle, coronal dentin) and the lowest bond strength for group G (conventional, conventional glass ionomer, root dentin).
Conclusion: All three factors of Er-YAG laser, glass ionomer containing titanium nanoparticle and coronal dentin had a positive effect on the improvement of the bond strength.
