Inflammatory response and immunohistochemical characterization of experimental calcium silicate-based perforation repair material.

This study compares the immunohistochemical reaction of a new experimental tricalcium silicate perforation repair material to mineral trioxide aggregate (MTA) and Biodentine. A total of 162 mature premolar teeth from 12 dogs were divided into three experimental groups (n = 54 teeth each) according to the evaluation period: 1, 2 and 3 months. Each group was further divided into two equal subgroups (n = 27 teeth each) according to the time of repair: immediate repair and delayed repair. Each subgroup was subdivided according to the material used into three experimental subdivisions (n = 8 teeth each): MTA, Biodentine (Septodont) and experimental material, and two control subdivisions: positive control (n = 2 teeth) and negative control (one tooth). Under general anaesthesia, access cavity was done. Cleaning and shaping were performed using ProTaper universal rotary instruments. The canals were obturated using cold lateral compaction technique with Gutta percha and Adseal sealer. Furcation perforations were created then randomly sealed using the three materials either immediately or after one month (delayed repair). Inflammatory cell count and immunohistochemical analysis of osteopontin-positive area fraction were digitally analysed using the ImageJ software. Delayed furcal perforation repair showed significantly higher inflammatory cell count than immediate repair. No significant difference in inflammatory cell count and immunohistochemical analysis was detected between the three tested materials. The immunohistochemical analysis revealed the highest immunopositive area fraction in the 3-month evaluation period. The experimental tricalcium silicate cement performed similarly to Biodentine and MTA regarding the osteopontin expression during perforation repair, suggesting it is a suitable alternative with favourable handling characters.

Biological evaluation of hesperidin for direct pulp capping in dogs' teeth.

This study compared the biological effect of Hesperidin, Mineral Trioxide Aggregate (MTA)-Angelus and calcium hydroxide for direct pulp capping. A total of 126 dogs, teeth were divided according to the post-treatment evaluation period into three groups (42 teeth each), group I: 2 weeks, group II: 4 weeks and group III: 8 weeks. Each group was further subdivided according to the pulp capping material into three subgroups (14 teeth each), subgroup A (Hesperidin), subgroup B (MTA-Angelus) and subgroup C (Dycal). Both inflammatory response and dentine bridge formation were assessed by histopathology. All data were statistically analysed. Resolution of the inflammation was recorded by the time with a significant difference between subgroups   within the same group (P<.05). Hesperidin, MTA-Angelus and Dycal showed either mild or moderate inflammation at 2 weeks with significant differences between subgroups (P < .05). At 4 and 8 weeks, there were no significant differences between subgroups (P > .05). Absence of complete or partial calcified bridge with no odontoblastic layer was reported in all subgroups at 2 weeks while at 4 weeks, the majority of samples in Hesperidin and MTA subgroups showed amorphous calcified deposit. At 8 weeks, there was no significant difference (P > .05) between subgroups except that 78.5% and 92.9% of Hesperidin and MTA-Angelus samples, respectively, showed moderate dentine bridge. Also, 78.5% of Hesperidin and Dycal samples revealed moderately thick dentine bridge while 78.7% of MTA-Angelus showed a thin dentine bridge with a significant difference between them (P < .05). In conclusion, Hesperidin is a promising pulp capping material inducing mild inflammation and good dentine bridge formation.

Influence of insulin on the healing of exposed dental pulp after pulp capping: An experimental study in a dog model.

BACKGROUND: This study investigates the influence of insulin on pulp tissue healing after pulp capping in diabetic dogs. METHODS: Diabetes mellitus was induced in four dogs, and their blood glucose levels were adjusted by insulin to normoglycemic level in two dogs (normoglycemic group) and to hyperglycemic level in two dogs (hyperglycemic group). Class V buccal cavities were performed in 15 teeth in each diabetic dog and two normal dogs (control group). The three groups (30 teeth each) were divided according to the capping materials into three subgroups (10 teeth each) including: subgroup A - mineral trioxide aggregate (MTA), subgroup B - bioaggregate (BA), and subgroup C - calcium hydroxide (Ca(OH)2 ). Each subgroup was divided into two subdivisions according to the evaluation period, subdivision 1: 1 month and subdivision 2: 2 months. Qualitative and quantitative evaluations of the inflammation and dentine bridge formation were assessed histologically. RESULTS: The hyperglycemic diabetic group exhibited significant higher inflammatory cell count and scores and lower dentine bridge thickness than those of the normoglycemic diabetic and control groups (P < .05). There were no significant differences in these parameters between the normoglycemic diabetic and control groups (P > .05). CONCLUSION: Insulin has favourable effects on the pulp tissue healing after pulp capping in diabetic dogs.

A comparative study of the physicochemical properties of hesperidin, MTA-Angelus and calcium hydroxide as pulp capping materials.

AIM: This study compared the setting time, radiopacity, solubility and pH changes between Hisperidin cement, MTA-Angelus and Calcium hydroxide cements. METHODS: The study was conducted on 3 equal groups of samples of the evaluated capping materials including; Hisperidin (group I, N = 24), MTA-Angelus (group II, N = 24) and Dycal (group III, N = 24). According to the assessed property, these groups were further subdivided into three equal subgroups (8 samples each) including; subgroup A for assessment of the setting time, subgroup B for assessment of radiopacity and subgroup C for assessment of the solubility of the material and evaluation of pH. All recorded data were tabulated and statistically analyzed. RESULTS: The highest mean value of setting time was for the MTA-Angelus followed by Hesperidin and Calcium hydroxide with 72.83, 48.26 and 1.58 min, respectively. MTA-Angelus had the highest radiopacity value and followed by Calcium hydroxide then Hesperidin. Hesperidin showed the solubility in distilled water (≈45% mass loss) in relation to Calcium hydroxide (≈19% mass loss). On the other hand, MTA-Angelus showed 9% increase in weight. On contrast to MTA and Calcium hydroxide, Hesperidin showed decrease in pH value throughout the evaluation periods. Higher pH values in MTA-Angelus and Calcium hydroxide were reported in comparison with Hesperidin. CONCLUSION: Despite its slight acidic nature, lower radiopacity and longer initial setting time, Hesperidin, as a natural product, is a promising pulp capping material. Further research on Hesperidin powder is recommended to improve its physicochemical properties and to assess its biological actions.

Regenerative potential of immature permanent non-vital teeth following different dentin surface treatments.

This study evaluates the regenerative potential of immature permanent non-vital teeth following different dentin surface treatments in dogs. Periapical lesions and necrotic pulps were induced in 288 roots of 144 teeth in twelve dogs. Teeth were randomly divided into 3 equal groups according to the evaluation period. Each group was subdivided into 8 subgroups according to the treatment modalities including; blood clot, blood clot and collagen, blood clot and Ethylenediaminetetraacetic acid (EDTA), blood clot, collagen and EDTA, blood clot and Mixture Tetracycline Citric Acid and Detergent (MTAD), blood clot, collagen and MTAD, positive control and negative control. Apart from control subgroups, all infected root canals were cleaned with sodium hypochlorite solution and triple antibiotics paste before different treatment protocols. After different treatments, the root length, thickness and apical diameter were evaluated by radiographic examination. Histopathological examination was carried out to evaluate the inflammation, bone/root resorption, tissue in-growth in pulp space, new hard tissue formation and apical closure. Using EDTA solution as a surface modifier showed significantly higher levels of tissue in-growth in the pulp space after 6 weeks and 3 months. Addition of collagen as a scaffold caused significantly more bone/root resorption than the other subgroups while EDTA caused significantly lower inflammatory cell counts only after 2 weeks. Final rinse with 17% EDTA solution before blood clot induction has positive impact on tissue interaction along dentinal walls without modification of the cell type. Moreover, the use of collagen as a scaffold material and MTAD as a surface modifier did not improve the quality of the regenerative process.