Evaluation of the Regenerative Capacity of Demineralized Bone Matrix vs Fat Graft in Alveolar Cleft Model in Albino Rats.

AIM: This study was performed to evaluate the regenerative capacity of demineralized bone matrix vs fat graft, both guided by pericardium membrane in alveolar cleft model in albino rats. MATERIALS AND METHODS: A total of 72 rats were required in this study. A surgical bone defect with a 7 mm length × 4 mm width × 3 mm depth was created as a model of an alveolar cleft, then the rats were divided randomly into four equal groups each group contained 18 rats: control group (defect only), the membrane group (the defect was covered by the pericardium membrane), the demineralized bone matrix (DBM) group (the defect was filled with DBM guided by pericardium membrane) and fat group (the defect was filled with a fat graft guided by the pericardium membrane). Around 6 rats from each group were euthanized after 2, 4, and 8 weeks. Skulls were scanned with cone beam computed tomography (CBCT) and harvested for histological evaluation with routine H&E immunohistochemical stains (Anti-osteocalcin and Anti-Wnt5a). The data was recorded and statistically analyzed by a two-way ANOVA. RESULTS: The study showed a notable formation of new bone, and expression of OCN and Wnt5a were notably increased by time in the fat group. However, the density of bone grafts and OCN and Wnt5a expression decreased with time in the DBM group. Control and membrane groups showed negative OCN and Wnt5a immune-reactivity in the cleft site. CONCLUSION: Fat graft results were superior to DBM results with regard to mucosal closure and accelerated bone regeneration, and may represent an effective treatment for alveolar cleft reconstruction. CLINICAL SIGNIFICANCE: Finding an inexpensive, accessible, biocompatible and easily manipulated treatment for craniofacial reconstruction and fat graft fulfilled the desired aims. Further investigations with prolonged evaluation periods are needed. How to cite this article: Abdel Raouf E, Elsherbini AM, Abdel Salam Yousef Y, et al. Evaluation of the Regenerative Capacity of Demineralized Bone Matrix vs Fat Graft in Alveolar Cleft Model in Albino Rats. J Contemp Dent Pract 2024;25(6):554-562.

Altered coronal tissue of the human dental pulp in chronic hepatitis C virus infected patients.

INTRODUCTION: Hepatitis C virus (HCV) infection is characterized by a high rate of chronicity and concerns 170 million individuals worldwide. Extrahepatic manifestations are frequently observed in patients with chronic viral hepatitis. Although extrahepatic manifestations do exist with all hepatitis viruses, they are more commonly associated with chronic HCV infection. This study aimed to evaluate qualitatively and quantitatively the effect of chronic HCV infection on the coronal tissue of the human dental pulp. METHODS: Thirty sound impacted teeth were obtained from healthy individuals as healthy controls. The patient group included another 30 sound impacted teeth obtained from chronic HCV-infected patients. The coronal pulp tissues were carefully removed, fixed, and processed to be stained with hematoxylin-eosin, alcian blue (2.5)/periodic acid-Schiff, van Gieson, and fibronectin. RESULTS: The tissue sections of chronic HCV patients revealed disorganized pulp tissue, chronic inflammatory cell infiltrate, thickening, stenosis and occlusion of large-sized blood vessel arteriole, and collapsed venule and lymphatic system. The acidic, neutral, and mixed mucins were increased, whereas the amount of collagen was decreased, accompanied with marked decrease in the distribution and quantity of fibronectin glycoprotein. Application of Kruskal-Wallis test showed that there were statistically significant changes between the 2 groups (P ≤ .05). CONCLUSIONS: The coronal tissue of the dental pulp, like any other body tissues, is affected by chronic HCV infection, with an inappropriate cellularity, vasculature, and extracellular matrix proteins. The clinician should be alerted to these histologic changes and their subsequent implications.

Effects of phosphoric acid concentration and etching duration on enamel and dentin tissues of uremic patients receiving hemodialysis: an AFM study.

PURPOSE: Using atomic force microscopy (AFM), the purpose was to investigate the effect of phosphoric acid (H3PO4) concentration and etching duration on surface roughness (Ra) and micromorphology of enamel and dentin substrates of uremic patients receiving hemodialysis. MATERIALS AND METHODS: Sixty-three enamel and dentin slabs were prepared from 42 sound natural molars collected from uremic patients under hemodialysis and mechanically polished up to 4000-grit roughness. Nine slabs of each substrate were not etched (control group). The remaining slabs were divided into two experimental groups (n = 27) according to etchant concentration (37% or 42%). In each group, 9 specimens were etched for 15, 30, and 60 s. The surface morphology of the control and test specimens was examined by AFM operated in "contact" mode. The obtained Ra was subjected to statistical analysis. RESULTS: Statistical analysis showed that increasing the duration of acid application (irrespective of acid concentration and type of substrate) significantly increased the amount of Ra. H3PO4 at a concentration of 42% was more effective at producing Ra than was H3PO4 at 37% for all 3 application times. The Ra quantity produced by H3PO4 at 42% was time specific, with 15 s being significantly less effective than 30 or 60 s. However, 60 s was significantly better than 30. CONCLUSION: The findings of this study support the use of 42% H3PO4 for etching uremic hard tooth tissues for 60 s.

Vasculitis of dental pulp associated with cryoglobulinemia in hepatitis C virus patients: case report.

INTRODUCTION: This report presents a case of impacted lower third molar extracted for surgical reasons in patient with uncontrolled hepatitis C. After decalcification, dental pulp vasculature and its tissue quality were investigated. METHODS: Serial sections of 4-µm thickness along the midline buccolingually for the demineralized specimen were obtained, mounted on a glass slide, stained with hematoxylin-eosin, covered, and viewed under the light microscope. RESULTS: The histologic investigation of the pulp tissue revealed thickening, stenosis, and occlusion of the vessel wall, ectopic calcification of the pulp tissue in close association with pulpal blood vessels, interrupted and vacuolated odontoblastic layer in the coronal pulp chamber, with an inflammatory cell infiltrate throughout the pulpal tissue. CONCLUSIONS: Cryoglobulinemia associated with uncontrolled hepatitis C virus infection in patients endangers the dental pulp vasculature and alters its normal tissue architecture.

Effect of 16% carbamide peroxide bleaching gel on enamel and dentin surface micromorphology and roughness of uremic patients: an atomic force microscopic study.

OBJECTIVES: To investigate the effect of 16% carbamide peroxide bleaching gel on surface micromorphology and roughness of enamel and root dentin of uremic patients receiving hemodialysis using atomic force microscopy (AFM). METHODS: A total of 20 sound molars were collected from healthy individuals (n=10) and uremic patients (n=10). The roots were separated from their crowns at the cemento-enamel junction. Dental slabs (3 mm x 2 mm x 2 mm) were obtained from the buccal surface for enamel slabs and the cervical third of the root surface for dentin slabs. Dental slabs were then flattened and serially polished up to #2500-grit roughness using silicon carbide abrasive papers. Half of the slabs obtained from healthy individuals and uremic patients were stored in artificial saliva and left without bleaching for control and comparison. The remaining half was subjected to a bleaching treatment using 16% carbamide peroxide gel (Polanight, SDI Limited) 8 h/day for 14 days and stored in artificial saliva until AFM analysis was performed. Statistical analysis of the roughness average (Ra) results was performed using one-way ANOVA and Bonferroni post hoc multiple comparisons test. RESULTS: The micromorphological observation of bleached, healthy enamel showed exaggerated prism irregularities more than non-bleached specimens, and this observation was less pronounced in bleached uremic enamel specimens with the lowest Ra. Bleached healthy dentin specimens showed protruded peritubular dentin and eroded intertubular dentin with the highest Ra compared to bleached uremic dentin. CONCLUSIONS: The negative effects of the bleaching gel on uremic tooth substrates are less dramatic and non-destructive compared to healthy substrates because uremia confers different micromorphological surface changes.

Influence of selective immunosuppressive drugs on the healing of exposed dogs' dental pulp capped with mineral trioxide aggregate.

INTRODUCTION: Immunosuppressive drugs are used in clinical medicine for a variety of disorders, but their effects on the reparative capacity of the dental pulp are unknown. This study evaluated the influence of selected immunosuppressive drugs on pulpal tissue healing after direct pulp capping of mechanically exposed dog's teeth with mineral trioxide aggregate (MTA). METHODS: Ten healthy male dogs were assigned into 5 experimental groups: a control group in which no drug was received and 4 experimental groups in which the immunosuppressive drugs prednisone, mycophenolate mofetil, sirolimus, and cyclosporine A were administered 45 days before the operative procedures and until the dogs were killed. Class V cavities were prepared on the buccal surfaces of 12 teeth in each dog. In each cavity, the pulp was exposed and capped with MTA. The pulpal tissue responses to capping material were assessed 65 days postoperatively. RESULTS: Compared with the control group, variable responses was recorded in the groups treated with mycophenolate mofetil, sirolimus, and cyclosporine A, which were characterized by moderate to severe inflammatory reactions, tissue necrosis, and total absence of hard tissue bridging. Pulpal tissue responses in the group treated with prednisone were characterized by inflammatory cell infiltration, limited tissue necrosis, as well as partial to complete hard tissue bridging. CONCLUSIONS: From these findings, it seemed evident that acceptable repair of the dentin-pulp complex, eg, wound healing with hard tissue formation after capping with MTA, is unlikely with mycophenolate mofetil, sirolimus, or cyclosporine A immunosuppressive drug therapy.

Long-term effect of Spirulina platensis extract on DMBA-induced hamster buccal pouch carcinogenesis (immunohistochemical study).

In cancer research, the use of complementary and alternative medicine has increased over the past decade. In this study, 80 male golden Syrian hamsters were divided into four equal groups; the right buccal pouches of the hamster rats in group 1 were painted with 0.5% solution of 7, 12-dimethylbenz[a]anthracene (DMBA), three times a week for 32 weeks. The same pouches of group 2 were subjected to the same DMBA painting; but at the same time, the animals received 10 mg/daily Spirulina platensis extract for the same period. In group 3, the same regimen of DMBA painting was done but for 24 weeks only and the daily systemically S. platensis was received for the 32 weeks. In group 4, neither DMBA painting nor S. platensis administration was done but pouches were painted with saline and served as a control one. Five rats from each group were sacrificed at 12, 24, 28, and 32 weeks, respectively. The required pouches were excised, fixed, and embedded in paraffin to be immunostained with proliferating cell nuclear antigen (PCNA). The results showed that increased PCNA expression was directly related to the severity of pathological alterations from normal epithelium to dysplasia and from dysplasia to squamous cell carcinoma (SCC) in the study groups at the different extended periods of DMBA application and S. platensis extract administration. Analysis of variance and Duncan's multiple-range test for PCNA labeling index were proved a high significant difference (P < 0.01) between the different groups. From the previous results, it can be concluded that S. platensis extract has a beneficial role in regression of cancer progression.

Bonding of resin composite to tooth structure of uremic patients receiving hemodialysis: shear bond strength and acid-etch patterns.

PURPOSE: To investigate the influence of uremia on the shear bond strength (SBS) of composite resin to enamel and dentin substrates with assessment of the micromorphological pattern of etched enamel and dentin surfaces using atomic force microscopy (AFM). MATERIALS AND METHODS: A total of 44 natural molars was collected from healthy individuals (n=22 molars) and uremic patients (n=22 molars). Each set of teeth was then divided into 2 equal subsets (n=11 molars) relative to the bonding substrate to be tested. In each subset, the surfaces of 7 molars were flattened and polished up to 2000-grit roughness using wet silicon carbide (SIC) abrasive papers. A three-step adhesive was used to bond Tetric Ceram composite buildups to the prepared tooth surfaces. All specimens were thermocycled before they were stressed in shear using a universal testing machine. Fractured specimens were stereomicroscopically examined to detect the mode of bond failure. In the remaining 4 molars, enamel and dentin specimens were prepared for AFM examination to assess the micromorphological patterns of acid-etched surfaces. RESULTS: The mean bond strength values in MPa to enamel (22.40 +/- 4.30) and dentin (17.97 +/- 4.65) of teeth of healthy individuals were significantly different (p < 0.001) from those to enamel (12.40 +/- 2.81) and dentin (7.83 +/- 2.05) of teeth of uremic patients. Most of the tested enamel specimens showed a mixed type of bond failure, but the adhesive type was predominant with dentin specimens. AFM examinations revealed a shallow etching pattern for uremic enamel and dentin specimens compared to those of healthy individuals. The mean roughness average (Ra) values after etching of healthy enamel (238.0 +/- 4.65) and dentin (267.0 +/- 4.79) were significantly different (p < 0.001) from those to etched uremic enamel (111.0 +/- 5.24) and dentin (143.0 +/- 2.16). CONCLUSION: Uremia adversely affects bonding of composite resin to enamel and dentin and confers an altered micromorphological etching pattern.