The Effect of Diabetes Mellitus on the Thickness of Gingival Junctional Epithelium (Study in the Experiment of Caspase-3)

Diabetes mellitus (DM) is a metabolic disorder manifested by abnormally high levels of blood glucose, resulting in hyperglycemia that affects the oral cavity, leading to periodontitis. The junctional epithelium (JE) is the epithelial component of the dento-gingival unit that is in contact with the toothsurface. Apoptosis and proliferation of JE are essential to maintenance JE thickness.  Apoptosis is programmed cell death that can be triggered by various signals and is characterized by well-defined morphologic changes and biochemical features. Caspase-3 is involved in the underlying mechanisms of apoptosis, and the activation of caspase-3 is considered to be the final step in many apoptosis pathways. Purpose of this study was to investigate the effect of DM on the expression of caspase-3 and the thickness of JE. Sixteen male Sprague-Dawley rats were used and divided equally into two groups: the diabetic group that injected intraperitoneal by streptozotocin (STZ) and negative control group. Measurements of blood glucose levels were analyzed before and at 2, 4 weeks after STZ injection. In addition, JE thickness and expression of caspase-3 were examined after 2 and 4 weeks. JE was stained by hematoxylin-eosin (H&E) staining for thickness measurement and the immunohistochemistry by using the anti-caspase-3 antibody for caspase-3 expression measurement and examined under light microscope. The results of the present study showed that a decrease of JE thickness and increase of caspase-3 expression were obtained while increasing the diabetic duration. Two ways Anova and Least Significant Difference (LSD) tests indicated a significant difference of JE thickness and caspase-3 expression between all groups except in diabetic group after 2 and 4 weeks. Also, caspase-3 expression in diabetic group after 2 and 4 weeks (P > 0.05) were not significantly different. It can be concluded that diabetes mellitus (DM) affected on the thickness and caspase-3 expression of JE. Furthermore, the results suggest that high expression of caspase-3 was associated with the diabetes-induced apoptotic cell-death resulting in reduction of JE thickness

The Effect of Toothbrushing Duration on Nickel Chromium Alloy Wear

Nickel-chromium alloy is a preferred material for fixed partial denture due to its low cost as well as good physical and mechanical properties. Tooth brushing using toothpaste produces abrasion on restoration, especially in a long period. This study aimed to observe the effect of toothbrushing duration on the wear of nickel-chromium alloy. Twenty four specimens of nickel-chromium alloy (Metal 4all, Ivoclar, USA) in 30X15X1mm3 dimension were treated using tooth brushing simulation machine (wear test machine, pin on plate unidirectional movement type) and toothpaste (modification of Balsam formula). The brushing durations were 30.9, 77.25, 123.6, and 154.5 hoursas the simulation of 2, 5, 8, and 10 years tooth brushing. Surface roughness and weight difference as abrasion indicator were measured and analyzed using one-way ANOVA followed by LSD test. Tooth brushing duration of 2, 5, 8, and 10 years increased nickel-chromium alloy surface roughness (Ra) by 0.16, 0.39, 0.43, and 0.56µm with weight loss of 8%, 15%, 23%, and 32 %, respectively. These differences were statistically significant (p <0.05). The result of LSD test showed a significant effect (p <0.05) between groups of toothbrushing duration. The increase of surface roughness affects the increase of wear volume of nickel-chromium alloy indicated by R = 0.11 for brushing duration of 2, 5, 8, and 10 years. The conclusion of this study was 10 years tooth brushing promoted wear on nickelchromium alloy, whichwas indicated by the increase in surface roughness and weight loss

Influence of Bacterial Endotoxin on Mucosal Immune Response to Phosphorylcholine

Bacterial lipopolysaccharide (LPS), a component of the outer membrane of gram-negative bacteriathat initiates inflammation by activation innate immune responses through Toll-like receptor 4(TLR4). However, the influence of LPS on the mucosal immune reactions remains to be addressed.This study was examined the effect of LPS in nasal vaccination model. BALB/c and C57BL/6 micewere nasally immunized with keyhole limpet hemocyanin (KLH) conjugated with hapten phosphorylcholine (PC) or trinitrophenol (TNP) with LPS as a mucosal adjuvant, in the presence orabsence of cholera toxin (CT). The antibody titers were measured in serum, saliva, and nasal washfluids by an enzyme-linked immunosorbent assay (ELISA) in IgM, IgG, and IgA isotype-specificmanner. The epitope-specific antibody production induced in blood and mucosal fluid was furtherenhanced by LPS for all isotypes examined. Besides, LPS, which has rarely been regarded as a mucosal adjuvant, was tested for its adjuvanticity by comparing the nasal immunization with PC-KLH plus LPS or with PC-KLH plus CT. LPS showed high adjuvanticity almost equal to CT. Possible differences of LPS from CT as a mucosal adjuvant remains to be elucidated

Identification of Veillonella spp. on Tongue Plaque and Saliva Using Real-Time PCR

Veillonella spp., Gram-negative obligate anaerobic cocci bacteria, amounts to 3% in the oral cavity, relies on the fermentation of lactate as a carbon and energy source for growth. The bacteria are considered anti-cariogenic as they metabolize lactic acid into propionic acid which increases oral environment’s pH and reduces demineralization rate of tooth structure. Identification of Veillonella spp. using traditional methods is difficult due to the lack of conventional phenotypic and biochemical tests. Thus, the biomolecular methods are suitable for the specific detection and identification of Veillonella spp. One of the biomolecular methods that can be used is real-time Polymerase Chain Reaction (PCR), which the results can be qualitative and quantitative. This study aimed to identify Veillonella spp. in tongue plaque’s and saliva’s samples using Real -time PCR. The DNA of Veillonella spp. derived from 36 samples, 18 samples of tongue plaque and 18 samples of saliva, were extracted using a freeze-thaw method and then quantified by real-time PCR using forward primer 5’-CCG TGA TGG GAT GGA AAC TGC-3’ and reverse primer 5’-CCT TCG CCA CTG GTG TTC TTC-3’. Veillonella spp. in 18 samples of tongue plaque was 3,06 x 107 CFU/ml and in 18 saliva samples was 1,51 x 105 CFU/ml.  It was concluded real-time PCR can detect Veillonella spp. from all tongue plaque’s and saliva’s samples.

Lithium Disilicate Glass-Ceramic Surface Appearance after Acid Surface Treatment

Dental ceramics are widely used and studied in dentistry because they are durable, aesthetically appealing and provide excellent biocompatibility. All glass-ceramic surfaces must be etched using hydrofluoric acid (HF) to increase surface roughness determined by roughness average (Ra) before cementation to a tooth surface. This research aimed to analyze the effect of hydrofluoric acid surface treatment concentration on the surface roughness of lithium disilicate glass ceramic. A total of fifteen discs of lithium disilicate glass ceramic were prepared (10mm in diameter and 1mm in thickness). Specimens were divided into 3 groups (n=5). Group A (control) was no treatment, group B was etched by 5% HF for 2 min, and group C was etched by 9.5% HF for 2 min. The etched surfaces were observed by Scanning Electron Microscope (SEM). The measurement of the Ra of the lithium disilicate glass ceramic was determined with surface roughness tester machine. The results showed that the means of Ra (μm) were 0.096±0.009μm, 0.608±0.054μm, and 0.892±0.101μm in group A, B, and C, respectively. The one-way ANOVA showed there was an effect of hydrofluoric acid surface treatment concentration on the surface roughness of the lithium disilicate glass ceramic. The post hoc test showed there was a difference of Ra (μm) among the experimental study groups (p<0.05). In conclusion, the concentration of hydrofluoric acid influences Ra of lithium disilicate glass ceramic

Isolation and Characterization of Mouse Specificity Protein 6 Promoter

Specificity protein 6 (SP6) is a member of the SP/Krüppel-like transcription factor family and plays key roles in tooth development. To study its biological roles, it is important to understand the spatiotemporal regulation of Sp6 gene expression. For this purpose, we first identified two separate 5' ends of the Sp6 cDNA by 5' RACE analysis using mouse mandibular RNA. Next, we isolated mouse genomic DNA fragments covering the Sp6 gene including two putative mouse Sp6 promoter regions and generated a series of luciferase reporter constructs. We confirmed the activity of both promoters by a luciferase assay and found strong second promoter activity in dental epithelial cells. Unexpectedly, we also detected potential third promoter activity in the intron 2 of the Sp6 gene. Last, we also found that bone morphogenetic protein and wingless signals could enhance Sp6 promoter activity in dental epithelial cells, suggesting the regulatory roles of two cytokines in Sp6 gene expression during tooth development. Our findings may shed new light on the regulatory mechanisms of Sp6 gene expression and provide a possible linkage between cytokine regulation of Sp6 expression and inductive epithelial and mesenchymal interactions

The Newly Bone Formation with Carbonate Apatite-Chitosan Bone Substitute in the Rat Tibia

Large bone defect still represent a major problem in orthopedics. A tissue engineering approach has been proposed where osteogenic cells, bioceramic scaffolds and growth factors can play in a role to the bone repair. Bone consist a mineral phase such as carbonate apatite and an organic phase such as collagen. Synthetic carbonate apatite ceramics are considered as promising alloplastic materials for bone substitute. Chitin is the organic matrix of the hard parts of exoskeleton of insect, crustacean and present in a small amounts in mushrooms. It is an insoluble, similar to cellulose and composed of N-acetylglucosamine unit. Partial deacetylation from chitin result in the formation of chitosan. Chitin’s properties as a flexible and strong material make it favourable as surgical thread. It has novel properties such as biocompatibility, biodegradability, anti bacterial, wound healing activity, tissue regeneration and hemostatic activitities. The composit from carbonate apatite and chitosan may have a great impact on human health care system as bioresorbable bone substitute. The aim of the study was to evaluate the newly bone formation on the bone healing of defect tibia treated with carbonate apatite-chitosan bone substitute. Eighteen Sprague Dawley rats, male, 3 months, weighing 250-300g used in this study. Bilateral defect were created in each tibia rat. The defects were filled with carbonate-apatite chitosan bone substitute. The rats were sacrificed after respectively 1, 2 and 3 weeks. The result of this study showed that carbonate apatite-chitosan significantly increased a number of osteoblast (p<0.05). Carbonate apatite-chitosan group showed that matrix deposition faster than the other groups and have a good interface with the old bone. These data indicate that carbonate apatite-chitosan are potential candidate for bone substitut

Oral Health Status Among Schoolchildren: Does Partnership With School of Dentistry Make A Difference?

The purpose of this study was to evaluate whether the partnership between 26 primary schools with the Faculty of Dentistry, Universitas Gadjah Mada, during the past 12 years improved oral health status of the schoolchildren. A sample survey was carried out, involving 106 fifth and sixth graders from 9 schools which have been participating in the partnership and 90 schoolchildren from non-participating schools. They were examined by trained dental students. Oral health status was represented by OHI-S and DMF-t measurement. Knowledge and attitude of oral health were measured using structured questionnaires. The study indicated that the means of OHI-S and DMF-t among schoolchildren participating in the partnership were 0.11 and 0.01 lower respectively compared to those of their counterparts, although the differences were not significant statistically. The knowledge and attitude among schoolchildren in the partnership were 2.49, 4.18, and 3.86 higher, all were highly significant (p < 0.001). Path analyses showed that the partnership reduced OHI-S and DMF-t with an overall path coefficients – 0.086 and -0.076 respectively. Although knowledge was associated with DMF-t and attitude with OHI-S, there were other unmeasured variables which were more strongly associated with oral health status of the schoolchildren

CDHA Ceramic Microspheres for Periodontitis Treatment: Synthesis, Characterization and Doxycycline Release Profiles

The present study is focused on the development of doxycycline loaded calcium–deficient hydroxyapatite (CDHA) microspheres for the treatment of periodontitis. The CDHA microspheres were formed by liquid immiscibility effect using gelatin and paraffin oil with varying Ca/P ratios using calcium hydroxide and diammonium hydrogen orthophosphate as precursors. The morphology of the microspheres as characterized by SEM was optimized by varying the gelatin content. The doxycycline incorporation and its release profiles were studied by UV-Visible spectroscopy in phosphate buffer at physiological conditions. The pH of the buffer solution was initially optimized to have maximum amount of drug loading. Doxycycline loading around the physiological pH of 7 has the highest amount of drug incorporation. All the microspheres exhibit similar release profiles with an initial gradual increase reaching a maximum value and then nearly constant release. The microspheres formed using 6% gelatin shows maximum amount of drug release of 80%

The Effect of Calcium Hydroxide on Fibroblast Cells Viability

Calcium hydroxide [Ca(OH)2] is widely used as medicament in dental pulp and root canal therapy. Previous studies demonstrate the ability of calcium hydroxide to induce necrosis in dental pulp tissue. However, the mechanism of tissue destruction remains unknown.  The aim of this study was to investigate fibroblast cell viability in response to calcium hydroxide exposure. In this study, Vero fibroblast cell line was treated with various concentrations of calcium hydroxide for 24 hours.  Cell viability was measured by using MTT assay. Our results showed significant decrease in cell viability after exposed with calcium hydroxide at concentration 62.5 and 125 µg/ml. The result indicated that calcium hydroxide induced cell death in Vero cell line in a dosedependent manner. This study suggests that fibroblast cell death may involved in the mechanism of pulp tissue necrosis caused by calcium hydroxid