Adam Husein

Effect of 940 nm low-level laser therapy on osteogenesis in vitro

Abstract. Bone regeneration is essential in medical treatment, such as in surgical bone healing and orthodontics. The aim of this study is to examine the effect of different powers of 940 nm diode low-level laser treatment (LLLT) on osteoblast cells during their proliferation and differentiation stages. A human fetal osteoblast cell line was cultured and treated with LLLT. The cells were divided into experimental groups according to the power delivered and periods of exposure per day for each laser power. The (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to determine cell proliferation. Both alkaline phosphatase and osteocalcin activity assays were assessed for cell differentiation. All treatment groups showed a significant increase in cell proliferation and differentiation compared to the control group. Regarding the exposure time, the subgroups treated with the LLLT for 6 min showed higher proliferation and differentiation rates for the powers delivered, the 300-mW LLLT group significantly increased the amount of cell proliferation. By contrast, the 100 and 200 mW groups showed significantly greater amounts of cell differentiation. These results suggest that the use of LLLT may play an important role in stimulating osteoblast cells for improved bone formation.

Overview of non-invasive factors (low level laser and low intensity pulsed ultrasound) accelerating tooth movement during orthodontic treatment

The need for orthodontic treatment is increasing all the time. As the treatment is time consuming ranging from a year to several years, any method of reducing the period of treatment and increasing the quality of the tissue will be beneficial to patients. The use of non-invasive techniques such as low level laser therapy and low intensity pulsed ultasound in accelerating orthodontic tooth movement are promising. Thus, this overview study will help to generate more understanding about the background information and the possible applications of them in daily orthodontics, depending on previous literature searching for reviews and original research articles.

Genotoxicity evaluation of locally produced dental porcelain--an in vitro study using the Ames and Comet assays.

The aim of this study was to determine the genotoxicity of a locally produced dental porcelain (Universiti Sains Malaysia, Malaysia) using the Ames and Comet assays. In the Ames assay, four genotypic variants of the Salmonella strains (TA98, TA100, TA1537 and TA1535) carrying mutations in several genes were used. The dental porcelain was incubated with these four strains in five different doses both in the presence and absence of metabolic activation (S9) and the result was assessed based on the number of revertant colonies. Concurrently, appropriate positive controls were used so as to validate the test. The average number of revertant colonies per plate treated with locally produced dental porcelain was less than double as compared to that of negative control. In the Comet assay, L929 (CCL-1 ATCC, USA) mouse fibroblast cells were treated with the dental porcelain in three different concentrations along with concurrent negative and positive controls. The tail moment which was used as a measurement of DNA damage was almost equal to that of the negative control, suggesting that the locally produced dental porcelain did not induce any DNA damage. The results indicated that the locally produced dental porcelain is non-genotoxic under the present test conditions.

Synergistic effects of chitosan scaffold and TGFβ1 on the proliferation and osteogenic differentiation of dental pulp stem cells derived from human exfoliated deciduous teeth.

OBJECTIVE Multipotent stem cells derived from human exfoliated deciduous teeth (SHED) represent a promising cell source for tissue regeneration. In the present study we decided to test the inductive effect of chitosan and transforming growth factor-β1 (TGFβ1) as a scaffold/factor combination on SHED proliferation and osteogenic differentiation. DESIGN Cell proliferation was quantitatively assessed by PrestoBlue, live/dead assay was performed and cell attachment to chitosan scaffold was examined by scanning electron microscopy (SEM). For osteogenic differentiation analysis, alkaline phosphatase activity was quantified, cells were stained with Alizarin Red, and the lineage specific genes/proteins ALP, COL I, BSP, and OCN were analysed by real-time PCR and Western blot. RESULTS SHED remained viable and attached well to the chitosan structure. Moreover, TGFβ1 significantly enhanced the proliferative activity of SHED on the chitosan scaffold. Our data further revealed that chitosan and TGFβ1 enhanced the osteogenic differentiation of SHED, as evidenced by high ALP activity, strong mineral deposition, and the up-regulation of ALP, COL I, BSP, and OCN gene/protein expression. CONCLUSION Together, data from our study indicate that the combination of chitosan scaffolds and TGFβ1 enhanced proliferation and osteogenic differentiation of SHED. These findings suggest that the combined application of chitosan scaffold and TGFβ1 in conjunction with SHED might be beneficial for in vivo bone regeneration.

The effect of different sealer placement techniques on sealing Ability: An in vitro study.

Aim: The aim of this in vitro study was to evaluate the sealing ability of an endodontic sealer following different techniques of its placement. Materials and Methods: A total of 119 permanent human anterior teeth were prepared by using manual Protaper® and randomly divided into three equal groups of 33 teeth each. The teeth were obturated with the cold lateral condensation technique and AH26 sealer which was placed by using the following: G1: rotary lentulo spiral; G2: manual lentulo spiral; and G3: master gutta-percha coating. The remaining 20 teeth served as positive and negative controls. The samples were immersed in the methylene blue solution for 3 days and longitudinally sectioned for dye penetration assessment and analyzed using a stereomicroscope. Results: There was no statistically significant difference (P = 0.305) among the three groups. However, the rotary lentulo spiral technique and the master gutta-percha coating technique showed the highest (4.5 mm) and the lowest (3.8 mm) microleakage values, respectively. Conclusion: Different techniques of sealer placement used in this study provided a comparable seal. However, the master gutta-percha coating technique might be preferable because of its ease of use.

Different surface preparation techniques of porcelain repaired with composite resin and fracture resistance

Background: Porcelain from prosthesis such as crown or bridge can be fractured if exposed to trauma; and, can be repaired at chairside using composite resin. Aim: To investigate the fracture resistance of few techniques of surface preparation in repairing fractured porcelain using composite resin. Materials and Methods: Eighty samples of porcelain blocks were divided into 4 groups for different surface preparations, such as, Cimara repairing kit; porcelain etch kit containing hydrofluoric acid; Panavia F resin cement; and, sandblasting using aluminium oxide, before composite resin (Filtek Z250, 3M ESPE) was bonded to the prepared porcelain blocks. Twenty others samples in the control group comprised of pure porcelain blocks. The fracture resistance of each sample was tested using Instron machine (UK). Results: With the exception of the group repaired using hydrofluoric acid (3.04±1.04 Mpa), all the other groups showed significant difference in the fracture resistance values when compared to the control group (3.05 ± 1.42 MPa) at P<0.05. Conclusions: Etching of the porcelain blocks with hydrofluoric acid holds promise in the repair of fractured porcelain with composite resin at chairside.

Isolation and Enhancement of a Homogenous in Vitro Human Hertwig’s Epithelial Root Sheath Cell Population

Hertwig’s epithelial root sheath (HERS) cells play a pivotal role during root formation of the tooth and are able to form cementum-like tissue. The aim of the present study was to establish a HERS cell line for molecular and biochemical studies using a selective digestion method. Selective digestion was performed by the application of trypsin-EDTA for 2 min, which led to the detachment of fibroblast-like-cells, with the rounded cells attached to the culture plate. The HERS cells displayed a typical cuboidal/squamous-shaped appearance. Characterization of the HERS cells using immunofluorescence staining and flow cytometry analysis showed that these cells expressed pan-cytokeratin, E-cadherin, and p63 as epithelial markers. Moreover, RT-PCR confirmed that these cells expressed epithelial-related genes, such as cytokeratin 14, E-cadherin, and ΔNp63. Additionally, HERS cells showed low expression of CD44 and CD105 with absence of CD34 and amelogenin expressions. In conclusion, HERS cells have been successfully isolated using a selective digestion method, thus enabling future studies on the roles of these cells in the formation of cementum-like tissue in vitro.

Gypsum-based biomaterials: Evaluation of physical and mechanical properties, cellular effects and its potential as a pulp liner.

This in vitro study aimed to evaluate setting time and compressive strength of gypsum-based chitosan biomaterials and its effect on proliferation of stem cells from human exfoliated deciduous teeth (SHED) and alkaline phosphatase (ALP) activity. Pure-GYP was mixed with water (2.5 g: 1.9 mL); Gyp-CHT was prepared with gypsum, chitosan, and water (2.5 g: 0.285 g: 1.9 mL). Cell viability and ALP activity were assessed at different periods. Data were analyzed using SPSS (p<0.05). The setting times were 2.7 min and 2.8 min for pure-GYP and Gyp-CHT, respectively. Significantly higher compressive strength was observed with Gyp-CHT. SHED treatments with both materials were not cytotoxic. ALP was consistently higher in the treated groups compared with the control. Cellular attachments were evident with SEM. Excellent cellular viability with pure-GYP and Gyp-CHT, as well as increased ALP activities, suggested the possibility of tertiary dentin formation. Further studies are necessary to evaluate the biomaterials for its pulp protective potentialities.

New Approach to 3D Printing of Facial Prostheses Using Combination of Open Source Software and Conventional Techniques: A Case Report

The wax sculpting of a maxillofacial prosthesis is challenging, time-consuming, and requires great skill. Rapid prototyping (RP) systems allow these hurdles to be overcome by enabling the creation of a customized 3D model of the desired prosthesis. Geomagic and Mimics are the most suitable software programs with which to design such prostheses. However, due to the high cost of these applications and the special training required to operate them, they are not widely used. Additionally, ill-fitting margins and other discrepancies in the final finished products of RP systems are also inevitable. Therefore, this process makes further treatment planning difficult for the maxillofacial prosthodontist. Here, we report the case of a 62-year-old woman who attended our clinic. Initially, she had presented with a right facial defect. This was later diagnosed as a squamous cell carcinoma and resected. The aim of this report is to describe a new technique for the 3D printing of facial prostheses which involves the combined use of open-source software, an RP system, and conventional methods of fabrication. The 3D design obtained was used to fabricate a maxillofacial prosthesis to restore the defect. The patient was happy with the esthetic outcome. This approach is relatively easy and cheap, does not require a high degree of non-medical training, and is beneficial in terms of clinical outcome.

Minimally Invasive Techniques to Accelerate the Orthodontic Tooth Movement: A Systematic Review of Animal Studies

Objective. To evaluate various noninvasive and minimally invasive procedures for the enhancement of orthodontic tooth movement in animals. Materials and Methods. Literature was searched using NCBI (PubMed, PubMed Central, and PubMed Health), MedPilot (Medline, Catalogue ZB MED, Catalogue Medicine Health, and Excerpta Medica Database (EMBASE)), and Google Scholar from January 2009 till 31 December 2014. We included original articles related to noninvasive and minimally invasive procedures to enhance orthodontic tooth movement in animals. Extraction of data and quality assessments were carried out by two observers independently. Results. The total number of hits was 9195 out of which just 11 fulfilled the inclusion criteria. Nine articles were good and 5 articles were moderate in quality. Low level laser therapy (LLLT) was among the most common noninvasive techniques whereas flapless corticision using various instruments was among the commonest minimally invasive procedures to enhance velocity of tooth movement. Conclusions. LLLT, low intensity pulsed ultrasound (LIPUS), mechanical vibration, and flapless corticision are emerging noninvasive and minimally invasive techniques which need further researches to establish protocols to use them clinically with conviction.