Abstract Purpose: To investigate whether photodynamic diagnosis (PDD) using a port able fluorescence spectrophotometer (FC-1) can easily and objectively discriminate between normal and tumor cells at the dental chairside, and to further compare it with PDD that requires speculum examination by focusing on protoporphyrin IX (PPIX). Methods: Three cell lines (2 human oral squamous cell carcinoma-derived cell lines, HSC-2 and HSC-3 cells, and oral keratinocytes, HOK cells) were cultured. 5-Aminolevulinic acid hydrochloride (5-ALA) and deferoxamine mesylate (DFO) were mixed in DMEM, and the mixture was set to Control (DMEM only) and PDD (5-ALA+DFO) groups. And then, a fluorescence was measured under room temperature (RT) and 37˚C (Incubation) by using FC-1. In this study, the two conditions were combined with the Control and PDD groups to form the Control/RT, Control/Incubate, PDD/RT, and PDD/Incubate groups. Additionally, the amount of singlet oxygen (¹O2) generated by irradiation with 405 nm LED was measured using electron spin resonance spectroscopy to detect PPIX in the cell supernatant after 24 hours. Results: In HSC-2 and HSC-3, the fluorescence intensity values increased significantly at 2 hours between the Control/RT and PDD/RT groups. In addition, there was a significant difference between HSC-2 and HSC-3 compared to HOK. In all cell lines, the fluorescence intensity values of the PDD/Incubate group were significantly higher than those of the PDD/Control group. The amount of ¹O2 generated by 405 nm LED irradiation was higher in the cell supernatants of all cell lines in the order of Control/RT < Control/Incubate < PDD/RT < PDD/Incubate group, and HSC-3 in the PDD/Incubate group showed a significant increase compared to HOK .Conclusion: It is suggested that PDD using FC-1 can clearly distinguish be tween normal cells and tumor cells in vitro studies using cell lines at 2 hours under 37˚C, and it can detect not only intracellular PPIX, but also extracellular PPIX.

Abstract Background: Dental students play a role in both oral and general health education in their communities, so it is important that they have good knowledge to enable them offer good counsel. Knowing the relationship between periodontal disease and systemic conditions will put them in better stead when giving oral health education. The aim of this study was to assess the level of knowledge among dental students of the relationship between periodontal dis eases and systemic conditions, and to determine whether there was a correlation between this knowledge and their oral hygiene practices. Methods: This was a cross-sectional study among dental students of the University of Port Harcourt, Rivers State, Nigeria. Consenting participants were given a self-ad ministered questionnaire eliciting socio-demographic information, knowledge about the relationship between periodontal diseases and systemic diseases, as well as oral hygiene practices. Each correct response on knowledge was scored as 1, while incorrect responses were scored 0, with a maximum score of 7. Participants’ knowledge was graded as poor (0 - 2), fair (3 - 5) and good (6 -7). Data was analyzed using IBM SPSS version 21. p ≤ 0.05 was considered statistically significant. Spearman’s ranked correlation was used to assess the correlation between knowledge of the relationship between periodontal dis eases and systemic diseases and oral hygiene practices. Results: There were 109 dental students (58 males, 51 females) in this study, with a mean age of 24.1 ± 3.6 years. Preclinical students were 43 (39.4%) while clinical students were 66 (60.6%). All (100%) participants knew that oral health was important to systemic health, with 89.9% knowing that periodontal disease was specifically linked to systemic disease. Only 50.5% of participants knew that there was a link between periodontal disease and diabetes mellitus. Sixty-four (58.7%) of the participants regularly cleaned in between their teeth. The most commonly used interdental cleaning aid was toothpick (45.0%). Clinical students had significantly better knowledge on the relationship between periodontal disease and systemic disease compared to pre-clinical students (p = 0.001). There was positive correlation between knowledge about periodontal disease and its link with systemic disease and better oral hygiene practices, but this was not statistically significant. Conclusion: The majority of dental students had a fair knowledge about the relationship between periodontal diseases and systemic diseases.

Abstract Statement of problem: Many processes have been applied to improve the fracture resistance of acrylic resin dentures by reinforcing them. The maximum goal of any denture repair is to restore the main strength of the denture and to avoid further fracture. Purpose: This study investigated the ability of self-curing acrylic resin to be strength and deflection of repaired acrylic resin joints reinforced with various reinforcement materials to resist fracture. Material and methods: Transverse strength of polymethyl methacrylate acrylic resin reinforced with glass fiber mesh, metal mesh, and metal wire was evaluated with a 3-point load test on 40 intact specimens (n = 10 for control group) (n = 10 per each reinforcement material group). Fractured joint margins were rounded, a 4-mm gap was placed between them, and then they were repaired with autopolymerizing acrylic resin and retested. Results: Transverse strength for the polymethyl methacrylate acrylic resin samples has showed fracture at the side of sample rather than in the middle area of reinforcement materials and some other samples showed bending statue rather than fracture. Conclusion: Reinforcement with glass fiber mesh, metal mesh, and metal wire produced transverse strength in the side area of resin denture base material rather than in the middle of reinforcement area with bending samples rather than fracture response .

Abstract Background: There are associations between the severity of periodontal diseases and some predisposing factors, such as age, race, and income rate. Therefore, the present study was designed to evaluate the extra-oral digital panoramic radiographic interpretation and clinical findings of stage IV periodontitis among some samples concerning Saudi/non-Saudi nationality. Material and Methods: The study comprised a random sample of 298 residents in Saudi Arabia referred to the internship program clinics at the College of Dentistry, King Khalid University. They were according to the age of participants as follows: youth (15 - 24 years), adults (25 - 64 years), and seniors (65 years and over) within two groups according to nationality (Saudi and non-Saudi). Clinical periodontal examination and radiographic extra oral digital panoramic radiographs were done, and then the periodontal parameters, the percentage of bone loss, and the pattern of bone loss were recorded. The data was collected, and the statistical analysis was performed with ANOVA test, Tukey’s test, Chi-square test, and T-test and considered a P-value at (p < 0.05) to be statistically significant differences and (p < 0.001) a high significant difference. Results: The samples included 62 (20%) youth participants with mean of age (21.806 ± 3.390), 182 (57%) adults’ participants with mean age (42.802 ± 9.094), and 54 (23%) seniors participants with a mean age (69.074 ± 6.810). There were highly statistically significant differences in the comparison between the participants’ ages (P < 0.001). But, there were no statistically significant differences in the comparison between the nationality of participants (p = 0.089). Adults participants had the highest score of PCR, CAL, PPD, BL, PBL, moreover, the highest scores of the clinical findings of stage IV of periodontitis when compared to youth and seniors, except % BL and GBI where seniors participants had the highest scores (p < 0.001). On the other hand, there were highly statistically significant differences in periodontitis grade modifiers (HbAic% and Number of cigarettes/day) in the comparison between the participants’ ages where HbAic% ≥ 7 and Smoker ≥ 10 cigarettes/days among the seniors participants were more than youth and adults (p < 0.001). The results demonstrate that non-Saudi participants had the highest periodontal parameters scores moreover the highest all scores of the clinical findings of stage IV of periodontitis except the bite collapse score, tooth mobility, vertical bone loss, furcation involvement, and less than 20 remaining teeth where they were more among Saudi than non-Saudi. There were no statistically significant differences in all clinical and radiographic findings in the comparison between Saudi and non-Saudi participants except clinical attachment loss and periodontal pocket depth (PPD) (p > 0.05). Conclusion: At the end of this study, we concluded that there are alterations in clinical and radiographic and clinical findings of stage IV periodontitis with the alteration of participants’ ages and nationality.

Abstract Objectives: Resin-based composites are the most widely used dental restorative materials. Bulk-fill resin composites are of rising interest as they can be clinically applied in thicker increments compared to conventional composites. The purpose of the study was to evaluate the flexural fatigue strength of a conventional and bulk-filled resin composite placed incrementally or non-incrementally. Methods: Resin composite specimens were fabricated using either a conventional (Brilliant EverGlow) or a bulk-fill (Fill-Up!TM) resin composite by either non-incremental filling (2 × 2 × 25 mm3) or in increments of (1 × 2 × 25 mm3). Specimens were stored in distilled water for 24 h or thermocycled for 5000 cycles. The static flexural strength (σ), flexural fatigue limit (FFL) after 105 cycles and post-fatigue flexural strength (PFσ) were measured. Data were analyzed using ANOVA, with a post-hoc Tukey’s test to compare mean FFL (p < 0.05). Results: Bulk-filled composites showed higher static σ and PFσ compared to conventional composites regardless of incremental cure or thermocycling (p < 0.05). However, the non-incrementally placed conventional composite exhibited superior FFL. Thermocycling caused a significant decrease in σ and FFL for conventional composites but not bulk-filled composites. There was no significant difference in PFσ compared to σ after 24 h storage, but a significant increase in PFσ after thermocycling (p < 0.05). Conclusions: The type of composite rather than incremental placement had a greater effect on flexural strength, suggesting that operator placement technique had less influence than material selection. Thermocycling in combination with cyclic loading caused a strengthening effect in the composites, likely due to the absorption and dissipation of stresses, thereby enhancing resistance to fracture.

Abstract Aim: Phosphatase and tension homolog (PTEN) has been known to maintain homeostatic control over the body. The roles of PTEN in periodontal complex are unknown. The purpose of this study was to investigate the role of PTEN in periodontal structures by removing PTEN from osteoblasts and odontoblasts. Materials and Methods: The function of this endogenous PTEN was evaluated by conditionally eliminating the PTEN gene using an Osteocalcin (OCN) Cre driver. The resulting OCN-Cretg/+; Ptenfl/fl mice were examined using micro-CT and histology, immunohistochemical analyses for osteogenic markers in the periodontal ligament (PDL) and bone turnover. Results: Bone apposition was increased around molar areas accompanying deposition of cementum in micro CT. Osteoprogenitor markers except for OCN in the PDL maintained their expression in both wild-type and OCN-Cretg/+; Ptenfl/fl mice. Both alkaline phosphatase activity and osteoclast activity increased in the PDL of OCN-Cretg/+; Ptenfl/fl mice compared to those in wild-type mice. Conclusions: Loss of PTEN causes an increase of bone turnover in the periodontal surrounding tissues with an increase of cementogenesis. These findings underscore the effect of PTEN on homeostasis of the periodontal ligament.

Abstract Purpose: In implant treatment, the abutments and superstructures form a transmucosal area. In addition to providing appropriate cleaning instructions to patients, its material properties must be carefully considered. It is not clear how much plaque adhesion occurs at each site during treatment process, and the effect of materials on plaque adhesion. Methods: In this study, 33 patients, 13 maxillary cases and 20 mandibular cases, who had implants placed in the missing molars were evaluated for the plaque adhesion of provisional restorations made of acrylic resin and monolithic zirconia final restoration after a period of more than 4 weeks. In addition, oral hygiene instructions were thoroughly given for 12 cases at the time of staining after the provisional restorations, and re-evaluated in 4 weeks. Results: About 20% of the buccal-lingual area of the prosthetic device fabricated with acrylic resin showed plaque staining, whereas about 40% of the area of the mesial and distal. On the other hand, for the zirconia final restorations, the percentage of staining was about 5% for buccal and lingual surface and 10% for mesial and distal surface. The stained area ratio of the provisional restoration correlated with the zirconia superstructure area ratio. Even with careful oral hygiene, it became clear that the amount of plaque adhesion due to the difference in materials could not be overcome. Conclusion: The zirconia superstructure is extremely good from the viewpoint of plaque adhesion, but cases with a large stained area at the time of provisional restoration should be carefully followed up.

Abstract Purpose: Surgical templates produced by digital simulation and CAD/CAM allow for three-dimensional control of implant placement. However, due to clinical limitations, there are complications during the use of the template. The purpose of this study was to summarize the complications associated with the use of surgical templates for static computer-aided implant surgery.Methods: Complications were collected during the observation period, and then their implant sites were reanalyzed with simulation software. Results: There were 104 cases during the observation period, 5 cases had complications. Mechanical complications were observed in four cases, including three cases in which the frame of the template fractured during implant placement surgery and one case in which the sleeve fell off the surgical template. In one case, there was an error in the planned position. All cases were mandibular molar cases, and all cases of frame fracture were at the free end defect site. All cases had a Hounsfield unit of more than 700 at the implant site, and some of them had a significantly small jaw opening. Conclusion: Although the spread of CAD/CAM surgical templates has made it possible to avoid problems caused by the position of the implant, it has been difficult to avoid fractures in cases of mandibular free end defects with high Hounsfield unit.

Abstract Purpose: Actinomyces israelii is known as the key species to cause classical actinomycosis. Although A. israelii is frequently isolated from human oral cavities, the distribution of this microorganism has been little reported. The purpose of the present study was to develop selective media (AISM) for the isolation of A. israelii and to assess the prevalence of this organism in the oral cavity. Methods: To examine the bacterial population in the oral cavity, a novel selective medium (AISM) was developed for isolating A. israelii. AISM consists of BHI, yeast extract, agar, ofloxacin, fosfomycin, colistin, and sodium fluoride. Results: A. israelii strains grew well on AISM. A. israelii was detected in all dental plaque samples collected from 20 subjects and the mean number of this organism in the samples was 7.9 × 104 CFU/ml. Conclusion: These results indicated that the selective medium was useful for the isolation of A. israelii and this organism was a part of the normal flora in the human oral cavity.

Abstract Purpose: Although the genus Candida is frequently isolated from human oral cavities, the distribution at the species level of these organisms has been little reported. The purpose of the present study was to assess the distribution at the species level of the genus Candida in human oral cavities. Methods: This study was performed using culture and Multiplex PCR methods. Moreover, the genotyping classification of C. albicans was analyzed with a PCR. Results: Of all subjects (n = 90), detection frequency of genus Candida was 42.2%. Genus Candida was not detected in the subjects between 0 to 9 years old, and there was no difference in the detection frequencies of this organism among each generation from 10s to 80s. C. albicans was the most dominant species,followed by C. parapsilosis, C. glabrata, and C. dubliniensis. Plural Candida species tended not to be detected in the individual sample. Genotype A was dominant in the C. albicans isolates. Conclusion: These results indicated that C. albicans of genotype A was dominant and that the genus Candida rarely coexists with other Candida species, in each individual oral cavity.

Abstract Melanotic neuroectodermal tumor of infancy (MNTI) is a rare benign, locally invasive neoplasm afflicting the infant more often in the craniofacial region. The current understanding is that this tumor’s origin is neural crest cells. The typical presentation is that a rapidly growing non-ulcerated anterior maxillary mass occurs in an infant usually less than six months old. This tumor may involve other areas including the ovaries, epididymis, femur, mandible and brain. We present that an 8-month-old infant with a maxillary lesion of MNTI appeared encapsulated, which is a hitherto unreported feature. Investigations leading to the diagnosis and the management of the case are also presented. The need to report cases of this rare entity cannot be overemphasized as this will go a long way in adding new knowledge about its biological nature.