MATERIALS AND METHODS: A total of 40 of the two types of fiber posts, namely, FRC Prostec (FRC) and Fiber KOR (KOR), were used for the experiment. UV irradiation was applied on top of the fiber post surface for 0, 15, 20, and 30 min. The irradiated surface of the fiber posts (n = 5) were immediately bonded with resin cement (Rely X U200) after UV irradiation. Shear bond strength (SBS) MPa was measured, and the dislodged area of post surfaces was examined with scanning electron microscopes. Changes in surface roughness (Ra) of the FRC group after UV irradiation were observed (n = 3) using atomic force microscopy. Data of SBS were statistically analyzed using one-way analysis of variance, followed by multiple comparisons (P < 0.05).
RESULTS: SBS was significantly higher for 20 min of UV irradiation of the FRC group while significantly higher SBS was observed with 15 min of UV irradiation of the KOR group. Resin cement was more evident (cohesive failure) on the dislodged post surface of the UV treated groups compared with the control. The surface roughness of the FRC post was Ra = 175.1 nm and Ra = 929.2 nm for the control and the 20 min group, respectively.
CONCLUSIONS: Higher surface roughness of the UV irradiated group indicated formation of mechanical retention on the fiber post surface. Evidence of cohesive failure was observed which indicated higher SBS of fiber post with the UV irradiated group.
MATERIALS AND METHODS: Total of 50 samples were selected for the study and were categorized into five groups and 10 samples in each group as Group I-oral leukoplakia (OL), Group II-oral lichen planus (OLP), Group III-oral submucous fibrosis (OSMF), Group IV-oral squamous cell carcinoma (OSCC) and Group V-normal oral mucosa (NOM) as control group. All the samples were assessed for the expression of E-cad by immunohistochemical study.
RESULTS: Upon assessing the expression of E-cad in OL, OSMF, OLP and OSCC, as majority of the samples with OSCC (90%), OL (80%), OLP (70%) and OSMF (60%) showed mild to moderate expression of E-cad staining, which was suggestive of reduction in dysplastic cells on comparison to NOM cells. This difference in expression and variation of E-cad upon comparison with normal mucosa was statistically significant (P < 0.001).
CONCLUSION: There is significant (P < 0.001) variation of expression of E-cad with the histopathological dysplasia of the oral precancerous lesions and conditions, and the tumor differentiation of the oral cancers. However, there was no correlation of the degree of loss of expression of E-cad with the degree of dysplasia or the tumor differentiation of oral cancers. We conclude with our study that, there is a variation in the expression of E-cad but its value as a prognostic marker is questionable.
MATERIALS AND METHODS: The samples were randomly selected from different states of Pakistan. Total 7168 variables were measured on plaster dental casts (128) and SM digital dental models (128) according to the selection criteria. For IMTSD, the 6 variable measured as for anterior tooth size (maxilla, mandibular), overall tooth size (maxilla, mandibular), Bolton's anterior ratios (BAR), and Bolton's overall ratios (BOR). The independent t-test and ANOVA were used for statistical analyses.
RESULTS: Significant sexual disparities in the sum of anterior tooth size and overall tooth size via DC and SM methods. No significant sexual disparities for BAR and BOR. No statistically significant differences were found in BAR and BOR between DC and SM. No significant differences were found on IMTSD ratio among different arch length and arch perimeters groups.
CONCLUSIONS: Norms were developed based on DC and SM for IMTSD. Sexual disparities were observed in the sum of teeth size. However, no significant differences in BAR and BOR for IMTSD between the two methods.
MATERIALS AND METHODS: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups.
RESULTS: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both.
CONCLUSIONS: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management.
MATERIAL AND METHODS: The three-dimensional (3D) finite element program (ANSYS software) was used to construct the mathematical model. Two 5-unit FPD'S were simulated, one with rigid connector and another one with nonrigid connector. For analysis, each of these models were subjected to axial and oblique forces under progressive loading (180, 180, 120, 120, 80 N force on first and second molars, premolars and canine respectively) and simultaneous loading (100, 100, 100, 100, 100 N force on first and second molars, premolars and canine respectively).
RESULTS: The rigid and nonrigid connector design have effect on stress distribution in 5-unit FPDs with pier abutments.
CONCLUSION: Oblique forces produce more stresses than vertical forces. Nonrigid connector resulted in decrease in stress at the level of prosthesis and increase in stress at the level of alveolar crest.
MATERIALS AND METHODS: Several electronic databases such as Google Scholar, PubMed, Science Direct, and Web of Science were systematically searched for studies published until July 2015.
RESULTS: EMG can be used in both diagnosis and treatment purpose to record neuromuscular activity. In dentistry, we can utilize EMG to evaluate muscular activity in function such as chewing and biting or parafunctional activities such as clenching and bruxism. In case of TMJ and myofascial pain disorders, EMG widely is used in the last few years.
CONCLUSIONS: EMG is one of biometric tests that occur in the modern evidence-based dentistry practice.
MATERIALS AND METHODS: Sixty maxillary central incisors were divided into Group I, II, and III with 20 samples each based on luting cement used. They were OF, self-adhesive (SA) cement, and total etch (TE) cement. These groups were subdivided into "a" and "b" of ten each based on the type of veneering materials used. Veneer discs were fabricated using Ormocer restorative (O) and pressable ceramic (C). Specimens were thermocycled and loaded under universal testing machine for SBS. The statistical analysis was done using one-way ANOVA post hoc Tukey honest significant difference method.
RESULTS: A significant difference was observed between the Groups I and II (P < 0.05). The highest mean bond strength when using ormocer veneer was obtained with the Group Ia (19.11 ± 1.92 Mpa) and lowest by Group IIa (8.1 ± 1.04 Mpa), whereas the highest mean bond strength while using ceramic veneer was of similar range for Group Ib (18.04 ± 4.08 Mpa) and Group IIIb (18.07 ± 1.40 Mpa). SEM analysis revealed OF and TE presented mixed type of failure when compared with SA where failure mode was totally adhesive.
CONCLUSION: OF was found equally efficient like TE. Bond strength of ormocer as a veneer was not inferior to ceramic making it one of the promising additions in the field of dentistry.
MATERIALS AND METHODS: This study is conducted at Hospital Universiti Sains Malaysia. UCLP group comprised 48 patients with nonsyndromic UCLP who have had the lip and palate repaired, whereas the control group comprised 48 healthy noncleft cases. The lateral cephalometrics measurements were used to determine the vertical height, sagittal depth of the face, and cranial base length and angle. Maxillary arch dimensions were measured on the study cast including arch width, depth, and length.
RESULTS: Vertical facial height and sagittal depth measurements showed a significant decrease (P < 0.05) in the mean growth pattern in UCLP group. The anterior cranial base length (S-N) was shorter in UCLP children (P < 0.001), while Ba-N length had no significant difference (P = 0.639). Nasion-Sella Tursica-Basion angle was significantly higher in the UCLP group (P = 0.016). Dental arch width with reference to canine-to-canine and first premolar-to- first premolar distance was significantly larger in control (P = 0.001).
CONCLUSION: Mean vertical and sagittal facial dimensions in the UCLP children who do not undergo orthodontic treatment are significantly lesser in all directions of growth than healthy noncleft children. The maxillary dental arch had a normal depth but constricted in width and arch length.
Materials and Methods: Sixty postmenopausal female patients aged 51-68 years were included in the study to assess the relationship between tooth loss and the level of blood pressure. The information including sociodemographics, last menstruation period, hypertension history, and the duration of having tooth loss was recorded. Blood pressure was measured using sphygmomanometer and the number of tooth loss was determined.
Results: The results showed a more significant tooth loss in hypertension (median: 23 + 4; interquartile range [IQR]: 6) compared to the normotension postmenopausal women (median: 18 + 6; IQR: 12; P < 0.05). Furthermore, obese patients had more tooth loss (median: 23 + 5; IQR: 8) than the overweight patients (median: 19 + 8; IQR: 8).
Conclusion: Tooth loss is associated with the increase of hypertension in postmenopausal women which may have a role in the development of vascular diseases.
Materials and Methods: CBCT images which show MFPMs recorded in HUSM Dental Clinic between January 2015 and June 2016 was obtained and analyzed for their number of roots and canals. A total of 208 CBCT images of MFPMs were collected; 118 patients had unilateral molars and 90 patients had bilateral molars. The following observations were made: (1) root number; (2) number of canals per root; and (3) comparisons of number of roots and canals according to gender, ethnicity, and position.
Results: The majority of cases of bilateral MFPM had the same number of roots (95.6%, 95% confidence interval [CI]: 89.01%, 98.78%) on both the right and left side and only 4 cases (4.4%, 95% CI: 1.22%, 10.99%) had 3 roots on the right and 2 roots on the left sides. The majority of cases had the same number of canals on both sides (66.7%, 95% CI: 55.95, 76.26%) and 33.3% (95% CI: 23.74%, 44.05%) with unequal number of canals. The occurrence of the number of canals was not independent of the sides of the arch (P < 0.001) and there was statistically significantly greater proportion of cases who had greater number of canals on the right side than the left (P = 0.03). The prevalence of right single-rooted MFPM was very small at 0.3% (n = 1) in a Malay male (95% CI: 0.00, 1.83) and the most prevalent was two roots first molar (88.4%). The number of roots was not associated with sex or ethnic group (P > 0.05). The MFPM with a single root was found to have only one mesial canal. For two rooted MFPM, the most prevalent occurrence was two canals at the mesial and one canal at the distal roots (59%); followed by single canals in each mesial and distal (21%) and double canals per root (18%). Three roots MFPM have either single or double canals in the mesial root and double canals in the distal root.
Conclusions: The majority of population in the East Coast region of Malaysia has two roots and three root canals in their MFPMs. There was no difference in the number of roots between gender and ethnic and canals between ethnic.
Materials and Methods: This cross-sectional study was conducted among the GDPs of Karachi. A questionnaire was designed to collect data from 100 GDPs. The questionnaire included general/demographic information (practitioner's education, experience, and place of practice) and an average number of fixed prosthesis constructed by the GDP. The questionnaire was further categorized to evaluate the knowledge/practice of pontic design selection and latest recommendations.
Results: For the maxillary anterior segment, the ridge lap pontic was the most common (32%) followed by the modified ridge lap (28%). In the maxillary posterior segment, the ridge lap pontic was the most common (37%) followed by sanitary design (34%). For the mandibular anterior segment, the modified ridge lap (50%) was the most common followed by ridge lap pontic (17%). In case of the mandibular posterior segment, the sanitary design (34%) was the most common followed by ridge lap pontic (30%).
Conclusions: The pontic design selection for the fixed prosthesis is a neglected domain. The contemporary guidelines are not followed with full spirit by the GDPs leading to wide variations in the pontic design selection.
Materials and Methods: Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold.
Results: The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality.
Conclusions: To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.
Materials and Methods: A retrospective study involved endodontically treated teeth of patients attending the Polyclinic, Kulliyyah of Dentistry, IIUM, from 2012 to 2015. Clinical and radiographic data were recorded and classified as successful or failed, and further analyzed by Fisher's exact test to measure the correlation between the variables using SPSS software version 16.0. Kappa test was used to measure the overall relationship between clinical and radiographic findings.
Results: A total of sixty teeth were evaluated clinically and radiographically, the overall success rate was 85% (n = 51). Correlation between the variables showed nonsignificant (P > 0.05) in the success rate among age, gender, and race, upper and lower arches and between anterior and posterior teeth at the time of treatment. At postendodontic fixed restorations, the variables showed statistically significant relationship with the success rate (P < 0.05).
Conclusions: Patients with no signs and symptoms and with no radiographical changes at the the time of clinical examination, showed the highest percentage of success rate (85%) of postendodontic fixed restorations. Age, gender, and race have no significant relations with the success rate of endodontically treated teeth.
MATERIALS AND METHODS: This cross-sectional observational study comprised 523 health science students. A well-structured online questionnaire consisting of closed-ended questions based on student's general information, Patient Heath Questionnaire (PHQ)-9 and Generalized Anxiety Disorder (GAD)-7 scales were used to assess the psychological impact of COVID-19.
STATISTICAL ANALYSIS: SPSS-25 was used to analyze the outcome of this study. Multiple linear regression analysis test was used to assess variables which had impact on PHQ-9 and GAD-7 scores among the participants. A p-value of ≤ 0.05 was considered as statistically significant.
RESULTS: Among the 523 participants, 365 (69.55%) students were from developing countries and 158 (30.21%) from developed countries; 424 (81.1%) students were tested negative for COVID-19 and 99 (18.9%) had suffered from severe acute respiratory syndrome coronavirus 2 infection during pandemic. The mean GAD-7 and PHQ-9 scores were 7.16 ± 5.755 and 7.30 ± 6.166, respectively. Significant impact on anxiety levels was associated with age, gender, education status, and COVID-19 positive patient, while depression was not significantly associated with gender, COVID-19, and its reported symptoms in participants.
CONCLUSION: As the world is trying to contain the health effects of COVID-19, the psychological effects might take a longer time to be addressed. Our study highlights the dire need to identify mental well-being of health science students as this may have a direct impact on their professional commitments and future responsibilities.
MATERIALS AND METHODS: This cross-sectional observational study was conducted at Altamash Institute of Dental Medicine, Karachi from June 2020 to August 2020. A total of 775 patients participated to fill questionnaire. After scrutiny, 25 questionnaire forms were excluded due to incomplete information. Questionnaire was divided in to four sections. First section obtained patients sociodemographic information, while knowledge of patients regarding cross-infection control during COVID-19 pandemic was evaluated in second section. Similarly, the purpose of third section was to assess attitude and fourth section was designed to evaluate practice. Likert's 3-point scale was used for registration of participant's response. The reliability of questionnaire was assessed through Crohnbach's α (α = 0.74). Statistical analysis was performed after entering data in to SPSS version 25. Independent t-test was used to evaluate the difference in patients' knowledge, attitude, and practice. A p-value ≤ 0.05 was considered as statistically significant.
RESULTS: Majority of the participants agreed that COVID-19 is a highly contagious disease (631, 97%) and daily screening of staff, dental assistants, dentists, and patients is necessary (568, 75.7%) along with proper sterilization of instruments and disinfection of dental operatory (650, 86.66%). A large number of participant also agreed that proper disposal of waste is utmost important for cross-infection control (601, 80.24%) and patient's waiting area should also be marked with social distancing sign (620, 82.66%). However, when asked about the common route of COVID-19 transmission in dentistry, 341 (45.5%) participants disagreed that it is not through aerosol (water droplets) generated during dental procedures.
CONCLUSIONS: Dental health professionals should take additional measures to educate dental patients on mechanism of potential spread of COVID-19 through the aerosols and droplets generated during dental procedures. They should also encourage the dental patients to be vigilant and question the cross-infection control measures practiced by the dentist to whom they go for dental treatment, and to decrease their chances of acquiring an infection during their visit to the dental office.