A comparison of different standard-setting methods for professional qualifying dental examination.

BACKGROUND: The outcome of assessments is determined by the standard-setting method used. Standard setting is the process of deciding what is good enough. A cutoff score of 50% was commonly used in dental schools in Malaysia. This study aims to compare the conventional, norm-referenced, and modified-Angoff standard-setting methods. METHODS: The norm-referenced method of standard setting was applied to the real scores of 40 final-year dental students on a multiple-choice question (MCQ), a short answer question (SAQ), and an objective structured clinical examination (OSCE). A panel of 10 judges set the standard using the modified-Angoff method for the same paper in one sitting. One judge set the passing score of 10 OSCE questions after 2 weeks. A comparison of the grades and pass/fail rates derived from the absolute standard, norm-referenced, and modified-Angoff methods was made. The intra-rater and inter-rater reliabilities of the modified-Angoff method were assessed. RESULTS: The passing rate for the absolute standard was 100% (40/40), for the norm-referenced method it was 62.5% (25/40), and for the modified-Angoff method it was 80% (32/40). The modified-Angoff method had good inter-rater reliability of 0.876 and excellent test-retest reliability of 0.941. CONCLUSION: There were significant differences in the outcomes of these three standard-setting methods, as shown by the difference in the proportion of candidates who passed and failed the assessment. The modified-Angoff method was found to have good reliability for use with a professional qualifying dental examination.

Effect of Luting Cements On the Bond Strength to Turkom-Cera All-Ceramic Material.

BACKGROUND: The selection of the appropriate luting cement is a key factor for achieving a strong bond between prepared teeth and dental restorations. AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material. MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - µm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test. RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05). CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.

Reliability and validity of MicroScribe-3DXL system in comparison with radiographic cephalometric system: Angular measurements.

AIM: The aim of the study was to assess the reliability and validity of cephalometric variables from MicroScribe-3DXL. MATERIALS AND METHODS: Seven cephalometric variables (facial angle, ANB, maxillary depth, U1/FH, FMA, IMPA, FMIA) were measured by a dentist in 60 Malay subjects (30 males and 30 females) with class I occlusion and balanced face. Two standard images were taken for each subject with conventional cephalometric radiography and MicroScribe-3DXL. All the images were traced and analysed. SPSS version 2.0 was used for statistical analysis with P-value was set at P<0.05. RESULTS: The results revealed a significant statistic difference in four measurements (U1/FH, FMA, IMPA, FMIA) with P-value range (0.00 to 0.03). The difference in the measurements was considered clinically acceptable. The overall reliability of MicroScribe-3DXL was 92.7% and its validity was 91.8%. CONCLUSION: The MicroScribe-3DXL is reliable and valid to most of the cephalometric variables with the advantages of saving time and cost. This is a promising device to assist in diverse areas in dental practice and research.

Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-ceramic Material.

AIM: The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan). MATERIALS AND METHODS: Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. RESULTS: The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups. CONCLUSION: In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks. CLINICAL SIGNIFICANCE: The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations.

The Relationship of Mandibular Morphology with Residual Ridge Resorption Associated with Implant-Retained Overdentures.

PURPOSE: The objective of this clinical study was to determine the relationship of mandibular morphology with residual ridge resorption (RRR) of implant-retained overdenture (IRO) patients. MATERIALS AND METHODS: RRR was quantified as change in bone volume over 1- and 2-year periods using cone beam computed tomography and a medical imaging program. Features of the mandibular morphology, namely the gonial angle, ramus length, ramus width, corpus length, and corpus height, were measured on three-dimensional models and correlated to the RRR. A total of 25 participants were treated with mandibular IROs opposing maxillary complete dentures. By the 2-year follow-up, radiographic data for 18 patients were complete for analysis. Of these 18 participants, half fall into the low gonial angle category and the other half into the high angle. RESULTS: The extent of RRR was highly variable among participants and ranged from -2 to +2 mm in depth over the 2-year period. The mean decrease in bone volume after the first year was 3.8 ± 4.5%. This rate decreased to 3.2 ± 4.1% after the second year. RRR occurs either by translation of the entire thickness of cortical layer apically or by thinning of the outer cortical layer. RRR was significantly correlated to gonial angle (r = .471; P = .048) and predominantly occurred in the molar region in low-angle participants and more anteriorly in high-angle participants. There was no association between RRR and ramus length (r = -.341; P = .166), ramus width (r = -.183; P =.468), corpus length (r = .057; P = .821), and corpus height (r = .097; P = .702). CONCLUSION: Within the limitations of this study, it may be concluded that gonial angle is significantly related to RRR associated with IROs.

Investigation of mucosa-induced residual ridge resorption under implant-retained overdentures and complete dentures in the mandible.

PURPOSE: This study aimed to investigate and compare the residual ridge resorption (RRR) induced by an implant-retained overdenture (IRO) and associative biomechanics and by a conventional complete denture (CD) without implants. MATERIALS AND METHODS: Cone beam computed tomography was used to quantify RRR in a three-dimensional (3D) manner before and after 1 year of treatment with either IROs or CDs. Twenty patients were treated with IROs, and nine patients were treated with CDs in the mandible. Their maximum bite forces were recorded. The same sets of high-resolution scan images were used to create patient-specific 3D finite element analysis models. The hydrostatic stresses, contact surface deformation, and strain energy absorption in soft tissue mucosa were correlated with the changes in RRR for patients with and without implants. RESULTS: With the IROs, contact surface deformation on the mucosa was two times greater than with CDs (0.32 ± 0.23 mm vs 0.16 ± 0.06 mm) and was in agreement with the amount of RRR measured, which was also two times higher for the IRO than the CD (-3.8% ± 4.5% vs -1.9% ± 0.4%). Taking into account the differences in bite forces with and without implants, which again were twice as high with IROs, the hydrostatic stress within the mucosa was found to correlate well to the RRR map measured over the 1-year interval of treatment. CONCLUSION: IROs resulted in at least twice the RRR as CDs. This could be caused by the higher hydrostatic stress and less effective energy absorption capabilities of the mucosa underneath the IRO. While implants associated with the IRO provide stronger bite force, they could potentially concentrate hydrostatic stress and cause greater RRR compared to a conventional CD.

General dental practitioners' views on early childhood caries and timing of the first dental visit in Selangor, Malaysia.

This survey evaluated the knowledge, attitudes, and practices of general dental practitioners (GDPs) in Selangor regarding early childhood caries (ECC) prevention and the recommended timing of a child's first dental visit. A questionnaire was mailed to 521 licensed GDPs. Descriptive statistics were used, and bivariate and logistic regression analyses were performed. The response rate was 52.6%. Although 89.8% mentioned counseling parents and caregivers, only 44.2% were familiar with anticipatory guidance. Whereas 98.2% agreed that early examinations are important to prevent ECC, only 51.8% were aware of the recommendation for a first visit by 12 months of age. GDPs who recommended early dental visits were significantly more likely to be recent graduates, more familiar with professional guidelines, and less likely to be deterred by a child's crying or behavior. In conclusion, GDPs in Selangor are aware about the importance of early dental visits in ECC prevention. However, a considerable number of them are still not aware of the recommendation that children must first visit the dentist by 12 months of age. Furthermore, some of their current practices in ECC management and prevention do not match professional recommendations.

Three dimensional quantification of mandibular bone remodeling using standard tessellation language registration based superimposition.

OBJECTIVE: The aim of this study was to evaluate a new method to quantify longitudinal mandibular bone remodeling three-dimensionally by superimposition of cone beam computed tomography images. MATERIALS AND METHODS: This method is used to quantify the treatment effects of implant-retained overdentures in 20 patients aged 52-79 at recruitment after 1 and 2 years post treatment. Three dimensional models of pre- and post-treatment were reconstructed for each patient and superimposed using Standard Tessellation Language registration method and segmentation. RESULTS: Color maps of the differences generated by superimposition allow detailed examination and quantification of the progressive dimensional changes of bone in a three-dimensional manner and enable the visualization of the apical displacement and thinning of the cortical layer of bone underneath the denture base. Most of the remodeling changes took place during the first year with a mean decrease in volume of 3.7% (SD = 4.4%; range = +3.7% to -15.9%, median = -3.7%). This remodeling pattern continued during the second year, but at a reduced rate of 2.5% per year (SD = 4.2%; range = +2.1% to -11.3%, median = -3.9%). CONCLUSION: Standard Tessellation Language registration based superimposition of cone beam computed tomography images may be considered an objective and reproducible method to three-dimensionally quantify mandibular bone remodeling.

Marginal integrity of turkom-cera compared to other all-ceramic materials: effect of finish line.

The aim of this study was to evaluate the marginal adaptation of Turkom-Cera all-ceramic crowns compared to In-Ceram and Procera AllCeram systems. The influence of finish line design (chamfer or shoulder) on the marginal adaptation of Turkom-Cera all-ceramic crowns was also investigated. Thirty human premolars were prepared with chamfer margins and assigned to either the Turkom-Cera, In-Ceram, or Procera system group. In addition, 10 premolars were prepared with rounded shoulder finish lines and assigned to an additional Turkom-Cera group. Ceramic copings (0.6-mm thick) were fabricated for each group following the manufacturers' instructions. The copings were seated on abutments using a special holding device that facilitated uniform loading, and marginal adaptation was assessed using a stereomicroscope. Data were analyzed using analysis of variance, the Tukey HSD post hoc test, and an independent samples t test. There was a statistically significant difference regarding marginal adaptation among the three all-ceramic systems (P < .05). There were no significant differences in the mean marginal discrepancies of Turkom-Cera crowns among chamfer and shoulder finish line groups (P > .05). Within the limitations of this study, the marginal discrepancies were all within the clinically acceptable standard. Int J Prosthodont 2011;24:379-381.

Malaysian dental graduates' competence in holistic care: what do graduates and employers think?

The purpose of this study was to explore the University of Malaya (UM) dental graduates' competence in holistic care in real settings from the employers' and graduates' perspectives. A self-administered questionnaire consisting of ten domains was sent to thirty senior dental officers of the Ministry of Health (MOH) and 164 UM graduates. In this article, nineteen major competencies that best represent the graduates' competence in the provision of holistic care are discussed. Each competency was rated on a scale of 1 (very poor) to 4 (very good) and was categorized as "poor and of major concern" (if less than 60 percent of respondents scored good or very good), "satisfactory and of minor concern" (60-69 percent), or "excellent" (70 percent and above). One hundred and six out of 164 graduates (64.6 percent) and twenty-nine out of thirty employers (96.7 percent) responded. Overall, the employers rated the graduates lower than what the graduates rated themselves on all items. While the graduates felt they were excellent and satisfactory in sixteen out of nineteen items (84.2 percent), the employers felt they were poor in fourteen out of nineteen (73.7 percent). Both groups agreed that the graduates were excellent in communication, but poor in life-saving skills, obtaining patient's family and psychosocial histories, and recognizing signs and symptoms (not intraoral) indicating the presence of a systemic disease. In conclusion, although the graduates felt competent in the majority of the holistic care competencies, the employers had some reservations over such claims. Outcomes of the study led to recommendations to incorporate longer community-based learning hours, an improved behavioral science component, a module for special care patients, and multidepartmental collaborative teachings in the new integrated program aimed for implementation in 2011.

Comparison of the load at fracture of Turkom-Cera to Procera AllCeram and In-Ceram all-ceramic restorations.

PURPOSE: This study investigated the occlusal fracture resistance of Turkom-Cerafused alumina compared to Procera AllCeram and In-Ceram all-ceramic restorations. MATERIALS AND METHODS: Sixmaster dies were duplicated from the prepared maxillary first premolar tooth using nonprecious metal alloy (Wiron 99). Ten copings of 0.6 mm thickness were fabricated from each type of ceramic, for a total of thirty copings. Two master dies were used for each group, and each of them was used to lute five copings. All groups were cemented with resin luting cement Panavia F according to manufacturer's instructions and received a static load of 5 kg during cementation. After 24 hours of distilled water storage at 37 degrees C, the copings were vertically compressed using a universal testing machine at a crosshead speed of 1 mm/min. RESULTS: The results of the present study showed the following mean loads at fracture: Turkom-Cera (2184 +/- 164 N), In-Ceram (2042 +/- 200 N), and Procera AllCeram (1954 +/- 211 N). ANOVA and Scheffe's post hoc test showed that the mean load at fracture of Turkom-Cera was significantly different from Procera AllCeram (p < 0.05). Scheffe's post hoc test showed no significant difference between the mean load at fracture of Turkom-Cera and In-Ceram or between the mean load at fracture of In-Ceram and Procera AllCeram. CONCLUSION: Because Turkom-Cera demonstrated equal to or higher loads at fracture than currently accepted all-ceramic materials, it would seem to be acceptable for fabrication of anterior and posterior ceramic crowns.

Effect of luting cements on the compressive strength of Turkom-Cera all-ceramic copings.

AIM: The objective of this study is to investigate the effect of different luting agents on the fracture strength of Turkom-Cera all-ceramic copings. METHODS AND MATERIALS: Standardized metal dies were duplicated from a prepared maxillary first premolar tooth using non-precious metal alloy (Wiron 99). Thirty Turkom-Cera copings of 0.6 mm thickness were then fabricated. Three types of luting agents were used: zinc phosphate cement (Elite), glass-ionomer cement (Fuji I), and a dual-cured composite resin cement (Panavia F). Ten copings were cemented with each type. All copings were cemented to their respective dies according to manufacturer's instructions and received a static load of 5 kg for ten minutes. After 24 hours of storage in distilled water at 37 degrees C, the copings were vertically loaded until fracture using an Instron Universal Testing Machine at a crosshead speed of 1 mm/minute. The mode of fracture was then determined. RESULTS: Statistical analysis carried out using analysis of variance (ANOVA) revealed significant differences in the compressive strength between the three groups (P<0.001). The mean fracture strength (in Newtons) of Turkom-Cera copings cemented with Elite, Fuji I, and Panavia F were 1537.4 N, 1294.4 N, and 2183.6 N, respectively. CONCLUSIONS: Luting agents have an influence on the fracture resistance of Turkom-Cera copings.