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Fulltext Shear bond strength of orthodontic adhesives on different tooth types : an in vitro study

Radzi, Z., Yahya, N.A., Kasim, N.H.A., Ismail, N.H., Ismail, N.A., Zamzam, N

Ann Dent, 2006;13(1):18-23.
MyJurnal

Introduction: Owing to the variety of materials and methods employed, comparison of the results and findings from bonding studies is difficult. Until recently, several types of teeth have been used in published research papers as a substrate in orthodontic bonding research including bovine incisors, fresh and rebonded human premolars. Objectives: The purpose of this study was to compare the shear bond strength of an adhesive bonded to different tooth surfaces (human premolar, bovine incisor and rebonded human premolar). Methods: Two groups of thirty premolar teeth and one group of bovine incisors had brackets attached in a standardized manner using Transbond XT (3M Unitek). The adhesive was cured using conventional halogen light and a specially designed tool to standardize the distance between the light curing tip and the adhesive. The debonding force was measured using Instron universal testing machine. ANOVA and Post Hoc Dunnett C test were performed to determine any significant difference among groups (p
Fulltext Synthesis and Characterizations of Novel Ca-Mg-Ti-Fe-Oxides Based Ceramic Nanocrystals and Flexible Film of Polydimethylsiloxane Composite with Improved Mechanical and Dielectric Properties for Sensors

Tripathy A, Pramanik S, Manna A, Shah NF, Shasmin HN, Radzi Z, et al.

Sensors (Basel), 2016;16(3):292.
PMID: 26927116 DOI: 10.3390/s16030292

Armalcolite, a rare ceramic mineral and normally found in the lunar earth, was synthesized by solid-state step-sintering. The in situ phase-changed novel ceramic nanocrystals of Ca-Mg-Ti-Fe based oxide (CMTFOx), their chemical reactions and bonding with polydimethylsiloxane (PDMS) were determined by X-ray diffraction, infrared spectroscopy, and microscopy. Water absorption of all the CMTFOx was high. The lower dielectric loss tangent value (0.155 at 1 MHz) was obtained for the ceramic sintered at 1050 °C (S1050) and it became lowest for the S1050/PDMS nanocomposite (0.002 at 1 MHz) film, which was made by spin coating at 3000 rpm. The excellent flexibility (static modulus ≈ 0.27 MPa and elongation > 90%), viscoelastic property (tanδ = E″/E': 0.225) and glass transition temperature (Tg: -58.5 °C) were obtained for S1050/PDMS film. Parallel-plate capacitive and flexible resistive humidity sensors have been developed successfully. The best sensing performance of the present S1050 (3000%) and its flexible S1050/PDMS composite film (306%) based humidity sensors was found to be at 100 Hz, better than conventional materials.
Fulltext The problems and impacts of orofacial pain among a group of Malaysian aborigines

Yusof ZYM, Mohamed NH, Radzi Z, Yahya NA, Ramli AS, Abdul Kadir R

Ann Dent, 2007;14(1):31-38.
MyJurnal

Background: The high prevalence and impacts of orofacial pain (OFP) have caused major sufferings to individuals and society. The purpose of the study was to investigate the problems and impacts of OFP among a group of Malaysian aborigines. The objectives were to determine (i) the prevalence, aetiology, duration, severity, types and persistence of OFP during the past 3 months preceding the study; (ii) its associated impact on daily performance; and (iii) the measures taken for pain relief.
Methods: This is a cross sectional study carried out in Kuala Lipis, Pahang involving 6 villages of Orang Asli Bateq and Semai. Study sample was chosen using convenient sampling including adults aged 16 years and above. Participants were invited for an interview using structured questionnaire followed by clinical examination. Data analysis was carried out using SPSS ver12.
Results: Response rate was low at 20% (n = 140). Over one-quarter (26.4%) of the sample experienced OFP in the previous 3 months. Toothache was found to be the main aetiology (83.3%) followed by gingival pain (18.9%), temporomandibular joint (10.8%) and facial pain (8.1%). Mean duration of pain was 9.8 days for toothache, 162.4 days for gingival pain, 7.3 days for TMJ and 5.7 days for facial pain. Of those who had OFP, over half rated the pain as moderate (37.8%) and severe (29.7%) and most of the pain was ‘intermittent’ in nature (81.1%). Over half (62.2%) admitted the pain had disappeared during the interview. In terms of pain relief, 56.8% of the sample used traditional medicine. The pain had impacted on the chewing ability (70.3%, p=0.01), ability to sleep at night (73.0%, p<0.001), levels of anxiety (70.3%), ability to perform daily chores (33.3%) and social life (35.1%) of the Orang Asli sample.
Conclusion: This study suggests the prevalence of OFP was high among the Orang Asli sample, which imposed considerable physical and psychological impacts on daily life.
Key words: orofacial pain; impacts; quality of life; Malaysian aborigines
Uniformly Porous Nanocrystalline CaMgFe1.33Ti₃O12 Ceramic Derived Electro-Ceramic Nanocomposite for Impedance Type Humidity Sensor

Tripathy A, Pramanik S, Manna A, Shasmin HN, Radzi Z, Abu Osman NA

Sensors (Basel), 2016 Nov 30;16(12).
PMID: 27916913

Since humidity sensors have been widely used in many sectors, a suitable humidity sensing material with improved sensitivity, faster response and recovery times, better stability and low hysteresis is necessary to be developed. Here, we fabricate a uniformly porous humidity sensor using Ca, Ti substituted Mg ferrites with chemical formula of CaMgFe1.33Ti₃O12 as humidity sensing materials by solid-sate step-sintering technique. This synthesis technique is useful to control the grain size with increased porosity to enhance the hydrophilic characteristics of the CaMgFe1.33Ti₃O12 nanoceramic based sintered electro-ceramic nanocomposites. The highest porosity, lowest density and excellent surface-hydrophilicity properties were obtained at 1050 °C sintered ceramic. The performance of this impedance type humidity sensor was evaluated by electrical characterizations using alternating current (AC) in the 33%-95% relative humidity (RH) range at 25 °C. Compared with existing conventional resistive humidity sensors, the present sintered electro-ceramic nanocomposite based humidity sensor showed faster response time (20 s) and recovery time (40 s). This newly developed sensor showed extremely high sensitivity (%S) and small hysteresis of <3.4%. Long-term stability of the sensor had been determined by testing for 30 consecutive days. Therefore, the high performance sensing behavior of the present electro-ceramic nanocomposites would be suitable for a potential use in advanced humidity sensors.
Fulltext Validation of the Malay version of Epworth sleepiness scale for children and adolescents (MESS-CHAD)

Lee WY, Lau MN, Soh EX, Yuen SW, Ashari A, Radzi Z

BMC Oral Health, 2023 Dec 19;23(1):1015.
PMID: 38115099 DOI: 10.1186/s12903-023-03762-w

BACKGROUND: Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) is a valid and reliable eight-item self-administered questionnaire for the assessment of excessive daytime sleepiness and is commonly used to screen sleep-disordered breathing for children and adolescents. The cross-sectional study aimed to translate and cross-culturally adapt ESS-CHAD into a Malay version of Epworth Sleepiness Scale for Children and Adolescents (MESS-CHAD) for the Malaysian population, and to assess the validity and reliability of MESS-CHAD.
METHODS: Forward-backward translation method was used to translate and cross-culturally adapt ESS-CHAD. Three linguistic experts and two paediatricians content validated the translated version. Face validity was conducted through audio-recorded semi-structured in-depth interviews with 14 native Malay-speaking children and adolescents followed by thematic analysis. The revised questionnaire was then proofread by a linguistic expert. A total of 40 subjects answered the MESS-CHAD twice, 2 weeks apart, for test-retest reliability and internal consistency. For criterion validity, 148 eligible subjects and their parents answered MESS-CHAD and the Malay version of Sleep-Related Breathing Disorder scale extracted from the Paediatric Sleep Questionnaire (M-PSQ:SRBD) concurrently. Variance Inflation Factor (VIF) and P values of the model's outer weight and outer loading were analysed using SmartPLS software to assess the indicator's multicollinearity and significance for formative construct validity.
RESULTS: Intraclass Correlation Coefficient (ICC) ranging from 0.798 to 0.932 and Cronbach's alpha ranging from 0.813 to 0.932 confirmed good to excellent test-retest reliability and internal consistency, respectively. Spearman Correlation Coefficient value of 0.789 suggested a very strong positive correlation between MESS-CHAD and M-PSQ:SRBD. VIF ranging from 1.109 to 1.455 indicated no collinearity problem. All questionnaire items in MESS-CHAD were retained as the P value of either outer model weight or outer model loading was significant (P