1.Mechanical And Surface Properties Of Initial And Working Aesthetic Orthodontic Archwires
Tang YC ; Peh XL ; Zakaria N N ; Radzi Z
Annals of Dentistry 2016;23(1):17-28
The study aimed to compare mechanical properties and surface characteristics of initial and workingaesthetic archwires with their conventional counterparts. High Aesthetic Sentalloy (full rhodium coatingnickel-titanium; Dentsply GAC) represented the initial aesthetic archwires; and FLI TRU-CHROME(labial PTFE-coated stainless steel; RMO) as the working aesthetic archwires; together with theirconventional counterparts were analysed. A three point bending test was conducted using a universaltesting machine (AGS-X SERIES, Shimadzu, Japan) to determine the load-deflection characteristics ofarchwires. Surface hardness was evaluated by Vickers microhardness test (HMV-FA, Shimadzu, Japan).A 3D Optical Surface Texture Analyzer (ALICONA, InfiniteFocus Real3D, Belgium) and a Field EmissionScanning Electron Microscope (FESEM, FEI Quanta 250, USA) were used for surface evaluation.Results showed that load-deflection characteristics of High Aesthetic Sentalloy archwires did not differfrom its control, whereas FLI TRU-CHROME archwires exhibited higher loading and unloading forcesthan its counterpart. No statistically significant difference in surface hardness was found between FLITRU-CHROME and its control archwires. The coating surfaces of both aesthetic archwires were rougherthan the non-coated conventional archwires, with similar roughness between non-coated surface of FLITRU-CHROME archwires and its counterpart. FLI TRU-CHROME archwires showed a distinct coatingthickness but coating layer is undefined in High Aesthetic Sentalloy archwires. In conclusion, the aestheticrhodium coated nickel titanium archwire has similar mechanical properties as control nickel titaniumarchwire without being adversely affected by the addition of the coating layer. The aesthetic coated PTFEstainless steel archwire has higher load response which could be an advantage as rigid wire in workingstage of orthodontic treatment. Based on their performance, their use could be recommended in caseswhere aesthetic aspect is crucial and where the friction aspect is not critical as their surface roughnessvalues increased.
2.The problems and impacts of orofacial pain among a group of Malaysian aborigines
Z.Y.M. Yusof ; N. Mohamed ; Z. Radzi ; N.A. Yahya ; A.S. Ramli ; R. Abdul-Kadir
Annals of Dentistry 2007;14(1):31-38
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.
3.Biomechanical Characteristics of Collagen Fibrils of Human Free Gingival Tissues- Atomic Force Microscope Study
Chang SV ; Ooi XD ; Z RADZI ; SM ISMAIL ; MT RAHMAN
Annals of Dentistry 2017;24(2):9-15
The information of biomechanical properties is crucial in the study of biological tissue and its clinical relevance. 3mm x 3mm free gingival human tissues was taken using disposable punch biopsy (Accu sharp blade, India) and stored in 0°C Freezer. The sample was sectioned to a thickness of 10μm using high profile microtome blade (Leica 818, Germany) and cryostat (Leica CM1850UV, United Kingdom). The sample was analysed using Atomic Force Microscope (Nanowizard® 3, JPK Instruments, Germany) at room atmosphere. The collagen fibrils of the free gingival tissues appeared to be stacked in basket weave like structure. The mean value of free gingival collagen fibrils width and the length of D-band were 106.71±11.18nm and 65.82 ± 3.04nm respectively. The Young’s modulus of collagen fibrils for human free gingival tissue at overlap region was 212.88 ± 242.58 MPa, whereas at the gap region was 207.00 ± 230.71 MPa. Within the limitation of the study, the collagen fibrils appeared to be stacked in basket weave-like structure. The length and width of the collagen fibril were similar to the values investigated using other techniques. There was significant linear relationship between Young’s modulus of overlap and gap regions.