The aim of the study was to determine the depth of cure of a new nanocomposite when exposed to different curing times and also when different shades were polymerized. The nanocomposite, Filtek Supreme (3M ESPE), was packed into 96 plastic cylindrical moulds measuring 4 mm in internal diameter and 8 mm in length and then polymerized using a conventional quartz-tungsten-halogen light curing unit. The first part of the study involved curing 16 samples each of A2 shade of the nanocomposite at exposure times of 20s, 40s, 60s and 120s. For the second part, a similar number of samples of the dentinal opacity shades of A2, B3 and A4 of the nanocomposite were polymerized at a constant exposure time of 40s. The depth of polymerization of the nanocomposite in each sample was measured using a digimatic indicator. Curing depths were found to increase significantly (P < 0.05) with longer exposure time (20s < 40s < 60s < 120s) and decrease significantly with darker shades (A2 > B3 > A4).
Background: Majority of root canal treatment in Malaysia was provided by general dental practitioner. The purpose of this study was to evaluate the knowledge and practice (canal’s preparation, use of materials) by them. Methods: A questionnaire was structured and distributed to 120 registered general dental practitioners in selected areas in Perak, Johor and Klang Valley regarding the provision of root canal therapy in their practices. The questionnaires were hand delivered and collected after 1 to 2 weeks. Results: Reply rate was 95% (n=114). The result demonstrated that 62% respondents indicated that they performed the root canal therapy (RCT) themselves. Out of these only 26% included molars in the treatment. Three quarters of them (77%) used step-back technique and 54% used stainless steel instruments to prepare the canals. The majority of the respondents (69%) used calcium hydroxide as intracanal medicaments. Only 30% used rubber dam for isolation whereas the rest used cotton rolls. The numbers of routine radiographs taken were two for anterior teeth and three for molar. Half of the respondents indicated that they usually completed the RCT for the anterior tooth within two visits whereas three visits were needed for the molar tooth. The results were analyzed descriptively. Conclusions: This study indicates that most of the general dental practitioners’ do not comply with quality standards guidelines such as use of rubber dam as isolation. Cotton roll was the most popular isolation method. In spite of this, most of the respondents tend to update their knowledge and practices with current techniques and materials.
This study evaluated the effectiveness of demineralized freeze-dried bone xenograft in reducing post-surgical pocket depth in moderate to advanced adult periodontitis in patients. Nine patients with a total of eighteen intrabony defects were selected for this study. The bony defects were matched for tooth type, location and pocket depth. Following an initial non-surgical treatment, only pockets of 5 to 7 mm deep were indicated for surgery. Periodontal pockets were measured pre-operatively and at 3, 6 and 9 months post-surgically. The study protocol included a split mouth design, where surgical treatment was carried out at both test and control sites. The test sites were assigned demineralized freeze-dried bone xenograft and the control sites were subjected to debridement alone without the use of demineralized freeze-dried bone xenograft. The results from this study showed a statistically significant difference in the mean pocket depth at 6 and 9 months post-operatively for both test and control groups, but there was no statistically significant difference at 3 months. In conclusion, demineralized freeze-dried bone xenograft was ineffective in reducing periodontal pocket depth in patients with moderate to severe periodontitis, as compared to surgical debridement alone.
Twenty-one patients who underwent ablative surgery for head and neck cancer at Bristol Dental Hospital and School, England between the years 1996 and 2002 were enrolled in the study. A self-completed questionnaire based on Head and Neck Specific measures was addressed to the patients. The overall post-operative quality of life among these patients is acceptable. About half of the patients complained of moderate to severe difficulty in opening mouth wide (55%) and dry mouth (45%) and about one-third had major problems in swallowing solid food (36%), sleep disturbance (32%), trouble eating and enjoying meals (32%) and speech problems (32%). The study shows a tendency for the quality of life to improve steadily with increasing post-operative interval. It is hoped that the results will provide an insight into the patients' functional and psychological recovery, which will in turn help to facilitate the planning of appropriate strategies to improve their quality of life.
Proliferating Cell Nuclear Antigen (PCNA) is one of the several markers of cellular proliferation. Epithelial proliferations play a significant role in the behaviour of odontogenic lesions. The objective of this study was to describe and compare the distribution of PCNA expression within the epithelial linings of odontogenic cysts. A total of 49 cases of odontogenic cysts consisting of 18 radicular cysts, 16 dentigerous cysts, 15 odontogenic keratocysts (OKCs) was studied. All tissues were processed routinely prior to embedding in paraffin. PCNA immunohistochemical staining was performed on 4 !-tm thick deparaffinized sections mounted on sialinized slides using the peroxidase antiperoxidase method. The distributions of PCNA expression in the cysts linings were noted and comparison was made qualitatively and quantitatively. PCNA labelling index was used for the quantitative assessment. The results showed that PCNA staining was distributed in the basal and supra basal cells for radicular cysts, dentigerous cysts, and OKCs. PCNA labelling index was highest in OKC (22.33±4.07). The high PCNA labelling index in OKC is indicative of high proliferative activity thus supporting previous reports of OKC as the most aggressive type of odontogenic cysts.
Decalcified permanent teeth were sectioned and stained with Van Gieson and Gomori trichome dyes. Sections dyed with the Van Gieson dye did not produce any zones in dentine but with the Gomori trichome dye, four different zones of dentine were produced. Zone 1 begins at the predentine-dentine junction while zone 4 ends at the enamel - dentine junction. In zone 1, the intertubular dentine was stained clearly while in zone 3 intense staining of the peritubular dentine was observed. The result of this study supports the previous findings reported by other workers that the formation of intertubular dentine takes place in zone 1 while peritubular dentine occurs in zone 3.
To date there is no standard protocol on evaluation of the masticatory performance in complete denture wearer even though many methods had been described in the literature for measurement of the masticatory performance of the complete denture wearers. The masticatory performances were measured either subjectively or objectively, but no positive correlation was found between subjective and objective measurement. Therefore, there is a need to standardize the objective measurement, as subjective measurements rely on patients’ perceptions, which is not reliable. Intra individual and inter individual variations that exist support the need to standardize the method of measurement.
This clinical case report details the clinical sequence of a 78-year-old male receiving prosthetic rehabilitation using an implant-supported screwretained fixed partial denture. Despite the limitations imposed, the aesthetic and functional demands of the patient were fulfilled by this prosthetic rehabilitation. The importance of detailed prosthetic planning and evaluation prior to implant surgery is essential, therefore ideally, it should be done by the same operator or a team of operators working together. Problems can arise when the construction of the prosthesis is performed by other people who are not involved in the planning stage.
Phosphophoryn, a higWyphosphorylated protein, is the most abundant protein among the non-collagenous protein of dentine. The staining of phosphophoryn can be done by using the silver colloid staining. In this paper, the staining effect of the silver colloid stain on both non-sclerotic and sclerotic dentine was investigated. Eight teeth from donors aged 14, 17, 22, 34, 55, 57, 60 and 65 were used for this experiment. The younger teeth were used to demonstrate normal root dentine while the older age teeth were used to demonstrate sclerotic root dentine at the apical region of the root. There was no staining of the normal root dentine as compared to sclerotic dentine when the silver colloid staining was used.
The ultrastructure of the odontoblast reflects the certain phases that the cell undergoes in their lifecycle. Ultrastructure studies of the odontoblasts have often been carried out using young teeth. In this study, teeth from an older individual have been used to study the odontoblasts from the crown and root area. The odontoblasts from the crown area retain their columnar shape while odontoblasts from the root area appeared to be flattened. The organelles present in the odontoblasts either from the crown or root area was observed to be reduced.
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
Simulated canals in clear resin blocks have been widely used in pre-clinical endodontic teaching. The artificial canal provides direct visualisation of procedures in root canal treatment. Stanuardised simulated root canals have been produced in the Faculty of Dentistry, University of Malaya for dental education and research. The canals are easy and inexpensive to construct. An outline of the method of construction of resin simulated canals is presented in this paper.
Background: MDM2 and p53 are involved in a negative feedback loop where p53 regulates MDM2 at the transcriptional level. MDM2, in turn, downregulates p53. This co-ordinated interaction between these proteins is set to play an important role in the regulation of cell cycle progression following DNA damage to cells. The over-expression of both p53 and MDM2 has been reported in various cancers. However there are only few studies discussing the co-expression of MDM2 with p53 in oral squamous cell carcinoma Aim: The purpose of this study was to determine the correlation of co-expression of p53, MDM2, and Ki-67 proteins with clinico-pathological factors in oral squamous cell carcinoma (OSCC) and to conduct a systematic review of the co-expression of p53/MDM2.
Method: This is a retrospective descriptive study and a systematic review. Formalin-fixed paraffinembedded tissues from 45 OSCC cases were stained by immunohistochemistry (IHC) for p53, MDM2, and Ki-67 proteins.
Results: Immuno-reactivity for p53, MDM2, and Ki-67 was seen in 75.6%, 97.8%, and 62.2% cases of OSCC respectively. The co-expression of p53 and MDM2 (p53/MDM2) was detected in 97.1%, however there was no significant correlation between p53 and MDM2 expression. Notably, p53/MDM2 coexpression was significantly associated with tumour differentiation (p-value = 0.045). The Ki-67LI was not significantly associated with neither MDM2 nor p53/MDM2 co-expression (p-value = 0.268, 0.916 respectively).
Conclusion: The expression of MDM2 was not signif icantly associated with p53 expression suggesting that MDM2 expression is mediated by p53-independent pathways or mutated p53 could not induce the expression of MDM2 in this set of OSCCs. The only clinico-pathological parameter that correlates significantly with co-expression of p53/MDM2 is tumour differentiation where it is suggestive that the co-expression of these 2 proteins is indicative of aggressive tumour behavior.
Tobacco use is linked with many serious illnesses, such as cancer, cardiopulmonary diseases, as well as with many health problems. Every year, the use of tobacco products causes a heavy toll of deaths and severe human disease worldwide. One of the many health problems linked to tobacco use is its detrimental impact on oral health. Tobacco causes a whole series of oral health problems, ranging from life-threatening (precancerous changes leading to oral cancer) and serious (periodontal disease, teeth decay) to social (bad breath). Tobacco is consumed through the mouth in a variety of forms, varied from smoked tobacco to smokeless tobacco chewing on itself or combined with areca nut. All these forms of tobacco have damaging effects on the oral health. The most significant preventive measure to prevent the oral health problems caused by tobacco use is to stop using tobacco products. The risk of developing oral cancer drops rapidly when a smoker ceases tobacco use. After ten years of not using tobacco, an ex-smoker/user's risk of oral cancers is about the same as that for someone who has never smoked. To stop using tobacco products is not an easy task. Fortunately, there are a number of therapies available to assist in quitting of tobacco. It is important to remember that, while it will be difficult, ceasing to use tobacco has immediate health benefits, including increased life expectancy and reduced risk of tobacco related diseases and conditions.
Differential diagnosis of orofacial pain is crucial, as the course of each process and its clinical management varies markedly. A case is illustrated here of trigeminal neuralgia in a 49-year-old Indian female whose complaint was initially diagnosed as dental pain leading to sequential extractions of her right mandibular and maxillary molars but with no pain abatement. Subsequent neurological assessment diagnosed her complaint as trigeminal neuralgia but pain remained poorly controlled even with high doses of carbamazepine and gabapentin. A dental referral and orthopantomographic examination revealed multifocal sclerotic masses in her jaws, suggestive of florid cemento-osseous dysplasia (FCOD). Right mandibular incisional biopsy confirmed the diagnosis. A decision was made to curette the right mandibular masses and lateralised the right inferior dental nerve. Follow-up disclosed considerable pain reduction. This case raises the issue as to whether the sclerotic bone masses in FCOD may have caused nerve compression which
aggravated her neuralgic pain.
Purpose of the study: The objective of this study was to investigate the existence of the golden proportion between the width of the maxillary anterior teeth of undergraduate dental students at University of Malaya. Materials and method: Standardised photographs of 100 dental students’ smiles displaying only the lips and the teeth were captured. The images were transferred to a personal computer and the width of the maxillary anterior teeth was measured using an Image
Analyzer (Leiqa QWin). Calculations were made according to the Theory of Golden Proportion. The
data were statistically analysed using paired student T-test (α
This cross-sectional study was carried out to identify A. actinomycetemcomitans and P. intermedia in the subgingival plaque of three ethnic groups (Malays, Chinese and Indians) in a selected group of adult Malaysians with advanced Chronic Periodontitis and to correlate these findings with their periodontal status. Thirty periodontally diseased adults were age, gender and ethnically matched with 30 healthy individuals. Clinical parameters were assessed for all. Subgingival plaque samples were collected for identification of A. actinomycetemcomitans and P. intermedia using polymerase chain reaction. Prevalence for P. intermedia (83.3%) was high and A. actinomycetemcomitans
(6.7%) low in the total subject population. P. intermedia and A. actinomycetemcomitans were more
prevalent in diseased (86.7%, 10% respectively) than in healthy (80%, 3.33% respectively) subjects. A. actinomycetemcomitans was detected in 15% Indians, 5% Malays but none of the Chinese subjects whereas P. intermedia was detected in 90% Malays, 85% Indians and 75% Chinese subjects. No significant association between presence of A. actinomycetemcomitans
and P. intermedia with race and periodontal disease status was found. Only A. actinomycetemcomitans had a significant association with clinical attachment level (CAL) (p < 0.05). In conclusion, in this small subject group, none of the pathogens were associated with race and periodontal disease status and only A. actinomycetemcomitans had a significant association with CAL.
A late adolescent patient presented with a Class III malocclusion on a skeletal Class III base, complicated by severe upper arch and moderate lower arch crowding, reverse overjet, anterior and bilateral posterior crossbites with displacement, proclined upper incisors, retroclined lower incisors, distally tipped lower canines and non-coincident centrelines. Treatment was undertaken on an extraction basis by employing the use of an upper removable appliance with Z-springs and posterior bite blocks to correct the anterior crossbite, quad helix and jockey arch for arch expansion, and pre-adjusted edgewise fixed appliance to level and align, space closure and achieve a mutually protective functional occlusion. This paper discussed the rational and evidences behind the treatment employed.
Osteosarcoma is a primary malignant neoplasm of the bone. Osteosarcoma of the jaws especially those of maxilla is rare. The diagnosis of osteosarcomas is difficult and challenging. In this case report we highlight a rare case of osteosarcoma of the maxilla in a 29 year old male patient which was highly aggressive and was initially diagnosed as rhabdomyosarcoma. This case highlights the difficulty in diagnosing osteosarcoma merely from incisional biopsy specimens which may not be representative of the whole tumour. Limited clinical information at incisional biopsy also adds to the difficulty in arriving at the definitive diagnosis. We further discuss the treatment modalities followed in this case.
Tumours that occur in the oral cavity may contain granular cells as a component of their pathology. A more common granular cell lesion occurring in the head and neck region is the granular cell tumour (GCT) that usually arises in the tongue or the buccal mucosa. Granular cell tumours are very rare in the parotid gland with only 11 cases previously reported in the English literature. We report a case of a benign tumour involving the parotid gland of a young female patient. The case was diagnostically challenging due to the large proportion of granular cells masking the underlying pathology. Histopathological features and immunohistochemical analysis favoured a diagnosis of a benign GCT. The present report provides an insight into the differential diagnosis and attempts to characterise the granular cells with the use of the wellestablished immunohistochemical markers and conventional histopathological techniques.