The light microscopic features of the dentine in three teeth from two cases of osteogenesis imperfecta (OJ) are presented. Results show that teeth in OJ distinctively have a more uniform and tubular mantle dentine, and a characteristic laminated circumpulpal dentine formed by distorted incremental bands alternating with parallel rows of interglobular dentine and interrupted by comet-shaped vascular canals. The study indicated that in the absence of overt OJ features, the changes in dentine alone are sufficiently characteristic to establish such a diagnosis.
The objectives of this Malaysian study were to investigate the relationship between severity of trauma and interval before treatment, and the effect of delayed treatment on prognosis. A total of 123 traumatized permanent incisors were observed over a 24-month period. Results of this study suggest that the interval between trauma and emergency treatment is directly related to the severity of injury and the level of dental awareness of the patients. However, prognosis of these teeth is greatly influenced by the interval between trauma and initial treatment. Pathological pulp changes in these teeth can occur as late as two years after injury and this justifies the necessity for a long observation period following treatment.
The medicaments used in this study were buffered glutaraldehyde and formocresol. Schiff's reagent was used in the quantification of aldehyde released into the collecting medium. The results of this study clearly show that formocresol diffused throughout the dentine and cementum within fifteen minutes following a pulpotomy procedure, whereas no diffusion of buffered glutaraldehyde was observed.
Calcifying odontogenic cysts (COCs) represent a group of lesions that may be broadly classified into two main entities: cysts and neoplasms. In the present study 30 non-neoplastic cystic COCs were examined by a quantitative histological method in an attempt to calibrate the relative distribution of the type of epithelial lining, intensity of ghost cell formation and the amount of dentinoid present. The results showed that there are two main types of cystic COC: an odontoma-producing type and a non-odontoma-producing variant. Morphologically, tooth-like structures were a valid distinguishing feature, while morphometrically the odontoma-producing variant showed a greater amount of luminal and mural dentinoid as well as luminal ghost cells. Demographic analysis also revealed that the odontoma-producing COC occurred in younger patients and showed an even sex distribution, whereas the non-odontoma-producing type was seen in older patients and showed a predilection for females. Both subtypes were more prevalent in the Chinese population and occurred preferentially in the maxilla.
The root canal walls of twenty -five deciduous molar teeth with exposed and necrotic pulps were examined using thescanning electronmicroscope. Immediately after extraction, all teeth were fixed in Kamosky's solution. The coronal portion of the tooth was sectioned at about 2mm above the enamel cemental junction.The mesial and distal roots were separat~d and either split in the mesio-distal or bucco-lingual direction. All specimens were prepared for SEM. Obsevations showed that all roots were infected with organisms consisting of cocciand short rods. Some of the coccihad penetrated the dentine layer. However, the distribution of organisms is. not uniform throughout thecanals. Bacterialinvasion ismostinthecoronal region and reduces towards the apical region: Accompanying bacterial invasion is root canal walls deterioration. The odontoblastic processes are the first to deteriorate followed by the predentine layer.
One hundred and ninety-eight single-rooted teeth from individuals aged 21-90 yr of Caucasian, Malay, Chinese Malay and Indian Malay origin were studied. Single or serial longitudinal sections of extracted teeth were cut following dye imbibition of patent dentinal tubules. The extent of sclerosis of apical dentinal tubules was assessed and correlated with the age of the individual. Correlation with age was higher in the Caucasian than the Malay races and within the Malaysian racial groups correlation with age was highest in the Malays and lowest in the Chinese. It is concluded that factors other than age may be important in the formation of sclerotic apical dentine in teeth of different racial origin. The effect of racial origin should be considered when using sclerosis as a means of age determination in forensic cases.
This study was undertaken to investigate the number and types (fluoride or non-fluoride) of toothpaste products available in the Malaysian market based on the label. Thirty-five brands of toothpaste were identified, of which ten (29%) were specifically recommended for children. Two of the children's toothpaste recommended that children below seven years old use a pea size amount of toothpaste. One (3%) was recommended for both children and adult. The remaining 24 (69%) did not state if they were recommended for either children or adults. To improve the flavour of the toothpastes, a variety of flavours had been added especially in children's toothpaste. Almost half of the toothpastes were for prevention of tooth decay and gum disease. Other indications were for tooth sensitivity, tooth whitening and stain removal. Twentyseven (77%) of the toothpastes were imported, while eight (23%) were made in Malaysia. Twenty-six (74%) of the toothpaste contained fluoride and the most common type of fluoride used was sodium monofluorophosphate (NaMFP). The fluoride concentration was not labeled in more than half (63%) of the fluoridated toothpaste. Of those that were fluoridated, different units of measurement were used. As there is no uniformity in the labelling of these products, it is recommended that the responsible authorities should take more action in enforcing proper labelling of the fluoride concentration in the toothpaste using standardized units.
The estimation of age of human foetal remains is of great medico-legal importance. When the remains are intact and fresh, various morphological features such as crown-heel length, weight, appearance of ossification centres particularly around the ankles and knees and other parameters could be used to make a reasonable estimation of the period of gestation. In cases of criminal abortion, infanticide and child murder the question of age of the foetus, viability, live birth and a separate existence become very important. In practice, often at the time of detection, the remains are decomposed or skeletonised. In such a situation the examination of developing teeth will provide a reliable answer pertaining to the foetal age, the possibility of a separate existence and even the period of survival after birth. The.age determination from dental examination is possible from approximately 10 weeks intrauterine up to old age. The presence of neonatal line (birth line) in both dentine and enamel indicates live birth and a separate existence. It is possible that the time period of survival can be estimated by measuring postnatal deposition of these hard tissues. An intact human foetus that has undergone mild to moderate putrefaction was studied. The study of the morphological features and the ossification centres suggested that its approximate age was around nine months intrauterine. It was not possible to decide whether it was a live birth and had a separate existence. The examination of the developing first deciduous molar of the mandible suggested the approximate age was around 30-32 weeks intrauterine. The importance of examination of developing teeth in foetal remains (including neonates), particularly associated with putrefaction or skeletonisation is emphasized.
Intracanal medicaments are recommended for use in replanted teeth to inhibit inflammatory root resorption. This study compared the effect of calcium hydroxide (Pulpdent) and a corticosteroid-antibiotic paste (Ledermix) on periodontal healing and root resorption following replantation. Incisors of eight Macaca fascicularis monkeys were extracted, stored dry for 15 min and replanted. After 11 days, root canals in two adjacent maxillary incisors were treated with one medicament and contralateral incisors with the other medicament, or left as untreated controls. Animals were sacrificed 8 weeks later and the teeth prepared for histomorphometric evaluation of periodontal ligament inflammation and root resorption. Periodontal ligament inflammation and inflammatory root resorption were markedly inhibited by both calcium hydroxide and corticosteroid-antibiotic relative to untreated controls. Replacement resorption was lowest in the corticosteroid-antibiotic group, and significantly (P<0.05) more normal periodontal ligament was present in this group (79.6%) than in calcium hydroxide and control groups (64.6% and 62.7%, respectively). Treatment with the corticosteroid-antibiotic inhibited inflammatory resorption and was slightly more effective than calcium hydroxide in producing a periodontal healing response.
Although rare, hard tissue deposits, namely dystrophic calcifications and cartilage, have been reported to occur in the connective tissue wall of the odontogenic keratocyst. However, dentinoid formation has not been previously documented. A case involving the left mandibular premolar-molar region in a 37-year-old Malay male is described here along with a brief review on the reported prevalence of hard tissue deposits in the odontogenic keratocyst. Differential diagnosis of this case from other dentinoid-forming odontogenic cysts and tumors-notably calcifying odontogenic cyst, odontoma, ameloblastic fibro-odontoma, central odontogenic fibroma and adenomatoid odontogenic tumor that may present with dentin/dentinoid formation-is discussed.
This study was conducted to determine the prevalence of pre-eruptive intracoronal dentin defects from panoramic radiographs from a group of children and young adults aged 20 years and below. The radiolucent lesions were noted with regard to which teeth were affected, the location of the defects and the size of the defects relative to the width of dentin. Out of 1007 radiographs examined, 275 (27.3%) have pre-eruptive dentin defects. The prevalence of anomaly among males was 28.4% as compared to 26.2% among females. However, the difference between genders was not significant, thus subsequent results have been combined. Of 275 subjects with dentin radiolucencies, 243 subjects (88.7%) had only one affected tooth, 30 subjects (10.9%) had two teeth affected and 2 subjects (0.7%) had three affected teeth. The tooth prevalence of the anomaly was 2.1% and most of the lesions occurred as a single occurrence on the affected tooth. Within each tooth type, the highest tooth prevalence of intracoronal dentin defect was found in the upper first premolar (5.1%). More than half of the lesions extended less than 1/3 of the width of the dentin thickness. The high prevalence of the condition indicates the need for increased awareness and recognition of this during radiographic examination of teeth in the pediatric age group in early pre-eruptive stages so that early detection and diagnosis can be made and treatment can be done at the most appropriate time.
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.
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.
Existing literature suggests a relationship between the amount of remaining tooth structure and the fracture resistance of the restored endodontically treated tooth. This study investigated the amount of tooth structure remaining following various tooth preparations used in the restoration of the endodontically treated maxillary second premolar. Illustrations of the maxillary second premolar in buccopalatal, mesiodistal and occlusal sections were drawn to scale. Outlines of various intra- and extracoronal preparations were superim-posed on the illustrations to reveal the amount of tooth tissue remaining in each case. Preparations for a ceramic inlay, inlay with palatal cusp coverage and onlay left 2.0-2.5mm of tooth structure buccally and palatally. Following preparation for a metal-ceramic crown, approximately 1.0mm of tooth structure remained buccally, and between 1.6mm-1.8mm palatally. Preparation for an all-ceramic crown was observed to leave 1.0mm-1.2mm of tooth structure surrounding what remained of the endodontic access cavity. It was concluded that decisions as to the type of definitive restoration to restore the endodontically treated maxillary second premolar may be influenced, amongst other factors, by information on the amount of tooth tissue remaining following preparation.
Tooth wear is the non-carious loss of tooth tissue due to attrition, erosion and/or abrasion. The amount of wear that accelerates physiological tooth wear is referred as pathological tooth wear. This study aims to determine the prevalence and mean scores according to mouth quadrant of raw tooth wear (RTW) and pathological tooth wear (PTW) and investigate sex association with PTW among 16-year-old secondary school children in Kota Bharu, Kelantan. This cross-sectional study involves 688 participants randomly selected from eight government secondary schools. The Smith and Knight Tooth Wear Index (TWI) was used. Data were analyzed using a simplified Microsoft Excel program developed based on the index to quantify PTW. Bar graphs were plotted to highlight the mean scores according to mouth quadrant. About 44% of participants were male and 56% were female. The prevalence of RTW and PTW among subjects was 100% and 20.1% respectively. It was found that 32.8% of tooth surfaces were affected with RTW and 0.7% of study subjects already had exposed dentine. The most affected quadrant for RTW and PTW was the upper and lower incisal quadrant respectively. Males had 92% more odds of developing tooth wear compared to females. In conclusion, all subjects have some degree of wear. About one-fifth of the study subjects were affected by PTW. The patterns of wear were similar to those encountered in the Western societies. There was statistically significant association between sex and PTW.
The objective of this study was to evaluate and compare the effect of times elapsed on the application of a single-step adhesive system and activation of light cured subsequently placed composite to the bond strength between composites and adhesives. This was an experimental study using fifteen teeth extracted human premolars, which were caries and pathology free. Sample of teeth were embedded up to cemento-enamel junction on box of acrylic resin. All teeth were cut to obtain flat occlusal dentin surfaces. The specimens were randomly selected and divided into three groups with five teeth each. All the teeth were assigned to single-step bonding system AQ Bond (Sun Medical Co. Ltd., Shiga, Japan) according to manufacturer’s direction. Group 1 was left for 45 seconds, group 2 for 2 minutes, while group 3 was 5 minutes before putting subsequently restorative material. Composite resin was applied in 3 mm diameter and 6 mm height of cylinder mold and cured according to manufacturer’s direction on the dentin surface. Shear bond strength were measured using a testing system (Instron 8874, Instron Corp., Canton, MA, USA) at a crosshead speed of 2 mm/min with cell load capacity of 25 KN. The bond-strengths between single step adhesive system (AQ Bond) and light cured composites were tested. Mann-Whitney test showed no significant differences in bond-strength between Group 1 and Group 2. However, there were significantly differences (p
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).
During post crown restoration, the preparation of the post canal can be fraught with difficulties resulting in widening, gouging and transportation of the post canal; sometimes with near root perforation. A technique is described to repair such iatrogenically damaged internal root canal walls using reinforcing resin composite and optic glass fibre posts. The root dentine, resin composite and glass fibres, having similar moduli of elasticity, will result in a repaired root with a ‘monolithic’ structure and possessing numerous desirable characteristics. This repair technique can easily be carried out in one sitting at the chairside thereby allowing the continued serviceability of the iatrogenically compromised root-filled tooth.
Desensitization of teeth after cavity preparation has been recommended in an attempt to avoid post-operative sensitivity. However, there is concern regarding application effect of desensitizing agent on shear bond strength of the adhesive system used. The purpose of our study was to compare the shear bond strength of adhesive system in two different dentin surface treatments, with and without desensitizing agent. Sixteen extracted human premolars were sectioned off at the coronal portion to expose the flat dentin surfaces. The surfaces were finished using 600 Grit Wet Silicon Carbide abrasive papers. The premolars were randomly assigned to two groups: control and treated with MS Coat desensitizing agent. The desensitizer was applied according to manufacturer’s instruction. Resin composite was bonded to each dentin surface using Prime & Bond ® adhesive system. The composite resin was debonded by shear stress. Mann-Whitney Test was used in statistical analysis. Our result showed that application of MS Coat desensitizing agent on dentin surface had significantly reduced the shear bond strength of the adhesive system used (z = - 0.14, p < 0.05). Thus, we conclude that shear bond strength of Prime & Bond ® NT (Dentsply, USA) adhesive system will be reduced if dentin surface is treated with MS Coat (Sun Medical, Japan) desensitizing agent.