Maxillary 1st Molar Research Articles

Qualitative assessment of the dental groove pattern and its uniqueness for forensic identification.

Introduction:Teeth are invaluable in both the living and the deceased for forensic identification and profiling purposes. The occlusal surface patterns in the molars of an individual depend on both intrinsic and extrinsic factors. The individualistic nature of the groove pattern can be used to determine the identity of an individual by the process of comparative identification.Aim and Objective:The objective of this study is to determine the uniqueness of the groove pattern among individuals by the means of digital analysis.Materials and Methods:An experimental study was conducted on 80 dental casts where the occlusal groove patterns of 1st and 2nd molars from each cast were traced digitally using image analysis software GIMP (v 2.10.6). The traced patterns were then examined to determine their uniqueness.Results:The most common groove patterns for the maxillary 1st and 2nd molars were found to resemble “Branched H” and “H”, respectively. “Y” pattern was observed to be the most common in mandibular 1st molar, whereas mandibular 2nd molar most commonly exhibited “+” pattern. No two groove patterns were similar in the analysis.Conclusion:Digital method of analysis is preferable over conventional manual methods as it is noninvasive and precise. The individualistic nature of occlusal groove patterns may play an important role in comparative forensic identification.

An Insight into Anatomical Variations in Maxillary Molars: A Case Series

The aim of this article is to show different anatomic complexities of the root canal system related to maxillary molars. Maxillary molars are presumed to have only three roots with three canals but this is not always the case, it might present with different variations. Some of the anatomical variations such as, mesiobuccal2 (MB2) canals in maxillary 1st and 2nd molars, two rooted maxillary 1st and 2nd molar, one rooted maxillary 2nd molar, C-shaped upper 2nd molar and maxillary 2nd molar with extra palatal root are reported in this case series. Hence, in treating each tooth every dentist must keep foresight that complex anatomy occurs often enough to be considered normal and manage them accordingly.

Distalization of Maxillary Molars by Miniscrews and EZ Slider

objectives: The aim of the current study was to evaluate distalization of the maxillary 1st molars by sliding mechanics depending on the numbers of miniscrews. Materials and Methods: The current study was conducted on a total sample of twenty adult orthodontic patients presented with class II maxillary permanent first molars indicated for distalization with an age ranged from 18-23 years. For every patient enrolled in the present study, routine orthodontic records were taken before the treatment and after eight months or the end of distalization. Patients were treated by using EZ slider as a distalizer with one miniscrew inserted on the buccal side between the 1st permanent molar and the 2nd permanent premolar and in the other side the distalizer EZ slider with two miniscrews inserted in which one inserted between the 1st permanent molar and the 2nd permanent premolar and the next miniscrew was inserted between the 2nd permanent premolar and the 1st permanent premolar. Results: The side in which two miniscrews inserted and the EZ slider showed more distal movement of the 1st permanent molar than the side with one miniscrew and the EZ slider due to the double force used. Conclusion: EZ slider is a simple and an effective appliance for molar distalization. Which has no specific protocol to be used effectively.

The Impact of Orthodontic Bands on the Marginal Periodontium of Maxillary First Molars: A Retrospective Cross-Sectional Radiographic Analysis.

Aim:Available information on the effect of orthodontic treatment on crestal alveolar bone levels measured in radiographs is contradictory. The aim of this study was to compare the alveolar bone level and periodontal ligament space of banded upper first molars to untreated controls.Materials and Methods:This retrospective cross-sectional radiographic study investigated alveolar bone levels of upper first molars of an orthodontic test group and an untreated control group of comparable age (15-16.25 years), using existing bitewing radiographs.Eighty-six individuals were included in each group. Three parameters were measured mesially and distally on both sides of the patient as follows: I) Alveolar Bone Level (ABL): measured as the distance between the cemento-enamel junction and the alveolar crest, II) the Periodontal Ligament Space (PLS): measured as the most coronal distance between the alveolar crest and the tooth surface, and III) angle between the lines (alveolar crests mesial and distal) and (cemento-enamel junction mesial and distal).Results:The mean duration of the orthodontic treatment in the test group was 2.5 years. The periodontal ligament space was statistically significantly wider on mesial areas of right molars (mean 0.2 mm, p<0.01), but there was no statistically significant difference found in the three other areas (distal part of the right molar, mesial and distal parts of the left molar). There was a statistically significant mean alveolar bone loss in the right and left mesial areas, respectively accounting for 0.3 mm (p<0.001) and 0.2 mm (p<0.01). No statistically significant alveolar bone loss was measured on the distal surfaces of the upper molars. The angle was wider on both sides for the test group (right p<0.001 and left p<0.05).Conclusions:A significant alveolar bone loss on the mesial tooth surface of upper first molars after orthodontic treatment was found with concurrent different levelling angles in the test group. On all other sites, no statistically significant changes were found. There was some minimal statistical significant alveolar bone loss after finishing treatment in patients who had orthodontic bands placed on their maxillary 1st molars, but no clinical significance was found.

Prevalence of hypercementosis in a Saudi Arabian population: A cone beam computed tomography study.

Objective: To determine the prevalence of hypercementosis in a Saudi Arabian population. Material and methods: A total of 642 CBCT scans from patients comprising 4471 teeth were incorporated in the study sample. All teeth were analyzed for the presence of hypercementosis in sagittal, axial and coronal plains by two qualified and experienced observers. The characteristics of the involved tooth in terms of gender, jaw and location were recorded from the CBCT scans. The obtained data were statistically analyzed using SPSS 21.0. The reliability of measurements was evaluated by kappa statistics. Results: Out of total 642 subjects hypercementosis was observed in 31 patients (4.82%) and 43 teeth (0.96%). Eight (2.68%) maxillary 1st molars, 6 (1.88%) mandibular 1st molars, 5 (1.46%) maxillary second molars, 7 (1.95%) mandibular 2nd molars, 9 (4.76%) maxillary 3rd molars and 8 (3.58%) mandibular 3rd molars were observed to have hypercementosis. Among males, 4.76% were affected with hypercementosis as compared to 4.86% of females (p=0.97). Likewise, no significant difference in the occurrence of hypercementosis was observed between maxillary and mandibular arches or between sides (p&gt;0.05). Conclusion: The prevalence of hypercementosis in a Saudi population was found to be 4.82% with respect to patients and 0.96% with respect to teeth. No significant propensity for gender, jaw and arch side was noted.

Evaluation of mesiodistal inclination of permanent maxillary and mandibular first molars in different Angle's molar relation: A cephalometric study

Introduction: Angle's molar relationship is the most widely used classification in spite of the introduction of various other classifications. At the end of the treatment, the molars are finished in a Class I, II, or III molar relation. Thus, it is important to know the ideal inclinations of upper and lower 1st molars, thereby assisting in achieving a stable relationship. Aims and Objectives: The aim and objective of this study was to evaluate the mesiodistal inclination of permanent maxillary and mandibular first molars in Angle's Class I, II, and III molar relationships in relation to the occlusal plane. Methodology: Lateral cephalograms of 16–30-year-old individuals with Class I, II, and III molar relations were selected and traced in Dolphin imaging software, and the angle between the first molar and occlusal plane was calculated. Results: There was a statistically significant difference in the inclination of maxillary 1st molar in between Class I and Class III. No significant difference was noted in the inclination of maxillary first molar in case of Class I and Class II. In case of mandibular molars, there was a statistically significant difference in case of Class I and Class II and between Class I and Class III. Conclusion: When the end molar relationship of a case is planned to be Class I, the upper molar should be at an angle of 84.12° to the occlusal plane. When the end molar relationship of a case is planned to be Class II, the upper molar should be 84.15° to the occlusal plane. When the end molar relationship of a case is planned to be Class III, the upper molar should be inclined at an angle of 87.07° to the occlusal plane.

EFFECT OF SURFACE TREATMENT OF ORTHODONTIC MINI-SCREW IMPLANTS ON THEIR STABILITY; IN VIVO STUDY

Purpose: To evaluate the effect of anodization surface treatment on the stability of minimplants ( MIs ) during en-masse retraction. Materials and Methods: The sample of this split mouth; clinical trial, consisted of 27 patients with an allocation ratio of 1:1. Forty five MIs (1.8 mm diameter and 8 mm length) were divided into: 27 MIs with surface treatment by anodization technique while the other 27 were with smooth surface (group B). Finishing, leveling and alignment, the surface treated MIs and the smooth ones were randomly inserted between the roots of maxillary 2nd bicuspid and 1st molar at the mucogingival junction on both sides of each patient. After two weeks healing period, bilateral extraction of maxillary 1st bicuspids were done. Closed coil spring was extended from the MI head to along hock secured onto the main arch wire between the maxillary lateral incisor and canine on both sides, delivering 200 g force per side to en-masse retract the upper anterior teeth. The average observation period lasted 9–12 months. Results: In total, 40 of 54 minimplants were able to achieve the treatment goals. In group A, 22 (81.5%) mini-screw implants presented long-term stability, while in group B, only 18 (66%) minimplants were stable throughout the treatment. This difference was statistically significant (P =.0311). The total success rate for all inserted miniscrew implants was 74%. Conclusion: Anodized surface treated orthodontic mini-screw implants are more stable than smooth surface one during en-mass retraction.

Opposite effects of mu and delta opioid receptor agonists on excitatory propagation induced in rat somatosensory and insular cortices by dental pulp stimulation

The insular cortex (IC) contributes to nociceptive information processing. IC neurons express opioid receptors, including the mu (MOR), kappa (KOR), and delta (DOR) subtypes. Opioidergic agonists suppress excitatory synaptic transmission in the cerebral cortex. In addition, morphine injection into the IC reduces responses to noxious thermal stimuli. However, the mechanisms of the opioid-dependent modulation of cortical excitation at the macroscopic level, which bridge the cellular and behavioral findings, have remained unknown. The present in vivo optical imaging study aimed to examine the effects of the agonists of each subtype on cortical excitatory propagation in the IC and the neighboring cortices, the primary (S1) and secondary somatosensory (S2) areas. To assess the opioidergic effects on the cortical circuits, we applied electrical stimulation to the maxillary 1st molar pulp, which induced excitation in the ventral part of S1 and the S2/insular oral region (IOR). The initial excitatory response was observed 10–14ms after stimulation, and then excitation propagated concentrically. DAMGO (10–100μM), an MOR agonist, suppressed the amplitude of cortical excitation and shrank the maximum excitation areas in S1 and S2/IOR. In contrast, 10–100μM DPDPE, a DOR agonist, increased the amplitude of excitation and expanded the area of maximum excitation. U50488 (10–100μM), a KOR agonist, had little effect on cortical excitation. These results suggest that MOR-induced suppression of excitatory propagation in the IC is an underlying mechanism of the powerful analgesic effects of MOR agonists. In contrast, DOR may play a minor role in suppressing acute pain.

Biomechanical Characteristics Of Micro-implant For Anchorage In Orthodontics – A Three-dimensional FEM Study

Orthodontic micro-implants have been used as stationary anchorage in recent years. A 3- Dimensional mathematical model was constructed that uses the finite element method which simulated an orthodontic implant maxillary 1st molar maxillary 2nd premolar with its periodontal ligament and cortical and cancellous bone. The stress and displacement on the implant-bone interface were analyzed on different angulations of the implant to the long axis of the maxillary molar 30ordm to 90ordm with a horizontal orthodontic force of 200gms.Results As the angulations decreased the von-mises stress and displacement at the cervix of the implant were decreased at 90ordm angulations the stress and displacement are 15.91mpa and -9.44 times 10 -4 respectively and at 300 angulations the stress and displacement are 7.7mpa and -8.50 times 10 -4 respectively.Conclusions On the basis of these results it is concluded that micro-implants can be safely loaded with 200gms of mesio-distal force. Maximum stress and displacement was recorded when the implant was placed perpendicular to the long axis of maxillary 1st molar.

The transcription factor mohawk homeobox regulates homeostasis of the periodontal ligament.

The periodontal ligament (PDL), which connects the teeth to the alveolar bone, is essential for periodontal tissue homeostasis. Although the significance of the PDL is recognized, molecular mechanisms underlying PDL function are not well known. We report that mohawk homeobox (Mkx), a tendon-specific transcription factor, regulates PDL homeostasis by preventing its degeneration. Mkx is expressed in the mouse PDL at the age of 10 weeks and expression remained at similar levels at 12 months. In Mkx-/- mice, age-dependent expansion of the PDL at the maxillary first molar (M1) furcation area was observed. Transmission electron microscopy (TEM) revealed that Mkx-/- mice presented collagen fibril degeneration in PDL with age, while the collagen fibril diameter gradually increased in Mkx+/+ mice. PDL cells lost their shape in Mkx-/- mice, suggesting changes in PDL properties. Microarray and quantitative polymerase chain reaction (qPCR) analyses of Mkx-/- PDL revealed an increase in osteogenic gene expression and no change in PDL- and inflammatory-related gene expression. Additionally, COL1A1 and COL1A2 were upregulated in Mkx-overexpressing human PDL fibroblasts, whereas osteogenic genes were downregulated. Our results indicate that Mkx prevents PDL degeneration by regulating osteogenesis.

Intrusion of Overerupted Molars by Corticotomy and Fixed Orthodontic Appliances

ABSTRACTIn this article, a review of the literature regarding the use of selective alveolar corticotomies (SAC) combined with orthodontic treatment was conducted, and the results of its use in a patient with overerupted maxillary 1st molars are described. Adequate intrusion was obtained within a short period of time, the protocol avoided the necessity of removal of sound tooth structure for crown lengthening, endodontic treatment, and full crown prosthetic restorations. Therefore, the obtained results indicate that SAC/orthodontic use is efficient in the intrusion of overerupted 1st molars and suggest its potential use in the treatment of other malocclusions.How to cite this articlede Souza MLAH, Soares RV, Zenóbio EG, Pithon MM, Oliveira DD. Intrusion of Overerupted Molars by Corticotomy and Fixed Orthodontic Appliances. Int J Experiment Dent Sci 2016;5(1):78-82.

Three-dimensional analysis of the distal movement of maxillary 1st molars in patients fitted with mini-implant-aided trans-palatal arches.

ObjectiveThe aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA).MethodsThe subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes.ResultsMean maxillary 1st molar distalization was 2.3 ± 1.1 mm, at a rate of 0.4 ± 0.2 mm/month, and rotation was not significant. Intermolar width increased by 2.9 ± 1.8 mm. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm.ConclusionsDistalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

치과 캐드/캠 시스템으로 제작된 지르코니아 single 코핑과 3-unit 구조물의 상대적 적합도 비교

Purpose: The purpose of this study was to assess the marginal and mesial fitness of zirconia single copings and 3-unit fixed partial dentures (FPDs) manufactured with an identical model. Materials and Methods: An epoxy model in which the maxillary right 2nd premolar is lost and maxillary 1st premolar and 2nd molar are formed as abutments was manufactured and scanned by using a laser scanner. A ten units of zirconia single copings were manufactured for maxillary 1st premolar and 2nd molar, respectively and the same number of 3-unit FPDs were manufactured. For the measurements of fitness, the manufactured silicone replicas were divided into four parts and the fitness were measured by digital microscope at measurement points (P1, P2, P3, P4 and P5) of each plane. The measured gaps were classified into three categories: marginal gap (MG, P1), axial gap (AG, average of P2 and P3), occlusal gap (OG, average of P4 and P5). Results: The ranges of MG, AG and OG for single copings were 18.47 - 40.54 µm, 39.73 - 73.61 µm and 116.90 - 134.69 µm, respectively. The ranges of MG, AG and OG for 3-unit FPDs were 45.95 - 87.44 µm, 23.78 - 57.00 µm and 99.89 - 131.06 µm, respectively. Conclusion: The result of the study shows that the MGs for 3-unit FPDs were higher than those of single copings, though they are within the range of clinical acceptance, indicating that the use of more homogeneous zirconia block and modification of sintering processes are needed to ensure the prevention of increase of gap in 3-unit FPDs. (J Dent Rehabil Appl Sci 2014;30(1):16-22)

Analysis of Root Canal Anatomy &amp; Morphological Variations of Maxillary 1st Molar by Different Methods - An In Vitro Study

Background: Successful endodontic treatment involves accurate diagnosis, good understanding of the biological principles and excellent execution of the treatment. To execute an excellent treatment, it’s imperative that the clinician has comprehensive knowledge of the root canal anatomy and then know-how to locate and treat this anatomy. Objective: To analyze the internal anatomy of the maxillary first molar, to report the incidence of fourth root canals by comparing the efficacy of three diagnostic methods, Operating microscope, Cone beam computerized tomography and clearing technique. Material methods: A sample size of 126 sound non carious, intact human maxillary 1st molar were taken for the study and were divided into three groups according of method of analysis of root canal system-(Group 1: operating microscope, Group 2: Cone beam computerized tomography, Group 3:clearing technique). Anatomical variation in form of additional canal in mesiobuccal root was analyzed for total incidence. Results: For statistical analysis, Mean and Standard deviation were calculated for each group by using chi square test which revealed statistically significant difference between group 2 and 3 and non-significant difference between group 1 and group 2.

The characteristics of epithelial cell rests of Malassez during tooth eruption of development mice

It has been demonstrated that Hertwig's epithelial root sheath (HERS) has an important role in root development, closely related to development of cementum epithelial rests of Malassez (ERM) as the residuum after HERS fragment, and is the exclusive epithelial structure in the mature periodontal ligament. Some studies reported that ERM may play a role in maintaining a stable environment of periodontal, and likely to be involved in regeneration of periodontal tissue, especially of cementum. However, the function of the ERM is not well understood. In this study, we observed the morphology and biological characteristics of ERM of the maxillary 1st molar with surrounding periodontal tissues of BALB/c mice during the period of tooth cusp erupted out of the gingiva to occlusion stability. Immunohistochemistry revealed ERM predominately located at the cervical and root furcation regions of the periodontal ligament. The number of ERM cells at the cervical and root furcation regions of the post-built occlusion stage decreased compared to pre-built occlusion stage and occlusion building stage. Transmission electron microscopy analysis showed that epithelial cell nuclei with typical features of apoptosis were observed at the post-built occlusion stage, and consistent with positive bodies labeled by TUNEL(terminal deoxy-transferase (TdT)-mediated dUTP-biotin nick end labeling), while proliferating cell nuclear antigen positive bodies mainly located at occlusion built stage. It suggests that ERM may regulate in alveolar bone remodeling in association with the periodontal ligament during tooth erupting to occlusion stability and may play important roles potentially in regeneration and homeostasis of the periodontal tissues.

Biomechanical characteristics of microimplant for anchorage in orthodontics: a 3D finite element model study.

In orthodontic treatment, anchorage control is essential for success. A recent development, stationary anchorage (micro- implants) eliminates one of the uncertainties of orthodontic tooth movement by offering absolute control over potentially undesirable counter movements. The objective of this study was to establish a 3D finite element model for microimplant and to analyze the influence of different angulations to the long axis of the teeth (30-90°) on the biomechanical characteristics of orthodontic anchorage implant-bone interface. Results of this study showed that largest stress and deformation was seen in the cortical bone and upper region of trabecular bone. Stress and deformation increased as the angulations of the implant to the long axis of the tooth increased. As the angulation of the implant to the long axis of maxillary 1st molar increased, stress and deformation also decreased. Maximum stress and displacement were recorded when implant was placed perpendicular to the long axis of maxillary 1st molar.

상악 열성장형 전치부 반대교합 아동에 있어서의 상악 치아 성숙도

초기 혼합치열기 어린이의 전치부 반대교합 평가과정에서는 부정교합의 골격적 특성이 강할수록 상악 치아의 맹출 및 형성이 현격히 지연되는 것이 흔히 감지되었다. 만일 두개안면부의 전후방적 골격적 특성이 치아의 성숙도와 연관성을 가진다면, 치아의 발육과 맹출에 대한 평가가 반대교합의 조기 감별진단의 한 도구로써 가치가 있을 것으로 판단되었다. 본 연구는 초기 혼합치열기의 상악 열성장형 반대교합 아동에 있어서 상악의 치아 석회화도와 맹출률, 그리고 측두방사선규격사진 분석을 통한 수종의 계측치 간 연관성을 규명할 목적으로 시도되었다. 부산대학교치과병원 소아치과에 교정적 목적으로 내원한 Hellman 치령IIA IIC 아동 중, 전치부 반대교합을 보이는 III급 부정교합 증례로부터 상악 열성장군과 상악 정상군 각 50례를 무작위 추출하여 연구 대상으로 하였다. 이들의 측두방사선 규격사진과 파노라마방사선사진을 이용하여 각 군의 골격적 양상, 상하악 치아의 석회화도와 맹출률을 구하고 그 차이와 상관성을 분석하여 다음과 같은 결과를 얻었다. 1. 양 군의 상악 치아 성숙도 비교에 있어서 상악 열성장군의 제 1대구치만 석회화도와 맹출률 이 낮게 나타났다(p<0.05). 2. 역령은 상악 치아의 석회화도와 맹출률과 높은 상관관계를 보였다(p<0.05). 3. 상하악의 전후방적 악골 관계중 Wits는 상악 제 1대구치의 석회화도와 맹출률 모두를, SNA는 맹출률을 예측할 수 있는 유용한 지표로 나타났다(p<0.05). In the process of assessing the children with anterior crossbite in early mixed dentition, it has frequently been detected that the stronger the skeletal pattern of the malocclusion is, the more markedly delayed the development and eruption of maxillary teeth are. If the anteroposterior characteristics of craniofacial skeleton has any relationship with dental maturation, the evaluation of dental development and eruption was thought to be able to contribute to early diagnosis of crossbite in children. This study was performed for the purpose of elucidating the relationship between dental maturation of maxillary teeth and some cephalometric values in children with anterior crossbite of maxillary undergrowth type in early mixed dentition. Among the children in Hellman dental age IIA and IIC who attended the Pediatric Dental Clinic of Pusan National University Hospital with orthodontic problems, cases with Class III malocclusion were classified and 50 cases of maxillary undergrowth type and type with normal maxilla respectively were randomly selected and studied as subjects. From their lateral cephalographs and panoramic radiographs, their anteroposterior skeletal features, the dental maturity and eruption rate were obtained of each group and data were analyzed to yield the results as follows: 1. Comparing the maturity of maxillary teeth of both groups, only the first molars of maxillary undergrowth group showed significantly slower development and eruption (p<0.05). 2. There was high correlation between maturation of maxillary 1st molar and chronological age(p<0.05). 3. Among the parameters of anteroposterior relationship of skeletal pattern in maxilla and mandible. Wits was revealed as a useful index to predict both the calcification and eruption rate of the 1st molars whereas SNA was to eruption rate(p<0.05).

Reasons for extraction of permanent teeth in Greece: a five-year follow-up study

To investigate the reasons for tooth extraction and their correlations with age and gender in Greece. The study population consisted of 1,018 patients, 560 males and 458 females, aged 18-74 years from a private practice in Greece. Each patient's age, gender, number of extracted teeth and the reasons for the extraction were recorded for a period of 5 years. Two thousand four hundred and eighteen permanent teeth were extracted for various reasons during the study period. The results showed that the main reasons for extraction were caries (45.6%), periodontal disease (32.1%), failed root canal treatment (7.3%) and root fracture (4.4%). Caries was the main reason for extraction in patients up to 44 years old (64.7%), while periodontal disease was the main reason for extraction in patients over years of age (77.6%). Maxillary and mandibular 1st and 2nd molars, were the most frequently extracted teeth due to dental caries. Premolars of the mandible and maxillary and mandibular anterior teeth were the most frequently extracted teeth due to periodontal disease. Although the targets of the WHO regarding the reduction of dental caries were accomplished, dental caries and periodontal disease are still the main reasons for tooth extraction regardless of the age of the patients.

Effect of betamethasone on the pulp after topical application to the dentin of rat teeth: vascular aspects of the inflammation

Objective:This study investigated the pulpal effect of topically applied betamethasone to the dentin of rat molars in the vascular phase of inflammation.Material and Methods:Deep cavities were prepared on the occlusal face of the maxillary right and left 1st molars with non-refrigerated inverted-cone steel burs at low speed. Three groups were formed: Group I was composed of right 1st molars; Group II was composed of left 1st molars that received the application of a drop of betamethasone on dentin surface for 5 min; and Group III (control) was composed of right 2nd molars that received no cavity preparation or betamethasone application. Changes in the vascular characteristics of the pulp tissue were checked by calculating the pulp vascular area in relation to its total area and the number of blood vessels per unit area. Data were subjected to ANOVA and Tukey's test (α=0.05).Results:Group I presented a significantly larger number of vessels (p<0.05) than Group II. Regarding the vascular/total area ratio (%), Group I presented statistically significantly higher values (p=0.01) than Groups II and III.Conclusion:Betamethasone applied on the dentin of rat teeth proved to reduce the vascular phase of pulp inflammation regarding vessel diameter and number of blood vessels.

Canal pattern in mesiobuccal root of maxillary molars of Nigerians

Objective: This in vitro study was carried out to investigate the variation (if any) in canal outline and number(s) in the mesiobuccal root (MBR) of maxillary first and second molar teeth of Nigerians, and its possible influences on the prognosis of root canal treatment. Method: One hundred and three (103) and eighty seven (87) extracted, root-planed maxillary first and second molars respectively were sectioned transversely at three different points corresponding to the cemento-enamel junction, the peak of the external outline of the furcation and the margin of the middle and apical thirds of the mesiobuccal root. The root canals were identified using size 15 K-files and the canal number noted for each sectioned piece. The canal number(s) obtained at the three levels were projected to determine the canal types. Result: Twenty- seven (26.2%) and 7(8%) of the MBR of maxillary 1st and 2nd molars showed double canals respectively at the chamber floor level. This figure increased to 44(42.7%) for the maxillary 1st molar at the cervical third of the root (p