Conduction of reparative dentin: A pulp protecting approach by indirect pulp capping in deep carious lesion with biodentine

This case report represents, the treatment of deep carious lesion in a male was done by using indirect pulp capping with biodentine. The clinical and radiological outcomes were evaluated. The patient was presented with mild to moderate sensitivity on thermal (cold) stimulation and discomfort associated with eating in the left mandibular first molar. The clinicoradiographical examination revealed a distoocclusal carious lesion, very close to the pulp, absence of radiolucencies in the periapical region and no periodontal space widening. Pulp sensitivity was confirmed by thermal pulp vitality test. Indirect pulp capping treatment was performed with biodentine. Following 6 months of the treatment, the clinical symptoms were resolved and a calcific bridge was found at the dentin over the pulp and biodentine interface that was indicative the evidence of reparative dentin formation

Palato-gingival groove: An innocuous culprit for endo-perio lesion

This case report represents the clinical management of tooth with palato-gingival groove in a right maxillary lateral incisor with endo-perio lesion leading to dento-alveolar abscess and sinus tract. The right maxillary lateral incisor was examined clinico-radiographically. On clinical examination, the offending tooth revealed localized swelling and an intraoral draining sinus pointing on the labial gingiva without any evidence of caries, discoloration and trauma. The palatal surface of lateral incisor showed a groove with mild calculus embedded in it. The radiographic examination revealed periapical radiolucency. This case provides an evidence of morphological defect of tooth. Complete clinical and radiological examination and adequate knowledge of such morphological/ developmental defects of teeth are necessary for recognition and identification especially because of their diagnostic complexity and further consequences.

Modeling and Performance Analysis of Relay-based Cooperative OFDMA Networks

Next generation wireless communication networks are expected to provide ubiquitous high data rate coverage and support heterogeneous wireless services with diverse quality-of-service (QoS) requirements. This translates into a heavy demand for the spectral resources. In order to meet these requirements, Orthogonal Frequency Division Multiple Access (OFDMA) has been regarded as a promising air-interface for the emerging fourth generation (4G) networks due to its capability to combat the channel impairments and support high data rate. In addition, OFDMA offers flexibility in radio resource allocation and provides multiuser diversity by allowing subcarriers to be shared among multiple users. One of the main challenges for the 4G networks is to achieve high throughput throughout the entire cell. Cooperative relaying is a very promising solution to tackle this problem as it provides throughput gains as well as coverage extension. The combination of OFDMA and cooperative relaying assures high throughput requirements, particularly for users at the cell edge. However, to fully exploit the benefits of relaying, efficient relay selection as well as resource allocation are critical in such kind of network when multiple users and multiple relays are considered. Moreover, the consideration of heterogeneous QoS requirements further complicate the optimal allocation of resources in a relay enhanced OFDMA network. Furthermore, the computational complexity and signalling overhead are also needed to be considered in the design of practical resource allocation schemes. In this dissertation, we conduct a comprehensive research study on the topic of radio resource management for relay-based cooperative OFDMA networks supporting heterogeneous QoS requirements. Specifically, this dissertation investigates how to effectively and efficiently allocate resources to satisfy QoS requirements of 4G users, improve spectrum utilization and reduce computational complexity at the base station. The problems and our research achievements are briefly outlined as follows. Firstly, a QoS aware optimal joint relay selection, power allocation and subcarrier assignment scheme for uplink OFDMA system considering heterogeneous services under a total power constraint is proposed. The relay selection, power allocation and subcarrier assignment problem is formulated as a joint optimization problem with the objective of maximizing the system throughput, which is solved by means of a two level dual decomposition and subgradient method. The computational complexity is finally reduced via the introduction of two suboptimal schemes. The performance of the proposed schemes is demonstrated through computer simulations based on OFDMA network. Numerical results show that our schemes support heterogeneous services while guaranteeing each user's QoS requirements with slight total system throughput degradation. Secondly, we investigate the resource allocation problem subject to the satisfaction of user QoS requirements and individual total power constraints of the users and relays. The throughput of each end-to-end link is modeled considering both the direct and relay links. Due to non-convex nature of the original resource allocation problem, the optimal solution is obtained by solving a relaxed problem via two level dual decomposition. Numerical results reveal that the proposed scheme is effective in provisioning QoS of each user's over the conventional resource allocation counterpart under individual total power constraints of the users and relays . Lastly, decentralized resource allocation schemes are proposed to reduce the computational complexity and CSI feedback overhead at the BS. A user centric distributed (UCD) scheme and a relay centric distributed (RCD) scheme are proposed, where the computation of the centralized scheme is distributed among the users and relays, respectively. We also proposed suboptimal schemes based on simplified relay selection. The suboptimal schemes can be combined with the distributed schemes to further reduce of signalling overhead and computational complexity. Numerical results show that our schemes guarantee user's satisfaction with low computational complexity and signalling overhead, leading to preferred candidates for practical implementation. The research results obtained in this dissertation can improve the resource utilization and QoS assurance of the emerging OFDMA networks.4 month

Five Root Canals for a Maxillary First Molar Tooth A Case Report

This case report represents assessment and management of a maxillary left first molar tooth containing five root canals by endodontic treatment. In this case Mesiobuccal 2 (MB2), Mesiopalatal (MP) and Distobuccal (DB) canals were missed as well as very poor obturation at palatal and mesiobuccal1(MB1) canal during previous treatment history. Three mesiobuccal (MB1, MB2, and MP), DB and palatal canals were identified and endodontic retreatment was done followed by final restoration. This case provides an evidence of variations in the root canals of the mesiobuccal root of maxillary first molar tooth. Complete clinical and radiographic examination and adequate knowledge of the morphology of this kind of teeth is necessary for successful clinical outcome.DOI: http://dx.doi.org/10.3329/bsmmuj.v5i1.11026 BSMMU J 2012; 5(1):61-64

Management of Tooth Resorption by Using Calcium Hydroxide: A Case Report

In this case report, the treatment of internal root resorption in a 24 years-old male was done by using nonsurgical root canal therapy and the clinical outcome was evaluated. Both the maxillary central incisors were examined clinico-radiographically. On clinical examination, the maxillary incisors were found discolored. Radiographic examination revealed a punched-out radiolucent lesion on the cervical area of pulpal canal of both of the teeth and periradicular radiolucency was also evident. Conservative non-surgical root canal treatment was performed with long term calcium-hydroxide therapy. Following eight months of the treatment, the resorption process was stopped and a calcific bridge was formed at the apex of the roots indicated the evidence of recalcification. Conventional root canal obturation method was implied followed by clinical and radiological evaluation for next two years.DOI: http://dx.doi.org/10.3329/bsmmuj.v5i1.11029 BSMMU J 2012; 5(1):72-75

Input switched closed-loop single phase SEPIC controlled rectifier with improved performances

DC power supply has become the driving source for some essential modern applications. Thereby, DC power conditioning has become a significant issue for engineers. Typically used rectifiers associated with a bridge structure is nonlinear in nature. Thereby, the current at input side of the rectifier contains harmonics, which also flow through the power line. The presence of harmonics causes several interruptions and reduce power quality. In this regard, a new close loop SEPIC controlled rectifier is proposed in this paper. The conventional scheme is arranged with a rectifier connected to a DC-DC converter, which is an open loop system. Consequently, such system cannot regulate voltage at load varying condition. The proposed SEPIC controlled rectifier can regulate voltage under load varying condition for a wide range. Additionally, the performance in terms of total harmonic distortion (THD) of input current and power factor at AC side are also within satisfactory range for the closed loop configuration. The controlled rectifier has four operating phases associated with switching states and input voltage polarity. The close loop configuration also incorporates a current and a voltage loop at the feedback path. The comparative studies have been performed among the proposed closed loop construction, the open-loop structure as well as the conventional construction. The effectiveness of the proposed controlled rectifier is verified in terms of THD and input power factor considering the results obtained from simulation

Price Behaviour of Major Cereal Crops in Bangladesh

The key concern of this research is to analyse the extent of the seasonal price fluctuation and spatial price relationship of major cereal crops viz., Boro paddy and wheat in different markets in Bangladesh. This study was entirely based on secondary data from the period of 1986-87 to 2009-10 from different sources. In estimating seasonal price fluctuation of selected crops it was found that crops prices fluctuated in different months within the year. The difference between peak and trough prices was higher for Boro paddy than wheat. Coefficient of variation was also higher for Boro paddy than wheat but these figures are decreasing gradually. The results of empirical evaluation of spatial price linkage through Engle-Granger co-integration method among regional selected markets of Bangladesh using harvest price of Boro paddy and wheat indicate that these markets were well integrated. That means, information about price changes are fully and instantaneously delivered to the other markets in Bangladesh. Price analysis and formation of policy at the aggregate level will be pertinent for policy implementation. Keywords: Price behaviour, Cereal crops, Market integration, Unit root, Engle-Grange

Evaluation of clinical and radiological outcomes of mineral trioxide aggregate and calcium hydroxide as indirect pulp capping agents in the treatment of deep carious lesion of permanent teeth

The maintenance of pulp vitality and conduction of reparative dentin can be possible by indirect pulp capping with mineral trioxide aggregate (MTA) and calcium hydroxide as pulp capping agents. The objective of the study is to assess the clinical and radiological outcomes of MTA and calcium hydroxide as indirect pulp capping agents in deep carious lesions of permanent teeth. The present study included 50 permanent teeth having deep carious lesions with reversible pulp status were selected and then randomly divided into two groups of 25 teeth in a group. Standard indirect pulp capping procedures were followed. Patients were recalled at 3, 6 and 12 months interval to assess postoperative pain, the vitality of the pulp and formation of reparative dentin. In all observation periods, MTA showed more capable of reducing pain and maintain pulp vitality which was statistically significant than that of calcium hydroxide. At 12 months observation period, 24 teeth (96%) of MTA and 19 teeth (76%) of calcium hydroxide showed reparative dentin formation. It can be concluded that MTA is more effective than that of calcium hydroxide.

Clinical and radiological evaluation of furcal perforation repaired by mineral trioxide aggregate and intermediate restorative material

The purpose of the present study was to assess the clinical and radiological outcome following repair of furcal perforation by mineral trioxide aggregate (MTA) and intermediate restorative material (IRM) in mandibular molar teeth. Forty teeth having furcal perforation were enrolled in this study, out of which 20 teeth were treated with MTA and the remaining 20 teeth were subjected to IRM treatment. Following perforation repair, all teeth were subjected to root canal treatment followed by final restoration. Clinical and radiological outcome was evaluated at 3, 6 and 12 months interval. The results showed that in both MTA and IRM groups, pain, tenderness on percussion as well as swelling and sinus was gradually decreased with the increase of the observation period. Furthermore, the widening of the periodontal ligament space and communi-cation with the oral cavity were gradually decreased. Although there was no significant differences between MTA and IRM at 3 and 6 months observation period but at 12 months, the clinical outcome between MTA and IRM was statistically significant (p<0.05). It can be concluded that repair of furcal perforation by MTA showed more effective than that of IRM

Reattachment of fractured anterior tooth fragment: An approach in endo esthetic view

Esthetic rehabilitation of crown fractured anterior teeth is one of the greatest challenges to the dental specialists in concern of long-term biological function. Traditional views demonstrate limitations with much controversy in MICD (Minimally invasive cosmetic dentistry) concept. To meet the challenge a new biological approach in endo esthetic view is considered. This case report represents the management of a fractured right maxillary central incisor tooth of 27 year-old-male patient where his own fractured tooth fragment restored by reattachment technique. The clinical examination revealed complicated crown fracture extended horizontally from mesial to distal and angulated incisally from palatal to labial with pulp exposure. The fracture was not evident labially. In this case, the procedure was used to repair the fracture tooth fragment included root canal treatment and glass fiber post for reinforcement. The tooth fragment was luted with light activated flowable composite resin.  Onward assessment showed a stable reattachment, good esthetic and function with healthy periodontium.