Reattachment of a fractured fragment to the remaining tooth is challenging but one of the best treatment protocol in regards to aesthetics, function as well as patients acceptance. This case report presents a 20 years old male with an oblique complicated crown fracture of maxillary left central incisor tooth. The procedure used to repair the fracture regarding this case included flap surgery with endodontic treatment. The root canal was filled with a root canal sealer and gutta-percha. After root canal obturation, fragments were reattached with duel cure composite resin using a glass fibre post. After 12 months evaluation, clinical and radiographic examinations showed a stable reattachment, good aesthetics and healthy periodontium.

The severity of the COVID-19 pandemic has created an emerging need to investigate the long-term effects of infection on patients. Many individuals are at risk of suffering pulmonary fibrosis due to the pathogenesis of lung injury and impairment in the healing mechanism. Fibroblasts are the central mediators of extracellular matrix deposition during tissue regeneration, regulated by anti-inflammatory cytokines including TGF-β. The TGF-β-dependent accumulation of fibroblasts at the damaged site and excess fibrillar collagen deposition lead to fibrosis. We developed an open-source, multiscale tissue simulator to investigate the role of TGF-β sources in the progression of lung fibrosis after SARS-COV-2 exposure, intracellular viral replication, infection of epithelial cells, and host immune response. Using the model, we predicted the dynamics of fibroblasts, TGF-β, and collagen deposition for 15 days post-infection in virtual lung tissue. Our results showed variation in collagen area fractions between 2% and 40% depending on the spatial behavior of the sources (stationary or mobile), the production rate of TGF-β, and the activation duration of TGF-β sources. We identified M2 macrophages as primary contributors to higher collagen area fraction. Our simulation results also predicted fibrotic outcomes even with lower collagen area fraction for a longer activation duration of latent TGF-β sources. Our results showed changes in fibrotic patterns with partial removal of TGF-β sources and significantly increased collagen area fraction with partial removal of TGF-β from the extracellular matrix in the presence of persistent latent TGF-β sources. These critical insights into the activity of TGF-β sources may find applications in the current clinical trials targeting TGF-β for the resolution of lung fibrosis.

Background: Particle size is a key parameter for drug-delivery nanoparticle design. It is believed that the size of a nanoparticle may have important effects on its ability to overcome the transport barriers in biological tissues. Nonetheless, such effects remain poorly understood. Using a multiscale model, this work investigates particle size effects on the tissue distribution and penetration efficacy of drug-delivery nanoparticles. Results: We have developed a multiscale spatiotemporal model of nanoparticle transport in biological tissues. The model implements a time-adaptive Brownian Dynamics algorithm that links microscale particle-cell interactions and adhesion dynamics to tissue-scale particle dispersion and penetration. The model accounts for the advection, diffusion, and cellular uptakes of particles. Using the model, we have analyzed how particle size affects the intra-tissue dispersion and penetration of drug delivery nanoparticles. We focused on two published experimental works that investigated particle size effects in in vitro and in vivo tissue conditions. By analyzing experimental data reported in these two studies, we show that particle size effects may appear pronounced in an in vitro cell-free tissue system, such as collagen matrix. In an in vivo tissue system, the effects of particle size could be relatively modest. We provide a detailed analysis on how particle-cell interactions may determine distribution and penetration of nanoparticles in a biological tissue. Conclusion: Our work suggests that the size of a nanoparticle may play a less significant role in its ability to overcome the intra-tissue transport barriers. We show that experiments involving cell-free tissue systems may yield misleading observations of particle size effects due to the absence of advective transport and particle-cell interactions.

Introduction:Both external & internal anatomy of a tooth is an important aspect of root canal treatment. Failure to detect and treat the second MB2 canal system will result in a decreased long-term prognosis. 1 The main reasons for endodontic failure are apical percolation and presence of micro organisms caused by incomplete instrumentation, inadequate cleaning, insufficient canal obturation and presence of untreated canals 2 . Unusual root and root canal morphology associated with molar teeth have been recorded in several studies in the literature. 3,4 The maxillary first molar is the largest tooth in volume and one of the most complexes in root and canal anatomy 5 . In a literature review, the morphology of the MB root of 8399 maxillary first molar teeth was assessed in 34 studies where two or more canals were present in 56.8% in average of all studies and one canal in 43.1%. And single apical foramen was 61.6% while two apical foramina were 38.3 %. 3 The distobuccal and palatal root was reported in 14 studies included 2576 teeth where the common root canal system configuration of the DB root canal was single 98.3% and two canals 1.7%, and the single apical foramina was present 98% of the time as well as the palatal root with single canal 99% and single apical foramina 98.8% respectively. 3 Also some case reports have shown few anomalies like four rooted maxillary first molar presenting mesiobuccal, distobuccal and two palatal root and each root containing single canal also five rooted with two MB, one DB and two palatal and each root containing single canal. Abstract: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.

Objective: To evaluate the clinical and radiological outcome of MTA in nonvital teeth with open apices. Methods: Twenty-five non-vital teeth with open apices were treated with MTA apexification procedure. Standard endodontic procedures were followed and an apical plug of at least 5 mm was created by using MTA after a calcium hydroxide intra-canal dressing for at least 1 week. Final obturation was done after 24 hours by vertical compaction technique using gutta percha. Patients were recalled at 3, 6, 9 and 12 months interval. Clinical outcome was evaluated by assessing pain, tenderness, mobility and sinus tract. Blind to the treatment record, two examiners assessed the pre-treatment and post-treatment radiographs. Each radiograph was scored with the Periapical Index (PAI) and the size of the apical lesion was measured. The presence of an apical bridge over MTA was also noted. Results: Clinically 92% success rate was found whereas radiologically absolute success rate was 84%. Before treatment the mean PAI was 3.6 and mean size of the lesion was 3.24 mm. But, after 12 months follow up, the mean PAI was 1.36 and the mean lesion size was 0.68 mm. An apical barrier over MTA was distinguishable in 5 cases. Conclusion: Apexification using MTA can be considered as a predictable treatment option than calcium hydroxide apexification. DOI: http://dx.doi.org/10.3329/updcj.v3i2.17994 Update Dent. Coll. j: 2013; 3 (2): 13-19

Background: The presence of a single root canal in mandibular first premolar cannot be assumed always. The variability in canal morpholohy of root canal includes the number & shape of the canal as well as pathways of the canals. Methods: In this study, 100 mandibular first premolar teeth were evaluated by clearing technique. Collected teeth were cleaned and merged with 5.25% NaOCl for 48 hours. Then the teeth were decalcified with 5% nitric acid for 72 hours followed by dehydrated sequentially with 80-100% alcohol. After dehydration, Indian Ink was injected into the canal through the previously prepared access cavity. Finally the teeth were made transperent by 98% methylsalicylate and examined. Results: Out of 100 mandibular first premolar teeth, 89 were single rooted, 10 with double rooted and only 1 was triple. On evaluation of canal configuration according to Weine classification, mandibular first premolars had 64% type I, 5% type II, 22% type III and 9% type IV. Apical delta was found incase of 8% mandibular first premolar tooth. Conclusion: Based on this study, mandibular first premolar teeth of Bangladeshi population have multiple roots and canals and variable canal configurations. DOI: http://dx.doi.org/10.3329/updcj.v2i2.15481 Update Dent. Coll. j: 2012; 2 (2): 03-07

The aim of this report is to discuss a case about a traumatized upper left central incisor presented with chronic periapical pathology with unusual presentation. In this case, the apical area of the tooth was exposed for a long period and the apex was open due to loss of affected tooth materials and its surrounding bone and soft tissue loss. The apical area was corrected with apical curettage and retrograde filling with Mineral Trioxide Aggregate (MTA) as well as soft tissue managed with pedicle flap design. The discolouration and mild shortening of the crown due to intrusive effect was managed by lamination of cosmetic restorative material. After 12 months follow up, the offending tooth was accepted both functionally and aesthetically. DOI: http://dx.doi.org/10.3329/updcj.v3i2.17998 Update Dent. Coll. j: 2013; 3 (2): 39-42

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