Alen Braut

The transition from pulpitis to periapical periodontitis in dogs' teeth.

The purpose of the study was to histologically analyse transition from pulpitis to periapical periodontitis on dogs teeth. Pulps of mandibular premolars (37 roots) were exposed using a low-speed handpiece. Teeth were left open to the oral environment for 20, 35, 50 and 65 days. After the experimental period animals were sacrificed. Undemineralised teeth with surrounding bone, embedded in methylmetacrylate, were prepared for standard histological analysis. All teeth with pulpitis (five roots), regardless of the experimental period, had acute serose periapical periodontitis. All teeth (15 roots) with partial pulp necrosis had subacute periapical periodontitis. Teeth with complete pulp necrosis (19 roots) had chronic periapical periodontitis and in one case suppurative apical periodontitis. The condition of the pulp correlates with the histopathological findings of periapical tissue in the open types of pulp infection. Acute periapical periodontitis begins during pulpitis and can occur before 20 days of pulp exposure in the dog.

Irrigation of human prepared root canal – ex vivo based computational fluid dynamics analysis

Aim To analyze the influence of the needle type, insertion depth, and irrigant flow rate on irrigant flow pattern, flow velocity, and apical pressure by ex-vivo based endodontic irrigation computational fluid dynamics (CFD) analysis. Methods Human upper canine root canal was prepared using rotary files. Contrast fluid was introduced in the root canal and scanned by computed tomography (CT) providing a three-dimensional object that was exported to the computer-assisted design (CAD) software. Two probe points were established in the apical portion of the root canal model for flow velocity and pressure measurement. Three different CAD models of 27G irrigation needles (closed-end side-vented, notched open-end, and bevel open-end) were created and placed at 25, 50, 75, and 95% of the working length (WL). Flow rates of 0.05, 0.1, 0.2, 0.3, and 0.4 mL/s were simulated. A total of 60 irrigation simulations were performed by CFD fluid flow solver. Results Closed-end side-vented needle required insertion depth closer to WL, regarding efficient irrigant replacement, compared to open-end irrigation needle types, which besides increased velocity produced increased irrigant apical pressure. For all irrigation needle types and needle insertion depths, the increase of flow rate was followed by an increased irrigant apical pressure. Conclusions The human root canal shape obtained by CT is applicable in the CFD analysis of endodontic irrigation. All the analyzed values –irrigant flow pattern, velocity, and pressure – were influenced by irrigation needle type, as well as needle insertion depth and irrigant flow rate.

Finite Element Analysis in Dental Medicine

Studying dental structures and surrounding tissues in the oral cavity presents the basis for understanding the occurrence of pathological process and enables the correct approach and treatment. Oral rehabilitation is inherently difficult, due to the functional and parafunctional forces within the mouth that result in extremely complex structural responses by the oral tissue [1]. The success of restorative materials depends on their properties to withstand and resist occlusal forces and successfully support the remaining oral structure [2]. Studies examining the biomechanical behavior of oral structures require sophisticated simulations of the fundaments of the stomatognathic system [3].

Vertical force and torque analysis during mechanical preparation of extracted teeth using hand ProTaper instruments

The purpose was to measure and analyse the vertical force and torque developed in the wider and narrower root canals during hand ProTaper instrumentation. Twenty human incisors were divided in two groups. Upper incisors were experimental model for the wide, while the lower incisors for the narrow root canals. Measurements of the force and torque were done by a device constructed for this purpose. Differences between the groups were statistically analysed by Mann-Whitney U-test with the significance level set to P<0.05. Vertical force in the upper incisors ranged 0.25-2.58 N, while in the lower incisors 0.38-6.94 N. Measured torque in the upper incisors ranged 0.53-12.03 Nmm, while in the lower incisor ranged 0.94-10.0 Nmm. Vertical force and torque were higher in the root canals of smaller diameter. The increase in the contact surface results in increase of the vertical force and torque as well in both narrower and wider root canals.

Conservative endodontic management of a fused tooth: A case report

OBJECTIVE To report a conservative treatment of a rare developmental anomaly. CASE REPORT A 73-year-old patient with previously initiated therapy and acute apical abscess of a maxillary right central incisor fused with the supernumerary tooth sought treatment. The conservative approach included nonsurgical root canal treatment and composite restoration. CONCLUSION This case illustrates the importance of an individual approach when treating anomalous teeth. Priorities in pain and infection management to properly and functionally restore teeth should be unaffected by age.