Association between apical periodontitis and secondary outcomes of atherosclerotic cardiovascular disease: A case-control study.

AIM: To evaluate the association between apical periodontitis (AP) and atherosclerotic cardiovascular disease (ASCDV). METHODOLOGY: A total of 65 periodontally and systemically healthy patients (age ≥ 40 years) were included in the study. Periapical status was assessed through dental examination and periapical radiographs; 33 subjects had AP (AP+), while 32 acted as control (AP-). Moreover, data regarding their periapical index (PAI) score and the Decayed, Missing, and Filled Teeth (DMFT) index were recorded. All subjects underwent echo-colour Doppler assessment of carotid intima-media thickness (CIMT), carotid plaques, degree of stenosis using the North American Symptomatic Carotid Surgery Trial (NASCET) method, maximum diameter of the abdominal aorta (maximum AA) and common iliac arteries (CIA) diameters. Furthermore, peripheral blood flow was also measured using the ankle-brachial index (ABI). Simple and multiple regression analyses were performed. RESULTS: Among AP+ patients, 57.58% disclosed at least one sign of subclinical carotid atherosclerosis. Multiple regression analysis identified AP as a significant risk indicator for carotid plaques [OR = 4.87 (1.27, 18.98; p = .021)] and marked carotid intima-media thickenings (OR = 14.58 [1.22, 176.15], p = .035). A significant association was established between AP and other cardiovascular (CV) variables (CIMT, NASCET, and maximum AA). On the contrary, a higher PAI score does not correlate to increased odds of carotid alterations, and the presence of AP did not prove any significant change in CIA and ABI. No significant correlation was established between DMFT and other variables. CONCLUSIONS: Results from the current study highlight that the presence of AP may be regarded as a risk indicator for ASCVD, with AP being associated with 5-fold increased odds of having carotid plaques and 15-fold increased odds of having marked carotid intima-media thickenings. Further studies should be conducted in order to verify whether AP treatment could be beneficial for ASCVD signs.

Influence of remaining tooth substance and post-endodontic restoration on fracture strength of endodontically treated maxillary incisors.

The aim is to evaluate the influence of remaining tooth substance and post-endodontic restoration on fracture strength of endodontically treated maxillary incisors. 150 maxillary central incisors were divided into three groups, Group 0, intact teeth; Group 1, removal of distal wall; Group 2, removal of mesial and distal walls, and further into two subgroups A0,A1,A2 and B0,B1,B2 according to post-endodontic restoration (post/no-post), then loaded to fracture. Interactions among variables and intergroup significance were tested with two-way ANOVA and Kruskal Wallis's tests (p≤0.05). Tukey's test was applied for multiple comparisons. Statistically significant differences were found between groups B1-A1, and B2-A2, but they were not found between B0-A0. Intragroup analysis showed statistically significant differences in both groups post/no-post with decreasing dental substance. Fiber post placement causes an increase in fracture strength and a reduction of irreparable fractures in endodontically treated maxillary central incisors that lost at least one wall.

Influence of single post, oval, and multi-post restorative techniques and amount of residual tooth substance on fracture strength of endodontically treated maxillary premolars.

PURPOSE: The aim of this study was to compare the influence of the number of coronal walls and post-endodontic restorations on the mechanical strength of 165 recently extracted endodontically treated maxillary premolars. METHODS: The teeth were divided into 3 control (no post) and 3 test groups according to the number of residual walls. Each test group was divided into subgroups according to the type of post-endodontic restoration (single, oval, and multi-post techniques). Samples were prepared conforming to the assigned subgroup. A universal loading machine applied a load parallel to the longitudinal axis of the teeth, thus simulating physiological occlusion. ANOVA and the Kruskal Wallis test were used for comparisons (P ≤ 0.05), and Tukey's test for multiple comparisons. RESULTS: For intact teeth, significant differences were found among all 3 subgroups, with single post showing the highest values. For 3 residual walls, oval post resulted in significantly lower values than single and multi-post systems. For 2 residual walls, the multi-post technique showed almost twice the resistance of oval post restorations. CONCLUSION: In oval canals the use of a single or multi-post technique increased post-and-core resistance even in intact teeth, whereas oval fiber posts showed no improvements. Multi-post design improved fracture resistance mostly in maxillary premolars lacking both marginal ridges.

Different Post Placement Strategies for the Restoration of Endodontically Treated Maxillary Premolars with Two Roots: Single Post vs Double Post.

AIM AND OBJECTIVE: The present study compared the fracture strength and failure pattern of endodontically treated, bi-rooted, maxillary premolars with different number of coronal walls and postendodontic restoration (one vs double post). MATERIALS AND METHODS: 105 premolars were divided into 3 groups according to the number of residual walls: control group (intact teeth; n = 15), group 1 (3 residual walls; n = 45), group 2 (2 residual walls; n = 45). Each test group was then divided into 3 subgroups (n = 15 each) according to postendodontic restoration: no post (A), 1 post (B) or 2 posts (C). A load was applied parallel to the longitudinal axis of the teeth, thus simulating physiological occlusion. ANOVA and Tukey's tests were used to detect fracture strength differences among groups, while Chi-square test was used to check differences in fracture pattern. RESULTS: No significant differences were observed between control group (intact teeth) and groups A1 (p = 0.999), B1 (p = 0.997) and C1 (p = 1.000); statistically significant differences were detected between control group and groups A2 (p < 0.001), B2 (p < 0.001) and C2 (p < 0.05). Different post placement techniques were non-significantly associated with fracture pattern in both groups 1 (p = 0.666) and 2 (p = 0.143) while, irrespective of the number of posts, the presence of the post was significantly associated with the fracture pattern in teeth with two residual walls. The double-post technique did not further improve the fracture resistance of hardly damaged endodontically treated maxillary bi-rooted premolars compared to single-post technique. Therefore, the insertion of a single post in the palatal canal could be a safer and more conservative choice. CLINICAL SIGNIFICANCE: The double-post technique did not further improve the fracture resistance of severely structurally compromised endodontically treated maxillary premolars with two roots compared to the single-post technique. Therefore, the safer and less invasive treatment is the placement of a single post in the palatal canal.

Evidence-based treatment planning for the restoration of endodontically treated single teeth: importance of coronal seal, post vs no post, and indirect vs direct restoration.

Every orthograde endodontic procedure requires restoration of the coronal (access) cavity. The specific type of treatment used in individual cases greatly depends on the amount and configuration of the residual coronal tooth structure. In practice there are Class I access cavities as well as coronally severely damaged, even decapitated, teeth and all conceivable manifestations in between. The latest attempts to review results from clinical trials to answer the question of whether post placement or crowning can be recommended for the restoration of endodontically treated teeth or not are inconclusive. For dental practitioners, this is not a satisfactory result. This appraisal evaluates available evidence and trends for coronal restoration of single endodontically treated teeth with a focus on clinical investigations, where available. It provides specific recommendations for their coronal restoration to assist clinicians in their decision making and treatment planning.

Influence of Access Cavity Preparation and Remaining Tooth Substance on Fracture Strength of Endodontically Treated Teeth.

INTRODUCTION: The purpose of this study was to assess the impact of access cavity preparation and the remaining tooth substance on the fracture strength of endodontically treated teeth. METHODS: One hundred sound mandibular first and second molar teeth were selected and divided into 1 control and 9 test groups (n = 10/group) as follows: control group, intact teeth; group 1, teeth prepared with traditional endodontic access cavity (TEC); group 2, teeth prepared with conservative endodontic access cavity (CEC); group 3, teeth prepared with truss endodontic access cavity (TREC); group 4, TEC + 3 residual walls; group 5, CEC + 3 residual walls; group 6, TREC + 3 residual walls; group 7, TEC + 2 residual walls; group 8, CEC + 2 residual walls; and group 9, TREC + 2 residual walls. After access cavity preparation, all test teeth were endodontically treated and restored. The specimens were then loaded to fracture in a universal loading machine (Triaxial Tester T400 Digital; Controls srl, Cernusco, Italy), and fracture values were recorded in newtons. The data were analyzed with 2-way analysis of variance and Tukey post hoc analysis for multiple comparisons (P < .05). RESULTS: Intact teeth were more resistant to fracture than the teeth in all the test groups. No statistically significant differences were found between the 3 tested access cavities (P > .05). Significant differences were observed between the different number of residual walls (P < .05). CONCLUSIONS: TRECs do not increase the fracture strength of endodontically treated teeth in comparison with CECs and TECs. Moreover, the loss of mesial and distal ridges reduced the fracture strength of teeth significantly.

Optimal mechanical design of anatomical post-systems for endodontic restoration.

This paper analyses the mechanical behaviour of a new reinforced anatomical post-systems (RAPS) for endodontic restoration. The composite restorative material (CRM) completely fills the root canal (as do the commonly used cast metal posts) and multiple prefabricated composite posts (PCPs) are employed as reinforcements. Numerical simulations based on 3D linearly elastic finite element models under parafunctional loads were performed in order to investigate the influence of the stiffness of the CRM and of the number of PCPs. Periodontal ligament effects were taken into account using a discretised anisotropic nonlinearly elastic spring system, and the full discrete model was validated by comparing the resulting stress fields with those obtained with conventional restorations (cast gold-alloy post, homogeneous anatomical post and cemented single PCP) and with the natural tooth. Analysis of the results shows that stresses at the cervical/middle region decrease as CRM stiffness increases and, for large and irregular root cavities that apical stress peaks disappear when multiple PCPs are used. Accordingly, from a mechanical point of view, an optimal RAPS will use multiple PCPs when CRM stiffness is equal to or at most twice that of the dentin. This restorative solution minimises stress differences with respect to the natural tooth, mechanical inhomogeneities, stress concentrations on healthy tissues, volumes subject to shrinkage phenomena, fatigue effects and risks of both root fracture and adhesive/cohesive interfacial failure.

Mechanical behaviour of endodontic restorations with multiple prefabricated posts: a finite-element approach.

This paper investigates some mechanical aspects of a new endodontic restoration technique, based on the idea that the root cavity can be more efficiently filled if multiple prefabricated composite posts (PCP) are employed. Multi-post technique increases bearing capacity and durability of endodontically treated teeth, as shown by numerical simulations performed through three-dimensional elastic finite-element static analyses of a lower premolar, constrained by a non-linearly elastic spring system representing the periodontal ligament, under several parafunctional loads. The influence of PCPs' number, material and dimensions is investigated by comparison of the resulting stress fields with those obtained in cases of traditional restorations (cast metal post and cemented single-PCP) and natural tooth, highlighting the advantages of the proposed technique when standard restorative materials are considered. A risk-analysis of root-fracture and interface-failure shows that cast gold-alloy post produces high stress concentrations at post-dentin interface, whereas multi-post solution leads to a behaviour closer to the natural tooth's, exhibiting some advantages with respect to single-PCP restorations. As a matter of fact, whenever PCPs' overall cross-section area increases, multi-post solution induces a significant reduction of stress levels into the residual dentin (and therefore the root-fracture-risk decreases) as well as of the expected polymerization shrinkage effects. Moreover, interfacial stress values in multi-post restorations can be higher than the single-PCP ones when carbon-fibre posts are considered. Nevertheless, the interfacial adhesive/cohesive failure-risk is certainly acceptable if glass-fibre posts are employed.