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In this narrative review, we investigate the essential role played by the computed tomography Aortic Valve Calcium Score (AVCS) in the cardiovascular diagnostic landscape, with a special focus on its implications for clinical practice and scientific research. Calcific aortic valve stenosis is the most prevalent type of aortic stenosis (AS) in industrialized countries, and due to the aging population, its prevalence is increasing. While transthoracic echocardiography (TTE) remains the gold standard, AVCS stands out as an essential complementary tool in evaluating patients with AS. The advantage of AVCS is its independence from flow; this allows for a more precise evaluation of patients with discordant findings in TTE. Further clinical applications of AVCS include in the assessment of patients before transcatheter aortic valve replacement (TAVR), as it helps in predicting outcomes and provides prognostic information post-TAVR. Additionally, we describe different AVCS thresholds regarding gender and the anatomical variations of the aortic valve. Finally, we discuss various scientific studies where AVCS was applied. As AVCS has some limitations, due to the pathophysiologies of AS extending beyond calcification and gender differences, scientists strive to validate contrast-enhanced AVCS. Furthermore, research on developing radiation-free methods of measuring calcium content is ongoing. [ABSTRACT FROM AUTHOR]

Background: At present, combined provision of direct composite restorations and dental bleaching has become increasingly popular to meet the esthetic demands of patients. This study aimed to assess the effect of internal bleaching on microtensile bond strength of composite to freshly veneered enamel. Methods: In this in vitro experimental study, 50 sound extracted human premolars were randomly divided into five groups (n=10). All teeth received composite veneers. Two groups underwent no further intervention and were subjected to measurement of microtensile bond strength of composite to enamel 24 hr and one week after the veneering. The remaining three groups underwent internal bleaching. Group 3 underwent bleaching one month after the veneering, and microtensile bond strength was measured after 24 hr. In groups 4 and 5, bleaching was performed immediately after the veneering. Microtensile bond strength was measured after 24 hr in group 4 and after one month in group 5. Data were analyzed using one-way ANOVA. Results: All the groups were not significantly different regarding the mean bond strength (p=0.110), but they were significantly different in terms of the mode of failure (p=0.01) such that the mode of failure was mainly adhesive in the three bleached groups. Conclusion: Internal bleaching after composite veneering has no significant effect on microtensile bond strength of composite to the enamel. [ABSTRACT FROM AUTHOR]

Introduction: Successful endodontic treatment depends on completely clearing, shaping, and filling the prepared canals. Knowledge of the common and aberrant varying pulp anatomies is essential for suitable root canal treatment. Since, this anatomy is complex and varies morphologically in different populations. This study aims to determine the number of roots, canals, and evaluation of mandibular premolars canals using cone-beam computed tomography (CBCT) images in one of Iran's northern provinces (Golestan). Materials and Methods: CBCT axial, coronal, and sagittal slices of two hundred and twelve mandibular premolars were analyzed to determine the number of roots and canals based on Vertucci type. The images were analyzed in a one-millimeter slice in mesiodistal and buccolingual dimensions based on gender. The data were analyzed using the Chi-score test to compare the components if the defaults were not established. A significance level of 0.05 was considered. Result: Of the two hundred twelve teeth evaluated, 130 (61.3%) were first premolars, and 82 (38.6%) were second premolars. Most first premolars (78.5%) and almost all second premolars (97.6%) had one root. Morphological types of root canals were identified based on Vertucci's classification types I, II, III, IV, V, or VIII, and type I was the most frequent. There were no significant associations between number of roots and sex (P>0.05). Conclusion: Mandibular premolars mostly had one root and type I Vertucci morphology. The frequency of two-canal premolars was higher in the male population. Although the abundance of two or three roots with different morphologies was also observed, the possibility of the presence of an additional root canal should be considered. [ABSTRACT FROM AUTHOR]

Abstract Background This study assessed the effect of corticotomy with Er: YAG (erbium-doped yttrium aluminium garnet) laser on the rate of canine retraction. Methods This randomized split-mouth controlled clinical trial was conducted on 12 patients undergoing orthodontic treatment with extraction of maxillary first premolars. Following initial leveling and alignment, an alginate impression was made from the maxillary arch, and Er: YAG laser corticotomy was performed in one of the maxillary quadrants of each patient. Canine retraction was started immediately after corticotomy by placement of nickel-titanium (NiTi) closed coil springs at both sides. At the end of each month, alginate records were repeated for 4 months. Study models were scanned, and the anteroposterior movement of canine was quantified bilaterally. Pain was also measured by a visual analog scale (VAS). Probing depth (PPD) of canines and two adjacent teeth was also evaluated and pulp vitality was assessed by performing the cold test. Data were analyzed by paired and independent t-test and one-way ANOVA (alpha = 0.05). Results The rate of canine retraction was significantly greater in the laser-assisted corticotomy quadrant than the control (P 0.05). Conclusions Flapless Er: YAG laser corticotomy significantly enhanced canine retraction rate with no adverse effect on other parameters.

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: This study assessed the effect of corticotomy with Er: YAG (erbium-doped yttrium aluminium garnet) laser on the rate of canine retraction. Methods: This randomized split-mouth controlled clinical trial was conducted on 12 patients undergoing orthodontic treatment with extraction of maxillary first premolars. Following initial leveling and alignment, an alginate impression was made from the maxillary arch, and Er: YAG laser corticotomy was performed in one of the maxillary quadrants of each patient. Canine retraction was started immediately after corticotomy by placement of nickel-titanium (NiTi) closed coil springs at both sides. At the end of each month, alginate records were repeated for 4 months. Study models were scanned, and the anteroposterior movement of canine was quantified bilaterally. Pain was also measured by a visual analog scale (VAS). Probing depth (PPD) of canines and two adjacent teeth was also evaluated and pulp vitality was assessed by performing the cold test. Data were analyzed by paired and independent t-test and one-way ANOVA (alpha = 0.05). Results: The rate of canine retraction was significantly greater in the laser-assisted corticotomy quadrant than the control (P < 0.05). No significant difference existed in posterior anchorage loss, canine rotation angle, PPD, pulp vitality, or pain score between two groups (P > 0.05). Conclusions: Flapless Er: YAG laser corticotomy significantly enhanced canine retraction rate with no adverse effect on other parameters. [ABSTRACT FROM AUTHOR]

Purpose: The existence of valves in the azygos vein are not discussed in depth in the current body of literature. Although the clinical relevance of the valves in these veins are not well understood, these valves may have implications in diagnostic imaging where their appearance on imaging studies can impact interpretation. This study aims to use cadaveric dissections to determine the anatomic prevalence and morphology of valves in the arch of the azygos vein in comparison to current data reported from clinical imaging studies and anatomy textbooks. Methods: Approval of this research study on human cadaveric specimen was sought from the St. George's University Institutional Review Board (IRB) and was deemed exempt from full review (IRB – 16015). This research project involved 47 azygos veins dissected from human cadaveric donor specimen. Azygos veins were harvested from the level of the diaphragm to the inflow into the superior vena cava for gross inspection of valve presence and morphology. The data collected was recorded and sorted by sex, valve presence, number and morphology and valve location. Chi square analysis was performed to assess possible relationships in valve findings based on sex. A brief search of the literature using the keywords “azygos vein” and “valves” was conducted to see the current understanding of azygos valve prevalence. Results: Of the donor specimen, 53.2% (25 of 47) were male and 46.8% (22 of 47) were female. Of the 47 cadavers that were dissected, 89.3% (42 of 47) were found to have valves in the azygos vein, while 10.6% (5 of 47) were found to have none. The azygos vein contained mostly one valve along its length, mainly located in the arch. The valves were unicuspid (8.5%; 4 of 47), bicuspid (70.2%; 33 of 47) or tricuspid (10.64%; 5 of 47). Dividing the arch of the azygos into quartiles, valves were found most commonly in the third quartile of the distance from the opening of the right superior intercostal vein into the azygos vein to the superior vena cava. Four cadavers had multiple valves, each with varying valve morphology. The length of the cusp of the bicuspid valve ranged from 10 mm to 12 mm. Conclusion: This study shows that the azygos vein contains valves, predominantly within the arch at a prevalence of 89.3%. The presence and variability in morphology of valves in the azygos vein and its potential implications for contrast appearance on imaging studies is clinically important. Radiologists should have a working knowledge of the different appearances of azygos arch valves to minimize the risks of confusing normal variations with thoracic pathology. Though not commonly described in anatomy texts, the findings of this research not only add more detail to the historical cadaveric study information on azygos vein valves, but also shows that the prevalence of azygos arch valves surpasses the numbers reported in clinical studies. As such, it provides support for the inclusion of azygos arch valves in anatomical textbooks and in the teaching of image interpretation.

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BACKGROUND: Tooth gemination is a single enlarged or joined tooth with a normal tooth count when the anomalous tooth is counted as one. Mandibular second premolars show an elevated variability of crown morphology. Only nine cases of isolated second premolar macrodontia have been reported in the literature. CASE DESCRIPTION: This case report presents the clinical and radiographic findings and conservative treatment of an atypical and rare case of localized bilateral molarization of mandibular second premolars. CONCLUSION: Dental professionals should acquire deeper knowledge about anomalies and plan treatment carefully to avoid unexpected complications during dental procedures caused by morphological ignorance. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to assess the frequency of mandibular second premolar (MnP2) distoangulation among orthodontic patients and the angular changes after a longitudinal follow-up. Methods The sample was collected from the orthodontic records of 865 patients. The distoangulation group was composed of 42 patients (mean age 9.29 ± 1.24 years, 16 male, 26 female) with distoangulation of MnP2. The control group was composed of 32 patients (mean age 9.38 ± 1.10 years, 15 male, and 17 female) without distoangulation of MnP2. Panoramic radiographs taken in the mixed (T1) and the early permanent dentition (T2) were analyzed in both groups. Longitudinal angular changes (distal angle θ and premolar-molar angle γ), degree of root formation, second premolar depth, and prevalence of associated dental anomalies were analyzed. Intergroup comparison was performed with Mann–Whitney, t-tests, and chi-square tests (P  < 0.05). Results The prevalence of MnP2 distoangulation in the mixed dentition was 4.85%. The distoangulation group showed a smaller initial distal angle (59.34o ± 8.41) when compared to control group (79.88o ± 7.60). The spontaneous eruption of the MnP2 with distoangulation was observed in 76.57% of the sample. MnP2 distoangulation was significantly associated with agenesis of its antimere, small maxillary lateral incisors, and deciduous molar infraocclusion. Limitations Severe cases of MnP2 distoangulation were absent in this study. Conclusions The frequency of MnP2 distoangulation among orthodontic patients was 4.85%. Mild to moderate distoangulated Mnp2 spontaneously uprighted from the mixed to the permanent dentition. Small lateral incisors, second premolar agenesis, and infraocclusion of deciduous molar were frequently found in cases with MnP2 distoangulation. [ABSTRACT FROM AUTHOR]

Foundation: advances in imaging and its implementation in Dentistry allow for better treatments. Objective: to describe the results of the orthoradial technique vs parallel technique in the identification of upper first premolars canals and lower first molars. Methods: observational, descriptive and cross-sectional study in patients in need of root canal treatment of upper first premolars or lower first molars, who attended the Dental Care Unit of the Andes Regional Autonomous University from April to August 2019. The sample consisted of 62 patients, separated into two upper premolar groups (n=30) or lower first molars (n=32) and both into two other groups according to the technique used (parallel technique and orthoradial technique). Results: in the upper first premolars, the orthoradial technique showed better results than the parallel technique to obtain accurate images (100% vs. 20%). In the lower first molars, the orthoradial technique showed superior results to the parallel technique for the mesiolingual canal (93.75% vs 31.25%) and distolingual canal (31.25% vs 12.5%). Root elongation predominated in the orthoradial technique (n=8), as did dental overlap (n=10). Conclusions: the orthoradial technique showed superior results when locating both the buccal and palatine canal in the upper first premolars and for the mesiolingual canal and the distolingual canal. Root elongation was observed to a greater extent in the orthoradial technique, as was dental overlap. [ABSTRACT FROM AUTHOR]

Endodontic treatment of second premolars is challenging due to their complex anatomy and the likelihood of anatomical variations. The current report presents successful treatments of mandibular and maxillary second premolars with different anatomies in a single patient. The first case involved a patient referred from a general practitioner who was unable to complete the root canal treatment of her mandibular second premolar with four root canals. The initial radiograph showed an apical radiolucency, periodontal ligament (PDL) widening, and a fast break suggesting the possibility of root canal branching. With the diagnosis of previous treatment and chronic apical periodontitis, the tooth was successfully retreated with the aid of cone-beam computed tomography (CBCT), a dental operating microscope, and ultrasonic tips. The second case was a maxillary second premolar with Vertucci's type VI root canal morphology, which was not responsive to pulpo-periapical tests. Along with a deep carious lesion and a PDL widening on the initial radiograph, a diagnosis of necrosis with chronic apical periodontitis was made. The root canals were located and treated using a combination of radiography with different angulation and CBCT. Both teeth were clinically and radiographically asymptomatic at the 4-month follow-up session. This case report highlights the importance of thorough preoperative evaluation and the use of advanced technology and techniques in achieving successful endodontic treatment outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To determine the prevalence of developmental defects of the enamel (DDE) in premolars whose infected predecessors were submitted to pulp therapy with antibiotic paste or extractions due to pulp necrosis.Materials and Methods: A cross-sectional study with a consecutive sample consisting of children and adolescents who presented with fully erupted premolars, was evaluated. Data were collected by dental examinations, in which the modified DDE index was applied. Dental records were evaluated and three groups of premolars were determined according to the clinical history of predecessors: GCTZ: with pulp necrosis and treated with CTZ (chloramphenicol, tetracycline, zinc oxide and eugenol) paste; GE: with pulp necrosis and treated by extraction; GH: healthy and physiologically exfoliated. Descriptive analysis and a logistic regression (p <0.05) were performed.Results: The study included 1017 premolars, DDE was present in 22.5%. Premolars belonging to the GE group presented higher odds of DDE (odds ratio (OR) = 3.52, 95% CI:2.29-5.40) than those of GCTZ group (OR = 2.43, 95% CI:1.51-3.91) and GH group (p <0.01). Enamel defects were more frequent in maxillary premolars (OR = 3.22, 95% CI:1.65-6.27, OR = 3.39, 95% CI:1.67-6.90, OR = 2.90, 95% CI:1.48-5.66 and OR = 3.10, 95% CI:1.54-6.23).Conclusions: The prevalence of enamel defects was higher in premolars whose predecessors were removed because of necrosis, followed by those treated with CTZ paste and those that were healthy by the time exfoliation occurred. [ABSTRACT FROM AUTHOR]

Introduction: The efficacy of the trigeminal nerve block varies between 70% and 98%, relying heavily on the accurate identification of anatomical landmarks. The anatomical position and incidence of supernumerary foramina of the supraorbital (SOF), infraorbital (IOF) and mental (MF) foramina vary amongst population groups, sex, age, and climate conditions. Hence, the localisation of the foramina is crucial in the administration of anaesthesia to the related nerves. The objective of this study was to document evidence of the morphology and morphometry of the SOF, IOF, and MF – in the form of a narrative review. Materials and methods: This review analyses reports on the localisation of the SOF, IOF and MF, and their variations (if any). A literature search was conducted on multiple electronic databases (PubMed, MEDLINE, Google Scholar and Science Direct). A total of 149 articles were eligible for inclusion in this review. Discussion and conclusion: The results of the literature search shows that the SOF has not been studied as extensively as the IOF and MF. Therefore, it is suggested that further research be conducted on the anatomy and clinical relevance of the SOF. The SOF, however, presents frequently as a notch and is, therefore, called the supraorbital notch. The IOF is often an oval-shaped opening and may present with one accessory foramen. The MF is often in line with the 2nd mandibular premolar tooth and may also have accessory openings. This review revealed that the IOF and MF frequently lie lateral to the SOF, contradicting standard anatomical literature which states that they all lie on the same vertical plane. Medical professionals should consider the location and shape of the studied foramina, and the occurrence of accessory foramina, to successfully administer the corresponding nerve block. Landmarks used to localise the foramina highlighted in this review may be applied to evaluate their clinical relevance.

Aim: The aim of this study was to access and compare fracture resistance of tooth restored with Cention-N, Zirconomer and Filtek Z350 XT. Materials and Methods: Seventy five extracted maxillary premolar were divided into five groups; (Group I) Unprepared intact teeth, (Group II) Teeth with class II mesio-occluso-distal (MOD) cavity prepared and unrestored, (Group III) Teeth with class II MOD cavity prepared and restored with Zirconomer (Shofu Inc), (Group IV) Teeth with class II MOD cavity prepared and restored with Cention N, (Group V) Teeth with class II MOD cavity prepared and restored with Universal Composite Restorative Material (Filtek Z350 XT). Specimen was individually tested in a universal testing machine for facture resistance. Results: Filtek Z350 XT showed statistically significant fracture resistance as compared to Group II, Group III and Group IV (P<0.001). Cention-N showed better fracture resistance than Zirconomer but didn't vary statistically. Conclusion: All the test restorative material showed acceptable fracture resistance under load. Long term clinical evaluation is required to access their behavior intraorally. [ABSTRACT FROM AUTHOR]

The aim of this paper is to assess the association between valve morphology and vortical structures quantitatively and to highlight the influence of valve morphology/orientation on aorta's susceptibility to shear stress, both proximal and distal. Four-dimensional phase-contrast magnetic resonance imaging (4D PCMRI) data of 6 subjects, 3 with tricuspid aortic valve (TAV) and 3 with functionally bicuspid aortic values (BAV) with right-left coronary leaflet fusion, were processed and analyzed for vorticity and wall shear stress trends. Computational fluid dynamics (CFD) has been used with moving TAV and BAV valve designs in patient-specific aortae to compare with in vivo shear stress data. Vorticity from 4D PCMRI data about the aortic centerline demonstrated that TAVs had a higher number of vortical flow structures than BAVs at peak systole. Coalescing of flow structures was shown to be possible in the arch region of all subjects. Wall shear stress (WSS) distribution from CFD results at the aortic root is predominantly symmetric for TAVs but highly asymmetric for BAVs with the region opposite the raphe (fusion location of underdeveloped leaflets) being subjected to higher WSS. Asymmetry in the size and number of leaflets in BAVs and TAVs significantly influence vortical structures and WSS in the proximal aorta for all valve types and distal aorta for certain valve orientations of BAV. Analysis of vortical structures using 4D PCMRI data (on the left side) and wall shear stress data using CFD (on the right side). [ABSTRACT FROM AUTHOR]

Aims: The study aimed to compare paravalvular leak (PVL) changes after a transcatheter aortic valve replacement (TAVR) with self-expandable prosthesis between different aortic valve morphologies and evaluate the impact of paravalvular leak regression on clinical prognosis. Methods: Patients with aortic stenosis (AS) successfully treated with a selfexpandable TAVR who were followed up for at least 1 year at our centre were consecutively enrolled from January 2016 to August 2019. Paired serial changes in paravalvular leak and other haemodynamic parameters by echocardiography were collected and compared between the bicuspid valve (BAV) and tricuspid aortic valve (TAV). A logistic regression model was used to explore the predictors of paravalvular leak regression (<1 grade) 1 year after transcatheter aortic valve replacement, while its impact on subsequent clinical outcomes (allcause mortality and rehospitalisation for heart failure (HF)) was further evaluated using Kaplan-Meier analysis. Results: A total of 153 bicuspid valve and 114 tricuspid aortic valve patients were finally enrolled; haemodynamic parameters and paravalvular leak severity were comparable before the discharge between the two groups. The peak transaortic velocity, mean transvalvular gradient, and effective orifice area all significantly improved (p < 0.05) without intergroup differences at all follow-up timepoints. Significant paravalvular leak reduction was observed only in the TAV group (1.75% vs. 4.39%, p = 0.029), while moderate paravalular leak was still more prevalent in BAV (7.19% vs. 1.75%, p = 0.041) at the 1-year follow-up. Multivariable analyses identified the bicuspid valve, asymmetric calcification, and undersizing as independent predictors of failure of the 1-year paravalvular leak reduction in patients with mild or moderate paravalvular leak after discharge. Patients without a paravalvular leak reduction within 1 year showed a relatively higher 2-year all-cause mortality and HF (HR: 5.994, 95% CI: 1.691-21.240, and p = 0.053) rates thereafter. Conclusion: In AS patients after self-expandable transcatheter aortic valve replacement, paravalvular leak regression within 1 year was less prevalent in bicuspid valve morphology. The failure of paravalvular leak reduction might lead to an increased risk of poorer prognosis in the long run. [ABSTRACT FROM AUTHOR]

Abstract Background There is a lack of available data on specific prognostic comparisons between transcatheter aortic valve replacement (TAVR) using self-expandable valves (SEV) in patients with stenotic Type 0, Type 1 bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). Objectives To evaluate the association between aortic valve morphology and outcomes following self-expandable TAVR. Methods Consecutive patients with aortic stenosis(AS) undergoing self-expandable TAVR were enrolled and categorized into three groups (Type 0/Type 1 BAV or TAV) according to the Sievers classification. The primary endpoint was a composite of all-cause mortality and rehospitalization for heart failure (HF) within 2 years. Secondary outcomes included procedural complications and major cardiovascular events observed in clinical follow-ups. Clinical outcomes at 2 years following TAVR were compared among three groups using Kaplan-Meier curve and multivariable Cox proportional hazards regression models. Results A total of 344 AS patients (Type 0: 86; Type 1: 109; TAV: 149) were enrolled. The presence of moderate or severe paravalvular leak (PVL) was significantly higher in patients with Type 0 and Type 1 BAV versus TAV (10.47% vs. 16.51% vs. 6.71%, p = 0.043). All-cause 30-day mortality (2.33% vs. 0.92% vs. 2.68%, p = 0.626) and 2-year mortality (3.49% vs. 5.50% vs. 6.71%, p = 0.657) was comparable among the three groups. However, rehospitalization for HF within 2 years was significantly higher in Type 1 BAV (11.63% vs. 20.18% vs. 8.72%, p = 0.020). Multivariate Cox analysis showed that a higher STS score, Type 1 BAV morphology and excess leaflet calcification (≥ median calcium volume (CV) of the entire population) were independent predictors for HF rehospitalization. Additional intragroup Kaplan‒Meier analysis showed that excess leaflet calcification could predict higher long-term mortality and rehospitalization risk for HF(HR (95% CI): 3.430 (1.166–10.090), log rank p = 0.017) in Type 1 BAV patients. Conclusion Outcomes of self-expandable TAVR in BAV-AS patients might vary depending on valve subtypes. BAV patients with excess leaflet calcification and a raphe, especially calcified, had an increased risk of moderate PVL and HF readmission in mid-to-long term follow-ups.

Purpose: This study evaluated anatomical variations in the root canals of the lower premolars and molars in a Brazilian sub-population using cone-beam computed tomography (CBCT). Materials and Methods: In total, 121 CBCT images of patients were selected from a database. All images contained lower first and second premolars and molars on both sides of the arch, fully developed roots, and no treatment, resorption, or calcifications. In each image, the root canals of the lower premolars and molars were evaluated according to the Vertucci classification in On-Demand 3D software in the multiplanar reconstruction with dynamic navigation. Twenty-five percent of the images were re-assessed to analyze intraobserver confidence with the kappa test. Data were statistically evaluated with linear regression to evaluate the correlations of anatomic variations with age and sex, and the Wilcoxon test to analyze the laterality of variations, with a significance level of 5%. Results: The intraobserver agreement (0.94) was excellent. In general, the root canals of lower premolars and molars showed a higher prevalence of type I than other Vertucci classification types, followed by type V in premolars and type II in molars. When the molar roots were evaluated separately, type II was more frequent in mesial roots and type I in distal roots. Although age showed no correlations with the results, sex and laterality showed correlations with tooth 45 and the lower second premolars, respectively. Conclusion: The lower premolars and molars of a Brazilian sub-population showed a wide range of root canal anatomic variations. [ABSTRACT FROM AUTHOR]

Introduction: the use of custom implants is a very common treatment; we assess and compare their behavior against that of conventional implants. This study aimed to make sure that the stress zones of the custom implant are different from those presented by the conventional prefabricated implant by photoelasticity. Methods: we subjected samples of n=10 bicuspid teeth, n=10 sintered custom implants, and n=10 conventional prefabricated implants to 3 fixed and controlled forces and observed the samples through a polariscope to analyze the distributions of effort generated. The effort zones present in the different samples were analyzed under 3 different forces. Results: the amounts of effort in the two types of implants under force 1 (chi-square test, p=0.596) are different, as is also the case under force 2 (chi-square test, p=0.407). Under force 3 (Levene test, p=0.899), there is no difference in the distributions of effort between the two types of implants. Conclusions: it was determined that the conventional prefabricated implant distributes and concentrates the effort generated under different forces better than the sintered custom implant.

Copyright of Revista de Odontopediatría Latinoamericana is the property of Asociacion Latinoamericana de Odontopediatria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: There is a lack of available data on specific prognostic comparisons between transcatheter aortic valve replacement (TAVR) using self-expandable valves (SEV) in patients with stenotic Type 0, Type 1 bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). Objectives: To evaluate the association between aortic valve morphology and outcomes following self-expandable TAVR. Methods: Consecutive patients with aortic stenosis(AS) undergoing self-expandable TAVR were enrolled and categorized into three groups (Type 0/Type 1 BAV or TAV) according to the Sievers classification. The primary endpoint was a composite of all-cause mortality and rehospitalization for heart failure (HF) within 2 years. Secondary outcomes included procedural complications and major cardiovascular events observed in clinical follow-ups. Clinical outcomes at 2 years following TAVR were compared among three groups using Kaplan-Meier curve and multivariable Cox proportional hazards regression models. Results: A total of 344 AS patients (Type 0: 86; Type 1: 109; TAV: 149) were enrolled. The presence of moderate or severe paravalvular leak (PVL) was significantly higher in patients with Type 0 and Type 1 BAV versus TAV (10.47% vs. 16.51% vs. 6.71%, p = 0.043). All-cause 30-day mortality (2.33% vs. 0.92% vs. 2.68%, p = 0.626) and 2-year mortality (3.49% vs. 5.50% vs. 6.71%, p = 0.657) was comparable among the three groups. However, rehospitalization for HF within 2 years was significantly higher in Type 1 BAV (11.63% vs. 20.18% vs. 8.72%, p = 0.020). Multivariate Cox analysis showed that a higher STS score, Type 1 BAV morphology and excess leaflet calcification (≥ median calcium volume (CV) of the entire population) were independent predictors for HF rehospitalization. Additional intragroup Kaplan‒Meier analysis showed that excess leaflet calcification could predict higher long-term mortality and rehospitalization risk for HF(HR (95% CI): 3.430 (1.166–10.090), log rank p = 0.017) in Type 1 BAV patients. Conclusion: Outcomes of self-expandable TAVR in BAV-AS patients might vary depending on valve subtypes. BAV patients with excess leaflet calcification and a raphe, especially calcified, had an increased risk of moderate PVL and HF readmission in mid-to-long term follow-ups. [ABSTRACT FROM AUTHOR]

Background and objectives: Microleakage at the interface of tooth structure and fissure sealant plays a crucial role in failure of the treatment. This in vitro study aimed to determine the microleakage of self-adhesive flowable composite resins as pit and fissure sealants. Material and Methods: 60 healthy extracted premolar teeth were randomly divided into the 4 groups (n=15), group 1) clinpro sealants (control), group 2) flowable composite resin with bonding agent (total-etch), group 3) flowable composite resin with self-etch bonding agent, and group 4) self-adhesive composite resin. After thermocycling the specimens were immersed in 2% methylene blue for 48 hours and then sectioned in the buccolingual direction. The microleakage was assessed by dye penetration using a stereomicroscope at 15X magnification. Data analysis was performed using SPSS version 18.0 as well as Mann-Whitney and Kruskal-Wallis tests. Results: There was a statistically significant difference in microleakage score between the groups (P-value = 0.006). The lowest mean of microleakage level was observed in the flowable composite group with total-etch bonding (group 2) 1.26±0.96, followed by the Clinpro sealant group (group 1) 1.62±1.20, and then the self-adhesive composite group (group 4) 1.85±1.00. Conclusion: Based on the results of this study, the microleakage of self-adhesive composite resin revealed no significant difference with conventional fissure sealant; however, the microleakage of these composite resin was higher than flowable composite resin with total-etch bonding agent.

Introduction: There are many anatomical maxillary premolars variants, which differ in different races. The lack of information on such variants adds to the failure of endodontic treatment. This aim of this study is to evaluate anatomy and morphology of such variants using cone-beam computed tomography (CBCT), and to evaluate dentin thickness of the buccal and lingual canals of maxillary single rooted premolars with two canals. Methods: In this in-vitro study fifty single rooted maxillary premolars with two canals were collected from medical centers in Mashhad, Iran. The number of canals was assessed using periapical radiography. CBCT was utilized to scan teeth and were evaluated within the axial section for the position of root canals with respect to outer root surfaces and canal variants based on Vertucci’s classification in apical, intermediate, and coronal sections. Result: The smallest dentin thickness was 0.40 and 0.83 ± 0.25 mm for the apical third in mesial and distal direction, respectively. Also, the largest result was 3.10 mm for the coronal third buccal direction. The largest relative frequency of Vertucci class types was found to be type IV, while the smallest relative frequency was derived to be type III. The results revealed that seventeen cases had isthmus. Conclusion: Because of the thin dentin related to the mesial aspect, it is required to utilize low-taper files. It is not recommended to make use of orifice shapers.

The palatal anchorage device (PAD) is commonly used in fixed appliance for anchorage, but the biomechanics of PAD in patients treated with clear aligners(CAs)remains poorly understood, especially in its elastic mode and force magnitude. This study aimed to assess the biomechanical effects of using PAD for retraction during clear aligner treatment (CAT) with the extraction of two maxillary first premolars. Four finite element models were created: (1) Incisors retraction (IR) with active contraction of the clear aligner only; (2) IR with PAD using different forces (50,75,100 g) or not; (3) PAD without IR (forces of 50,75,100 g), and (4) Different elastic directions (D1, D2, D3) from aligner to PAD without IR. IR caused lingual tipping and extrusion of the central incisors, as well as mesial and buccal tipping of the first molar. PAD during IR provided strong anchorage for the first molar, with elastics slightly increasing the lingual tipping and extrusion of the central incisors. Elastics applied to the U-shaped arch led to central incisor intrusion and reduced lingual retraction. The highest stress was observed on the mesial attachment of the canine. PAD effectively reinforced posterior anchorage in CAT, while anterior positioning facilitated anterior teeth intrusion. The biomechanical importance of the canine's mesial attachments in maxillary teeth treatment planning was highlighted., (© 2024. The Author(s).)

Background: To compare the impacts of different remineralizing agents on demineralized enamel, we focused on chitosan nanoparticles (ChiNPs) and silver nanoparticles (AgNPs)., Methods: This study was conducted on 40 extracted human premolars with artificially induced demineralization using demineralizing solution. Prior to the beginning of the experimental procedures, the samples were preserved in artificial saliva solution. The nanoparticles were characterized by transmission electron microscopy (TEM) and teeth were divided into four equal groups: Group A was utilized as a control group (no demineralization) and received no treatment. Group B was subjected to demineralization with no treatment. Group C was subjected to demineralization and then treated with ChiNPs. Group D was subjected to demineralization and then treated with AgNPs. The teeth were evaluated for microhardness. The enamel surfaces of all the samples were analysed by scanning electron microscopy (SEM) for morphological changes and energy dispersive X-ray analysis (EDX) for elemental analysis., Results: The third and fourth groups had the highest mean microhardness and calcium (Ca) and phosphorous (P) contents. SEM of these two groups revealed relative restoration of homogenous remineralized enamel surface architecture with minimal micropores., Conclusion: Chitosan nanoparticles (NPs) and silver NPs help restore the enamel surface architecture and mineral content. Therefore, chitosan NPs and AgNPs would be beneficial for remineralizing enamel., (© 2024. The Author(s).)

Objectives: To evaluate the amount of apically extruded debris and to determine the remaining filling material on the root canal walls by microcomputed tomography (micro-CT), following the root canal retreatment of root canals filled with different obturation techniques (single cone technique, thermoplasticised injection technique) and the different root canal sealers [bioceramic-based, epoxy resin-based root canal sealer]., Materials and Methods: 60 single rooted human premolar teeth were prepared with the ProTaper Gold system (Dentsply Maillefer) up to the F4 file and the samples were divided into 4 groups according to obturation procedures: Single cone technique + AH Plus sealer(epoxy resin-based root canal sealer, Dentsply International Inc., York, PA, USA); Single cone technique + Sure-Seal Root(bioceramic-based root canal sealer, Sure Dent Corporation, Gyeonggi-do, South Korea); thermoplastic injection technique[Calamus Dual Obturation System(Dentsply-Tulsa Dental, Tulsa, OK, USA)] + AH Plus(Dentsply International Inc.); Sure-Seal Root(Sure Dent Corporation) + Calamus Dual Obturation System (Dentsply-Tulsa Dental). The teeth were inserted into preweighed Eppendorf tubes and retreatment was performed. The tubes were kept in an incubator at 37 °C for 14 days to obtain the dry debris weight. Following the removal of the root canal fillings, the samples were scanned with a micro-CT device to analyse the volume of filling residues., Results: Retreatment of samples obturated with epoxy-resin or bioceramic based root sealers combined with Calamus system resulted in higher amount of apical extrusion compared to their combination with single cone technique (p = 0.026 for Single cone technique + AH Plus sealer vs Calamus + AH Plus sealer and p = 0.005 for Single cone technique + Sure-Seal root sealer vs Calamus + Sure-Seal root sealer). The most debris was observed in the Calamus + Sure-Seal root sealer group, the least debris was observed in the Single cone technique + AH Plus sealer group. The percentage of residues was the highest in the Single cone technique + Sure-Seal root sealer and the lowest in the Calamus + AH Plus sealer group, but there were no significant differences between groups (p = 0.463)., Conclusions: No correlation was observed among the groups in terms of extruded debris and remnants inside the root canal. When combined with bioceramic based sealer, thermoplasticised injection technique did not affect the cleanliness of root canal walls; however, it increased its apical extrusion potential during retreatment., Clinical Relevance: The obturation method does not play a role in the removability of bioceramic based root canal sealer, however the use of bioceramic-based root canal sealers with cold obturation techniques may be beneficial in preventing apical extrusion., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To determine and compare the cytotoxicity, odontoblast-like differentiation, shear bond strength (SBS) and Vickers microhardness of four commercial light-cured orthodontic adhesives., Methods: The orthodontic resins selected were Transbond XT - GI, Transbond Plus Color Change - GII (both from 3M Unitek), Enlight - GIII and Blugloo - GIV (both from Ormco). Samples were prepared, and leached monomers were obtained. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and deposited calcium was analyzed using Alizarin red staining (ARS). SBS and the adhesive remnant index (ARI) were determined using 120 human premolars. The Vickers microhardness test was performed on the resin discs., Results: All adhesives showed moderate to severe cytotoxicity (21-37%) and promoted similar formation of calcium deposits. A SBS of 6-8 MPa was achieved only by Blugloo (7.1 ± 2.4 MPa), and Enlight showed the lowest Vickers hardness score (40 ± 2.5 HV). Transbond Plus Color Change (score 0 = 42.9%) and Blugloo (score 0 = 46.4%) showed better ARI scores than Transbond XT (score 0 = 7.1%) and Enlight (score 0 = 3.6%)., Conclusion: On the basis of the properties evaluated, Blugloo seems to be the best option.

Objectives: To evaluate and compare the ion-releasing capability of three different restorative systems at the restoration/tooth interface elemental analysis using energy-dispersive X-ray technique. Additionally, micromorphological patterns of the restoration/tooth interfaces was investigated., Materials and Methods: Eighteen freshly extracted sound human premolars were collected for the study. The premolars were randomly assigned into 3 groups (n = 6) based on the type of restorative materials used: Giomer (Beautifill II), ion-releasing composite (Activa Presto), and RMGI (Riva Light Cure). Half of the specimens in each group were tested after 24 h (the "immediate group"), while the remaining half were tested after 6 months of storage in deionized water (the "delayed group"). Standardized box-shaped cavities along the cervical area of teeth crowns and restored them with the assigned restorative material following manufacturers' instructions. The specimens were sectioned buccolingually into 2 halves. One half of each specimen was subjected to elemental analysis using energy-dispersive X-ray technique (EDX), while the remaining half was sputter coated and underwent micromorphological analysis of the restoration/tooth interface using a scanning electron microscope (SEM). The collected data from elemental analysis test were tabulated and subjected to statistical analysis., Results: The two-way ANOVA test showed significant differences in both phosphorus and calcium levels among the tested restorative systems (p < 0.05). In the immediate subgroup, RMGI recorded the highest phosphorus level (0.1527), followed by the ion-releasing composite (0.1172), while Giomer exhibited the least levels (0.0326) (p < 0.05). The ion-releasing composite group had the highest calcium level (0.2797), followed by RMGI (0.248), and Giomer (0.2385) respectively (p < 0.05). In the delayed subgroups, Giomer recorded the highest phosphorus level (0.1526), followed by the ion-releasing composite (0.1058), and RMGI group (0.0466) respectively (p < 0.05). RMGI had the highest calcium level (0.2801), followed by the ion-releasing composite (0.2659), and Giomer had the lowest level (0.1792) (p < 0.05). The micromorphological analysis of the restoration/tooth interfaces showed good adaptation between the composite and tooth substrate in different restorative groups., Conclusions: The ion-releasing capability of the three restorative systems appears to be comparable. The rate of mineral release and diffusion is affected by time and composition., (© 2024. The Author(s).)

Purpose: To evaluate interfacial three-dimensional adaptation and internal voids of different flowable materials before and after cyclic fatigue in a simulated deep-margin elevation scenario., Methods: Eighty (n &#61; 80) extracted premolars were selected and two Class II cavities were prepared. The mesial one with cervical margin 1 mm above the cementum-enamel junction (CEJ) and the distal one with cervical margin 1 mm below the CEJ. After performing adhesive procedures, specimens were divided into four groups according to the employed materials for 2 mm horizontal deep-margin relocation: nanohybrid composite (Clearfil ES2, Kuraray); conventional viscosity flowable composite (Tetric Flow, Ivoclar); medium viscosity flowable composite (Majesty ES2 Low Flow, Kuraray); high viscosity flowable composite (Majesty ES2 Super Low Flow, Kuraray). All restorations were finalized by oblique layering with nanohybrid composite (Clearfil ES2, Kuraray). To reveal interfacial and internal gap progression, specimens were scanned with a micro-CT (SkyScan 1172), before and after 500,000 cycles of mechanical chewing simulation (50 N, 1 Hz). Data were imported into Mimics software after smoothing and region growing. Only the 2 mm margin relocation volumes were considered. Obtained masks were analyzed for noise removal and volume calculation. At baseline, interfacial gap progression and internal voids, expressed in mm3, were collected and statistically analyzed with two-way ANOVA (α 0.05) for the variables substrate and restorative materials followed by Tukey post-hoc test. An additional two-way ANOVA test, followed by Tukey post-hoc test, was performed to evaluate variation in interfacial gap progression after mechanical aging., Results: At baseline, the ANOVA test showed a significant difference for the variable restorative materials (p &#61; 0.01). More specifically, the Tukey post-hoc test revealed that the highly filled medium viscosity composite performed better than the conventional viscosity composite at baseline for the interfacial gap. The internal voids ANOVA test at baseline reported no significant differences for the variable tested. Analysis of variance for internal gap progression after thermocycling showed no differences for both substrate and restorative material employed., Conclusions: Highly filled medium viscosity composite performed significantly better than the conventional viscosity flowable composite for what concern baseline interfacial gaps. Artificial aging with a chewing simulator and thermocycling did not affect interfacial gap progression on enamel and dentin. The tested restorative materials performed equally after aging.

Background: Extracting the premolars is an effective strategy for patients with bimaxillary dentoalveolar protrusion. Clear aligners (CAs) close the extraction spaces through shortening the length of aligners. The contraction force generated by the terminal of aligners makes the posterior teeth tip mesially, which is known as the roller coaster effect. This phenomenon is even worse in the 2nd premolar extraction cases. Posterior anchorage preparation is commonly used to protect the angulation of molars, taking the form of presetting distal tipping value. However, the distal tipping design aggravates the anchorage loss of anterior teeth simultaneously. This study aimed to explore the different anchorage loss of the posterior teeth when the 1st or 2nd premolars were extracted using CAs, respectively in maxillary and mandibular arches, further providing guidance for anchorage preparation design in clinical practice., Methods: Two bimaxillary finite element models with different extraction patterns were established to simulate the anterior en-masse retraction process of the CAs. In Model 1, the maxillary and mandibular 1st premolars were extracted, while in Model 2, the 2nd premolars were extracted. Finite element analysis methods were utilized to analyze the tipping angle of the anterior and posterior teeth., Results: Compared between two models, the anterior teeth exhibited a greater lingual inclination tendency and the posterior teeth exhibited a slighter mesial tipping tendency in Model 1 regarding individual tooth. The closer to the extraction spaces, the greater the tip, and the distal tipping tendency of the 1st premolars was more evident than the mesial tipping tendency of the 1st molars in Model 2. Compared between the maxillary and mandibular arches, the mesial tipping tendency of individual posterior tooth was more evident in the maxilla. In addition, the highest hydrostatic stress of the periodontal ligaments was concentrated on the cervical and apical parts directly adjacent to the extraction spaces, and it exhibited relatively uniform distribution in Model 1., Conclusions: The individual posterior tooth showed the same mesial tipping direction but to different degree when the 1st or the 2nd premolars were extracted during clear aligner treatment. Presetting anchorage preparation design for the posterior teeth is essential to alleviate the roller coaster effect, especially in the 2nd premolar extraction cases. Furthermore, larger anchorage preparation value should be proposed for the maxillary posterior teeth., (© 2024. The Author(s).)

Objective: This study evaluated the force system generated by the Memory Titanol® spring (MTS) with different preactivation bends using an orthodontic force tester (OFT)., Methods: Three preactivations were tested using a 0.017 × 0.022-in stainless steel (SS) wire and a 0.018 × 0.025-in NiTi segment, with an activation of 30º in the posterior segment (β), with 0º (Group 1 [G1]), 45º (Group 2 [G2]), and 60º (Group 3 [G3]) in the anterior segment (α)., Results: The molars showed extrusion values of -1.33 N for G1 and -0.78 N for G2, and an intrusion value of 0.33 N for G3. The force in the premolars was intrusive with a variation of 1.34 N for G1 and 0.77 N for G2; and extrusive with a variation of -0.31 N for G3. Regarding the upright moment (Ty) of the molar, a distal moment was observed with values of 53.45 N.mm for G1 and 19.87 N.mm for G2, while G3 presented a mesial moment of -6.23 N.mm. G1, G2, and G3 all exhibited distal premolar moments (Ty) of 3.58, 2.45, and 0.68 N.mm, respectively., Conclusions: The tested preactivations exerted an extrusive force in G1 and G2 and an intrusive force in G3 during molar vertical movement. The premolar region in G1 and G2 showed intrusive force and distal moment.

Objective: To histomorphometrically determine the effects of hard- and/or soft-tissue augmentation by applying the early implant placement protocol., Materials and Methods: The distal roots of the maxillary second and third premolars were extracted in 10 mongrel dogs. After 1 month, early implant placement was performed in the distal roots, resulting in buccal dehiscence defects. Four treatments were then randomly applied: (1) guided bone regeneration (GBR), (2) connective tissue grafting (CTG), (3) simultaneous GBR and CTG (GBR + CTG) and (4) no further treatment (control). Healing abutments were connected to all implants to allow non-submerged healing. At 4 and 16 weeks, tissue sections were harvested and histomorphometric analyses were performed., Results: Group GBR presented the largest total tissue thickness at 4 weeks, but underwent a greater remodelling compared with the other groups between 4 and 16 weeks. At 16 weeks, the overall tissue thickness was largest in group GBR + CTG. This group was also the most favourable in terms of the level of the margo mucosae and the presence of mineralized tissue at the coronal level. Group CTG demonstrated a stable tissue thickness over time, with a larger thickness at 16 weeks compared with group GBR., Conclusion: Simultaneous CTG and GBR resulted in the most-favourable tissue thickness when applying the early implant placement protocol., (© 2024 The Author(s). Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Introduction: To assess the effect of combinations of two different endodontic sealers used in initial and endodontic retreatment on the bond strength of the secondary obturation and the penetrability of the sealers., Methods: Forty-eight mandibular premolars were used, receiving standardized endodontic access and biomechanical preparation. Twenty-four teeth received AH Plus sealer (AHP) in primary obturation and the others received Bio-C Sealer (BCS). Retreatment protocol was performed with an R50 instrument. The samples were further subdivided into four groups (n = 12) based on the combination of primary/secondary obturation sealers: AHP/AHP; AHP/BCS; BCS/AHP; and BCS/BCS. Four samples from each subgroup received the addition of fluorophores to the sealer for penetrability analysis using laser scanning confocal fluorescence microscopy. The root portion on the 8 push-out samples was sectioned into 6 slices of 1.0 mm. Bond strength (BS) was assessed using a universal testing machine until displacement of the filling mass. Failure pattern was evaluated under a stereomicroscope (20× magnification). BS data were analyzed using two-way analysis of variance followed by Tukey's test (P < .05), and the association between the failure pattern and BS value was assessed using the chi-square test (P < .05). Penetrability was qualitatively evaluated., Results: The highest BS values were observed in the AHP/AHP (4.54 ± 1.5 MPa) and BCS/AHP (5.00 ± 1.0 MPa) groups (P < .05), with a higher percentage of adhesive failures to the filling material for all groups. Laser scanning confocal fluorescence microscopy images indicated greater penetrability of AHP compared to BCS, both in initial treatment and retreatment., Conclusion: AHP sealer exhibited higher BS and greater penetrability compared to BCS sealer., (Copyright © 2024 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The purpose of this clinical trail was to assess the clinical behavior of posterior composite restorations supported by a substantial foundation of flowable short fiber-reinforced composite SFRC (everX Flow, GC, Japan) used without proximal surface coverage with particulate filler resin composite (PFC). Seventy patients (20 males, 50 females; mean age: 30 ± 10 years) were randomly enrolled in this trial. Patients received direct restorations of either SFRC covered only on the occlusal surface (1-2 mm) by conventional PFC composite (G-ænial Posterior, GC), or plain conventional PFC composite without fiber-reinforcement, in Class II cavities in premolar and molar vital teeth. One operator made all restorations using one-step, self-etch bonding agent (G-ænial Bond, GC) according to manufacturers' recommendations. Two blinded trained operators evaluated the restorations at baseline, at 6, 12 and 18 months using modified USPHS criteria. Results indicated that, in both groups and at different follow-up intervals, according to evaluated criteria, restorations were rated mostly with best score (Alpha) (p > 0.05). For the marginal integrity after 6 months, a single case in the intervention [increased to 3 (8.8%) after 18 months] and 3 (9.7%) cases of the control group [increased to 4 (12.9%) after 18 months] had Bravo score but with no significant difference (p > 0.05). For color match measured after 6 and 18 months, three (8.8%) cases had Bravo score in the intervention group. The use of flowable SFRC composite without any PFC surface coverage proximally in Class II restorations demonstrated satisfactory clinical outcome throughout the 18-month follow-up., (© 2024. The Author(s).)

Objective: Endocrowns can be fabricated from various materials as a treatment option for endodontically treated teeth. This mixed cohort study aimed to demonstrate the clinical efficacy of Endocrowns made of feldspathic, zirconia lithium silicate, and lithium disilicate ceramics using a chairside CAD/CAM system., Methods: The present study compared the clinical outcomes of 141 Endocrown restorations in posterior teeth of 85 patients in a two-year follow-up. The efficacy of restorations was evaluated in three aspects: esthetics, biological response, and function, with the aid of the FDI guideline, and presented as descriptive analyses. Additionally, the data were analyzed using Chi-square and Spearman correlation tests. The significance level was set at p = 0.05., Results: The study findings revealed that the type of restorations (feldspathic ceramic, zirconia lithium silicate, and lithium disilicate) (p > 0.05) and underlying teeth (molars and premolars) (p > 0.05) play no part in restorations' failure. Caries' recurrence is primarily responsible for the failure of the endocrowns. Secondary caries and radiolucency were observed in four teeth (2.83 %). The clinical efficacy of 126 restorations (89.36 %) fell into the category of "clinically excellent" and "clinically good." Ten restorations (7.09 %) were classified as "clinically sufficient/satisfactory," and only five restorations (3.54 %) needed replacement due to having "clinically unsatisfactory" and "clinically poor" quality., Conclusions: Endocrowns showed a high success rate and durability in the short term, therefore can be considered a safe choice for restoring endodontically treated teeth. It is worth noting that caries were the most common reason for the failure of the restorations., Clinical Significance: Endocrowns made of different ceramics have been proven reliable restorations for endodontically treated molars and premolars., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To assess the fracture resistance and failure mode of endodontically treated premolars reconstructed by different preparation approaches: cervical margin relocation (CMR) and crown lengthening (CL) with complete ferrule (CLF) and partial ferrule (CLPF) with three different post and core systems., Materials and Methods: In this in vitro study, 100 maxillary premolars were assigned to the following 10 groups according to their preparation approach and type of post and core system (n = 10): (I) control (intact teeth), (II) prefabricated fiber post (PFP) and composite core with CMR (PFP-CMR), (III) polyethylene fiber-reinforced composite (PEFRC) with CMR (PEFRC-CMR), (IV) casting post (CP) and core with CMR (CP-CMR), (V) PFP-CLPF, (VI) PEFRC-CLPF, (VII) CP-CLPF, (VIII) PFP-CLF, (IX) PEFRC-CLF, and (X) CP-CLF. After thermomechanical loading, the fracture resistance and failure mode were assessed. Data were analyzed statistically (α = 0.05)., Results: In all post and core systems, the CLPF approach had lower fracture resistance than CMR (p < 0.05); CLF showed higher fracture resistance than CLPF only in the PFP system (p = 0.038). In PEFRC and CP systems, the difference between CLF and CLPF was not significant (p > 0.05). No significant difference was found in fracture resistance of different post and core systems with the same preparation approach (p > 0.05). CLPF showed the highest frequency of favorable, and CLF showed the highest frequency of unfavorable fractures., Conclusion: CLPF yielded lower fracture resistance than CMR. The difference in fracture resistance was not significant between CLF and CMR but the frequency of unfavorable fractures was higher in CLF than in other groups., (© 2023 by the American College of Prosthodontists.)

Objective: This study aimed to determine the survival of class II composite restorations in premolars and molars with and without base bulk-fill composite in general dental practice., Materials and Methods: We collected data from the electronic patient files of the Public Dental Services in the City of Oulu, Finland. The timespan of data collection was from August 15th, 2002, to August 9th, 2018. The data consisted of class II composite restorations both with and without base bulk-fill composite. We compared the survival of these restorations using Kaplan-Meier survival curves, the log-rank test, survival rates, and the Wilcoxon signed ranks test., Results: We observed 297 restorations in 96 patients. The five-year survival rates for restorations with and without base bulk-fill composite were comparable in premolars (77.5% and 77.4%, respectively) but different in molars (69.9% and 57.8%, respectively, p = 0.069). In molars, the restorations with base bulk-fill composite exhibited a higher survival rate in 14 patients, whereas in 11 patients the restorations without base bulk-fill composites exhibited a higher survival rate. In 24 patients the survival rates were similar for restorations with and without the base bulk-fill composite (p = 0.246)., Conclusions: The restorations with and without base bulk-fill composite had similar longevity., Clinical Relevance: Base bulk-fill composites are safe to use in general practice due to their similar survival rates compared to conventional composites., (© 2024. The Author(s).)

BACKGROUND The aim of this study was to evaluate the time-dependent release of calcium (Ca⁺⁺) and hydroxyl (OH⁻) ions from 3 different pulp dressing materials used to cap root canal orifices in pulpotomized premolars. MATERIAL AND METHODS Freshly extracted (n=40) premolars were subjected to standardized pulpotomy procedure and finally restored in 5 groups using resin-modified glass ionmmer liner (RMGI) and bonded resin composite directly against the pulp chamber's floor (Control, G2) and over 3 different orifices' capping materials - Dycal (G3), Endo Sequence root repair material (ESRRM, G4), and mineral trioxide aggregate (MTA) Angelus (G5). Another 10 sound premolars served as the Reference group (G1). The restored teeth were incubated at 37±1°C in sealed containers filled with deionized water to assess Ca⁺⁺ and OH⁻ ions release after 24 h and at 1, 4, and 8 weeks. Two-way ANOVA and Tukey's comparisons at alpha=0.05 were used to statistically analyze the collected data. RESULTS Two-way ANOVA revealed significant differences in Ca⁺⁺ ions between test groups at different testing time intervals (P<0.05). Despite the constant (Tukey's, P<0.05) pH levels (OH⁻ release), Group 5 specimens exhibited higher Ca⁺⁺ ion release in comparison to Groups 4 and 3 at different testing timepoints (Tukey's, P<0.05). CONCLUSIONS Although all the assessed pulp dressing materials had equivalent and stable pH levels, ESRRM and MTA-Angelus had the highest Ca⁺⁺ ion release at the assessment intervals.

Objectives: This study aimed to investigate if CPP-ACP / infiltrating resin was superior in treating enamel demineralization during orthodontic therapy compared with fluoride varnish, in order to provide early-intervention implications for dental professionals., Materials and Methods: In the in-vitro study, premolars were grouped into four: remineralization with fluoride varnish / CPP-ACP, sealing with infiltrating resin, and negative control. Experimental demineralization of enamel surfaces was analyzed using techniques of QLF, SEM, EDS and micro-hardness testing. An in-vivo intervention study was conducted on patients randomly assigned into three groups. At the baseline and every-3-month follow-up, QLF parameters were compared temporally and parallelly to yield potential implications for promotion in clinical practice., Results: The in-vitro study performed on 48 experimental tooth surfaces demonstrated that sealing with infiltrating resin reduced enamel surface porosity and increased surface micro-hardness significantly. In the in-vivo intervention study on 163 tooth surfaces, it was suggested that for those who meet the criteria of -10 < ΔF < -6 and - 1000 < ΔQ < -20 at the baseline, all these treatment methods could achieve acceptable outcomes; with the rising of absolute values of ΔF and ΔQ, sealing with infiltrating resin showed more evident advantages., Conclusion: For enamel demineralization during orthodontic therapy, all the treatment methods involved in this study showed acceptable effectiveness but had respective characteristics in treatment effects. QLF parameters could be used as indicators for clinical early-intervention strategy with regards to this clinical issue., Clinical Relevance: With QLF parameters, clinical early-intervention strategy for enamel demineralization during orthodontic therapy could be optimized., (© 2024. The Author(s).)

Background: Infected dentinal tubules are a possible source of bacteria that are responsible for the failure of root canal treatment. Therefore, disinfection of dentinal tubules by increasing the penetration of the irrigation solution is important for success in retreatment cases. This study utilized confocal laser scanning microscopy (CLSM) to assess and compare the impact of XPR, ultrasonic irrigation (UI) and sonic activation (SA) on NaOCl penetration into dentinal tubules following endodontic retreatment., Methods: A total of forty mandibular premolars were enrolled in this investigation. Following root canal preparation up to ProTaper X3 file (30/0.07), root canals were obturated with gutta-percha and bioceramic root canal sealer with single cone technique. The root canal filling materials were removed using ProTaper nickel-titanium rotary retreatment files until the working length was reached. The retreatment procedure was finalized using the ProTaper Next X4 (40/0.06). The teeth were divided into four groups based on the irrigation activation technique: control (conventional needle irrigation), SA, UI and XPR. During the final irrigation procedure, Rhodamine B dye was introduced to 5% NaOCl for visualization via CLSM. Subsequent to image acquisition, the maximum penetration, penetration percentage, and penetration area were calculated. Data were statistically analyzed using the Kruskal-Wallis, Friedman, and Bonferroni Dunn multiple comparison tests through R software (p < 0.05)., Results: In the middle third, UI yielded a significantly higher penetration percentage than the control group (p < 0.05). The UI and XPR groups showed increased penetration percentages in the coronal and middle thirds compared with the apical third (P < 0.05). Maximum penetration was notably reduced in the apical third than in comparison with the coronal and middle thirds in all groups (p < 0.05). In the control, SA and XP groups, the penetration area was ranked in descending order as coronal, middle and apical (p < 0.05). Conversely, in the ultrasonic group, the penetration area was significantly lower in the apical third than in the middle and coronal thirds (p < 0.05)., Conclusions: UI enhanced the penetration percentage in the middle third of the root compared with that in the control group. XPR and SA showed no significant effect on NaOCl penetration following retreatment., (© 2024. The Author(s).)

Background: Partial coverage concepts have met the main goal of conservative dentistry. Vonlays, which combine features of veneers and onlays, are a recent alternative to full coverage designs and overlay partial coverage restorations. This in vitro study was conducted to compare the fracture resistance of the newly introduced pressable zirconia-reinforced lithium silicate with pressable lithium disilicate ceramic and to determine the optimal preparation design for partial coverage on upper premolars., Methods: Fifty-two duplicated epoxy resin dies were prepared following vonlay and overlay preparation guidelines. For each preparation (n = 26), the specimens were divided into two subgroups to be restored with lithium disilicate (IPS e.max Press) or zirconia-reinforced lithium silicate (Vita Ambria) (n = 13 each). Ceramic vonlays and overlays were bonded using dual cure resin cement, subjected to thermomechanical fatigue, and the load to fracture was tested by using a universal testing machine. The specimens were fractographically analyzed via scanning electron microscopy (SEM). The normality of the fracture resistance data was checked using the Shapiro‒Wilk test and Q‒Q plots, and two-way ANOVA was used to assess the effect of the type of preparation and ceramic material on the fracture resistance., Results: The group of overlays restored with zirconia-reinforced lithium silicate showed the highest mean fracture load (1218.69 N), while the group of vonlays restored with lithium disilicate had the lowest mean fracture resistance (967.15 N). The effect of preparation design and material type on fracture resistance was significant for both factors, p = 0.003 and p < 0.0001, respectively. Different features of the fracture surfaces, such as arrest lines, hackles, and directions of crack propagation, were observed., Conclusions: Zirconia-reinforced lithium silicate exhibited greater resistance to fracture compared to lithium disilicate, making it a potential substitute for partial coverage restorations. Additionally, the overlay showed superior fracture resistance when compared to the vonlay preparation design., (© 2024. The Author(s).)

Background: Recently, prosthodontic approaches involve more conservative procedures that include less invasive finish line preparations that use less ceramic thickness., Aim of the Study: This in vitro study aimed to evaluate the effect of vertical preparation and modified vertical preparation designs on the marginal adaptation and fracture resistance of two types of ceramic crowns using CAD/CAM technology., Materials and Methods: Two typodont maxillary first premolars were embedded in acrylic resin. Forty positive replicas of epoxy resin dies were used that were divided into two groups depending on the preparation design (n = 20); Group V (Vertical): dies with feather edge finish line and Group MV (Modified vertical): dies with feather edge finish line, where a reverse shoulder of 1 mm depth was placed on the buccal surface 1.5 mm from the occlusal surface. Each group was further subdivided into two subgroups according to the type of ceramic material (n = 10): Subgroup Va and subgroup MVa for lithium disilicate (e.max CAD) and subgroup Vb and subgroup MVb for zirconia (zolid ht+). Crown restorations were made with CAD-CAM technology. The marginal adaptation was assessed using a stereomicroscope both prior to cementation and after cementation and aging. Fracture resistance was tested with a universal testing machine, and the data were statistically analyzed., Results: Marginal adaptation showed no significant differences between subgroups before or after cementation and aging. Three-way ANOVA indicated that preparation design (p = 0.516) and material (p = 0.269) had no significant effect, but cementation had a significant effect (p < 0.0001) on the marginal adaptation. According to two-way ANOVA test, Subgroup (MVb) showed the highest result followed by subgroup (Vb) and subgroub (MVa) and the least was subgroub (Va). Fracture modes showed no significant differences among the subgroups (p = 0.982)., Conclusions: Marginal adaptation of lithium disilicate and zirconia crowns remained clinically acceptable regardless of preparation design. While the modified vertical preparation with a reverse shoulder notably enhanced the fracture resistance of both materials, with zirconia demonstrating superior fracture resistance compared to lithium disilicate with average values exceeding premolar biting force., (© 2024. The Author(s).)

Background: Tyrosine-rich amelogenin peptide (TRAP) is the main amelogenin digestion product in the developmental enamel matrix. It has been shown to promote remineralization of demineralized enamel in our previous study. However, direct evidence of the effect of TRAP on the morphology and nanostructure of crystal growth on an enamel surface has not been reported. This study aimed to examine the effect of TRAP on the morphology of calcium phosphate crystals grown on early enamel erosion using a pH-cycling model., Methods: Eroded lesions were produced in human premolars by 30-second immersion in 37% phosphoric acid. Forty-five samples of eroded human premolar enamel blocks were selected and randomly divided into 3 groups: deionized water (DDW, negative control); 100 µg/mL TRAP, and 2 ppm sodium fluoride (NaF, positive control group). For 14 days, the specimens were exposed to a pH-cycling model. Using scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods, the surface morphology, calcium-phosphorus ratio, and enamel surface roughness were examined. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to assess crystal characteristics., Results: After pH-cycling, compared to the two control groups, the surface of the eroded enamel of the peptide TRAP group shows a large number of new, densely arranged rod-like crystals, parallel to each other, regularly arranged, forming an ordered structure, with crystal morphology similar to that of natural enamel. The crystals are mostly hydroxyapatite (HA)., Conclusion: This study demonstrates that the peptide TRAP modulates the formation of hydroxyapatite in eroded enamel and that the newly formed crystals resemble natural enamel crystals and promote the remineralization of enamel, providing a promising biomaterial for remineralization treatment of enamel lesions., (© 2024. The Author(s).)

Background: White spot lesions are a widespread undesirable effect, especially prevalent during fixed orthodontic treatments. The study compared the in vitro enamel remineralization potential of undemineralized dentin matrix (UDD) versus chicken eggshell powder (CESP) for artificially induced enamel lesions., Methods: 100 caries-free and sound maxillary premolars were randomly divided into four groups each contain 25 teeth: Group I (Baseline): No treatment was done to the enamel surface. Group II (Negative control ): The enamel surface of the teeth underwent demineralization using demineralizing solution to create artificial carious lesions then kept in artificial saliva. Group III (CESP treated): After demineralizing the tooth surface, the teeth have been suspended in the CESP remineralizing solution. Group IV (UDD treated): After enamel demineralization, the teeth were suspended in UDD remineralizing solution. The remineralization potential was assessed by Vickers microhardness testing, scanning electron microscopic examination (SEM), and energy dispersive X-ray (EDX)., Results: The current study demonstrated an increase in the mean microhardness of CESP and UDD-treated groups; however, It was nearer to the baseline level in the UDD group. SEM imaging revealed greater enamel remineralization in the UDD group compared to the remaining groups. The UDD group disclosed complete coverage for the prismatic enamel compared to the CESP group, which revealed a partially remineralized enamel surface. Interestingly, the Ca/P ratio increased significantly in the CESP group compared to the negative control group. In contrast, a higher significant increase in the mean Ca/P ratios was recorded in the UDD group compared to the test groups., Conclusion: biomimetic UDD and CESP powder should be utilized to treat enamel early carious lesions. However, UDD demonstrated the most significant remineralization potential., (© 2024. The Author(s).)

Impacted teeth are significant dental anomalies affecting primary and mixed dentition, potentially causing issues with permanent teeth and affecting dental and facial aesthetics. Supernumerary teeth are commonly impacted in the anterior maxilla, while premolars are the third most common in permanent dentition, after third molars and canines. Untreated impactions can lead to complications such as delayed or ectopic eruption of adjacent teeth, resulting in crowding, midline diastema, or nasal cavity eruption. Early diagnosis and prompt treatment are essential to prevent these issues. Despite advanced surgical techniques, some complications can be iatrogenic, making awareness and preventive measures crucial. This article presents a series of cases highlighting common complications and precautions associated with the management of dental impactions. Timely diagnosis and proactive management can mitigate complications from impacted teeth. Dental surgeons should remain vigilant for clinical signs and unexpected findings during routine examinations., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Arora et al.)

Background: Mandibular second premolar agenesis is a common problem in orthodontics and is often treated in conjunction with maxillary counterbalancing extractions. However, in cases without maxillary crowding or dental protrusion, space closure may pose challenges leading to compromised occlusal results or patient profile. Multiple techniques have been described to treat these patients; nevertheless, there is a paucity of data comparing effectiveness of space closure utilizing various anchorage techniques. The goal of this study is to assess the effectiveness of the Herbst device during mandibular molar protraction and compare it to the use of temporary anchorage device (TADs) in patients with mandibular second premolar agenesis., Materials and Methods: This retrospective study included 33 patients with mandibular premolar agenesis treated without maxillary extractions. Of these patients, 21 were treated with protraction Herbst devices and 12 with TADs. Changes in molar and incisor positions, skeletal base positions and occlusal plane angulations were assessed on pretreatment (T0) and post-treatment (T1) lateral cephalograms. Scans/photographs at T0 and T1 were used to evaluate canine relationship changes representing anchorage control. Space closure and breakage/failure rates were also compared. Data was analyzed with paired and unpaired t-tests at the significance level of 0.05., Results: Within the Herbst group, changes in mandibular central incisor uprighting and mandibular molar crown angulations were statistically significant. However, no significant differences were noted between the Herbst and TAD groups. Protraction rates as well as overall treatment times were comparable (0.77 mm/month vs. 0.55 mm/month and 3.02 years vs. 2.67 years, respectively). Canine relationships were maintained or improved toward a class I in 82.85% of the Herbst sample, compared to in 66.7% of the TAD sample. Emergency visits occurred in 80.1% of the Herbst group, with cementation failures or appliance breakages as the most common reasons., Conclusion: The Herbst device could be a viable modality in cases with missing mandibular premolars where maximum anterior anchorage is desired, or if patients/parents are resistant to TADs. Furthermore, they could be beneficial in skeletal class II patients with mandibular deficiency who also need molar protraction. However, the increased incidence of emergency visits must be considered when treatment is planned., (© 2024. The Author(s).)

Purpose: This retrospective observational study aims to evaluate the outcome of a new alveolar ridge preservation (ARP) technique, "Lamina Socket Sealing" (LSS) technique, using a porcine barrier., Methods: 36 subjects with maxillary premolars to be extracted and extensive alveolar wall defects were enrolled and treated. Porcine-derived barriers and mesenchymal membrane were used to seal the extraction socket with alveolar particulate graft. The outcome variables were: radiographical bone changes and clinical outcomes., Results: 36 subjects, 21 females and 15 males were treated. The change in mm (mean + SE) of horizontal ridge width from baseline to 4 months after surgery at the coronal level of the alveolus was +1.25 ± 0.20 mm (P< 0.05), mean level was +0.34 ± 0.1 mm (P< 0.05) and at the apical level was +0.08 ± 0.17 mm (P> 0.05) which was not statistically significant. The buccal and palatal height changes in mm (mean + SE) from baseline to 4 months after surgery were respectively 1.21 ± 0.17 mm for the buccal wall (P< 0.05) and 1.06 ± 0.24 mm for the palatal wall (P< 0.05). The bone volume of all sites allowed for the placement of the planned implants., Clinical Significance: The alveolar ridge preservation technique (Lamina Socket Sealing) using resorbable heterologous cortical lamina with flapless approach allowed not only the preservation of the damaged post-extraction socket, but also minimal ridge augmentation, according to the principles of guided bone regeneration., Competing Interests: The authors declared no conflict of interest with respect to the research, authorship, and/or publication of this article. Dr. Passarelli and Dr. Lopez contributed equally to this study. Dr. Chiapasco and Dr. D'Addona contributed equally to this study., (Copyright©American Journal of Dentistry.)