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Purpose: To evaluate the effect of three different curing protocols based on different ratios of self-curing and light-curing periods on the bond strength and nanoleakage of fiber posts luted with dual-curing selfadhesive cements. Materials and Methods: A total of 48 single-root teeth were endodontically treated and obturated, and an 8-mm post space was prepared with dedicated drills. Specimens were randomly divided into two groups according to the self-adhesive cement employed: group 1 (G1) = PANAVIA SA Plus (Kuraray Noritake), and group 2 (G2) = Bifix SE (VOCO). The specimens were further divided into three subgroups (n = 8 each) according to the light-curing protocol applied: no light-curing (SG1), 20 seconds of light-curing 20 seconds after cement injection (SG2), and 20 seconds of light-curing 120 seconds after cement injection (SG3). Slices of 1-mm thickness were prepared for the pushout test and nanoleakage analyses of the coronal and apical regions after 24 hours of storage in artificial saliva. Results were statistically analyzed with threeway ANOVA and Tukey post hoc tests. Statistical significance was set for P < .05. Results: Three-way ANOVA analysis showed that the factors of cement (P = .02) and curing protocol (P < .001) had a significant influence on bond strength. Tukey post hoc test reported that light-curing 120 seconds after injection showed higher bond strength compared to both no light-curing and photoactivation after 20 seconds. Conclusion: To achieve the highest bond strength with self-adhesive cements, photoactivation with a 120-second delay after mixing is required. There is no difference between light-curing immediately and light-curing 20 seconds after mixing. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the fracture strength of endodontically treated molars filled with different composite resins with vs without fiber reinforcement. Materials and Methods: A total of 60 intact mandibular molars were selected and endodontically treated. A standardized mesio-occlusal-distal cavity was prepared with cervical margins 1 mm above the cementoenamel junction and oral and buccal walls with 1.5-mm thickness. Universal adhesive was used in all specimens in etch-and-rinse mode. Specimens were divided into four groups (n = 15 each) according to restoration technique: group CSM = adhesive overlay with hybrid ceramic; group EXP = direct restoration with short fiber-reinforced composite; group ESU = direct restoration with nanohybrid composite; and group EST = direct restoration with nanohybrid composite reinforced with horizontal bidirectional glass fibers placed over the pulpal chamber floor. After 7 days of storage in water, samples were loaded until fracture using a universal testing machine. The maximum breaking loads were recorded in Newtons, and statistical analysis was then conducted with two-way ANOVA and post hoc Tukey test. Fragments were analyzed using scanning electron microscopy. Results: Mean fracture resistance values were: CSM = 1,428.91 ± 316.90 N; EXP = 1,874.57 ± 299.47 N; ESU = 1,557.44 ± 355.65 N; and EST = 1,870.27 ± 145.11 N. The CSM and EXP groups showed the highest strength values when compared to the other groups. The variable fiber insertion did not significantly alter the fracture resistance. The origin of the fracture was always located on the occlusal surface, mainly in the major contact loading area. Conclusion: The use of fiber-reinforced composite showed great improvement in fracture resistance, similar to a cuspal coverage restoration. However, only short fiber-reinforced composites showed a favorable fracture pattern. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin. Methodology: This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty‐two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post‐surgery. Student's t‐test (p <.05) was used to compare the EPT values at baseline and T4. anova (p <.05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p <.05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response. Results: At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p >.05), but significant differences were observed for EPT values between T1 and T4 (p <.05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points. Conclusions: These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post‐surgery follow‐up with TPT and EPT is recommended to assess pulp status. [ABSTRACT FROM AUTHOR]

(1) Background: The objective of this in vitro study was to evaluate the impact of different etching times and ethanol pre-treatments on the immediate bond strength of a hydrophilic multi-mode universal adhesive (Clearfil Universal Bond Quick, Kuraray, UBQ) and on the consequent gelatinolytic activity of metalloproteinases (MMPs) on radicular dentin. (2) Methods: Sixty single-root teeth were selected and divided into four groups according to the adhesive protocol applied for fiber post cementation: (G1) 15 s H3PO4 application + UBQ; (G2) 30 s H3PO4 application + UBQ; (G3) 15 s H3PO4 application + ethanol pre-treatment + UBQ; (G4) 30 s H3PO4 + ethanol pre-treatment + UBQ. After adhesive procedures, fiber posts were luted into the post space with a dual-curing cement (DC Core, Kuraray) and light-cured for 40 s. To perform the push-out test and nanoleakage analyses for both coronal end apical areas, 1 mm slices were prepared, following a 24 h storage period in artificial saliva. Additionally, an in situ zymographic assay was conducted to explore endogenous MMP activity within the radicular layer. Results were statistically analyzed with ANOVA and Tukey post hoc tests. Statistical significance was set at p < 0.05. (3) Result: ANOVA revealed a statistically significant difference in push-out bond strength related to the pre-treatment variable but did not highlight any significance of etching time. Specimens pre-treated with ethanol wet bond application showed higher bond strength (p < 0.01). In situ zymography quantification analyses revealed that all tested groups, independently of etching time end ethanol pre-treatment, activated MMP gelatinolytic activity. A significant increase in MMP activity was detected for the 30 s etching time. However, ETOH pre-treatment significantly reduced MMP activity within the adhesive interface (p < 0.01). (4) Conclusions: The tested adhesive showed similar results regardless of the etching time protocol. The gelatinolytic activity of MMPs was observed in all the groups. Further investigations and extended follow-ups are required to validate the results of the present study in vivo. [ABSTRACT FROM AUTHOR]

Purpose: To three-dimensionally evaluate the interfacial gap of bulk-fill resin composites applied in deep Class-I restorations with different layering techniques and curing modes. Materials and Methods: Ninety-six (n = 96) samples were prepared with standardized deep Class-I cavities and adhesive procedures. Four materials were tested: SDR (SDR), SonicFill2 (SF), Admira Fusion X-Tra (AFXT), Filtek Supreme XTE (FS). Four subgroups (n = 6) were created according to layering and curing techniques: 2+2mm increments with soft start curing (SG1), 2+2 mm with conventional curing (SG2), a 4-mm increment with soft start curing (SG3), a 4-mm increment with conventional curing (SG4). All samples underwent micro-CT scans; afterwards, voids surrounding the restorations automatically underwent a thresholding procedure (Mimics, Materialise; Geomagic Studio 12, 3D Systems) to analyze the 3D interfacial gap. Statistical analysis was performed using three-way ANOVA with Tukey’s test (significance p < 0.05). Results: Statistically significant differences were reported between materials, layering techniques and their interaction. No statistically significant differences were reported for polymerisation mode. Bulk-fill materials showed average interfacial gap volumes ranging from 0.031 mm³ to 0.200 mm³, while FS showed volumes ranging from 0.416 mm³ to 1200 mm³. Conclusions: All bulk-fill materials performed statistically significantly better than did FS (p < 0.05), with no statistically significant differences between them. Curing mode did not influence interfacial gap volume in any group (p > 0.05), while bulk-filling vs layering influenced the volume of interfacial gaps only in the FS group, which performied better when incrementally applied. Regarding gap localisation, the floor of the cavity was the area with the highest likelihood of gaps in all samples. [ABSTRACT FROM AUTHOR]

(1) Background: A Dynamic Navigation System (DNS) is an innovative tool that facilitates the management of complex endodontic cases. Despite the number of advantages and limitations of this approach, there is no evidence-based information about its efficiency in comparison with that of the traditional method in endodontics. (2) Objectives: We aimed to explore any beneficial effects of the DNS and compare the outcomes of DNS vs. free-hand (FH) approaches for non-surgical and microsurgical endodontics. (3) Methods: A literature search was conducted in August 2023 to identify randomized, experimental, non-surgical, and microsurgical endodontic studies that compared the DNS with FH approaches. The procedural time (ΔT, s), substance loss (ΔV, mm3), angular deviation (ΔAD, °), coronal/platform linear deviation (ΔLD_C, mm), and apical linear deviation (ΔLD_A, mm) were recorded and analyzed. Quality and risk of bias assessments were conducted according to the Quality Assessment Tool For In Vitro Studies. A meta-analysis was performed using mean difference and standard deviation for each outcome, and heterogeneity (I2) was estimated. p < 0.05 was considered significant. (4) Results: One-hundred and forty-six studies were identified following duplicate removal, and nine were included in the systematic review and meta-analysis. The overall risk of bias was classified as low. The DNS was found to be more accurate and efficient than the FH approach was, resulting in a significantly shorter operation time (p < 0.00001) and less angular (p ≤ 0.0001) and linear deviation (p ≤ 0.01). For substance loss, the advantage of the DNS was significant only for microsurgery (p = 0.65, and p < 0.005, for non-surgical and microsurgical procedures, respectively). A reduced risk of iatrogenic failure using the DNS was observed for both expert and novice operators. (5) Conclusions: The DNS appears beneficial for non-surgical and microsurgical endodontics, regardless of the operator's experience. However, appropriate training and experience are necessary to access the full advantages offered by the DNS. [ABSTRACT FROM AUTHOR]

This study investigated variation in working length during multiple‐visit endodontic treatment. Patients (N = 106) with pulpitis or pulp necrosis, with or without apical periodontitis, were included. During the first appointment, glide path was performed with ProGlider and shaping with ProTaper Next. Working length was detected four times. Working length was then re‐recorded prior to filling during the second appointment and a 0.5 mm threshold was selected as the minimum clinically meaningful variation. A logistic regression model was used to evaluate the impact of tooth anatomy, preoperative pulp status, apical periodontitis and lesions of endodontic origin on working length variation. Working length varied between first and second appointments in 34% of patients. The presence of apical periodontitis was the only variable significantly associated with variation in working length (p = 0.011). These data suggest that working length should be re‐checked prior to root canal filling to prevent procedural errors. [ABSTRACT FROM AUTHOR]

Background: The labial frenulum may be associated with traction on the marginal gingiva of the incisors with resulting gingival recession, a condition known as "pull syndrome". In this case, performing a frenulectomy at least 6 months before root covering surgery is necessary. Recently, tissue adhesives have been studied as a good alternative to conventional sutures. Methods: A 34-year-old female affected by pull syndrome of the central lower incisors underwent frenulectomy, and an n-hexyl-cyanoacrylate tissue adhesive was used to ensure wound closure. Results: The patient was instructed in hygiene maneuvers and rinsed with 0.12% chlorhexidine-based mouthwash for 15 days. The glue was partially removed at 7 days, and for the remaining, natural disposal time was expected. The wound healing process was complete after 15 days with minimal postoperative discomfort. Conclusion: This n-hexyl-cyanoacrylate surgical glue could be proposed as a viable alternative to conventional sutures during surgical procedures involving wide flaps with the impossibility of first-intention healing. Moreover, it could be indicated to reduce operative time and patients' discomfort, even if these hypotheses should be confirmed by future clinical studies. [ABSTRACT FROM AUTHOR]

Purpose: The management of complicated crown-root fractures is challenging for endodontic restoration. The present case describes a patient who sustained trauma to the maxillary right central incisor. Materials and Methods: Clinical and radiographic examination showed a complicated crown-root fracture and incomplete root development with periapical radiolucency and inadequate endodontic treatment with overfilling. Orthograde retreatment with MTA apical closure combined with a microsurgical approach to remove of extruded material was performed. Coronal sealing was accomplished with a direct adhesive restoration and marginal relocation. Results: A 5-year follow-up showed complete healing of the periapical lesion and correct preservation of function and esthetic parameters. Conclusion: A modern minimally invasive treatment protocol allows the maximum conservation of residual dental tissues. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate interfacial gap and fracture resistance of endodontically treated maxillary premolars, restored with different glass-fiber reinforced materials. Materials and Methods: Eighty-four extracted intact premolars were endodontically treated and MOD cavities prepared. Specimens were divided into 7 groups (n = 12 for each) as follows: sound teeth (G1); no restoration (G2); direct composite restoration with fiber-reinforced composite (everX Posterior GC) (G3); direct composite restoration (Filtek Supreme XTE, 3M Oral Care; "FSXTE") (G4); a horizontal layer of high-viscosity flowable composite (G-ænial Flow, GC) was placed on the pulp chamber floor, 10 mm x 3 mm glass fibers (everStick NET, GC) were inserted into the cavity (G5); same procedure as in group 5 except the direct restoration was made incrementally with FSXTE (3M Oral Care) (G6); composite overlays were placed (G7). Specimens were scanned with micro-CT to evaluate 3D interfacial gaps before and after chewing simulation using Mimics software to calculate voids between restoration and tooth (dentin and enamel). These data (in mm³) were collected for statistical analysis. Thereafter, specimens were loaded to fracture using a universal testing machine. Maximum breaking loads were recorded in Newton (N). The data obtained were analyzed using two-way ANOVA and post-hoc Tukey's test (p < 0.05). Results: ANOVA showed that horizontal glass-fiber insertions statistically significantly reduced interfacial gaps after chewing simulation. No differences in fracture resistance were found between Filtek Supreme XTE and everX Posterior; moreover, glass-fiber insertion did not significantly improve fracture resistance in either case. Composite overlays achieved significantly better fracture toughness than did direct restorations. Conclusions: For the direct restoration of endodontically treated premolars, the insertion of glass fibers into direct composite restorations was unable to guarantee a significant increase in the fracture resistance or a significant change in the fracture pattern. However, it significantly reduced interfacial gap volume after cycling fatigue. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the immediate and aged bond strength and interfacial nanolaekage of different adhesives and protocols on dental elements prepared with diamond burs and Er:YAG laser. Materials and Methods: Forty molar crowns were flattened and a standardized smear layer was created. Teeth were divided into two main groups according to the dentin cutting technique: 1. Er:YAG laser for 30 s at 30 Hz repetition rate, 250 mJ energy per pulse, and water spray irrigation set at level 8; and 2. diamond bur. Each group was then divided into subgroups according to the adhesive protocol: SG1: dentin etching for 15 s followed by universal adhesive application (All Bond Universal, Bisco); SG2: universal adhesive application (All Bond Universal); SG3: two-step self-etch adhesive application (Clearfil SE Bond 2, Kuraray Noritake); SG4: etching followed by 3-step etch-and-rinse adhesive application (Optibond FL, Kerr). After curing the adhesives, resin composite buildups of 4 mm were made and specimens were sectioned to obtain 1-mm-thick sticks in accordance with the μTBS test technique. Sticks were stressed to failure at baseline and after 6 months of storage in artificial saliva. Three teeth per group were prepared for nanoleakage interfacial analyses. Data were statistically analyzed with three-way ANOVA and Tukey's post-hoc test (p < 0.05).Results: A significant difference in bond strengths was found for treatment, aging, and adhesive protocol. Nanoleak age analysis showed higher marginal infiltration in Er:YAG-treated groups both at baseline and after aging. Conclusions: Surfaces prepared with diamond burs presented higher bond strengths than did those prepared with Er:YAG laser. Adhesive protocols and aging could influence the adhesive-dentin interface. Further studies are necessary to validate the results obtained. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the shaping ability of a modified ProTaper Next technique (PTNm) with that of TruNatomy (TN) in lower molars mesial curved canals using micro-computed tomography (Micro-CT). Sixty mesial canals of first mandibular molars were randomly assigned between two groups (n = 30). After canal scouting with K-File #10, glide path and shaping were carried out with TN or PTNm systems. The PTNm sequence consists of ProGlider, followed by ProTaper Next X1 and apical finishing with NiTiFlex #25 up to working length (WL) to ensure adequate apical cleaning. Samples were scanned using micro-CT and pre- and post-shaping volumes were matched to analyse geometric parameters: the volume of removed dentin; the difference of canal surface; centroid shift, minimum and maximum root canal diameters; cross-sectional areas; the ratio of diameter ratios (RDR) and the ratio of cross-sectional areas (RA). Measurements were assessed 2 mm from the apex and in relation to the middle and coronal root canal thirds. Data were analysed using ANOVA (p < 0.05). No statistically significant differences were found between the groups for any parameter at each level of analysis, except for RA at the coronal level (p = 0.037). The PTNm system showed the tendency to enlarge more in the coronal portion with a lower centroid shift at apical level compared with TN sequence (p > 0.05). Both PTNm and TN sequences demonstrated similar maintenance of original anatomy during the shaping of lower molar mesial curved canals. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the wear rate of polymer-infiltrated network composites and ceramics against enamel in a bruxism-simulated scenario. Ninety-six (n = 96) molars were divided into six groups (n = 16) according to their occlusal material: group 1—a polymer-infiltrated network ceramic (PINC); group 2—a second polymer-infiltrated network ceramic (PINC2); group 3—nanohybrid resin-based composite (CO); group 4—cubic zirconia (ZR); group 5—lithium disilicate (LS); and group 6—sound enamel (EN). A laser scanner was used to digitalize all of the occlusal surfaces before and after a fatigue test, which was conducted with a chewing simulator set at 80 N and semicircular movement in order to simulate bruxist movement and loads. Statistical analysis of volume loss was performed with a one-way ANOVA and post hoc Bonferroni test. ZR had significantly inferior wear to PINC (p ≤ 0.01) and CO (p = 0.04). LS wore the antagonist enamel significantly more than PINC, CO, PINC2 and EN (p ≤ 0.01). On the other hand, ZR wore the antagonist enamel significantly more than CO (p ≤ 0.01) and PINC2 (p = 0.05). In conclusion, PINCs better preserved antagonist enamel at the expense of a higher wear of their own. LS causes significantly higher enamel wear compared with PINCs. ZR caused significantly higher enamel wear compared with CO and PINC2, but it was wear-resistant. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the antibacterial efficacy and penetration depth into dentinal tubules of a solution of chitosan nanodroplets (NDs) loaded with Benzalkonium Chloride (BAK). Seventy-two human single-root teeth with fully formed apex were used. Cylindrical root dentin blocks were longitudinally sectioned and enlarged to a size of a Gates Glidden drill #4. After sterilization, root canals were infected with Enterococcus faecalis ATCC 29212 and further incubated for three weeks. Specimens were assigned to three experimental groups (n = 20), plus positive (n = 6) and negative (n = 6) controls. In the first group, irrigation was achieved with 2 mL of NDs solution loaded with BAK (NDs-BAK), in the second with 2 mL of 5% sodium hypochlorite (NaOCl) and in the last with 2 mL of 2% chlorhexidine (CHX). Specimens were rinsed and vertically fractured. Confocal laser scanning microscopy (CLSM) and viability staining were used to analyze the proportions of dead and live bacteria quantitatively. The volume ratio of red fluorescence (dead) was calculated in 3D reconstructions. Data were analyzed by one-way ANOVA and post hoc Bonferroni tests (p < 0.05). The ratio of red fluorescence over the whole green/red fluorescence resulted in a significant comparison of NDs-BAK with NaOCl (p < 0.01) and NaOCl with CHX (p < 0.01). No differences were found between NDs-BAK and CHX (p > 0.05). The mean depth of efficacy was, respectively: NDs-BAK 325.25 μm, NaOCl 273.36 μm and CHX 246.78 μm with no statistical differences between groups. The NaOCl solution showed the highest antimicrobial efficacy, but nanodroplets with BAK seemed to have the same effect as CHX with a high depth of efficacy. [ABSTRACT FROM AUTHOR]

Objective. The purpose of this ex vivo study was to compare the trueness of traditional and digital workflows and to analyze the interfacial fit of CAD/CAM restorations on gypsum and 3D-printed casts (3DC). Methods: Forty patients underwent indirect posterior adhesive restorations. After tooth preparation, both traditional and chairside procedures were followed. Obtained models were scanned to generate STL files of the intraoral impression (IOS), the conventional cast (RS), and the 3D-printed cast (3DCS). Superimposition of the casts was performed to evaluate trueness. Then, for each preparation, two identical CAD/CAM restorations were milled and luted on RS and 3DC. Micro-CT scan was performed to evaluate 3D interfacial fit. Results. Surface trueness analysis showed no significant differences among groups (p > 0.05), with average trueness ranging from 11.56 to 17.01 µm. Micro-CT analysis showed significant differences between gypsum casts (average ranging from 135.78 to 212.31 µm) and 3DC (average ranging from 57.63 to 144.55 µm) for both marginal and internal fit. Conclusions. In adhesive restorations manufacturing, digital and conventional procedures generate casts that are not significantly different. Marginal fit of adhesive restorations is similar to conventional crown design and clinically acceptable. It is assumable that a direct digital workflow could benefit from the usage of 3DC. [ABSTRACT FROM AUTHOR]

To measure the thickness homogeneity of Invisalign (Align Technology Inc, San José, Calif) aligners with micro-computed tomography (micro-CT) scans. Starting from micro-CT scanning of 20 different aligners, multiplanar reconstructions were obtained. An orthodontist blinded about the study measured aligner thickness in different regions (molar, canine, incisor) and in different sites (gingival–buccal, buccal, occlusal, lingual, and gingival–lingual). To assess various thicknesses in different aligner sites and regions, the sample was stratified into subgroups and linear regression analysis was performed. Descriptive analysis showed that mean thickness of aligners in the incisor region ranged from 0.582 mm to 0.639 mm, in the canine region from 0.569 mm to 0.644 mm, and in the molar region from 0.566 mm to 0.634 mm. Student's t-tests showed no significant differences in the aligner thickness of different regions when data were stratified by different sites. Student's t-tests showed significant differences in thickness homogeneity for the molar region when the data were stratified by tooth (mean difference = 0.068 mm; 95% confidence interval, 0.009–0.126 mm; P =.024). Invisalign aligner thickness is characterized by small differences. The only significant difference was revealed in the molar region where thickness of the gingival–lingual edge is significantly thinner than that measured at the occlusal aspect. From a clinical perspective, the results of the present study could be considered to explain the reduced predictability of several orthodontic tooth movements in the molar region. [ABSTRACT FROM AUTHOR]

Featured Application: Root canal shaping techniques influence patients' postoperative quality of life after a primary root canal treatment. The introduction of more flexible reciprocating instruments with different alloy and geometry could lead to a general improvement of the postoperative symptoms. Patient-centered outcomes are crucial to evaluate the quality of the root canal treatment. Postoperative pain is a frequent complication of root canal treatment. It could worse patients' quality of life (QoL) and it may be associated to several factors, including the shaping technique. The aim of the study was to compare the impact of WaveOne Gold (WOG) and WaveOne Classic (WOC) reciprocating instrumentation on postoperative QoL after single-visit primary root canal treatment. Healthy subjects with pulp necrosis on multirooted teeth were observed. Canal shaping was performed with WaveOne Gold Primary (n = 25) or WaveOne Classic Primary (n = 29) and canal filling was completed with a carrier-based technique. Mean and maximum scores for postoperative pain were assessed through a Visual Analogue Scale (VAS) and QoL indicators were evaluated with a self-assessment questionnaire based on a Likert scale. Postoperative pain curves were similar in both groups (mean pain p = 0.43; maximum pain p = 0.27) and quality of life indicators showed no significant differences (p > 0.05). There was a more favourable trend of QoL values in the WOG group, reaching statistical significance on day six posttreatment (p = 0.021). Within the limitations of the study, reciprocating instrumentation may have an impact on patients' QoL, but the innovative geometrical and alloy properties of the WaveOne Gold seemed to induce a faster resolution of the postoperative symptoms. [ABSTRACT FROM AUTHOR]

Featured Application: Bioceramic materials have been recently proposed for several applications in endodontic practice. The impact of their setting time and chemical composition on biocompatibility is still controversial. This in vitro study evaluated the osteogenic potential of different bioceramic formulations. Recently, pre-mixed bioceramics in fast set formulations have been increasingly utilized in clinical practice as an alternative to mineral trioxide aggregate (MTA) for their shorter setting time and better handling properties. However, the impact on their osteogenic potential, due to modifications in chemical composition to promote a fast setting, is still unclear. This molecular and in vitro study compared the osteogenic potential of root repairing material putty fast set (FSP) with root-repairing material putty (RRMPU), root-repairing material paste (RRMPA), Biodentine™ and MTA. The null hypothesis tested was that there are no differences among the tricalcium silicate materials in terms of osteogenic potential. Standardized discs were cultured with MG-63 human osteoblastic-like cells to assess biocompatibility, the activity of alkaline phosphatase (ALP) and osteogenic potential. Biocompatibility was evaluated at baseline and after 24 and 48 h. Osteogenic differentiation was assessed after 15 days. Data were analyzed with one-way ANOVAs and Tukey's post-hoc test (p < 0.05). All materials showed biocompatibility and bioactivity. ALP activity, which induces mineral nodule deposition, increased in all the cements tested, with a significant increase in RRMPU (p < 0.001) and FSP (p < 0.001) samples versus MTA. In vitro mineralization was significantly increased for RRMPU (p < 0.0001), FSP (p = 0.00012) and Biodentine™ (p < 0.0001) versus MTA. The bioceramics tested showed higher levels of biocompatibility and bioactivity than MTA; a higher capacity for mineralization was observed with RRMPU and FSP versus MTA. [ABSTRACT FROM AUTHOR]

Featured Application: The influence of brushing motion on root canal anatomy preservation after shaping with NiTi single file reciprocating instruments was evaluated. The brushing movement may accentuate canal transportation especially in the coronal third. Brushing motion has been proposed for endodontic single-file reciprocating systems to eliminate coronal interferences, but it may hesitate in a less conservative root canal shaping. The aim of the study was to compare the maintenance of the original root canal anatomy using the WaveOne Gold (WOG) technique with or without a brushing motion. Sixty extracted human mandibular first molars were selected. Manual canal scouting and mechanical glide path were performed. Samples were randomized into two groups (n = 30): WOG Primary was used to shape the mesio-lingual canals without (NB group) or with (B group) an intentional brushing motion. Specimens were scanned with micro-computed tomography (micro-CT) before and after instrumentation in order to match the volumes. Increases in canal volume and surface area were measured. Centroid shift and thickness of removed dentine from the inner curvature were assessed at the furcation, 1.5 mm and 3 mm apically from the furcation, and in relation to the point of maximum curvature. Data were analyzed by one-way ANOVA and post-hoc Student–Newmann–Keuls tests (p < 0.05). No brushing technique resulted in being significantly associated with a better maintenance of the canal anatomy, especially in the coronal third (p < 0.05). When using the WOG system, a no-brushing technique resulted in less invasive shaping, reducing the risk of stripping. [ABSTRACT FROM AUTHOR]

Featured Application: Finite element analysis is proposed as a reliable tool for the evaluation of the shaping ability of NiTi rotary instruments during an early design phase. This method could significantly reduce instrument development time and costs without the use of prototypes. The aim of this study was to evaluate the contact pressure distribution of two different nickel-titanium (NiTi) endodontic rotary instruments against the root canal walls and to virtually predict their centering ability during shaping with finite element analysis (FEA). Resin blocks simulating root canals were used. One was shaped with ProGlider and ProTaper Next (PTN) X1-X2 and one with ScoutRace and BioRace (BR) 1, 2 and 3. Both resin blocks were virtually replicated with computer-aided design (CAD) software. The endodontic instruments ProTaper Next (PTN) X2 and BioRace BR3 were also replicated with CAD. The NiTi instruments and the shaped blocks geometries were discretized and exported for FEA. The instrument rotation in the root canals was simulated. The finite element simulation was performed by applying an insertion and extraction force of 2.5 N with a constant rotational speed (300 rpm). To highlight possible differences between pressure distributions against the root canal portions outside and inside the canal curvature, the parameter Var was originally defined. Var values were systematically lower for PTN X2, revealing a better centering ability. FEA proved effective for the virtual prediction of the centering ability of NiTi instruments during an early design phase without the use of prototypes. [ABSTRACT FROM AUTHOR]