Premolars Research Articles

Multi-Scale Characterization of Conventional and Immediate Dental Implant Systems

We hypothesized that the different post-implantation healing stages between the conventional and immediate implantations produce different amounts and tissue composition of the peri-implant bone. Thus, the objective of the current study was to examine whether the stability of dental implant systems is associated with characteristics of the interfacial bone area at different post-implanation healing periods. Mandibular molars were extracted from each beagle dog. After 10 weeks post-extraction, a screw-type titanium dental implant was placed in the molar location following a conventional dental implant (Con) procedure. Simultaneously, mandibular premolars were extracted and the same type of dental implant was placed in the distal site of the extracted premolar root following an immediate dental implant (Imm) procedure. The implant stability quotient (ISQ) values were not significantly different between Con and Imm groups at 0-, 3-, and 6-weeks post-implantation. However, 3D micro-computed tomography and 2D histological images confirmed that the Imm system had more gaps between the bone and implant than the Con system. On the other hand, the nanoindentation modulus value at the bone–implant interface was significantly higher for the Imm group than the Con group at both 3 weeks and 6 weeks post-implantation. The current results from multi-scale characterization suggest that the higher interfacial bone quality of the Imm system, despite its earlier post-implantation stage, plays a crucial role in maintaining stability comparable to that of the Con system.

ETIOPATHOGENIC ASPECTS OF ODONTOGENIC MAXILLARY SINUSITIS OF PERIAPICAL ORIGIN

Anatomically, the roots of the upper premolar and molar teeth are near the maxillary sinuses. Thus, periapical inflammation of the elements close to the sinuses enables the formation of odontogenic sinusitis. This study aimed to analyze the available literature on the etiopathogenic aspects of odontogenic maxillary sinusitis of periapical origin. A literature review was conducted in the following databases: SciELO, MEDLINE/Pubmed, and LILACS, using the keywords "Maxillary Sinusitis", "Dentistry", "Tooth" and "Infection". Articles written in English, Spanish, and Portuguese were included; those that fit the focus of the paper and those that were most relevant in terms of outlining the desired information. Papers reporting odontogenic sinusitis arising from an operative process were excluded. Odontogenic maxillary sinusitis (OMS) occurs due to sinus infection caused by inflammation of one or more dental elements near this cavity. Despite presenting specific features, sinusitis of odontogenic and non-odontogenic origin are quite similar, making the differential diagnosis difficult. Cone-Beam Computed Tomography (CBCT) is considered the reference standard for diagnosis, and the best treatment is to eliminate the causal factor. It was also found that apical periodontitis is the main non-iatrogenic cause and premolars and molars are the most affected teeth due to their anatomical location near the maxillary sinuses. The anatomical location of the maxillary sinus and the roots of the molars and premolars will allow, through the proximity between them, the OMS. In cases where periodontitis has proven to be the most frequent non-iatrogenic cause of this condition, also due to a great symptomatological similarity with non-odontogenic sinusitis, complementary examinations such as CBCT are necessary. Moreover, the treatment can be performed in a case-specific manner, through accurate diagnosis and etiopathogenesis.

Influence of sonic activation of epoxy-resin and calcium silicate sealer on postoperative pain: a patient-blinded, parallel group, randomized clinical trial

BackgroundThis clinical study aims to compare postoperative pain after single-visit root canal treatment of teeth with asymptomatic apical periodontitis using epoxy-resin-based AH Plus and calcium silicate-based Endosequence BC sealers with or without sonic activation.MethodsThis study included 72 individuals with one first or second mandibular premolar tooth with asymptomatic apical periodontitis. They were randomly divided into four groups according to the root canal sealer (AH Plus or Endosequence BC) and activation protocol (sonic activation or non-activation) (n = 18). The participants were ask to rate their postoperative pain intensity on a NRS scale as none, minimal, moderate, or severe after 24 h, 48 h, 72 h, and 7 days following treatment. Patients were also asked to record the number of prescribed analgesic medication tablets (400 mg of ibuprofen) taken. Statistical analysis were performed using the Mann-Whitney U test, the Friedman test, the Spearman’s correlation test, the Chi-square test. Significance level was established at 0.05.ResultsThere was no statistically significant difference in postoperative pain scores or analgesic intake between AH Plus and Endosequence BC sealers regardless of the activation protocol (p > 0.05). There was no statistically significant difference in postoperative pain scores between the sonic activation and non-activation groups (p > 0.05). A weak positive correlation was detected between Endoactivator sonic activation and sealer extrusion (r = 0.36).ConclusionsAH Plus and EndoSequence BC root canal sealers showed similar results in terms of prevalance and intensity of postoperative pain. Sonic activation and non-activation groups had similar postoperative pain scores.Clinical trial registrationThe study was retrospectively registered with ClinicalTrials.gov (NCT06403293). Date of Registration: 07/05/24.

Root canal cleanliness and debris extrusion following retreatment of thermoplastic injection technique and bioceramic-based root canal sealer.

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]. 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 14days 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. 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). 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. 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.

Effectiveness of Activated Sodium Hypochlorite Irrigation by Shock Wave-Enhanced Emission Photoacoustic Streaming, Sonic and Ultrasonic Devices in Removing Enterococcus faecalis Biofilm From Root Canal System.

Aim: To compare shock wave-enhanced emission photoacoustic streaming (SWEEPS) with sonic- and ultrasonically activated irrigation systems in removing Enterococcus faecalis biofilm from the root canal system. Methodology: Fifty human single-canalled mandibular premolars were included in the study. After access cavity preparation, the root canals were prepared to a standardized size and taper. Then, the entire root surface was covered with two layers of resin, and the root apices were sealed before sterilization. All root canals were inoculated with E. faecalis biofilm, and the samples were incubated aerobically for 2 weeks at 37 °C. Biofilm formation was confirmed by scanning electron microscopy. All samples were randomly divided into five groups (n = 10 each) based on their irrigation activation method as A (no treatment or negative control), B (no irrigation or positive control), C (sonically activated irrigation (SAI)), D (ultrasonically activated irrigation (UAI)), and E (needle irrigation activated by an Er: YAG laser device using a SWEEPS quartz tip (SWEEPS)). Then, dentine chips were retrieved, vortexed, and diluted for colony-forming unit counts. Data were analysed using analysis of variance and post-hoc Tukey tests (α = 5%). Results: All methods could significantly reduce E. faecalis biofilm compared with control so that the UAI, SWEEPS, and SAI groups indicated a 23.54%, 14.89%, and 7.81% biofilm reduction, respectively. UAI demonstrated a significantly more effective reduction of E. faecalis biofilm than SAI (p = 0.004). Conclusions: All irrigation activation methods significantly reduced E. faecalis biofilm, with ultrasonic use being the most effective.

Fechamento de diastemas com faceta direta de resina composta: relato de caso

The search for an aesthetic standard is increasingly frequent and restoring a harmonious smile represents a real challenge for restorative dentistry. Composite resins are aesthetic and adhesive materials that have received special attention for ensuring predictable and lasting results with minimal tooth sacrifice. The technique of making direct veneers is simple, but requires discretion and attention from its indication to the final stages of its execution. The procedure has high success rates and predictable results with desirable longevity for anterior teeth. The objective of this study was to present a clinical case of diastema closure with direct composite resin veneers on anterior teeth and maxillary first premolars, with the aid of diagnostic wax-up for better accuracy of work on anterior teeth. It is concluded that the application of the direct restorative technique allowed a fast, low, cost and less invasive treatment. Providing a satisfactory result, raising self-esteem and allowing a restoration of the patient's facial aesthetics.

Efficacy of Bone Anchored Pendulum Appliance Over Conventional Pendulum Appliance during Molar Distalization in the Orthodontic Management of Class II Malocclusion : A Systematic Review

Background: Pendulum appliance used commonly used to achieve molar distalization in the management of borderline class II malocclusion is associated with mesial tipping of the maxillary premolars and proclination of maxillary incisors post-distalization, resulting in round tripping and increased treatment time. Bone Anchored Pendulum Appliance (BAPA) is one of the modifications of the pendulum that could effectively prevent anchorage loss. Aim: To evaluate the effectiveness of Bone Anchored Pendulum Appliance(BAPA) over the Conventional Pendulum Appliance(CPA) for the distalization of maxillary molar in the management of Class II malocclusion. Materials and Methods: A web search was done in Google Scholar, MEDLINE, Web of Science, LILAC and COCHRANE Library databases using PRISMA guidelines. The search included RCTs and Non RCTs (Both Prospective and Retrospective studies) comparing distalization achieved by BAPA with CPA in Class II malocclusion. The Risk of bias was assessed using the ROBINS - I tool. Results: Of the initial 745 articles, 5 studies met the inclusion criteria and were included to the systematic review. The BAPA showed between 4.8 -6.4 mm of molar distalization and between 9 °-11.3° of distal tipping of molars while the distalization achieved with CPA was between 2mm -6.4mm with 6.67° -14.50° of distal tipping. While CPA groups showed mesial tipping of premolars, distal tipping of premolars was observed with the BAPA appliances. Conclusions: BAPA were found to significantly reduce anterior anchorage loss, distalise the premolars and molars. There is moderate evidence that BAPA provides greater distalization with reduced incidence of unwanted tooth movements.

ProDesign Logic Files Effect on Apical Foramen Wear and Shape Transformation After Foraminal Enlargement.

This study aimed to evaluate the effect of ProDesign Logic files 45.01 and 50.01 on apical foramen wear and shape transformation after foraminal enlargement at tooth length (TL) and 1 mm beyond. Sixty freshly extracted single-rooted lower human premolars teeth were distributed randomly into five groups (n = 12): Group 1 (40.05 WL) (control): No foraminal enlargement, Group 2 (45.01 TL): Specimens underwent foraminal enlargement with 45.01 Prodesign Logic file at TL; Group 3 (45.01 TL + 1): Specimens underwent foraminal enlargement with 45.01 Prodesign Logic file at 1 mm beyond TL; Group 4 (50.01 TL): Specimens underwent foraminal enlargement with 50.01 Prodesign Logic file at TL; Group 5 (50.01 TL + 1): Specimens underwent foraminal enlargement with 50.01 Prodesign Logic file at 1 mm beyond TL. Scanning electron microscopy was used to evaluate apical foramen variations and shape alterations. Data were analyzed by Student's t-test, Kruskal-Wallis, and Mann-Whitney test. Significant differences (p < 0.01) were observed among all tested groups compared to the control group in terms of the average worn area of the apical foramen. Foraminal enlargement led to significant shape transformation, resulting in round-shaped foramina. ProDesign Logic 45.01 and 50.01 files at TL causes notable wear and round-shaped foramina.

Post-Space Disinfectants With Sodium Hypochlorite and Methylene Blue Loaded in Silver and Quartz Nanoparticles Activated by Photodynamic Therapy. A SEM Analysis.

Post-space disinfectants methylene blue loaded with silver (Ag) and Quartz nanoparticles (NPs) and MB alone activated by photodynamic therapy (PDT) on the survival of Enterococcus faecalis, smear layer (SL) removal efficacy, and extrusion bond strength (EBS) of fiber posts to canal dentin. Hundred mandibular premolars underwent root canal treatment using the rotary ProTaper system. The canals were obturated and post-space was prepared up to a length of 8 mm, maintaining a 5 mm seal. To assess antibacterial efficacy E. faecalis were inoculated in the canal (n = 20). The samples were then randomly allocated into four groups according to the canal disinfectant used to sterilize the canals. Group 1: 2.5% NaOCl+17% EDTA, Group 2: MB-PDT, Group 3: MB@QP-PDT, and Group 4: MB@AgNP-PDT (n = 25). SEM analysis was conducted on five samples from each disinfectant group to assess the removal of the SL. Survival rates were calculated (n = 5 from each group). Glass fiber post (GFP) was cemented to the root dentin of the remaining samples followed by artificial aging. Sectioning of the specimens was performed in all three-thirds of the canals. PBS was assessed followed by failure evaluation. ANOVA and Tukey post hoc test were used to compare the E. faecalis survival rate and PBS of fiber post among different investigated groups. Group 4 (MB@AgNP-PDT) treated canals exhibited the minimum survival rate (0.30 ± 0.04 CFU/mL) of E. faecalis and maximum PBS. However, the highest survival rate and minimum bond strength of GFP were observed in Group 1 (NaOCl+17% EDTA) and Group 2 (MB-PDT) treated teeth respectively. The highest SL removal was recorded in the coronal section of the samples of Group-4 disinfected with MB@AgNP-PDT. The lowest removal of SL was recorded in Group 2 samples sterilized with MB-PDT at apical one-third. Silver nanoparticles when utilized as nano-carriers to enhance the efficiency of MB activated by PDT, have been shown to exhibit the highest antimicrobial potency, improved capacity for SL removal and improved PBS.

Anchorage loss of the posterior teeth under different extraction patterns in maxillary and mandibular arches using clear aligner: a finite element study

BackgroundExtracting 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.MethodsTwo 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.ResultsCompared 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.ConclusionsThe 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.

Wide Restorative Emergence Angle Increases Marginal Bone Loss and Impairs Integrity of the Junctional Epithelium of the Implant Supracrestal Complex: APreclinical Study.

To assess the influence of the emergence angle on marginal bone loss (MBL) and supracrestal soft tissue around dental implants. In six mongrel dogs, the mandibular premolars and molars were extracted. After 3 months of healing, four dental implants were placed in each hemimandible. The implants were randomly allocated to receive one of four customized healing abutments, each with a different value of the restorative emergence angle: 20°, 40°, 60° or 80°. Intra-oral radiographs were taken after placing the healing abutments and at 6, 9, 16 and 24 weeks of follow-up. Then, micro-CT and undecalcified histology and synchrotron were performed. MBL over time was analysed with generalized estimating equations (GEEs) and adjusted for baseline soft-tissue thickness. From implant placement to 24 weeks, GEE modelling showed that the MBL at mesial and distal sites consistently increased over time, indicating MBL in all groups (p < 0.001). The model indicated that MBL varied significantly across the different restorative angles (angle effect, p < 0.001), with 80° showing the greatest bone loss. Micro-CT, histology and synchrotron confirmed the corresponding trends and showed that wide restorative angles (60° and 80°) impaired the integrity of the junctional epithelium of the supracrestal tissue. A wide restorative angle increases MBL and impairs the integrity of the junctional epithelium of the implant supracrestal complex.

Influence of Endodontic Cavity Design on Interfacial Voids, Class II Resin Composites Sealing Ability and Tooth Fracture Resistance: An In Vitro Study.

Objective: The aim of this in vitro investigation is to study the effect of endodontic cavity design on interfacial voids, class II resin composite sealing ability, and fracture resistance in mandibular premolars. Methods: A total of 48 single-rooted mandibular premolars received compound class II preparations with either traditional flare access cavities (group A) or contracted endodontic cavity preparations (group B). Each study group was subdivided according to the coronal restoration into two sub-groups as α and β. In the α group, a microhybrid composite was used after etch-and-rinse bonding technique using an MDP-containing universal adhesive. In the β group, a self-adhesive composite was used as coronal restoration after endodontic treatment (n = 12) for each subgroup. A micro-CT analysis was performed to assess the obturation interfacial voids and tracing of class II cervical interfacial adaptation. The tooth fracture resistance testing was then performed adding an extra group of 12 sound non-prepared teeth, which were tested as the control for fracture strength testing. A one-way ANOVA and post-hoc testing were used together with descriptive statistics for an analysis of the mean values of obturation interfacial voids. A two-way ANOVA was used to assess the fracture resistance test results, and to find the influence of endodontic access design and the type of composite material on the fracture resistance testing. Chi-square testing was employed to analyze the cervical interfacial seal of the class II restorations. Results: A one-way ANOVA revealed that there were no statistically significant differences between test groups in the amount of obturation interfacial voids (p > 0.05). There were no statistically significant differences between test groups in terms of cervical interfacial sealing ability (p > 0.05). A two-way ANOVA revealed that no statistically significant differences between test groups including the control group existed in terms of the fracture resistance testing (p > 0.05). Conclusions: Although it does not improve tooth fracture resistance, the contracted endodontic access cavity does not deteriorate the quality of obturation in terms of the interfacial porosity. The self-adhesive composite does not improve the efficiency of cervical interfacial adaptation or tooth fracture resistance regardless of the endodontic access cavity shape, yet it revealed a substantial load-bearing capacity.

Periodontal Ligament Reactions to Orthodontic Force: A Transcriptomic Study on Maxillary and Mandibular Human Premolars.

Orthodontic force (OF) induces a variety of reactions in the periodontal ligament (PDL) that could potentially account for individual variability regarding orthodontic tooth movement (OTM). This study investigates the transcriptomic profile of human PDL tissue subjected to OF invivo for 7 and 28 days, additionally comparing the differences between maxillary and mandibular PDL. Healthy patients requiring orthodontic premolar extractions were randomly assigned to one of three groups: control (CG) where no OF was applied, 7 days and 28 days, where premolars were extracted either 7 or 28 days after the application of a 50-100 g OF. Total RNA was extracted from the PDL tissue and analyzed via RNA-seq. Differentially expressed genes (DEGs) were identified using a false discovery rate and fold change threshold of < 0.05 and ≥ 1.5 respectively. Functional and Protein-Protein Interaction analysis were performed. After 7 days of OF, the reaction of PDL to OF is characterized by cell responses to stress, increased bone resorption, inflammation and immune response, and decreased bone formation. In contrast, after 28 days, bone regeneration is more prominent, and processes of bone homeostasis, immune response, and cell migration are present. The response of maxillary and mandibular PDL was different. Bone resorption was observed in the maxilla at 7 and 28 days, while in the mandible expression of cell proliferation and transcriptional activity were predominant after 28 days of OF. The early reaction of the PDL to OF corresponds with increased bone resorption and decreased bone formation. After 28 days, bone formation became more prominent. The maxillary and mandibular PDL present asynchronous responses during OTM. These findings enhance our comprehension of the mechanisms underlying the origin-specific responses of PDL to different lengths of OF, which is potentially relevant in the development of personalized therapeutic strategies.

Root Canal Morphology of Premolars in Population of Hyderabad, Pakistan: A Cone Beam Computerised Tomographic Analysis.

To investigate the mean tooth length and root canal configuration of human maxillary and mandibular premolars in the population of Hyderabad, Pakistan, using Cone Beam Computed Tomography (CBCT). Observational study. Place and Duration of the Study: Department of Operative Dentistry and Endodontics, Liaquat University of Medical and Health Sciences, Jamshoro, Sindh, Pakistan, from December 2022 to March 2023. Using retrospective analysis of CBCT scans, tooth length, the number of roots, and root canal configuration of 536 mandibular and maxillary premolars were assessed in the subpopulation of Pakistan. The data were analysed employing descriptive statistics, Chi-square tests, and One-Way ANOVA to determine the association between various factors and root canal morphology. Vertucci Type 1 (one canal) was the most common configuration in maxillary premolars, with frequencies ranging from 46.3 to 52.2%. The mean length of all 8 premolars ranged from 20.56 mm to 21.58 mm. C-shaped canal configurations were observed in a small percentage of maxillary and mandibular premolars, with C1 being the most common. No significant association was found between gender and canal configuration or tooth length, and in tooth lengths among different canal configurations. Vertucci Type 1 was the most common configuration in maxillary premolars, followed by Vertucci Type 4. Single-rooted premolars were more prevalent, while two-root configurations were less common. C-shaped canal configurations were observed in a small percentage of premolars, with higher frequency in mandibular premolars. Cone beam computed tomography, Dental anatomy, Endodontics, Premolars, Root canal morphology.

Colloidal platinum nanoparticles enhance resin-dentin bonding durability

ObjectivesThis study aims to investigate the effect of colloidal platinum nanoparticles (CPN) on the durability of resin-dentin bonding performance with contemporary adhesives. MethodsSixty non-carious human maxillary premolars were subjected to microtensile bond strength (µTBS) testing and divided into two main groups: CPN-treated and untreated. Within each group, specimens were randomly allocated to Clearfil Megabond 2 (MB2), Scotchbond Universal Plus Adhesive with self-etch mode (SE-SUP), and etch-and-rinse mode (ER-SUP) subgroups (n = 10/group). CPN was applied to dentin in the MB2 and SE-SUP groups for 20 s, followed by rinsing before adhesive application. In the ER-SUP group, CPN was applied after etch-and-rinse. The µTBS was tested after 24 h, 6 months, and 1 year, and the fracture modes were observed using SEM. The µTBS data were analyzed using a two-way ANOVA and post-hoc Tukey HSD test (α = 0.05). An additional twelve premolars underwent TEM/STEM/EDX for ultra-morphological observations. ResultsThe application of CPN significantly prevented a decline in the µTBS of both the MB2 and SE-SUP groups. No significant decrease was observed in the ER-SUP group, either with aging or CPN application. Ultra-morphological images revealed platinum nanoparticles attaching to the collagen fibrils of the hybrid layer regardless of aging. It was highlighted that the nanoparticles attached to the banded collagen in the aging groups were observed. SignificanceCPN exhibits the potential in enhancing the longevity of resin-dentin bonding in SE mode.

Comparative evaluation of wettability of AH plus, Ceraseal and Guttaflow bioseal root canal sealers on root canal dentin: An in vitro study

Abstract Context: Effective root canal treatment relies on the ability of sealers to wet and penetrate the root canal system, ensuring a tight seal and preventing bacterial leakage. The current study investigates the wetting ability of newer root canal sealers by evaluating their contact angle. Aim: The objective of the present study was to evaluate and compare the wetting behavior of Guttaflow bioseal, Ceraseal, and AH plus root canal sealers. Materials and Methods: Decoronation and apical third resections of thirty extracted singlerooted human mandibular premolars were done. The roots were then split longitudinally into two halves buccolingually. The root dentin surfaces were treated using 10 mL 3% sodium hypochlorite for 5 min, 10 mL of 17% ethylenediaminetetraacetic acid for 5 min, and 2% chlorhexidine for 10 min. Then, these sixty dentin bars were randomly divided into three groups (n = 20): Group 1 – AH Plus, Group 2 – Ceraseal, and Group 3 – Guttaflow bioseal. The controlled volume of 0.1 mL sealer has been dispensed onto the dentin specimen using a micropipette. The contact angle of a drop of sealer was measured after 5 min using Ossila goniometer. Statistical Analysis Used: The data were analyzed using one-way analysis of variance and Tukey post hoc tests. The statistical significance was at P &lt; 0.05. Results: The mean contact angle values for AH Plus sealer were lower when compared to the other two sealer groups which is statistically highly significant. Conclusions: AH Plus showed lesser contact angle thereby better wettability than Ceraseal and Guttaflow bioseal on the root canal dentin surface.

A confocal laser scanning microscopic analysis of efficacy of different activated irrigants in the removal of calcium hydroxide medicament and subsequent penetrability of Bio-C sealer – An in vitro study

Abstract Aim: The aim of the study was to investigate the efficacy of different irrigants activated by pro-agitator tip system (PATS) Vario on the removal of calcium hydroxide medicament and subsequent penetration depth of Bio-C sealer. Materials and Methods: Fifty single-rooted mandibular premolars were selected. Access cavities were prepared; biomechanical preparation was done. Metapex that had been combined with rhodamine B dye was used to fill each sample. All the samples were divided into five groups (n = 10) – Group I: chitosan–citrate, Group II: intracanal heated sodium hypochlorite (NaOCl), Group III: phytic acid, Group IV: SmearClear, and Group V: saline. All samples were obturated using gutta-percha and Bio-C sealer (combined with fluorescein dye). Later, all samples were sectioned at 3, 6, and 9 mm from the apex and observed under a confocal microscope for residual Ca(OH)2 and sealer penetration into dentinal tubules. Results: The saline group exhibited the least amount of sealer penetration and high residual Ca(OH)2, both of which were statistically significant (P ≤ 0.05). Conclusion: The use of PATS Vario for irrigant activation enhanced the calcium hydroxide removal efficacy and penetration of Bio-C sealer into dentinal tubules. The elimination of calcium hydroxide and sealer penetration, from the apical region of the tooth, can be accelerated by intracanal heating of NaOCl.

Effects of Time-Elapsed Bleaching on the Surface and Mechanical Properties of Dentin Substrate Using Hydrogen Peroxide-Free Nanohydroxyapatite Gel.

There is a critical need to address concerns surrounding the potential impact of bleaching gels specifically on the tooth substrate. Therefore, this laboratory investigation aimed to assess the impact of a hydrogen peroxide (HP)-free bleaching (HiSmileTM) in comparison to an HP-based bleaching (Opalescence RegularTM) on the surface and mechanical characteristics of tooth substrate. Sixty sound human premolar teeth were sectioned to produce dentin fragments and divided into two primary groups based on the bleaching agent used. Each group was subdivided into three subgroups (n = 10) per distinct bleaching regimens: (T1) fragments underwent a 7-day immersion in distilled water at 37°C without any bleaching treatment, (T2) fragments underwent a 7-day immersion in distilled water at 37°C, with the application of bleaching gel occurring on the seventh day for 10minutes, and (T3) fragments underwent a bleaching regimen for seven consecutive days, each session lasting for 10minutes. The initial and final evaluations of surface roughness, nano-hardness, and elastic modulus were performed. Following the bleaching regimens of T3, a composite stub was fabricated on the dentin fragments for the shear bond strength (SBS) test. Statistical testing was accomplished using the analysis of variance (P < 0.05). HP-based bleaching gel showed significant differences between measurement intervals in surface roughness, elastic modulus, and SBS parameters (P < 0.05). In contrast, HP-free bleaching gel showed insignificant differences within the group (P > 0.05). The SBS between dentin-composite was significantly affected with the use of HP-based bleaching gel, while HP-free bleaching gel showed insignificant difference between measurement intervals. The qualitative validation of the treatment's impact was further demonstrated using the scanning electron microscopy. The findings suggest that the bonding stability of composite restorations to dentin may be compromised after bleaching with an HP-based gel, whereas immediate bonding procedures can be safely conducted following the application of an HP-free bleaching gel.

The chromatograph evaluation of white spot lesion treated with magnesium gel and diode laser: an in vitro study

Objective. White spot lesions are one of the most common concerns of orthodontic therapy. The present study was accomplished to evaluate the ability of Magnesium gel at different concentration and diode laser in combination compared with commercially available 1.23% APF in color restoring of WSL on permanent teeth. Methods. 42 extracted sound upper premolar teeth were recruited for this study. WSL was artificially induced, until it appears in wet and dry condition on buccal surface of each tooth. Different approaches have been utilized for treatment WSL. 6 experimental groups were involved: Group A: Control, Group B: 0.5%MgCl2 gel, Group C: 1%MgCl2 gel, Group D: 0.5%MgCl2 gel and Diode laser, Group E: 1%MgCl2 gel and Diode laser and Group F: 1.23%APF. The difference between the displayed color and the original color standard (ΔE) was assessed by colorimeter. The surface topography of teeth samples from each tested group was examined by a SEM. Collected data were investigated using one-way ANOVA followed by Duncan post hoc test at p ≤0.05. Result. A significant difference in (ΔE) was noticed among groups (p = 0.006). Group (B) showed the lowest ΔE value (9.4 ± 1.6), followed by group (D) (10.2 ± 1.1), group (F) (10.4±2.6), group (A) (11.6 ± 1.3), group (C) (12.9 ± 2.3) and group (E) (13.2 ± 1.3). Conclusion. In present study, topical application of 0.5% MgCl2 gel ensure color reinstating compared to other groups.

Evaluation of the Remineralization Potential of an Herbal Non-fluoridated Dentifrice on Carious Lesions: An In Vitro Study

Background: This in vitro study compared the remineralization potential of Dabur red (DR), a non-fluoridated herbal toothpaste, with Colgate Strong Teeth (CST), a fluoride-based toothpaste, on permanent teeth with artificially created white spot lesions. Vickers microhardness (VMH), quantitative light-induced fluorescence system (QLF), and scanning electron microscopy (SEM) were used for data analysis. Methods: Enamel samples were prepared from the buccal surface of forty-five extracted maxillary premolars and subjected to demineralization to achieve adequate fluorescence loss (ΔF). The samples were divided into DR, CST, and control groups (n=15) and underwent 21 days of pH cycling. VMH was measured at baseline and after 21 days. QLF imaging was performed on days 7, 14, and 21. One randomly selected sample from each group underwent SEM examination to compare morphological variations. The statistical analysis was conducted using SPSS 22.0. Intra-group comparisons were made with repeated measures of analysis of variance (ANOVA), and one-way ANOVA with Tukey’s post-hoc test was utilized for inter-group comparisons (P&lt;0.05). Results: Mean VHN increased significantly in all three groups from baseline (DR=40.47, CST=41.91, control=36.42) to the 21st day (DR=119.47, CST=120.36, control=74.36) (P=0.00). Significant differences were found between the control and test groups, but not between DR and CST. No statistically significant difference was observed in ΔF at baseline and 7 days, but there were significant differences among the groups at 14 and 21 days. SEM images revealed dense mineralization for both DR and CST. Conclusion: After 21 days of in vitro remineralization, both DR and Colgate toothpaste demonstrated similar remineralizing potential as evaluated by surface MH and QLF.