Multiple PDT sessions with chlorin-e6 and LL-37 loaded-nanoemulsion provide limited benefits to periodontitis in rats.

Background: The combination of photodynamic therapy (PDT) and LL-37 has never been tested in an animal study and our research team background suggests this strategy might be a promising alternative to intensify periodontitis resolution. This study aimed to assess the effects of multiple sessions of PDT with chlorin-e6 conjugated to the antimicrobial peptide LL-37 loaded nanoemulsion, as adjunctive therapy in experimental periodontitis in rats.

Methods: Experimental periodontitis was induced in 81 rats.

Enamel caries lesions, with and without initial cavitation, in relation to anatomical areas of the proximal surface in deciduous molars.

Objective: proximal enamel caries lesions (PEC) are believed to initiate and progress to cavitation below the proximal contact area (PCA), but no evidence exists on the location of initial carious cavitation on the proximal surface with functional PCA. This study aimed to test the association of anatomical areas of the proximal surface with the severity of PEC and the frequency of cavitation in PEC in primary molars DESIGN: laboratory, observational, transversal study. Exfoliated primary molars (n = 33) with functional PCA (biofilm-free PCA surrounded by biofilm) had their proximal surfaces (one/tooth) divided anatomically into up to nine areas: 3 areas based on the occlusal/cervical PCA boundaries (areas I, II, and III; occluso-cervically) and 3 areas based on the bucco/lingual PCA boundaries (A, B, and C), with area IIB representing the PCA and area IIIB as the sub-PCA (below the PCA).

Root canal curvature influences uncontrolled removal of dentin and cleaning efficacy after ultrasonic activation.

This study evaluated the correlation between root canal curvature and the effects of ultrasonic irrigation in the following parameters: volume of uncontrolled dentin removal (UDRVol), maximum depth of dentin defects, removal of accumulated hard tissue debris (AHTD), and canal transportation in prepared curved root canals. Twenty-four human permanent mandibular molars were divided into two groups according to root canal curvature: moderate curvature (MC: mean 25°); and severe curvature (SC: mean 48°). The specimens were scanned using an X-ray microcomputed scanner (Skyscan 1172) before and after cleaning and shaping and after the final irrigation protocol with ultrasonic irrigation.

Fluorotic Enamel Susceptibility to Dental Erosion and Fluoride Treatment.

The purpose of this in vitro study was to test the hypothesis that fluoride treatment can prevent dental erosion on fluorotic enamel of different severities. It followed a 3×2 factorial design, considering a) fluorosis severity: sound (TF0, Thylstrup-Fejerskov Index), mild (TF1-2), moderate (TF3-4); and b) fluoride treatment: 0 (negative control) and 1150ppmF. Human molars with the three fluorosis severities (n=16, each) were selected and randomly assigned to the two fluoride treatments (n=8).

Effect of Three Chemical Agents on Stain Removal from Dentin Caries Lesions Treated with Silver Diamine Fluoride.

Introduction: This in vitro study aimed to evaluate the effect of three different chemical agents on stain removal and mineral uptake of artificial dentin caries (ADC) lesions treated with silver diamine fluoride (SDF).

Methods: Baseline L*a*b* values were determined in polished human permanent dentin blocks, and ADC lesions were induced with an acid gel for 1 week. Samples were assigned to four groups; in three groups, half of each sample received SDF (30% SDF for 3 min), while the other half received SDF followed by a bleaching treatment protocol (garlic extract, bentonite, or 35% hydrogen peroxide).

Susceptibility of fluorotic enamel to dental erosion-abrasion.

Dental hard tissue conditions can be of pre- or post-eruptive nature, such as enamel fluorosis and erosive tooth wear (ETW), respectively. Dental enamel fluorosis is caused by the chronic and excessive intake of fluoride during enamel development, leading to increased fluoride concentration and increased porosity. ETW has become a common clinical condition and often impairs dental function and aesthetics.

Effect of multidrug solution for the treatment of chemotherapy-induced oral mucositis .

Objective: Evaluate the effect of a multidrug solution, adopted by a referral hospital for cancer to control and treat chemotherapy-induced oral mucositis in rats.

Methods: Oral mucositis (OM) was induced by 5-Fluorouracil (5-FU), and the animals were treated with saline (n = 8, G1), 0.12% chlorhexidine (n = 8, G2); and multidrug solution (n = 8, G3).

Influence of carbonated acid beverage on fracture resistance and marginal gap formation in different restorative approaches to non-carious cervical lesions.

Objective: This study is to evaluate fracture resistance, failure mode, and gap formation at the restorative interface of unrestored or restored non-carious cervical lesions (NCCLs) submitted to a short-term erosive environment.

Materials And Methods: Artificial NCCLs were produced in vitro in bovine incisors, and were randomly divided into four restorative resins groups (n = 22): nanohybrid-NR; bulk-fill-BR; flow with a nanohybrid layer-FNR; bulk-fill with a nanohybrid layer-BNR; and a group unrestored-UR (n = 16). Half of the specimens were submitted to an erosive challenge (per 5 min, 3 × a day for 7 days, before and after restoration), and the other half, was immersed in artificial saliva.

Organic volume and permeability variations in the surface layer of artificial and natural enamel carious lesions.

Objectives: Test the hypothesis the type of enamel caries (natural, artificial induced by gel, and artificial induced by acid solutions) affect the organic volume and the permeability of the surface layer in enamel caries lesions.

Design: Artificial enamel caries, induced by either acidic solution (organic-poor; Group 1) or acidic gel (organic-rich; Group 2), and natural non-cavitated inactive approximal enamel caries lesions (NEC; Group 3) were obtained, from which longitudinal ground sections were prepared. Measurements of the mineral (V) (by microradiography), and water (α) and organic (β) volumes (by optical birefringence) were obtained at three points in the surface layer (n = 30/group).

Improved mineralization of dental enamel by electrokinetic delivery of F and Ca ions.

This in vitro study evaluated the effects of the infiltration of F and Ca ions into human enamel by electrokinetic flow (EKF) on the enamel microhardness and F content. Sound human enamel ground sections of unerupted third molars were infiltrated with de-ionized water by EKF and with F ion by EKF respectively. All samples were submitted to two successive transverse acid-etch biopsies (etching times of 30 s and 20 min) to quantify F ion infiltrated deep into enamel.

New Theory Illustrates the Formation of Enamel CUP-Shaped Lesions on Occlusal Surfaces.

We propose a new theory for enamel cupping lesions formation. At early stages, naturally formed cupping lesions showed increased porosity at two structural prismatic traits: the central cone extending into the enamel-dentine junction and the type-I Hunther-Schreger bands (HSB), suggesting them to be the main drivers for cupping lesion formation and development. In addition, these lesions were circumscribed by type-II HSBs, which present lower surface porosity and higher resistance to wear.

Structure and Chemical Composition of ca. 10-Million-Year-Old (Late Miocene of Western Amazon) and Present-Day Teeth of Related Species.

Molecular information has been gathered from fossilized dental enamel, the best-preserved tissue of vertebrates. However, the association of morphological features with the possible mineral and organic information of this tissue is still poorly understood in the context of the emerging area of paleoproteomics. This study aims to compare the morphological features and chemical composition of dental enamel of extinct and extant terrestrial vertebrates of Crocodylia: Purussaurus sp.

Comparison of Self-Etching Adhesives and Etch-and-Rinse Adhesives on the Failure Rate of Posterior Composite Resin Restorations: A Systematic Review and Meta-Analysis.

The aim of this study was to perform a systematic review with meta-analysis on the comparison of self-etching adhesives and etch-and-rinse adhesives with respect to the failure rate of posterior composite resin restorations. The study protocol was registered in PROSPERO (CRD42017078015), following PRISMA recommendations and PICO search strategy. Literature search was performed in the following databases: MEDLINE, ISI Web of Science, LILACS, SCOPUS, and Cochrane Library through July 2021.

Comparative Analysis of Continuous versus Reciprocating Instruments in Retreatment of Flat-oval Root Canals.

Introduction: Flat-oval root canals of incisors can be problematic in retreatments. This study assessed the efficacy of continuous and reciprocating rotation instruments in retreatment of flat-oval root canals in lower incisors via micro-computed tomography (micro-CT). File systems studied were ProTaper universal retreatment rotary system associated with ProTaper Next (PTUR+PTN), D-RaCe associated with iRaCe (DR+iR), Reciproc (REC), and WaveOne (WO).

Development of castor polyurethane scaffold (L.) and its effect with stem cells for bone repair in an osteoporosis model.

The development of 'smart' scaffolds has achieved notoriety among current prospects for bone repair, especially for chronic osteopathy, such as osteoporosis. Millions of individuals in the world suffer from poor bone healing due to osteoporosis. The objective of this work was to produce and characterize castor polyurethane (PU) scaffolds (L.

Shaping efficiency of XP-endo shaper and Mtwo instruments in long oval root canals: A micro-CT study.

This study evaluated the shaping ability of XP-endo Shaper and Mtwo systems in long-oval-shaped canals of extracted human mandibular molars using micro-computed tomography (micro-CT). Images recorded before and after preparation were evaluated for morphometric measures regarding increase in canal volume, dentin removed, surface area, untouched walls and structure model index (SMI). Data were statistically analysed using the Mann-Whitney test with 5% of significance.

The effect of high concentration of zoledronic acid on tooth induced movement and its repercussion on root, periodontal ligament and alveolar bone tissues in rats.

Zoledronic acid (ZA) is often prescribed for osteoporosis or resorptive metabolic bone disease. This study aims to evaluate the effect of ZA on orthodontic tooth movement (OTM) and root and bone resorption and its repercussion on root, periodontal ligament and alveolar bone tissues. The experimental group consisted of 72 Wistar rats divided in four subgroups: Naive, Saline and Zoledronic Acid groups at the concentration of 0.

Susceptibility of Dental Enamel of Different Ages to Caries-Like Lesion Development.

This study investigated the impact of estimated age, anatomical location, and the presence of wear facets on the susceptibility of enamel to develop caries-like lesions. Extracted human premolars (n = 261) had their age estimated between 10 and 93 years old, using established forensic methods. Specimens of enamel (4 × 4 mm) were prepared from the middle of the buccal surfaces, preserving the outer surface layer.

Orofacial antinociceptive activity and anchorage molecular mechanism in silico of geraniol.

We aimed to evaluate the orofacial antinociceptive effect of geraniol in mice and its molecular anchorage mechanism. Seven mice per group (probabilistic sample) were treated with geraniol (12.5, 25 and 50 mg/kg, i.

Variation in mineral, organic, and water volumes at the neonatal line and in pre- and postnatal enamel.

Objetives: The neonatal line (NNL) in enamel is hypomineralized, but quantitative data on the enamel component volumes of the NNL are lacking. This study aimed at quantifying the variation in the mineral, organic, and water volumes at the NNL and in pre- and postnatal enamel.

Materials And Methods: In buccal enamel longitudinal ground sections of exfoliated primary incisors (upper and lower; n = 17), the enamel component volumes were quantified at five histological sites (located at 40 μm intervals along a transversal line): the NNL, two sites in prenatal enamel, and two sites in postnatal enamel.

Morphologic Changes of Apical Foramen and Microcrack Formation after Foraminal Enlargement: A Scanning Electron Microscopic and Micro-computed Tomographic Analysis.

Introduction: The aim of the present study was to evaluate the morphologic changes on the apical foramen and the formation of dentinal microcracks after foraminal enlargement in straight and curved root canals using scanning electron microscopic (SEM) and micro-computed tomographic (micro-CT) analyses.

Methods: Sixty teeth were selected and divided into 2 experimental groups: GI (incisors/straight group, n = 30) and GM (molars/curved group, n = 30). Each group was divided into 2 subgroups (n = 15) according to the analysis performed: SEM or micro-CT analysis.

Microtomographic analysis of the effect of sodium alendronate on orthodontic movement in rats.

Objective: To evaluate the effect of sodium alendronate on orthodontic tooth movement in rats using microtomographic analysis.

Settings And Sample Population: Thirty male Wistar rats (Rattus norvegicus) were divided into three groups of 10 rats and administered saline (control), 1 mg/kg sodium alendronate or 6 mg/kg sodium alendronate, respectively.

Materials And Methods: The drug was administered once per week for 5 weeks by gavage.

Deformation behavior of normal human enamel: A study by nanoindentation.

Tooth enamel has an important mechanical function for human dental health, yet characterizing its mechanical properties is not trivial due to its complex nanoporous structures. We examined the distribution of hardness and modulus across the lingual-buccal enamel cross-section by nanoindentation. At the occlusal surface, the hardness and modulus of enamel were found to be 5.

Hydrolytic degradation of different infiltrant compositions within different histological zones of enamel caries like-lesions.

This study evaluates the effects of resin infiltrant composition and caries histological zone on the hydrolytic degradation of resininfiltrated artificial bovine enamel caries (RI-AEC). Different resin infiltrants were tested (n=26 per group): Icon (G1); TEGDMA 60%, UDMA 20%, and HEMA 20% (TUH); TEGDMA 80% and HEMA 20% (TH); and TEGDMA 75% and Bis-EMA 25% (TB). Following caries infiltration, samples were cut perpendicularly, and transverse microhardness were analyzed (at two histological zones: surface layer and lesion body) before and after 21 days of water immersion.