Effect of coenzyme Q10 on tibial fracture resistance in nicotine-exposed rats.

The study aimed to evaluate the potential protection against fractures of oral Q10 supplementation in the tibias of rats exposed to nicotine. Nicotine is known to negatively impact bone density and increase the risk of fractures, in addition to affecting other systems such as the gastrointestinal system, impairing its absorption capacity, negatively affecting bone health. To investigate this, eighty male rats were divided into four groups (n = 20) receiving either nicotine hemisulfate or saline solution (SS) for 28 days. Two daily subcutaneous applications were administered accordingly. Concurrently, vegetable glycerin and Q10 gavage began on day "0". SS: the animals in this group received two daily subcutaneous applications of sodium chloride solution during the entire trial period. 30 days after starting the SS applications subcutaneously, the animals received vegetable glycerin daily until the end of the experiment. SS-Q10: the animals received the SS protocol and daily supplementation with Q10 until the end of the experiment. NIC: The animals received the protocol for NIC and vegetable glycerin daily until the end of the experiment. NIC-Q10: The animals received the protocol for NIC and daily supplementation and Q10 until the end of the experiment. Euthanasia occurred at 7 and 28 days after the beginning the gavage. The tibiae collected were processed for morphometric, densitometric, mechanical, and microtomographic (micro-Ct) analysis. A complementary analysis of intestinal changes was performed. The groups that received Q10 showed slightly better results regarding the mechanical resistance and micro-Ct parameters and to intestinal histomorphometry, as compared with groups not supplemented with Q10. Thus, in rats, it can be concluded that coenzyme Q10 exhibited a protective property to the skeletal system and the gastrointestinal tract, even in the presence of nicotine.

Micro-computed tomographic evaluation of dentinal microcracks in response to progressive taper enlargement in root canals of maxillary molars.

AIM: To investigate the development of dentinal microcracks resulting from the progressive enlargement of the buccal canals of maxillary molars with and without the MB2 canal employing instruments with the same tip and four different tapers. METHODOLOGY: Twenty maxillary molars with (n = 10) and without (n = 10) the MB2 canal underwent micro-CT scanning. Their mesiobuccal and distobuccal canals were sequentially enlarged using nickel-titanium instruments with sizes 25/.03, 25/.05, 25/.06 and 25/.08v. Subsequent scans were conducted after each canal enlargement. The preoperative scans were coregistered with their respective datasets, and the cross-sectional images were carefully examined to identify dentinal defects. This process, conducted twice at two-week intervals, involved two examiners. Intra- and inter-examiner calibrations were validated using the Kappa index. The incidence of microcracks was reported as a percentage frequency. RESULTS: The intra- and inter-examiner Kappa values were 0.85 and 0.88, respectively, indicating excellent agreement. Dentinal microcracks were detected in 1206 out of 42 975 cross-sectional image slices (2.8%). Molars with MB2 canal exhibited more slices (4.5%) than teeth without MB2 (0.9%). Every dentinal microcrack observed in the images after root canal preparation was already present in the corresponding images taken before root canal preparation. CONCLUSION: The progressive enlargement of root canals using instruments with different tapers did not induce the formation of new dentinal microcracks in maxillary molars, regardless of the presence of the MB2 canal.

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). PEC (ICDAS scores 1 and 2-3) and cavitation in PEC were quantified in all areas using stereomicroscopy and microCT. PEC volume was quantified in areas IIB and IIIB under microCT RESULTS: PEC severity increased occluso-cervically. PCA and sub-PCA presented different PEC severities (higher in sub-PCA) and similar PCE volumes, but the odds of carious cavitation were much higher (Odds ratio = 197.4; 95 % CI: 8.7/4480.7) in the PCA than in the sub-PCA (no cavitation). CONCLUSION: PCA presented lower PEC severity and similar PEC volume compared to sub-PCA, but PCA concentrated all cavitations in PEC, supporting a new model for the pathogenesis of PEC.

Experimental Periodontitis Worsens Dopaminergic Neuronal Degeneration.

AIM: To investigate the hypothesis supporting the link between periodontitis and dopaminergic neuron degeneration. MATERIALS AND METHODS: Adult male Wistar rats were used to induce dopaminergic neuronal injury with 6-hydroxydopamine (6-OHDA) neurotoxin and experimental periodontitis via ligature placement. Motor function assessments were conducted before and after periodontitis induction in controls and 6-OHDA-injury-induced rats. Tissue samples from the striatum, jaw and blood were collected for molecular analyses, encompassing immunohistochemistry of tyrosine hydroxylase, microglia and astrocyte, as well as micro-computed tomography, to assess alveolar bone loss and for the analysis of striatal oxidative stress and plasma inflammatory markers. RESULTS: The results indicated motor impairment in 6-OHDA-injury-induced rats exacerbated by periodontitis, worsening dopaminergic striatal degeneration. Periodontitis alone or in combination with 6-OHDA-induced lesion was able to increase striatal microglia, while astrocytes were increased by the combination only. Periodontitis increased striatal reactive oxygen species levels and plasma tumour necrosis factor-alpha levels in rats with 6-OHDA-induced lesions and decreased the anti-inflammatory interleukin-10. CONCLUSIONS: This study provides original insights into the association between periodontitis and a neurodegenerative condition. The increased inflammatory pathway associated with both 6-OHDA-induced dopaminergic neuron lesion and periodontal inflammatory processes corroborates that the periodontitis-induced systemic inflammation may aggravate neuroinflammation in Parkinson's-like disease, potentially hastening disease progression.

Topological analysis of the three-dimensional radiodensity distribution of fish otoliths: Point sampling effects on dimensionality reduction.

Otoliths are calcified structures found in the inner ears of teleost fish, pivotal in marine biology for studies on metabolism, age, growth, and the identification of fish stocks, potentially leading to sustainable management practices. An important feature of this structure is its density, as it corresponds to modifications in the crystalline form of calcium carbonate during the fish's lifetime, resulting in variations in its final shape. The internal and external 3D radiodensity of otoliths from different species was obtained utilizing micro-computed tomography, however, an appropriate methodology for describing and conducting comparative studies on these data appears to be absent in the current body of literature. Therefore, we study otolith density variations from 3D computed tomography images, employing the Ball Mapper technique of Topological Data Analysis. We focus on reducing the computational cost of this analysis by applying probabilistic sampling and assessing its effects on the density variations provided by the Ball Mapper graph. To determine the sample size, we used the topology to establish what we term "Topological Sample Validation", which provided the minimum resolution with the same density information as raw data. Sample representativeness was validated through non-parametric statistical tests on the density variable. Based on the network's structural characteristics, network properties allowed for evaluating similarity between graphs. Besides the small sample size, remarkable correlations were obtained between age and network variables. Additionally, the Ball Mapper technique proved effective as a preprocessing algorithm for tomographic images, enabling the segmentation of undesired features in the object of interest.

Study protocol on the impact of postnatal maternal separation stress on dental enamel formation in a murine experimental model.

Dental development is a complex process influenced by genetic and environmental factors. Dental enamel, primarily composed of hydroxyapatite, is formed through complex cellular and biochemical mechanisms. Although this is a stable process, genetic, nutritional, and environmental factores can lead to developmental defects such as hypomineralization and hypoplasia. Molar incisor hypomineralization is a type of hypomineralization that represents a public health challenge. Its etiology is not yet fully understood, but factors such as hypoxia, medication exposure, adverse events in early childhood, and genetic influences are considered. This study protocol aims to investigate whether postnatal adverse events can impact amelogenesis, exploring the role of stress in the etiology of dental enamel defects. Specific objectives include evaluating enamel structure and mechanical properties by comparing the offspring of rats exposed to postnatal maternal separation with control animals (non-exposed). Additionally, we will evaluate weight, length, survival assessment, and developmental milestones between the groups. Macrophotographic analysis, microtomography, microhardness testing, and electron microscopy will enable a detailed assessment of enamel morphology and its mechanical properties. Histological and molecular analyses-such as immunohistochemistry, indirect immunofluorescence, and in situ zymography-will be performed to evaluate possible changes in proteins and enzymes that are essential for proper enamel biomineralization.

Ionizing radiation effects on osseointegration: a pre-clinical study.

The purpose of this study was to evaluate the effect of a single dose of ionizing radiation (30 Gy) on the osseointegration of implants in the rabbit tibia. Twenty rabbits received two dental Morse-tapered junction implants and one implant in each tibia. The animals were randomly divided into two groups (n=10), non-irradiated (NoIr) and irradiated (Ir), wherein the Ir group received a single dose of 30 Gy radiation 2 weeks after implant installation. Microtomographic analyses (BV/TV) and histomorphometric assessments (BIC and BABT) were performed 4 weeks after implant installation. One-way ANOVA, Tukey's test, and Student's t-test (α=0.05) were used for data analysis. The results showed that BV/TV did not differ significantly between the Ir and NoIr groups (P = 0.071). In the histomorphometric analysis, neither BIC nor BABT showed significant differences between the NoIr and Ir groups (p>0.05). In conclusion, ionizing radiation in dental implants does not appear to interfere with osseointegration when installed prior to irradiation.

Socket preservation following tooth extraction: an experimental study comparing ß-Tricalcium phosphate and F18 bioglass in rats.

PURPOSE: To evaluate the efficacy of two third-generation resorbable biomaterials-F18 bioglass and ß-tricalcium phosphate (ß-TCP)-in promoting new bone formation in post-extraction sockets in rats. ß-TCP, a synthetic porous ceramic, is well-established in clinical use, while F18 bioglass, a novel silica based bioglass. METHODS: After extraction of the right upper incisor of 45 rats, the sockets were filled either with F18 or ß-TCP, or left to naturally fill with a blood clot in control group. To quantify new bone formation, five animals from each group were euthanized at 7, 14, and 28 days post-extraction. Subsequently, the hemi-maxillae were analyzed using microtomography and histomorphometry. RESULTS: Two-way ANOVA revealed significant differences in bone neoformation. ß-TCP induced notably higher levels of new bone growth compared to the control group, as evidenced by microtomographic parameters such as bone volume (p = 0.033), bone surface (p = 0.039), and trabecular thickness (p = 0.002). F18 bioglass also induced higher new bone growth compared to the control group, evidenced by bone volume (p = 0.039). Although F18 bioglass did not significantly differ from the control group in other microtomographic parameters of new bone formation, its overall performance was comparable to that of ß-TCP. CONCLUSION: ß-TCP has proven to be effective in promoting new bone formation. Although F18 bioglass did not significantly differ from the control group in several microtomographic parameters, its overall capacity to promote new bone growth was comparable to that of ß-TCP. This outcome supports the use of F18 bioglass as a promising alternative biomaterial for alveolar ridge preservation.

Vertical root fractures and cracked teeth: post-endodontic root dentinal status through micro-CT assessment after ex vivo fiber post removal.

OBJECTIVES: This study aimed to investigate cracked teeth and vertical root fracture observable on micro-CT images of extracted roots of mandibular incisors, after fiber post removal. MATERIALS AND METHODS: Thirty mandibular incisors were selected with any degree of slight incisal wear inspected with the aid of a stereomicroscope under 12x magnification, in order to have a group of young adult specimens according to the criteria of Hugoson et al. A sample of twelve mandibular incisors were selected, aged between 20 and 30 years old, with similar dentine volume and thickness. The specimens were scanned in a micro-computed tomography (micro-CT) device and submitted to root canal shaping, root canal filling, post space preparation, post placement and post removal. RESULTS: From a total of six experimental endodontic timepoints until post removal of 12 mandibular incisors, 64,800 cross-sectional images were analyzed and no vertical root fracture (VRF) or cracked tooth were detected. CONCLUSIONS: Micro-CT assessment after ex vivo fiber post removal did not detect vertical root fracture or cracked tooth formation in the root canal walls of mandibular incisors. CLINICAL RELEVANCE: This study highlighted that fiber post removal per se was not able to propagate VRF or cracked tooth formation or promoted any interruption of the integrity of human root dentin.

Histomorphometric and Micro-CT Evaluation of Cerabone and Bio-Oss in Maxillary Sinus Lifting: A Randomized Clinical Trial.

Background and Objectives: The loss of teeth in the posterior maxillary region often leads to significant alveolar bone resorption and maxillary sinus pneumatization, complicating dental implant placement. Maxillary sinus grafting, typically using autogenous bone, is a common solution. However, autogenous bone grafts require additional surgical procedures, leading to increased morbidity. This study aims to compare the efficacy of two xenografts, Bio-Oss and Cerabone, in promoting new bone formation in maxillary sinus grafting through histomorphometric analysis and micro-computed tomography (micro-CT). Materials and Methods: A total of 22 maxillary sinuses (12 right and 10 left) were grafted, with 12 using Cerabone and 10 using Bio-Oss. Six months post-grafting, biopsies were collected for histomorphometric analysis to measure new bone formation, connective tissue, and residual biomaterial. Additionally, micro-CT analysis was performed to assess bone volume fraction, trabecular thickness, number, and separation. Results: Histomorphometric analysis showed that the Cerabone group had a higher average new bone formation (25.94% ± 10.55) compared to the Bio-Oss group (17.29% ± 4.61), with a statistically significant difference (p = 0.02). Micro-CT analysis revealed that the bone volume fraction in the Cerabone group was significantly higher compared to the Bio-Oss group, with significant differences in trabecular thickness (p = 0.02) but not in trabecular number or separation. Conclusions: The study demonstrates that both xenografts are effective in promoting new bone formation in maxillary sinus grafting. However, Cerabone showed superior performance in terms of new bone formation and bone volume fraction, suggesting it may be a more effective option for maxillary sinus augmentation procedures.

Supplementary methods for filling material removal: A systematic review and meta-analysis of micro-CT imaging studies.

OBJECTIVE: To evaluate the efficacy of supplementary methods, including Passive Ultrasonic Irrigation (PUI), ultrasonic inserts, XP-Endo Finisher, XP-Endo Finisher R, Easy Clean, sonic activation, and the Er:YAG laser (SWEEPS), in removing residual filling material (RFM) during endodontic retreatment. METHOD: Five electronic databases and gray literature were searched on May 5, 2024. Two independent reviewers selected laboratory studies that assessed the efficacy of supplementary methods for RFM removal using micro-CT imaging. The methodological quality of the studies was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies. A meta-analysis was conducted to compare the pooled mean values of initial and final RFM volumes after the use of different supplementary methods. RESULTS: Thirty-two studies were included in the qualitative analysis, and seventeen were included in the meta-analyses. Only seven studies (21.9 %) fulfilled all criteria of the methodological quality checklist. No supplementary method has been able to eradicate RFM from root canals. However, the quantitative analysis demonstrated that using PUI, ultrasonic inserts, XP-Endo Finisher, and XP-Endo Finisher R instruments effectively reduced RFM (p < 0.05). In contrast, Easy Clean, sonic activation, and Er:YAG laser (SWEEPS) did not demonstrate a significant reduction (p > 0.05). CONCLUSION: Supplementary methods were unable to completely remove RFM from the canal walls during endodontic retreatment. However, the use of PUI, ultrasonic inserts, XP-Endo Finisher, and XP-Endo Finisher R instruments has been shown to significantly reduce the amount of RFM. CLINICAL SIGNIFICANCE: Clinicians are encouraged to incorporate supplementary methods for filling material removal during endodontic retreatment to enhance the cleaning of root canal walls.

Healing effect of curcumin on tooth extraction sockets in diabetic rats.

OBJECTIVE: Diabetes mellitus (DM) delays wound healing, including those following tooth extractions. Curcumin (CCM) can promote soft tissue and bone healing. The present study investigates the healing effects of CCM on tooth extraction sockets in diabetic rats. METHODOLOGY: Ninety-six male Wistar rats were divided into the following four groups: Control+Corn Oil (CO), Control+CCM, DM+CO, and DM+CCM. Each group was subdivided into 7-, 14-, and 28-day time point subgroups comprising eight rats. All animals had their maxillary first molars extracted. CCM-treated rats received 100 mg/kg of CCM orally for 7, 14, and 28 days. The lesion area was evaluated using macroscopic analyses, whereas socket healing was assessed by hematoxylin and eosin staining. Keratinocyte growth factor (KGF), Runt-related transcription factor 2 (Runx2), and collagen type I (COL1) expression levels were obtained using quantitative polymerase chain reaction (qPCR). Bone healing was analyzed by means of microcomputed tomography (µCT). RESULTS: After 7 days, the groups showed no significant differences in lesion area and by day 14, no lesions were present. CCM treatment increased KGF mRNA expression in diabetic rats; however, diabetic rats showed delayed bone healing unrelated to CCM. CCM treatment resulted in increased Runx2 mRNA expression only in control rats, whereas COL1 mRNA expression remained unaffected by CCM. CONCLUSION: CCM shows potential as a soft tissue healing enhancer in diabetic rats and could serve as an additional treatment to promote soft tissue repair in diabetic individuals. Although CCM did not impact alveolar bone healing, it may enhance bone healing in other skeleton regions.

Fish: a new xenograft source for maxillary sinus lifting.

OBJECTIVE: Although autogenous grafting is accepted as the gold standard in intraoral grafting, xenogenous grafts are frequently used in sinus lift surgeries due to their osteoinductive and osteoconductive properties. This study aimed to investigate the efficacy of fish spine-derived xenogenic grafts in sinus augmentation surgery. MATERIAL AND METHODS: In this study, a fish spine-derived xenogenic graft was produced for comparison with autogenous graft and bovine derived xenogenic grafts. Twenty-one New Zealand rabbits were used. Autogenous grafts (AG- Group 1), as well as bovine-derived (bHAP - Group 2) and fish spine-derived (fHAP - Group 3) xenogenic grafts were placed in the right and left sinuses of rabbits. The animals were sacrificed at the 4th and 8th weeks. New bone formation (NBF) was evaluated through histological examination, while bone volume (BV), new bone surface/bone volume (BS-BV), new bone surface/tissue volume (BS-TV), and trabecular separation (Tb-Sp) were assessed via Micro-CT. Statistical significance was considered at p<0.05. RESULTS: Histological examination revealed a significant difference in NBF between AG-bHAP (p<0.001), as well as between fHAP-bHAP (p<0.001) in the fourth-week group. No significant difference was found in the eighth-week group (p=0.130). In the eighth-week group, a statistically significant difference was found between fHAP and bHAP in terms of BV. (p=0.007). CONCLUSION: Although both graft materials used in this study showed positive effects on bone regeneration, fHAP and AG presented similar effects on bone regeneration and were superior to bHAP.

Refeeding partially reverses impaired fracture callus in undernourished rats.

Background: Adequate nutritional intake plays a crucial role in maximizing skeletal acquisition. The specific effects of a general food restriction and refeeding on fracture healing are yet to be fully understood. The aim of this study was to assess the impact of general food restriction and refeeding on fracture repair. Methods: Fifty-four male Wistar Hannover rats were randomly assigned into three groups: (1) Sham: Sham rats with femoral fracture; (2) FRes: Food-restricted rats with fracture, (3) Fres+Ref: Fres rats with refeeding. Following weaning, the FRes and Fres+Ref groups received 50% of the food amount provided to the Shams. In the sixth week of the experiment, all animals underwent a mid-right femur bone fracture, which was subsequently surgically stabilized. Following the fracture, the Fres+Ref group was refed, while the other groups maintained their pre-fracture diet. Bone calluses were analyzed on the fifth-day post-fracture by gene expression and on the sixth-week post-fracture using dual-energy X-ray absorptiometry, morphometry, histomorphometry, immunohistochemistry, computed microtomography, and torsion mechanical testing. Statistical significance was determined at a probability level of less than 0.05, and comparisons were made using the ANOVA test. Results: Food restriction resulted in significant phenotypic changes in bone calluses when compared to sham rats characterized by deterioration in microstructure (i.e., BV, BV/TV, Tb.N, and Conn.D) reduced collagen deposition, bone mineral density, and mechanical strength (i.e., torque at failure, energy, and stiffness). Moreover, a higher rate of immature bone indicated a decrease in bone callus quality. Refeeding stimulated bone callus collagen formation, reduced local resorption, and effectively restored the microstructural (i.e., SMI, BCa.BV/TV, Tb.Sp, Tb.N, and Conn.D) and mechanical changes (i.e., torque at failure, energy, and angular displacement at failure) caused by food restriction. Despite these positive effects, the density of the bone callus, collagen deposition, and OPG expression remained lower when compared to the shams. Gene expression analysis didn't evidence any significant differences among the groups. Conclusions: Food restriction had detrimental effects on osseous healing, which was partially improved by refeeding. Based on these findings, new research can be developed to create targeted nutritional strategies to treat and improve fracture healing.

Influence of minimally invasive cavities on color stability of dental crowns with different filling sealers.

The minimally invasive endodontic access is not directly associated with tooth discoloration in the presence of bioceramic or epoxy resin-based root canal sealers. This study aimed to evaluate the influence of minimally invasive access and endodontic sealer composition on the color stability of endodontically-treated teeth, the restorative material adaptation, and the presence of remaining filling material in the pulp chamber. Endodontic access surgery was performed in maxillary central incisors, either through conservative or minimally invasive approaches, and the root was filled with AH Plus or Bio-C Sealer. The crown color was measured with a spectrophotometer at baseline and after root obturation, restoration, and specimen storage for one year in an oven. The occurrence of voids in the restoration and the remaining filling material was analyzed using micro-CT scans. The Yellowness Index (YI) and color changes (∆E00) were calculated after each color measurement. Data of micro-CT were submitted to 2-way ANOVA, and YI and ∆E00 were analyzed with repeated-measures ANOVA. Pair-wise comparisons were performed with Tukey's test (α = 0.05). The experimental conditions had no effect on the presence of the remaining material. The minimally invasive access associated with Bio-C Sealer resulted in more voids between the restoration and the remaining filling material. Only the evaluation time affected YI and ∆E00 values. Specimens became more yellow after filling and storage in the oven (the highest ∆E00 values). The present study showed that sealer and minimally invasive cavities are not associated with crown color stability following endodontic treatment.

Microtomographic and histological evaluation of two bioceramics as pulp capping agents in vivo.

Maintaining pulp vitality and function is a priority of the medicaments employed in pulp therapy to preserve tooth integrity. Aim: This study evaluated inflammatory response and reparative dentin bridge formation after direct pulp capping with two different bioceramics. Materials and Method: This was an in vivo controlled experimental study on 12 male Wistar rats. Pulpotomies were performed and the exposed pulps were capped with Biodentine or Neo MTA. After 15, 45 and 90 days, maxillary segments were obtained and prepared for histologic analysis and Micro-CT. Hounsfield Units (HU) were quantified. Results: Micro-CT analysis showed greater mineralization at 90 days with Neo MTA than with Biodentine. HU did not differ significantly (p >0.05) between molars treated with Biodentine and Neo MTA at 15 and 45 days, but at 90 days, there was statistically significant difference (p <0.05) between them. Reparative dentin was observed near the pulp exposure and canal orifice with both bioceramics. At 45 and 90 days, molars treated with Neo MTA showed mineralized tissue filling the canal orifice. Molars treated with Biodentine showed mineralized tissue and dentin bridge at the site of exposure at 45 days, and total pulp exposure coverage and mineralized entin matrix at 90 days. Conclusions: Biodentine and Neo MTA induce the formation of reparative dentin bridge after 45 days with inflammatory cell infiltrate.

Mantener la vitalidad pulpar y su función es una de las prioridades de los medicamentos utilizados en la terapia pulpar con la finalidad de preservar la integridad del diente. Objetivo: El objetivo de este estudio fue evaluar la respuesta inflamatoria y la reparación del puente dentinario con dos biocerámicas. Materiales y Métodos: Se realizó un estudio experimental in vivo en 12 ratas Wistar formando dos grupos de estudio (n = 6), en las que se realizaron pulpotomías. Posterior a 15, 45 y 90 días, se obtuvieron segmentos de los maxilares y se prepararon los especímenes para análisis histológicos y cortes microtomográficos. Las Unidades Hounsfield (UH) se cuantificaron. Resultados: El análisis microtomográfico mostró un incremento en la mineralización después de 90 días con Neo MTA comparado con Biodentine. No existió diferencia significativa (p >0.05) entre las UH posterior a 15 y 45 días, sin embargo, a los 90 días hubo diferencia significativa (p <0.05) entre Biodentine y Neo MTA. A los 45 y 90 días los molares tratados con Neo MTA mostraron la formación de tejido mineralizado en el orificio comunicados. Los molares tratados con Biodentine mostraron la formacion de tejido mineralizado, a los 45 dias se observó un puente de dentina en el sitio expuestos y una cobertura total de la exposición pulpar y una matriz de dentina mineralizada a los 90 días. Conclusiones: Biodentine y Neo MTA inducen la formación del puente dentinario reparador posterior a 45 días con infiltrado de células inflamatorias.

Calcium silicate-based intracanal medication: Physicochemical properties and effectiveness of techniques for removing medication from the human root canal.

OBJECTIVE: Our purpose was to investigate the physicochemical properties of Bio-C Temp, a bioceramic intracanal medication, and whether its residues remain adhered to the dentine walls after conventional manual irrigation (CMI) or passive ultrasonic irrigation (PUI) in comparison to Calen. METHODS: The pH after 12 hours, 1 day, 3 days, 7 days, 14 days, 21 days and 28 days, and the flow, radiopacity, and the solubility of the medications after immersion for 7 and 30 days in distilled water (dH2O) or phosphate-buffered saline (PBS) solution were evaluated. Filling capacity, and volumetric changes after 14 days were assessed by micro-computed tomography (micro-CT). The residues of medications after CMI or PUI were analysed with scanning electron microscopy. Statistical analysis was performed using ANOVA and Tukey's post-hoc test, Student's t test or the Kruskal-Wallis and Dunn post-hoc test (α = 0.05). RESULTS: Bio-C Temp presented a lower pH, flow, volumetric change, and weight loss after immersion in PBS on the 7th and 14th days (p < 0.05) and greater radiopacity and filling capacity (p < 0.05) than Calen. Both medications showed lower solubility in PBS than in dH2O (p < 0.05). There was no difference in the residue content of the two medications between two irrigation methods in three-thirds of the roots (p > 0.05). CONCLUSION: Although Bio-C Temp had less volumetric loss and satisfactory filling capacity, this medication provided lower alkalinity than did Calen. Furthermore, neither CMI nor PUI completely removed the medicament residues within the human root canal.

Minocycline reduces alveolar bone loss and bone damage in Wistar rats with experimental periodontitis.

This study aimed to investigate the impact of minocycline on the alveolar bone in experimental periodontitis in rats. Thirty Wistar rats were randomly assigned to three groups: control without periodontitis; experimental periodontitis induced by ligature; experimental periodontitis + intraperitoneal administration minocycline for seven days. Ligatures remained in place in both periodontitis groups for 14 days. At the end of the experiment, the animals were euthanized and one hemimandible underwent micro-computed tomography (micro-CT) analysis to assess vertical bone loss and alveolar bone quality. Histopathological analysis was performed on the other hemimandible. Statistical analysis was performed using ANOVA with Tukey's post-test (p<0.05). The results showed a significant reduction in vertical bone loss in the animals treated with minocycline compared with untreated animals. Minocycline also preserved the alveolar bone thickness, number, spacing, and bone volume to tissue volume ratio. Histopathological analysis indicated that minocycline reduced bone resorption, decreased inflammatory response, and maintained the bone collagen fibers. This study demonstrated the effectiveness of minocycline in reducing vertical bone loss and preserved bone quality in rats with experimental periodontitis. The results of this study indicate that minocycline has the potential to serve as an additional treatment option for periodontitis. However, further research is warranted to assess the efficacy and safety of minocycline use in patients with periodontitis.

Atorvastatin Accelerates Alveolar Bone Loss in Type 1 Diabetic Rats Submitted to Periodontitis.

Periodontal bone loss is potentiated by diabetes. Despite the beneficial anti-inflammatory and antiresorptive effects of Atorvastatin (ATV) on periodontitis, it has been reported to increase the risk of diabetes, which may modify the course of periodontal disease. Therefore, this study aimed to evaluate the effect of ATV on alveolar bone in rats with periodontitis and diabetes. For this, 72 Wistar rats were divided into groups: Naïve (N) not submitted to any procedure; Experimental periodontitis (EP) group submitted to ligature-induced periodontitis; diabetes mellitus (DM), submitted to EP and receiving single dose of streptozotocin (60 mg/kg, i.p.) after 12 hours of fasting; and ATV DM, submitted to EP and DM and receiving orally 27 mg/kg of ATV, 30 minutes before ligature placement, and continued daily until the 11th day. Animals from EP and DM received saline solution 0.9% as placebo. Glycemic levels measured in all animals and then were euthanized. Maxillae were collected for macroscopic, micro-tomographic, and microscopic analyses. DM caused intense bone loss (60%), characterized by a reduction in trabecular thickness and bone volume. DM reduced osteoblasts, increasing osteoclast counts, and induced an inflammatory infiltrate in the periodontium. ATV was found ineffective in protecting bone in diabetic rats, exacerbating bone loss by 21%. Additionally, ATV significantly increased blood glucose levels. In summary, ATV did not prevent alveolar bone loss or modulate inflammation in DM animals undergoing EP. ATV also increased blood glucose levels in these animals. Therefore, the systemic use of ATV in uncontrolled diabetic conditions should be carefully evaluated.

Enhancing osteoblast differentiation and bone repair: The priming effect of photobiomodulation on adipose stromal cells.

Cellular therapy using adipose tissue-derived mesenchymal stromal cells (at-MSCs) has garnered attention for the treatment of bone defects. Therefore, preconditioning strategies to enhance the osteogenic potential of at-MSCs could optimize cell therapy outcomes, and photobiomodulation (PBM) therapy has emerged as an effective, noninvasive, and low-cost alternative. This study explored the impacts of PBM on at-MSCs differentiation and the subsequent repair of bone defects treated with cell injection. Rat at-MSCs were cultured and irradiated (at-MSCsPBM) following the PBM protocol (660 nm; 20 mW; 0.714 W/cm2; 0.14 J; 5 J/cm2). Cellular differentiation was assessed based on the expression of gene and protein markers. Reactive oxygen species (ROS) were detected using fluorescence. At-MSCsPBM were injected into 5-mm calvarial lesions, and bone formation was analyzed using micro-CT and histological evaluations. At-MSCs were used as control. Data were analyzed using the ANOVA or t-test. At-MSCsPBM exhibited high levels of gene and protein runt-related transcription factor-2 (Runx2) and alkaline phosphatase (Alp) expression. PBM increased ALP activity and significantly reduced ROS levels. In addition, PBM increased the expression of Wnt pathway-associated genes. In vivo, there was an increase in the morphometric parameters, including bone volume, percentage of bone volume, bone surface area, and trabecular number, in at-MSCsPBM-treated defects compared with those in the control. These findings suggest that PBM enhances the osteogenic potential of at-MSCs, thereby supporting the advancement of improved cellular therapies for bone regeneration.