Can the Remaining Coronal Tooth Structure Influence the Mechanical Behavior of Nonpost Full Crowns?

OBJECTIVES: This study investigated the impact of the remaining coronal tooth structure on the mechanical behavior of nonpost (NP) full crowns on endodontically treated maxillary central incisors. MATERIALS AND METHODS: Forty bovine incisors with NP and 2-mm of ferrule were divided into four groups based on the remaining structure: complete 2-mm ferrule (NP-2), absence of mesial and distal ferrule effect (NP-BL), absence of buccal and lingual ferrule effect (NP-MD), and no ferrule (NP-0). The specimens underwent a stepwise stress fatigue test until fracture occurred, and stress distribution was analyzed using in silico finite element analysis (FEA). Additionally, groups with endodontic posts (P) were simulated in the FEA. RESULTS: The results showed that the survival rates varied among the different groups under oblique loading. The NP-2 group exhibited the highest survival rate, with all samples enduring loads up to 200 N and some surviving up to 520 N. The NP-MD and NP-BL groups had lower survival rates, while the NP-0 group had the poorest survival rate. The predominant failure mode was a nonrepairable root fracture. FEA results indicated no significant difference between groups with and without posts. NP intraradicular restorations on nonweakened roots with a minimum height of 2mm and partial or total ferrule thickness of 1mm offer a promising treatment option. CONCLUSION: A complete 2-mm ferrule was found to be the most favorable configuration for NP full crowns. However, maintaining the remaining tissue is crucial, as both combinations with preserved ferrule effect exhibited superior behavior in terms of fatigue and fracture load compared to the group with no ferrule. These findings contribute to understanding the mechanical considerations for NP full crowns and provide insights into treatment planning and design choices in restorative dentistry.

Correlation between Tooth Position Parameters and Apical Fenestration: A Cone-Beam Computed Tomography Study.

This study aimed to assess the relationship between apical fenestration-a defect in the alveolar bone involving the root apex-and tooth position in all tooth groups, excluding the third molars, utilizing cone-beam computed tomography (CBCT) images. A total of 800 CBCT scans (400 maxillary and 400 mandibular) from patients undergoing various treatments were examined by a single professional (radiologist and endodontist). Statistical analyses, including the chi-square test or Fisher's exact test, were conducted using R software 2.7.3 (R Foundation, Vienna, Austria). Results indicated a significant association (p ≤ 0.05) between apical fenestration and tooth position. In the upper teeth, apical fenestrations were notably present in the mesio-buccal (17.17%) and disto-buccal (11.07%) roots of the first molars. Conversely, apical fenestrations in the lower teeth were relatively less frequent. The study revealed a negative correlation between apical fenestration and mesial inclination, rotation, and extrusion in the upper teeth. However, a positive correlation was observed between apical fenestration and lingual inclination in the upper teeth. In conclusion, this study illuminates the distribution of apical fenestration and its correlation with tooth positions, offering insights into factors influencing this defect in dental anatomy. The findings enhance our understanding of nuanced relationships between tooth position and apical fenestration in the upper and lower dental arches.

Assessing the cyclic fatigue resistance and sterilization effects on replica-like endodontic instruments compared to Reciproc Blue.

This study aimed to evaluate the effect of the number of uses and autoclave sterilization on the cyclic fatigue resistance of four replica-like instruments RC Blue; Only One File Blue; Recip One Blue; and Micro Blue compared to the original system Reciproc Blue (VDW, Munich, Germany). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). Fifty molars were instrumented by ten instruments (n=10). After sterilization in an autoclave, the  instruments were analyzed by SEM. This procedure was repeated twice more using different molars, totaling 3 rounds of instrumentation, sterilization and SEM analysis. Then, ten different instruments from each brand were tested for cyclic fatigue resistance. Number of uses data were analyzed using Chi-squared analysis, and cyclic fatigue data were analyzed by one-way Anova followed by Tukey's test as the data had normal distribution. The fracture times for all systems had no significant difference, but Micro Blue had significantly lower values than the other systems (p < 0.05). The SEM analysis showed distortions in the instruments after the 3rd use. Therefore, all tested instruments except of Micro Blue have similar resistance to cyclic fatigue, and all are reliable for use in up to 2-cases.

Saliva culture as a predictive indicator for current blood infections and antimicrobial resistance in the ICU setting.

Antimicrobial resistance is a worldwide health problem and patients in intensive care are more vulnerable, requiring strict control measures and early identification. Currently, clinical culture materials are used to identify the bacterial agent, but saliva culture is not validated, which has great clinical relevance because it participates in several pathophysiological processes. The aim of this study was to validate saliva culture in an intensive care unit environment, determining its diagnostic value for infection. For this purpose, the results of the 39-month surveillance cultures, from the database of a private hospital were evaluated. A total of 323 cultures were paired between saliva, tracheal secretions, blood and urine from patients who were hospitalized for more than 5 days. The search for correlations between the results was performed using the Spearman correlation test. Severity and evolution data were also correlated. It was possible to correlate the presence of Klebsiella spp. between blood culture and saliva culture in 25% of the results (r = 0.01) and the correlation between saliva and tracheal secretion was 33% (r = 0.33447) with p < 0.0001. In conclusion, saliva can be an excellent discriminator of systemic infections, and can be considered a useful culture in clinical practice.

Synergistic Antibiofilm Action of Cinnamomum verum and Brazilian Green Propolis Hydroethanolic Extracts against Multidrug-Resistant Strains of Acinetobacter baumannii and Pseudomonas aeruginosa and Their Biocompatibility on Human Keratinocytes.

The accumulated dental biofilm can be a source of oral bacteria that are aspirated into the lower respiratory tract causing ventilator-associated pneumonia in hospitalized patients. The aim of this study was to evaluate the synergistic antibiofilm action of the produced and phytochemically characterized extracts of Cinnamomum verum and Brazilian green propolis (BGP) hydroethanolic extracts against multidrug-resistant clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa, in addition to their biocompatibility on human keratinocyte cell lines (HaCaT). For this, High-performance liquid chromatography analysis of the plant extracts was performed; then the minimum inhibitory and minimum bactericidal concentrations of the extracts were determined; and antibiofilm activity was evaluated with MTT assay to prevent biofilm formation and to reduce the mature biofilms. The cytotoxicity of the extracts was verified using the MTT colorimetric test, evaluating the cellular enzymatic activity. The data were analyzed with one-way ANOVA and Tukey's tests as well as Kruskal-Wallis and Dunn's tests, considering a significance level of 5%. It was possible to identify the cinnamic aldehyde in C. verum and p-coumaric, caffeic, and caffeoylquinic acids as well as flavonoids such as kaempferol and kaempferide and Artepillin-C in BGP. The combined extracts were effective in preventing biofilm formation and reducing the mature biofilms of A. baumannii and P. aeruginosa. Moreover, both extracts were biocompatible in different concentrations. Therefore, C. verum and BGP hydroethanolic extracts have bactericidal and antibiofilm action against multidrug resistant strains of A. baumannii and P. aeruginosa. In addition, the combined extracts were capable of expressively inhibiting the formation of A. baumannii and P. aeruginosa biofilms (prophylactic effect) acting similarly to 0.12% chlorhexidine gluconate.

Effect of Remineralization Pretreatments on Human Dentin Permeability and Bond Strength.

This study aimed to evaluate Nd:YAG laser, calcium phosphate, and adhesive system effect as different pretreatments in different protocols on dentin permeability (DP) and bond strength (BS). Fifty human dentin discs were used (4 mm in diameter and 1,5 mm in height). Specimens were divided into five groups (n = 10): (A): adhesive system (control); (AL): adhesive system + Nd:YAG laser; (LAL): Nd:YAG laser + adhesive system + Nd:YAG laser; (PAL): calcium phosphate-based dentin desensitizer TeethMate + adhesive system + Nd:YAG laser; and group (PLAL): Nd:YAG laser + calcium phosphate-based dentin desensitizer + adhesive system + Nd:YAG laser. All materials were used according to the manufacturers' instructions. The specimens were submitted to artificial aging (5,000 thermal cycles and 12 × 104 mechanical cycles) then a bond test was performed. DP was measured using the split chamber model. Data were submitted to one-way analysis of variance (ANOVA), paired t-test, RM ANOVA, and Tukey test (p < 0.05). All treatments were effective in DP reduction. For BS, the groups PAL and PLAL had improved BS with a statistically significant difference of the control group (A). Nd:Yag laser irradiation and calcium phosphate-based desensitizing agents significantly reduced DP, and the association between them could improve the BS on resin-human dentin interface.

Antifungal Action of Herbal Plants' Glycolic Extracts against Candida Species.

Candida spp. cause fungal infection that affects patients' oral health. This study aimed to evaluate the isolated and synergistic antifungal effect of Rosa centifolia L., Curcuma longa L., Rosmarinus officinalis L., and Punica granatum L. glycolic extracts against Candida albicans, Candida dubliniensis, Candida tropicalis, and Candida krusei planktonic and biofilm forms. The plant extracts were chemically characterized and the main compounds were quantified by high-performance liquid chromatography (HPLC-DAD) analysis. The minimum inhibitory and minimum fungicidal concentrations of the extracts were determined, and antibiofilm activity was evaluated by MTT assay. Data were analyzed by one-way ANOVA and Tukey's tests, and by Kruskal-Wallis and Dunn's tests, considering a significance level of 5%. The main compounds identified in each of the extracts were: p-coumaric acid (2153.22 µg/100 mL) in the rosemary extract, gallotannins (4318.31 µg/100 mL) in the pomegranate extract, quercetin derivatives (3316.50 µg/100 mL) in the extract of white roses, and curcumin (135.09 µg/100 mL) in the turmeric extract. The combination of R. centifolia and C. longa glycolic extracts was effective against C. albicans, C. dubliniensis, and C. tropicalis biofilms over different periods (p < 0.05). The combination of R. officinalis and P. granatum glycolic extracts was effective against C. albicans and C. krusei biofilms after 30 min, and against C. tropicalis after 24 h, with all combinations showing an average reduction of 50% in cell viability (p < 0.05). In conclusion, the combined plant extracts have antifungal and antibiofilm action against Candida spp. in different concentrations and times of action.

Antimicrobial action of four herbal plants over mixed-species biofilms of Candida albicans with four different microorganisms.

This study aimed to evaluate the antimicrobial effect of four herbal plants glycolic extracts over mixed-species biofilm composed of Candida albicans (C. albicans) and another pathogenic bacterium as alternative therapy to be investigated. Four plants extract of Pfaffia paniculata roots; Hamamelis virginiana leaf, Stryphnodendron barbatiman tree bark and Gymnema sylvestre stem and leaves were tested over multi-species biofilm of C. albicans (ATCC 18804) and Streptococcus mutans (ATCC 35688), Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 4083) or Pseudomonas aeruginosa (ATCC 15442) for 5 min and 24 h and colony forming units per millilitre was calculated. The data were analysed using Kruskal-Wallis with Dunn's test (p ≤ 0.05). All tested extracts showed antimicrobial action over the mixed-species biofilms after 24 h. Some extracts eliminated totally the biofilms. The glycolic extract of P. paniculata, H. virginiana, S. barbatiman and G. sylvestre are effective over mixed-species biofilms and may be indicated as endodontic irrigant or intracanal medication.

Antimicrobial and Antibiofilm Effect of Brazilian Green Propolis Aqueous Extract against Dental Anaerobic Bacteria.

Green propolis may represent a promising therapeutic alternative against dental anaerobic pathogens because of its antimicrobial action. This study aimed to evaluate the antimicrobial and antibiofilm actions of Brazilian green propolis aqueous extract (BGP-AqExt) against dental anaerobic bacteria. The minimum inhibitory concentration (MIC) and minimum microbicide concentration (MMC) of the extract were determined against the standard strains (ATCC) of Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Porphyromonas gingivalis and Porphyromonas endodontalis. BGP-AqExt was chemically characterized by high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis. Antibiofilm action was measured by MTT and crystal violet tests. The data were statistically analyzed by ANOVA and Tukey (5%) tests. The extract had antimicrobial action against all tested anaerobic bacteria, with an MIC value of 55 mg/mL for all bacteria, an MMC of 27.5 mg/mL for F. nucleatum and P. micra and 55 mg/mL for P. intermedia. Chemically, BGP-AqExt is composed of quercetin, gallic acid, caffeic and p-coumaric acid, drupani, kaempferol and Artepillin C. Significant reductions in biomass and metabolic action of biofilms were found after BGP-AqExt application. Therefore, BGP-AqExt has an antimicrobial and antibiofilm effect against dental anaerobic bacteria.

The biocompatibility and antifungal effect of Rosmarinus officinalis against Candida albicans in Galleria mellonella model.

This study was performed to evaluate the biocompatibility and antifungal effect of Rosmarinus officinalis against Candida albicans in Galleria mellonella model. Five different concentrations of R. officinalis glycolic extract (50; 25; 12.5 e 6.25 mg/mL) were used to evaluate its biocompatibility in G. mellonella model, in which the nystatin suspension (100; 50; 25; 12.5 e 6.25%) was used as a control group. The antifungal action of R. officinalis glycolic extract was evaluated on C. albicans for 72, 48 and 12 h at two different phases: (1) using the extract as therapeutic agent; and (2) using the extract as prophylactic agent. PBS was used as a negative control group. G. mellonella survival curves were plotted using the Kaplan-Meier method and statistical analysis was performed using the log-rank test (Mantel-Cox) and the significance level was set at (α ≤ 0.05). There was no significant difference among the groups in which all were biocompatible except of a significant death rate of 26.6% with nystatin 100%. In phase 1, it was found that after 7 days, there was no statistically significant difference among the prophylactic treatment groups. In phase 2, the groups of R. officinalis 6.25 mg/mL for 72 h and R. officinalis of 12.5 mg/mL for 24 h promoted the survival rate of the larvae in comparison with the control group with a significant difference (p = 0.017) and (p = 0.032) respectively. Therefore, R. officinalis extract is biocompatible in different concentrations and can be used as a prophylactic agent against fungal infection.

Biological and chemical properties of five mineral oxides and of mineral trioxide aggregate repair high plasticity: an in vitro study.

Calcium silicate-based cements have diverse applications in endodontics. This study aimed to evaluate the antibiofilm action, biocompatibility, morphological structure, chemical composition and radiopacity of Five Mineral Oxides (5MO), Mineral Trioxide Aggregate Repair High Plasticity (MTA Repair HP), and Mineral Trioxide Aggregate (MTA) cements. MTT analysis was used to test the antibiofilm action of these cements against five anaerobic microorganisms, and test their biocompatibility with mouse macrophage (RAW 264.7) and osteoblasts (MG-63) cultures. Their morphological structure and chemical composition were evaluated by scanning electron microscopy (SEM) coupled to energy dispersion X-ray spectroscopy (EDX), and the phase analysis was performed by X-ray diffraction (XRD). Conventional radiography was used to assess the radiopacity of the cements. 5MO, MTA Repair HP and MTA were effective against Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum and Prevotella intermedia, they were biocompatible with macrophages and osteoblasts after 5 min of contact, and they had adequate radiopacity to be used clinically. Bismuth oxide (Bi2O3) is used as a radiopacifier in MTA and 5MO, and calcium tungstate, in MTA Repair HP. Titanium dioxide (TiO2) (ANATASE) is responsible for the antimicrobial action and biocompatibility of 5MO.

Curcuma longa L. Extract and Photodynamic Therapy are Effective against Candida spp. and Do Not Show Toxicity In Vivo.

Radiotherapy induces a higher level of Candida spp. colonization, resulting in oral candidiasis. This study aimed to evaluate the phototransformation potential of the glycolic extract of Curcuma longa (C. longa); the antifungal activity of C. longa, curcumin, and antifungal photodynamic therapy (aPDT) with blue light-emitting diodes "LED" on Candida albicans and Candida tropicalis in vitro; and the toxicity of C. longa and curcumin in Galleria mellonella model. In order to confirm the light absorption capacity of the C. longa extract, its phototransformation potential was evaluated. The antifungal effect of C. longa, curcumin, and aPDT was evaluated over Candida spp. Finally, the toxicity of C. longa and curcumin was evaluated on the Galleria mellonella model. The data were analyzed using the GraphPad Prism 5.0 software considering α = 5%. It was found that C. longa, curcumin, and aPDT using blue LED have an antifungal effect over C. albicans and C. tropicalis. The extract of C. longa 100 mg/mL and curcumin 200 µg/mL do not show toxicity on Galleria mellonella model.

The Effect of Aloe vera and Chlorhexidine as Disinfectants on the Success of Selective Caries Removal Technique: A Randomized Controlled Trial.

This study aimed to evaluate the effect of Aloe vera and chlorhexidine "CHX" as disinfectants on the success of selective caries removal technique in deep carious lesions. A total of 60 patients with: (I) deep class II carious lesion diagnosed with reversible pulpitis; (II) good oral hygiene; (III) no gingival recession or periodontal diseases; (IV) no antibiotic or antifungal treatment in the last three months; and (V) no systematic disease or pregnancy were included in the study. Sixty patients were distributed randomly to three experimental groups (n = 20): Group 1: no disinfectant solution was applied (control group); group 2: the cavity was filled with 2% CHX for 5 mins and then dried with a sterilized cotton pellet; group 3: the cavity was filled with Aloe vera extract for 5 mins and then dried with sterilized cotton pellet. One week later, only teeth with vital pulp characteristics were restored definitely with resin composite. After 18 months, clinical and radiographic examination was performed by using a blinded separated evaluator. The data were tabulated and analyzed using the chi-square test by SPSS 13.0 with a significance level (p ≤ 0.05). It was observed that 13 teeth of the control group, 14 teeth of the CHX group, and 16 teeth of the Aloe vera group were diagnosed with healthy vital pulp after 18 months. There was no significant difference between the CHX and the control group; however, there was a significant difference between the Aloe vera and control group (p ≤ 0.007). Aloe vera extract as a cavity disinfectant increases the success rate of selective caries removal technique of deep carious lesions.

Antimicrobial Action, Genotoxicity, and Morphological Analysis of Three Calcium Silicate-Based Cements.

This study is aimed at evaluating five mineral oxides (5MO), mineral trioxide aggregate repair high plasticity (MTA HP), and mineral trioxide aggregate (MTA) in relation to the antimicrobial action over Porphyromonas gingivalis, Porphyromonas endodontalis, Parvimonas micra, Fusobacterium nucleatum, and Prevotella intermedia; the genotoxicity over mouse macrophage (RAW 264.7) and osteoblast (Mg-63) cultures; and the morphological analysis using scanning electron microscopy (SEM) analysis (50 k and ×100 k). Sodium hypochlorite (NaOCl), calcium hydroxide, and saline solution were used as control groups in the different analysis. All data were submitted to a normality test and then analyzed with one-way ANOVA, Tukey, and Kruskal-Wallis and Dunn tests, considering α ≤ 0.05 significance level. It was found that over P. gingivalis and P. endodontalis, there was no a significant difference between the calcium silicate-based cements (CSC) and the control group of saline solution, and only 5MO was similar to the NaOCl group. However, over P. micra, all groups were effective and showed a statistically significant difference compared to the saline solution group. Conversely, none of the groups were effective over F. nucleatum and P. intermedia, except of the NaOCl group. There was a significant difference between 5MO and MTA groups in comparison with NaOCl and MTA HP over osteoblasts and macrophages after 24 hours. SEM images showed small irregular particles interspersed with some elongated needle-like particles and small irregular particles with some larger particles as well as elongated particles. It was concluded that 5MO, MTA, and MTA HP have effective antimicrobial action over P. micra. However, only 5MO is effective over P. gingivalis and P. endodontalis. Besides, 5MO and MTA are not genotoxic over mouse macrophage (RAW 264.7) and osteoblast (Mg-63) cultures.

Antibiofilm action of Persea americana glycolic extract over Acinetobacter baumannii and absence of toxicity in Galleria mellonella.

OBJECTIVES: This study aimed to evaluate the antibiofilm activity and toxicity of the glycolic extract of Persea americana "P. americana" over multidrug-resistant strains of Acinetobacter baumannii "A. baumannii" as alternative therapy to be investigated. METHODS: A bacterial inoculum of each bacterial strain (4a, 5a, 9a, 12a, ATCC 19606) of A. baumannii was prepared and adjusted by the spectrophotometer. The microdilution broth method was performed to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). P. americana glycolic extracts were obtained of the tree stalk and leaves. The biofilm viability was tested by MTT assay after 5 min exposure. The toxicity of the extracts was tested by invertebrate model Galleria mellonella. The data were analyzed by ANOVA, Tukey test and log-rank method (α=0.05). RESULTS: The extract showed an inhibitory and bactericidal action over all the tested strains with the lowest MIC value observed for the reference strain (3.12 mg/mL). The extract did not demonstrate toxicity in any of the tested concentrations (12.5, 25 and 50 mg/mL) in Galleria mellonella larvae, with a survival percentage above 80% after 168 h. CONCLUSIONS: The glycolic extract of P. americana has microbicidal and antibiofilm activity on multidrug-resistant clinical strains of A. baumannii and showed low toxicity for the invertebrate model G. mellonella.

Fracture resistance and stress distribution of weakened teeth reinforced with a bundled glass fiber-reinforced resin post.

OBJECTIVES: To make an in vitro assessment of fracture resistance of weakened and non-weakened teeth receiving intraradicular reinforcement using Rebilda bundled glass fiber-reinforced composite posts (GT), Rebilda conventional glass fiber posts (RP), or both systems combined (GT + RP). MATERIALS AND METHODS: Eighty sound bovine incisors were prepared and divided randomly into eight groups as follows: (a) nWnR: without simulating weakness, and without intraradicular reinforcement; (b) WnR: simulating weakness, but without intraradicular reinforcement; (c) nWGT: without simulating weakness, but with GT; (d) WGT: simulating weakness, and with GT; (e) nWRP: without simulating weakness, but with RP; (f) WRP: simulating weakness, and with RP; (g) nWGTRP: without simulating weakness, but with GT + RP; (h) WGTRP: simulating weakness, and with GT + RP. The specimens were subjected to the load-to-fracture test using the DL-2000MF universal testing machine. The finite element method assessed the mechanical behavior and stress distribution in endodontically treated teeth. RESULTS: The groups nWGTRP and WGTRP presented the best results in the load-to-fracture test, with the former being better than the latter, but with no statistically significant difference (P > 0.05). However, there was a significant difference between these and the other groups (P < 0.05), except for nWRP. Stress distribution inside the canal wall was different among the groups, with promising mechanical behavior for nWGTRP and nWRP. CONCLUSIONS: The Rebilda conventional fiber post (RP), combined with the Rebilda bundled glass fiber-reinforced composite post (GT) improves the resistance and stress distribution of immature teeth. CLINICAL RELEVANCE: Longitudinal fracture is less frequent in teeth restored with GT and RP posts.

Guided endodontic access of severe calcified tooth without incisal edge ­ case report / Acesso endodôntico guiado de dente calcificado severamente sem borda incisal ­ relato de caso

Pulp tissue may suffer calcification because of trauma, operative procedures or carious lesions. This paper aimed to report and discuss the guided endodontic access as an alternative treatment. A 52 years old female patient had severe root canal calcification of tooth #11 associated with a radiolucent periapical lesion. Firstly, the crown and metal post and core were removed. A digital impression and cone-beam computed tomography "CBCT" scans were performed and imported to implant planning software (SimPlant Version 11; Materialise Dental, Leuven, Belgium).The guided endodontic access template was designed to allow the drill to reach a distance of 2 mm short of the apical foramen, once printed, it was tested in the mouth to evaluate its insertion and stability in the dental arch. The calcified root canal was penetrated using the access drill rotating by a low-speed hand-piece (10,000 rpm) under saline solution irrigation through advancing movements. Then, the apical foramen was negotiated with C-Pilot files #10 and #15. The working length was measured using the iPex-II apex locator. The instrumentation was carried out with Reciproc R50 and 2.5% sodium hypochlorite. One week later, a full-ceramic crown preparation was performed, and polyvinyl siloxane impression was carried out. A total of three follow-up sessions were performed after one week, one and twelve months. Bone neoformation was observed in the site of the periapical lesion and the patient had no signs or symptoms of any discomfort. Therefore, guided endodontics is indicated for severe calcified root canals.(AU)

O tecido pulpar pode sofrer calcificação por trauma, procedimentos cirúrgicos ou como resposta a lesões cariosas. Este trabalho teve como objetivo relatar e discutir o acesso endodôntico guiado como opção de tratamento. Paciente do sexo feminino, 52 anos, com calcificação severa do canal radicular do dente 11 associada a lesão periapical radiolucida. Na primeira intervenção clínica, a coroa e o pino de metal foram removidos. Uma impressão digital e imagens de CBCT foram realizadas e importadas para o software de planejamento de implante (SimPlant Versão 11; Materialize Dental, Leuven, Bélgica) tentando projetar um modelo de acesso endodôntico guiado para permitir que a broca alcance uma distância de 2 mm antes do forame apical, uma vez impresso, foi testado na boca para avaliar sua inserção e estabilidade na arcada dentária. O canal radicular calcificado foi penetrado com broca de acesso girando por peça de mão de baixa velocidade (10.000 rpm) sob irrigação com solução salina por meio de movimentos de avanço. Em seguida, o forame apical foi negociado com as limas C-Pilot nº 10 e nº 15. O comprimento de trabalho foi determinado usando o localizador de ápice iPex-II. A instrumentação foi realizada com Reciproc R50 e hipoclorito de sódio 2,5%. Uma semana depois, foi realizado o preparo da coroa total em cerâmica e a moldagem com polivinilsiloxano. Um total de três sessões de acompanhamento foram realizadas após uma semana, um e doze meses. A neoformação óssea foi observada no local da lesão periapical e a paciente não apresentava sinais ou sintomas de qualquer desconforto. Portanto, o acesso endodôntico guiado é indicado para canais radiculares calcificados severamente.(AU)

Effect of Passive Ultrasonic Irrigation over Organic Tissue of Simulated Internal Root Resorption.

This study aimed to evaluate the efficacy of passive ultrasonic irrigation (PUI) on dissolving the organic tissue inside simulated internal root resorption (IRR) using sodium hypochlorite (NaOCl) or chlorhexidine (CHX). A total of 40 human lower premolars were collected based on dimensional and morphological similarities. The roots were embedded in cylinders (3 cm diameter; 2.5 cm height) of self-cured acrylic resin, and then an IRR was simulated. The specimens were divided into 4 groups (n = 10) according to irrigation protocols: group 1: CHX + PUI; group 2: CHX; group 3: NaOCl + PUI; group 4: NaOCl. The total irrigation time was 150 s at a flow rate of 5 mL/min. A tissue mass of porcine palatine mucosa was used to simulate the organic tissue, it was weighed before and after the irrigation using an analytic balance, and the difference between both readings was calculated and transferred to percentage values. Data were submitted to statistical analysis using two-way ANOVA (factors: irrigant type and with/without PUI) and Tukey's test for multiple comparisons among the experimental groups (α = 0.05). There was a significant difference in both factors (irrigant: p=0.04; PUI: p ≤ 0.001). The groups that used PUI were more effective in dissolving the organic tissue of the IRR simulation than the groups without PUI. PUI is more effective than the syringe and needle irrigation in organic tissue dissolution.

Endodontic Perforation Closure by Five Mineral Oxides Silicate-Based Cement with/without Collagen Sponge Matrix.

Endodontic perforations are common accidents that occasionally happen as a result of misuse or difficult anatomy of some teeth; it may lead to teeth loss unless a good management is provided. Bioceramic (silicate-based) cements like mineral trioxide aggregate have a big role in management of such accidents. This case report aimed to evaluate the ability of five mineral oxides cement "5MO" in sealing two root canal perforations (furcation and postdrill perforations) and inducing clinical and radiographic healing in the periodontal tissues with/without the use of collagen sponge matrix. A 58-year-old healthy female was referred to our dental office complaining of severe pain in the upper left premolars' region. Periapical radiographic examination revealed unsatisfactory root canal treatment of the teeth #24 and #25 with a furcation perforation and a postdrill perforation, respectively. Cone-beam computed tomography "CBCT" scans confirmed the findings of the periapical radiography and revealed the presence of radiolucent lesions surrounding the apex of both teeth #24 and #25. The treatment plan was a nonsurgical root canal retreatment by endodontic access through the full-ceramic crowns. After three years of follow-up, CBCT scans revealed a complete healing and bone formation on both premolars. This case report indicates the use of 5MO cement for endodontic perforations management.

Effect of Nd:YAG Laser with/without Graphite Coating on Bonding of Lithium Disilicate Glass-Ceramic to Human Dentin.

This study evaluated the effect of different surface treatments on the tensile bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. Fifty truncated cone-shape glass-ceramics were divided into five groups (n = 10): G1, control: 10% hydrofluoric acid (HF); G2, Nd:YAG laser + silane; G3, Sil + Nd:YAG laser; G4, graphite + Nd:YAG laser + Sil; and G5, graphite + Sil + Nd:YAG laser. Fifty human third-molars were cut to cylindrical shape and polished to standardize the bonding surfaces. The glass-ceramic specimens were bonded to dentin with a dual-cured resin cement and stored in distilled water for 24 h at 37ºC. Tensile testing was performed on a universal testing machine (10 Kgf load cell at 1 mm/min) until failure. The bond strength values (mean ± SD) in MPa were G1 (9.4 ± 2.3), G2 (9.7 ± 2.0), G3 (6.7 ± 1.9), G4 (4.6 ± 1.1), and G5 (1.2 ± 0.3). Nd:YAG laser and HF improve the bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. The application of a graphite layer prior to Nd:YAG laser irradiation negatively affects this bonding and presented inferior results.