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AIM: Natural bioactive products have been tested as alternative antimicrobial agents. This study evaluated the effect of Punica granatum extract (PGE) on oral multispecies biofilms. METHODOLOGY: Lyophilized extracts from pomegranate peel were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography (UPLC). Oral multispecies biofilms from 2 donors were grown on four collagen-coated hydroxyapatite discs. After incubation for 7 days or 3 weeks, the biofilms were exposed to water (control), 2% CHX, 10% PGE, 20% PGE or 30% PGE for 3 min. The proportions of dead bacteria were assessed by the live/dead staining and confocal microscopy. After the analysis, the best PGE concentration (30%) was combined with CHX. The experimental phases were repeated using water, 2% CHX, 30% PGE and 30% PGE + 2% CHX. Five random areas of the biofilm on each disc were scanned, resulting in 20 scanned areas for each group. RESULTS: Regarding the biofilm volume, no differences were found amongst solutions (p = .111). The PGE solution killed bacteria effectively in 1-week, 2-week and 3-week-old-plaque biofilms, ranging from 37 to 55.3%, depending on the PGE concentration. The 30% PGE (a) (p = .0009) had greater antibiofilm effectiveness than 2% CHX (b), which killed bacteria in the 25.2 to 48.7% range. The 10% and 20% PGE had intermediate values (ab), without significant differences from 30% PGE (p = 1.002). Water (c) had the lowest proportion of dead bacteria (p < .00001) in a range of 5 to 6.7% and lower effectiveness in killing bacteria (p < .05). The PGE alone or mixed with 2% CHX had greater anti-biofilm effectiveness than CHX (p < .05). The old plaque biofilms were more resistant than the 7-day-old plaque (p < .05). CONCLUSIONS: The 30% PGE (alone or combined with CHX) exhibited a greater antibiofilm effect on oral multispecies biofilms grown on hydroxyapatite discs than 2% CHX.
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AIM: To evaluate the association between the promoter region of defensin beta 1 (DEFB1) genetic polymorphisms and persistent apical periodontitis (PAP) in Brazilian patients. METHODOLOGY: Seventy-three patients with post-treatment PAP (PAP group) and 89 patients with root filled teeth with healed and healthy periradicular tissues (healed group) were included (all teeth had apical periodontitis lesions at the beginning of the treatment). Patients who had undergone at least 1 year of follow-up after root canal treatment were recalled, and their genomic DNA was extracted from saliva. Two single nucleotide polymorphisms (SNPs) in DEFB1 at the g. -52G>A (rs1799946) and g. -20G>A (rs11362) positions were analysed using real-time polymerase chain reaction. The chi-squared test was performed, and the odds ratios were calculated using Epi Info 3.5.2. Logistic regression analysis in the codominant model, using the time of follow-up as a variable, was used to evaluate the SNP-SNP interaction. All tests were performed with an established alpha of 0.05 (P = 0.05). RESULTS: For the rs11362 polymorphism in the codominant and recessive models, patients who carried two copies of the T allele had a significantly lower risk of developing PAP (P = 0.040 and P = 0.031, respectively). For the rs1799946 polymorphism in DEFB1 in the codominant and recessive models, carrying one copy of the T allele significantly increased the risk of developing PAP (P = 0.007 and P = 0.031, respectively). In the logistic regression, both polymorphisms were associated with PAP as well as the SNP-SNP interaction (P < 0.0001). CONCLUSIONS: Polymorphisms in DEFB1 genes were associated with the development of post-treatment persistent apical periodontitis.
Assuntos
Periodontite Periapical , beta-Defensinas , Brasil , Predisposição Genética para Doença , Genótipo , Humanos , Periodontite Periapical/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , beta-Defensinas/genéticaRESUMO
AIM: To evaluate the effect of carbodiimide (EDC) and chlorhexidine (CHX) on the bond strength (BS) of resin cement to root dentine of teeth submitted to radiotherapy. METHODOLOGY: One hundred and twenty extracted maxillary canines were selected and assigned to 2 groups (n = 60): nonirradiated and irradiated (30 cycles of 2 Gy, total 60 Gy). Roots lengths were standardized, and canals were prepared and filled. Post spaces were then prepared, and the samples were redistributed according to dentine treatment (n = 20): saline solution (SF); CHX 2%; or EDC 0.5M. After drying the post space, fibreglass posts were cemented. Cross-sectioned slices were obtained, and in half of the specimens of each subgroup (n = 10), the analysis was performed immediately; the others (n = 10) were stored for 10 months before analyses. The most cervical slice of each third was subjected to a push-out test and failure pattern analysis (n = 10), and the most apical slice submitted to the analysis of the adhesive interface by SEM (n = 5). The bond strength data were submitted to anova and Tukey tests, the adhesive interface adaptation was submitted to Kruskal-Wallis and Dunn's tests, and the Chi-square test was used to evaluate the type of failure. RESULTS: The irradiated specimens had significantly lower bond strength (13.8 ± 4.3) than the nonirradiated (18.1 ± 3.1; P < 0.001). For the irradiated teeth, the bond strengths were significantly lower in the SF and CHX groups (P < 0.001). Also, the bond strengths reduced significantly after 10 months in the SF and CHX groups (P < 0.001). Cohesive failures occurred in dentine for irradiated specimens. Poorer interface adaptation, dentine fractures and microfractures were observed in irradiated specimens, and better adaptation was observed for specimens after EDC treatment. CONCLUSIONS: Radiotherapy was associated with lower bond strength and worse interface adaptation. Dentine treatment with EDC contributed to adhesive interface longevity during the cementation of glass fibre posts in nonirradiated and irradiated teeth.
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Colagem Dentária , Técnica para Retentor Intrarradicular , Carbodi-Imidas , Clorexidina , Cavidade Pulpar , Análise do Estresse Dentário , Dentina , Vidro , Teste de Materiais , Cimentos de ResinaRESUMO
AIM: To evaluate the bond strength and adhesive interface between several resin cements and root dentine immediately and 6 months after radiotherapy. METHODOLOGY: Sixty maxillary canines were selected and randomly assigned to two groups (n = 30): one group was not irradiated and the other one was subjected to a cumulative radiation dose of 60 Gy. The teeth were sectioned to obtain roots 16 mm long and the canals were prepared with the Reciproc system (R50) and filled using a lateral condensation technique with an epoxy resin sealer. Each group was divided into three subgroups (n = 10) according to the resin cement used for fibreglass fibre post cementation: RelyX-U200, Panavia-F2.0 and RelyX ARC. The posts were cemented in accordance with the manufacturer's recommendations. Three 1-mm-thick dentine slices were then obtained from each root third. The first two slices in the crown-apex direction of each third were selected for the push-out test. The failure mode after debonding was determined with a stereo microscope. The third slice from each root third was selected for scanning electron microscopy (SEM) analyses to examine the resin cement-dentine interface with 100, 1000, 2000 and 4000× magnification. Bond strength data were analysed by anova and Tukey's test (α = 0.05). RESULTS: Significantly lower bond strength (P < 0.0001) was obtained after irradiation compared to nonirradiated teeth. RelyX-U200 cemented fibre posts had the higher bond strength (15.17 ± 5.89) compared with RelyX ARC (P < 0.001) and Panavia-F2.0 (P < 0.001). The evaluation after 6 months revealed lower bond strength values compared to the immediate values (P < 0.001) for irradiated and nonirradiated teeth. Cohesive failures occurred in the irradiated dentine. SEM revealed fractures, microfractures and fewer collagen fibres in irradiated root dentine. RelyX-U200 and Panavia-F2.0 were associated with a juxtaposed interface of the cement with the radicular dentine in irradiated and nonirradiated teeth, and for RelyX ARC, hybrid layer formation and tags were observed in both irradiated and nonirradiated teeth. CONCLUSION: Radiation was associated with a decrease in the push-out bond strength and with lower resin cement/root dentine interface adaptation. Self-adhesive resin cement was a better alternative for fibre post cementation in teeth subjected to radiation therapy. The bond strength decreased after 6 months.
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Colagem Dentária , Dentina/efeitos dos fármacos , Radioterapia/métodos , Cimentos de Resina/química , Cimentos de Resina/efeitos da radiação , Raiz Dentária/efeitos dos fármacos , Bis-Fenol A-Glicidil Metacrilato/química , Bis-Fenol A-Glicidil Metacrilato/efeitos da radiação , Cimentação/métodos , Cimentos Dentários/química , Cimentos Dentários/efeitos da radiação , Materiais Dentários/química , Materiais Dentários/efeitos da radiação , Análise do Estresse Dentário , Resinas Epóxi/química , Resinas Epóxi/efeitos da radiação , Vidro , Cimentos de Ionômeros de Vidro/química , Cimentos de Ionômeros de Vidro/efeitos da radiação , Humanos , Teste de Materiais , Polietilenoglicóis/química , Polietilenoglicóis/efeitos da radiação , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/efeitos da radiação , Técnica para Retentor Intrarradicular , Materiais Restauradores do Canal Radicular/química , Materiais Restauradores do Canal Radicular/efeitos da radiação , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de SuperfícieRESUMO
AIM: To evaluate the effect of ultrasonic and sonic activation of two root canal sealers on interfacial adaptation and push-out bond strength (BS) to root canal dentine. METHODOLOGY: The root canals of seventy-eight roots of maxillary canines were prepared with NiTi rotary instruments under irrigation with 2.5% NaOCl and 17% EDTA. Canals were filled by lateral condensation of gutta-percha and AH Plus (n = 39) or MTA Fillapex (n = 39). Three subgroups (n = 13) were formed according to sealer activation: no activation (NA), sonic activation (SA, 20 s) and ultrasonic activation (US, 20 s). In three specimens of each subgroup, 0.1% rhodamine B was added to the sealer. Three 1-mm-thick slices were obtained from each root third. The first and second were used for push-out BS test and the third for a qualitative analysis of interfacial adaptation (gaps) and voids by confocal laser scanning microscopy (CLSM). Intratubular penetration of rhodamine B-labelled sealer was also assessed by CLSM. Data were analysed by two-way anova and Tukey's test (α = 0.05). RESULTS: AH Plus (2.58 ± 1.21) had higher push-out BS than MTA Fillapex (1.45 ± 0.71) (P = 0.000). UA (2.64 ± 1.44) had higher BS (P = 0.000) than NA (1.58 ± 0.73) and SA (1.83 ± 0.85), which did not differ significantly from each other (P = 0.3303). The coronal third had higher BS (2.48 ± 1.49) than the middle (2.08 ± 0.94) (P = 0.0003) and apical (1.48 ± 0.58) (P = 0.00) thirds. For both sealers, UA was associated with a more homogeneous filling material with better interfacial adaptation and greater quantity, density and length of tags in dentinal tubules. When UA was used, the tags had similar quantity, density and length to those formed without activation, but interfacial gaps and voids were observed. CONCLUSION: Ultrasonic activation was associated with higher BS values, deeper intratubular penetration and greater interfacial adaptation to root dentine than sonic activation and no activation techniques, AH Plus had higher BS values than MTA Fillapex irrespective of the type of activation.
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Colagem Dentária , Análise do Estresse Dentário , Materiais Restauradores do Canal Radicular , Sonicação/instrumentação , Terapia por Ultrassom/instrumentação , Humanos , Teste de Materiais , Preparo de Canal Radicular/instrumentação , Irrigação Terapêutica/instrumentaçãoRESUMO
AIM: To evaluate the wear of root wall surfaces, the bond strength of sealers to dentine and the demineralization around root filling materials after canals were exposed to acid challenge in situ. METHODOLOGY: Eighty-seven roots of mandibular incisors were selected. Thirty-two were used in the laboratory bond strength study (n = 8), and 55 in the in situ study (n = 11). Root canals were prepared biomechanically and then filled with gutta-percha and AH Plus, MTA Fillapex, Sealapex or Endofill. For 14 days, 11 participants used intra-oral devices with five sterilized roots (four experimental and one control - only canal prepared). Drops of sucrose were dripped onto roots allowing the accumulation of biofilm on canal surfaces. Roots were removed, sectioned and analysed for the following: bond strength of filling material using a push-out test and also wear profile and dentine demineralization using confocal microscopy. Bond strength (MPa) was evaluated by two-way anova and Tukey test (α = 0.05), and wear profile was assessed by Kruskal-Wallis and t-tests (α = 0.05). RESULTS: AH Plus had the highest bond strength values. Intermediate results were found in roots with MTA Fillapex and Endofill, whilst Sealapex had inferior results (P < 0.05). No significant differences were found amongst root thirds (P > 0.05). For wear profile, samples were associated with degradation of the filling materials after exposure to the oral environment (P < 0.05). Roots had signs of demineralization around the filling material when Sealapex and Endofill were used. CONCLUSIONS: Sealers were not able to prevent degradation of the adhesive interface and dentine. AH Plus and MTA Fillapex had superior bond strength to dentine and less intense demineralization around the root filling.
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Colagem Dentária/métodos , Cavidade Pulpar/patologia , Selantes de Fossas e Fissuras/uso terapêutico , Desgaste dos Dentes/diagnóstico , Adulto , Colagem Dentária/efeitos adversos , Humanos , Microscopia Confocal , Selantes de Fossas e Fissuras/efeitos adversos , Desgaste dos Dentes/etiologia , Desgaste dos Dentes/patologia , Adulto JovemRESUMO
AIM: To evaluate the efficacy of four final irrigation protocols on the reduction of hard-tissue debris accumulated within the mesial root canal system of mandibular first molars using micro-CT analysis. METHODOLOGY: Forty mesial roots of mandibular molars with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci's Type I configuration) were selected and scanned at a resolution of 8.6 µm. Canals were enlarged sequentially using WaveOne Small and Primary instruments activated in reciprocating motion without intracanal irrigation to allow debris to accumulate within the mesial root canal system. Then, specimens were anatomically matched and distributed into four groups (n = 10), according to the final irrigation protocol: apical positive pressure (APP), passive ultrasonic irrigation (PUI), Self-adjusting File (SAF) and XP-endo Finisher (XPF). The final irrigation procedures were performed over 2 min using a total of 5.5 mL of 2.5% NaOCl per canal. Reconstructed data sets were coregistered, and the mean percentage reduction of accumulated hard-tissue debris after the final irrigation procedures was compared statistically between groups using the anovapost hoc Tukey test with a significance level set at 5%. RESULTS: Reduction of accumulated hard-tissue debris was observed in all groups after the final irrigation protocol. Overall, PUI and XPF groups had higher mean percentage reductions of accumulated hard-tissue debris (94.1% and 89.7%, respectively) than APP and SAF groups (45.7% and 41.3%, respectively) (P < 0.05). No significant differences were found when comparing the results of PUI and XPF groups (P > 0.05) or APP and SAF groups (P > 0.05). CONCLUSIONS: The PUI technique and XP-endo Finisher instrument were associated with significantly lower levels of AHTD compared with conventional irrigation and the modified SAF system protocol in mesial root canals of mandibular molars.
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Cavidade Pulpar/cirurgia , Dente Molar/cirurgia , Preparo de Canal Radicular/métodos , Irrigação Terapêutica/métodos , Cavidade Pulpar/diagnóstico por imagem , Humanos , Mandíbula , Dente Molar/diagnóstico por imagem , Microtomografia por Raio-XRESUMO
AIM: To evaluate the effect of root canal cross-sectional shape on single-cone root filling bond strength, as well as to determine the percentage of gutta-percha-filled areas (PGFA) and sealer-filled areas (PSFA), establishing a relationship between these variables. METHODOLOGY: Distal roots of mandibular molars were selected using microcomputed tomography imaging and allocated into three groups (n = 10) according to canal shape: round, oval and long oval. The canals were prepared with an R40 reciprocating instrument and filled with matching single-cone gutta-percha and AH Plus sealer. Two 1-mm-thick dentine slices were obtained from each third of each root. PGFA and PSFA were calculated in digital images (x25 magnification) of each slice. Next, the slices were subjected to a push-out test and the failure modes (adhesive, cohesive or mixed) were assessed. Data were analysed using parametric tests (P < 0.05). RESULTS: In the coronal (2.17 ± 0.56MPa) and middle thirds (1.78 ± 0.45MPa), the round canals were associated with higher bond strength values (P < 0.01), with no difference between the groups for the apical third (P > 0.05). Adhesive and mixed failures predominated in round canals, whilst cohesive failures were more frequent in oval and long oval canals. Round canals had significantly higher PGFA and lower PSFA than all other groups (P = 0.000). The PGFA and PSFA had a positive (r = 0.521, P = 0.000) and a negative (r = -0.523, P = 0.000) correlation with bond strength, respectively. CONCLUSION: Bond strength values of gutta-percha and sealer were affected by canal shape. Higher percentage of gutta-percha-filled area resulted in higher bond strength to dentine.
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Colagem Dentária , Materiais Restauradores do Canal Radicular , Colagem Dentária/normas , Guta-Percha , Humanos , Dente Molar , Materiais Restauradores do Canal Radicular/normasRESUMO
The aim of this study was to evaluate the chemical stability of endodontic-treated root dentin after different laser irradiations through Raman spectroscopy. Fifty maxillary canines were selected and prepared with K3 system. Roots were randomly distributed into five groups (n = 10) according to the surface treatment: GI (water), GII (NaOCl + EDTA), GIII (NaOCl + EDTA + 980 nm Diode laser), GIV (NaOCl + EDTA+ 1064 nm Nd: YAG laser) and GV (NaOCl + EDTA+ 2780 nm Er,Cr: YSGG laser). Lasers were applied for 20 s. Samples were bisected, and the organic and inorganic content of dentin was analyzed by Raman spectroscopy. Data were submitted to ANOVA and Tukey tests (p < 0.05). None of the surface treatments alter the inorganic content (cts) (p = 0.183). Roots irradiated with Er,Cr: YSGG laser had a reduced collagen content (GV-290.7 ± 41.7) compared with the water-treated roots (GI-328.3 ± 63.5) and those treated with NaOCl + EDTA (GII-333.9 ± 55.8). Roots irradiated with Er,Cr: YSGG laser also showed a higher inorganic/organic ratio (GV-9.5 ± 1.1) than roots treated with water (GI-7.7 ± 1.5), NaOCl + EDTA (GII-8.0 ± 1.4) and diode laser (GIII-8.2 ± 1.6). Both organic and inorganic contents increased from cervical to apical thirds in all groups. None of the surface treatments were able to promote changes in the inorganic content of the root dentin; treatment with NaOCl + EDTA combined with Er,Cr: YSGG altered collagen.
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Dente Canino/efeitos da radiação , Dentina/efeitos da radiação , Lasers Semicondutores , Lasers de Estado Sólido , Raiz Dentária/efeitos da radiação , Dente Canino/química , Dentina/química , Humanos , Hidrocarbonetos/química , Fosfatos/química , Análise Espectral Raman , Raiz Dentária/químicaRESUMO
AIM: To evaluate the removal of accumulated hard-tissue debris (AHTD) from the root canal system of mandibular molars by positive and negative pressure irrigation systems, using micro-CT imaging analysis. METHODOLOGY: Mandibular molars with a single canal in the distal root and 2 canals connected by an isthmus in the mesial root were matched based on similar morphological dimensions using micro-CT evaluation and assigned to 2 experimental groups (n = 20 mesial and 10 distal canals), according to the irrigation protocol: apical positive (conventional irrigation) or negative (EndoVac system) pressure. Changes in root canal volume and surface area as well as percentage of uninstrumented canal wall surface and accumulated hard-tissue debris (AHTD) after canal preparation were compared statistically using the independent sample t-test and Mann-Whitney U-test, with the significance level set at 5%. RESULTS: Volume, surface area and percentage of static voxels in either mesial or distal root canal systems were not significantly different between groups before or after root canal preparation (P > 0.05). After preparation, AHTD was not observed in the distal canal of both groups. However, in the mesial root canal system, the conventional irrigation group was associated with a significantly higher median percentage of AHTD (11.48%; IQR: 5.9-22.6; range: 1.86-41.98) than the EndoVac group (3.40%; IQR: 1.5-7.3; range: 0.82-12.84) (P < 0.05). CONCLUSIONS: Neither irrigation protocol succeeded in rendering the mesial canal system free of AHTD; however, apical negative pressure irrigation resulted in lower levels of AHTD than conventional irrigation.