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1.
J Dent ; 91: 103231, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31712128

RESUMO

OBJECTIVES: To compare the anti-biofilm efficacy of two antimicrobial peptides (AMPs), 1018 and DJK-5, in disrupting canal wall biofilms in the isthmus, canal and dentinal tubules of single-rooted maxillary premolars. METHODS: Enterococcus faecalis single-species biofilms were formed in-situ in the root canal system of the premolars (n = 91). Confocal laser scanning microscopy, bacterial sampling, colony-forming unit counting, XTT assay, lactate dehydrogenase assay and phenol-sulphuric acid method were used to identify the anti-biofilm efficacy of both AMPs and their influence on bacterial metabolic activity. RESULTS: Both AMPs disrupted in-situ E. faecalis biofilms and altered their metabolic activity. At 20 µg/mL, the d-enantiomeric AMP DJK-5 killed 55.5 %, 57.3 % and 55.8 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, in 1 min. In contrast, the l-enantiomeric AMP 1018 only eradicated 25.6 %, 25.5 % and 27.5 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, within the same time. Anti-biofilm efficacy of the root canal irrigants tested were in the order: 6 % NaOCl > 20 µg/mL DJK-5 > 10 µg/mL DJK-5 > 20 µg/mL 1018 > 10 µg/mL 1018 > 0.9 % NaCl. CONCLUSIONS: The present results are confirmatory of previous studies, in that d-enantiomeric AMPs exhibit more potent antibacterial properties than l-enantiomeric AMPs against E. faecalis biofilms within the canal space. Nevertheless, the potency of both AMPs are concentration-dependent. Incorporation of these agents into EDTA, a non-antibacterial calcium-chelating irrigant for removal of the inorganic component of the canal space debris, does not reduce the efficacy of either AMP. CLINICAL SIGNIFICANCE: The present study provides the proof of concept that incorporation of an antimicrobial peptide into a calcium-chelating root canal irrigant enhances the disinfection of intratubular single-species biofilms during smear layer and smear plug removal.

2.
J Endod ; 45(5): 651-659, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30833094

RESUMO

The purpose of this study was to report the clinical efficacy of decompression for 3 cases with large periapical lesions and to review technique details. Three cases with large periapical cystic lesions were treated with decompression after root canal treatment. A traditional decompression technique was used for the first case. After aspiration, mucogingival incision, irrigation, and incisional biopsy, a pediatric endotracheal tube was sutured in place and kept for 3 weeks for lesion debridement. An aspiration/irrigation technique was adopted for the second case. An 18-G needle with a syringe was used to aspirate the cystic lesion. Two needles were then inserted into the lesion; copious saline irrigation was delivered from 1 needle and until clear saline was expressed from the other. For the third case, decompression was accomplished with a surgical catheter that was subsequently replaced with a gutta-percha plug after 1 month. None of the 3 cases underwent complete enucleation and root-end surgery. Healed lesions or lesions in healing were observed after 1 to 2 years. Based on the presented cases and published case reports on decompression, a literature review was provided covering indications, technique details, modification, and prognosis of decompression in endodontics. For large periapical cystic lesions, conservative decompression may be used for certain cases before or in lieu of apical surgery. Decompression enables healing of large, persistent periapical lesions after root canal treatment.


Assuntos
Cisto Radicular , Tratamento do Canal Radicular , Criança , Guta-Percha , Humanos , Prognóstico , Cisto Radicular/terapia , Resultado do Tratamento
3.
Adv Sci (Weinh) ; 5(10): 1800873, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30356983

RESUMO

Biomineralization in vertebrates is initiated via amorphous calcium phosphate (ACP) precursors. These precursors infiltrate the extracellular collagen matrix where they undergo phase transformation into intrafibrillar carbonated apatite. Although it is well established that ACP precursors are released from intracellular vesicles through exocytosis, an unsolved enigma in this cell-mediated mineralization process is how ACP precursors, initially produced in the mitochondria, are translocated to the intracellular vesicles. The present study proposes that mitophagy provides the mechanism for transfer of ACP precursors from the dysfunctioned mitochondria to autophagosomes, which, upon fusion with lysosomes, become autolysosomes where the mitochondrial ACP precursors coalesce to form larger intravesicular granules, prior to their release into the extracellular matrix. Apart from endowing the mitochondria with the function of ACP delivery through mitophagy, the present results indicate that mitophagy, triggered upon intramitochondrial ACP accumulation in osteogenic lineage-committed mesenchymal stem cells, participates in the biomineralization process through the BMP/Smad signaling pathway.

4.
J Dent ; 79: 68-76, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30296552

RESUMO

OBJECTIVE: To investigate the anti-biofilm efficacy of root canal irrigants in canal spaces, isthmi and dentinal tubules of root canals ex vivo. METHODS: Fifty-one single-rooted premolars, each containing an isthmus, were instrumented, autoclaved and inoculated with Enterococcus faecalis for 4 weeks. One specimen was sectioned for bacteria-specific staining to confirm the presence of biofilms using light microscopiy. The remaining specimens were randomly divided to five groups: (1) 0.9% NaCl, (2) SilverSol/H2O2, (3) HYBENX, (4) QMix 2 in1, (5) 6% NaOCl. Bacterial sampling was performed before (S1) and after (S2) canal irrigation. Diluted bacteria suspension was cultured for 48 h for counting the colony forming units (CFU). Percentages of dead bacteria and biofilm thickness were evaluated by confocal laser scanning microscopy (CLSM). Metabolic activity, lactic acid and polysaccharide synthesis of E. faecalis derived from S2 samples were analysed. RESULTS: The percentages of dead bacteria were significantly affected by the factor "irrigant" (p < 0.001) and the factor "location" (p = 0.017). The percentages of dead bacteria in the isthmi and canals were both in the ordor: NaCl < SilverSol/H2O2 < HYBENX < QMix 2 in1 < NaOCl (p < 0.05). Only 6% NaOCl disrupted biofilms and significantly reduced their thickness. The CFU, metabolic activity, polysaccharide and lactic acid production of E. faecalis were all reduced by the disinfecting solutions. CONCLUSIONS: SilverSol/H2O2 and HYBENX were less adept than QMix 2 in1 at killing biofilm bacteria in root canals. None of these antibacterial irrigants were effective, compared with 6% NaOCl, in disrupting biofilms. CLINICAL SIGNIFICANCE: There is advantage in using HYBENX or QMix 2 in1 to kill intratubular bacteria biofilms because of their capability in removing the inorganic component of the smear layer. SilverSol/H2O2 requires extra time to eradicate intratubular biofilms upon removal of the organic and inorganic components of the smear layer by other root canal irrigants.


Assuntos
Enterococcus faecalis , Irrigantes do Canal Radicular , Biofilmes , Cavidade Pulpar , Peróxido de Hidrogênio , Hipoclorito de Sódio
5.
J Dent ; 78: 46-50, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30077808

RESUMO

INTRODUCTION: The present study examined the effects of irrigant flow rate and simulated intraosseous sinusoidal pressure on the rate of NaOCl extrusion from the apical terminus of a faux root canal. METHODS: An extrusion setup was designed to enable irrigant extrusion to be opposed by 30 mm Hg simulated intraosseous pressure. The faux canal apex was opposed by atmospheric + 30 mm Hg pressure (experimental) or atmospheric pressure only (control group). Using five irrigant delivery rates (15.6 8.0, 4.0, 3.4 or 3.0 mL/min), the extrusion rates of 2% NaOCl from the faux apex were measured in both groups (n = 16). Data were analysed with two-factor ANOVA and pairwise comparisons at α = 0.05. Correlation between NaOCl delivery rates and extrusion rates in both groups were analysed with the Pearson product-moment procedure. RESULT: Irrespective of the presence or absence of simulated sinusoidal pressure, NaOCl extrusion rates were positively-correlated with irrigant flow rates. For the factor "irrigant flow rates", significant differences in NaOCl extrusion rates were identified among all flow rates (p < 0.05), except for the pairwise comparison between 4.0 and 3.4 mL/min in the control. For all irrigant flow rates, NaOCl extrusion rate was significantly lower in the presence of 30 mm Hg simulated sinusoidal pressure than that obtained in the absence of opposing pressure (p < 0.05). CONCLUSION: In the presence of 30 mm Hg simulated intraosseous pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min. CLINICAL SIGNIFICANCE: When opposed by intraosseous sinusoidal pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min.


Assuntos
Pressão , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de Sódio , Irrigação Terapêutica , Humanos , Agulhas , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio/uso terapêutico
6.
J Dent ; 75: 105-112, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29908290

RESUMO

OBJECTIVE: To evaluate the efficacy of EDDY, a new sonic-powered irrigation system, in reducing intracanal bacteria load. METHODS: Thirty-eight instrumented, autoclaved single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. Two teeth were used as negative control without bacterial contamination. For the bacteria-inoculated teeth, 6 were used as positive control without irrigation. The remaining 30 teeth were randomly divided into 2 groups (N = 15), using 3% NaOCl as irrigant: (A) 30-gauge syringe needle irrigation (SNI), (B) EDDY (VDW, Munich, Germany). Twelve teeth per group and 4 teeth in the positive control were evaluated for bacterial reduction using MTT assay. The remaining teeth were split for BacLight LIVE/DEAD staining to examine the percentages of live/dead bacteria present in the dentinal tubules from different canal locations (coronal, mid-root and apical portions of the canal space) using confocal laser scanning microscopy (CLSM). RESULTS: MTT assay indicated that both SNI and EDDY significantly reduced overall intracanal bacterial load compared with the positive control, with no significant difference between the two techniques. CLSM indicated that EDDY had better intratubular bacterial killing efficacy than SNI in the coronal and mid-root portions of the canal space only but not in the apical portion. In all canal locations (coronal, mid-root apical), both systems failed to eliminate bacteria that proliferated deep within the dentinal tubules. CONCLUSION: With the use of 3% NaOCl, sonic-powered irrigant activation with EDDY tips did not provide additional advantage over SNI in killing Enterococcus faecalis from deep intraradicular dentin. CLINICAL SIGNIFICANCE: Both the sonic-powered root canal irrigant activation system and syringe needle irrigation can reduce intracanal bacteria load but are incapable of completely killing all bacteria that resided deep within the dentinal tubules of root canals infected with Enterococcus faecalis.


Assuntos
Cavidade Pulpar , Irrigação Terapêutica , Antibacterianos , Enterococcus faecalis , Alemanha , Humanos , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de Sódio
7.
J Dent ; 72: 71-75, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29571954

RESUMO

OBJECTIVES: The effect of irrigation time on the antimicrobial efficacy of an apical negative pressure irrigation system was examined in vitro, followed by validation of the antimicrobial effect in vivo using the identified optimal irrigation time. METHODS: For the in vitro experiment, 44 extracted premolars were decoronated, instrumented, autoclaved and inoculated with Enterococcus faecalis (ATCC 29212) for 21 days. Four teeth were used as positive control, without irrigation. Each of the remaining 40 teeth was irrigated with 2.5% NaOCl, delivered via the EndoVac MacroCannula for 10 s, and subsequently via the EndoVac MicroCannula for 15, 30, 45, 60 or 90 s per canal, respectively (N = 8). After irrigation, microbial samples were collected, transferred to BHI broth and incubated for counting of bacterial colony forming units (CFUs). Based on the in vitro results, 8.25% NaOCl was delivered via the EndoVac MicroCannula for 60 s, during root canal treatment of 20 human subjects presented with apical periodontitis. Microbial samples retrieved in vivo prior to canal instrumentation (S0), after chemomechanical debridement (S1) and after irrigation with EndoVac (S2) were cultured in an anaerobic chamber for 7 days for CFU evaluation. RESULTS: Compared with the control, irrigation significantly reduced bacterial populations (p < .05). Irrigation delivery via the EndoVac demonstrated improved antibacterial efficacy with increased irrigation time (p < .05). Samples retrieved from canals after NaOCl delivery in vivo with the EndoVac for 60 s were all culture-negative. CONCLUSIONS: Microbial elimination may be achieved with 8.25% NaOCl delivered via the EndoVac apical negative pressure irrigation device for 60 s. CLINICAL SIGNIFICANCE: With the use of the EndoVac apical negative pressure irrigant delivery system, optimal elimination of the intracanal bacterial load can only be achieved when sodium hypochlorite is delivered via the MicroCannula for at least 60 s per canal.


Assuntos
Anti-Infecciosos/uso terapêutico , Enterococcus faecalis/efeitos dos fármacos , Pressão , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Ligas , Carga Bacteriana , Dente Pré-Molar , Desbridamento/métodos , Cavidade Pulpar/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Desinfecção/métodos , Humanos , Periodontite Periapical/tratamento farmacológico , Tratamento do Canal Radicular/instrumentação , Hipoclorito de Sódio/uso terapêutico , Tiossulfatos , Fatores de Tempo
8.
Dent Mater ; 34(2): 317-330, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29179973

RESUMO

OBJECTIVES: The objective of the present study was to elucidate the mechanism of bioactive molecule extraction from mineralized dentin by calcium hydroxide (Ca(OH)2) and tricalcium silicate cements (TSC). METHODS AND RESULTS: Transmission electron microscopy was used to provide evidence for collagen degradation in dentin surfaces covered with Ca(OH)2 or a set, hydrated TSC for 1-3 months. A one micron thick collagen degradation zone was observed on the dentin surface. Fourier transform-infrared spectroscopy was used to identify increases in apatite/collagen ratio in dentin exposed to Ca(OH)2. Using three-point bending, dentin exposed to Ca(OH)2 exhibited significant reduction in flexural strength. Using size exclusion chromatography, it was found that the small size of the hydroxyl ions derived from Ca(OH)2 enabled those ions to infiltrate the intrafibrillar compartment of mineralized collagen and degrade the collagen fibrils without affecting the apatite minerals. Using ELISA, TGF-ß1 was found to be extracted from dentin covered with Ca(OH)2 for 3 months. Unlike acids that dissolve the mineral component of dentin to release bioactive molecules, alkaline materials such as Ca(OH)2 or TSC released growth factors such as TGF-ß1 via collagen degradation. SIGNIFICANCE: The bioactive molecule extraction capacities of Ca(OH)2 and TSC render these dental materials excellent for pulp capping and endodontic regeneration. These highly desirable properties, however, appear to be intertwined with the untoward effect of degradation of the collagen matrix within mineralized dentin, resulting in reduced flexural strength.


Assuntos
Compostos de Cálcio/química , Hidróxido de Cálcio/química , Colágeno/efeitos dos fármacos , Colágeno/metabolismo , Cimentos Dentários/química , Dentina/efeitos dos fármacos , Silicatos/química , Fator de Crescimento Transformador beta1/metabolismo , Apatitas/química , Capeamento da Polpa Dentária , Dentina/química , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Sci Rep ; 7(1): 1582, 2017 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-28484231

RESUMO

Sodium hypochlorite is an effective irrigant for chemical debridement of root canals. However, increasing the intracanal pressure during irrigant delivery may result in irrigant extrusion into the bone and soft tissues surrounding the tooth. Because clinicians often encounter teeth with intracanal communications, the objective of the present study was to examine the effects of canal anastomosis on the generation of periapical fluid pressure at different fluid flow rates and insertion depths. Two similar polycarbonate models were used to simulate a single root with double canals, one containing, and the other without communicating channels between the canals. For both models, periapical pressure increased with increasing irrigant flow rates and insertion depths of a 30-gauge side-venting needle. In the presence of communicating channels, the magnitude of pressure build-up decreased by almost 90% irrespective of the fluid flow rate or needle insertion depth. Pressure reduction in anastomoses-containing roots provides an explanation why pressure generation in single roots is considerably higher. Nevertheless, it is still possible in teeth with canal anastomoses for pressure exceeding the intraosseous pressure to be generated when the fluid flow rate is sufficiently high and when the needle tip is close to the apical terminus.


Assuntos
Líquidos Corporais/efeitos dos fármacos , Cavidade Pulpar/cirurgia , Agulhas , Cimento de Policarboxilato/química , Pressão , Irrigantes do Canal Radicular/farmacologia , Raiz Dentária/efeitos dos fármacos , Anastomose Cirúrgica , Cavidade Pulpar/diagnóstico por imagem , Humanos , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X
10.
Acta Biomater ; 49: 16-35, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27845274

RESUMO

Antimicrobial peptides (AMPs) are short cationic host-defense molecules that provide the early stage of protection against invading microbes. They also have important modulatory roles and act as a bridge between innate and acquired immunity. The types and functions of oral AMPs were reviewed and experimental reports on the use of natural AMPs and their synthetic mimics in caries and pulpal infections were discussed. Natural AMPs in the oral cavity, predominantly defensins, cathelicidins and histatins, possess antimicrobial activities against oral pathogens and biofilms. Incomplete debridement of microorganisms in root canal space may precipitate an exacerbated immune response that results in periradicular bone resorption. Because of their immunomodulatory and wound healing potentials, AMPs stimulate pro-inflammatory cytokine production, recruit host defense cells and regulate immuno-inflammatory responses in the vicinity of the pulp and periapex. Recent rapid advances in the development of synthetic AMP mimics offer exciting opportunities for new therapeutic initiatives in root canal treatment and regenerative endodontics. STATEMENT OF SIGNIFICANCE: Identification of new therapeutic strategies to combat antibiotic-resistant pathogens and biofilm-associated infections continues to be one of the major challenges in modern medicine. Despite the presence of commercialization hurdles and scientific challenges, interests in using antimicrobial peptides as therapeutic alternatives and adjuvants to combat pathogenic biofilms have never been foreshortened. Not only do these cationic peptides possess rapid killing ability, their multi-modal mechanisms of action render them advantageous in targeting different biofilm sub-populations. These factors, together with adjunctive bioactive functions such as immunomodulation and wound healing enhancement, render AMPs or their synthetic mimics exciting candidates to be considered as adjuncts in the treatment of caries, infected pulps and root canals.


Assuntos
Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Materiais Biomiméticos/uso terapêutico , Cárie Dentária/tratamento farmacológico , Polpa Dentária/microbiologia , Animais , Peptídeos Catiônicos Antimicrobianos/farmacologia , Materiais Biomiméticos/farmacologia , Cárie Dentária/microbiologia , Polpa Dentária/efeitos dos fármacos , Endodontia , Humanos , Imunomodulação/efeitos dos fármacos
11.
Dent Mater ; 32(10): 1235-1247, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27497745

RESUMO

OBJECTIVES: An experimental discoloration-free calcium aluminosilicate cement has been developed with the intention of maximizing the beneficial attributes of tricalcium silicate cements and calcium aluminate cements. The present study examined the effects of this experimental cement (Quick-Set2) on the mineralogenic characteristics of osteogenic lineage-committed human dental pulp stem cells (hDPSCs), by comparing the cellular responses with a commercially available tricalcium silicate cement (white mineral trioxide aggregate (ProRoot(®) MTA); WMTA). METHODS: The osteogenic potential of hDPSCs exposed to the cements was examined using qRT-PCR for osteogenic gene expressions, Western blot for osteogenic-related protein expressions, alkaline phosphatase enzyme activity, Alizarin red S staining, Fourier transform infrared spectroscopy and transmission electron microscopy of extracellular calcium deposits. RESULTS: Results of the six assays indicated that osteogenic differentiation of hDPSCs was significantly enhanced after exposure to the tricalcium silicate cement or the experimental calcium aluminosilicate cement, with the former demonstrating better mineralogenic stimulation capacity. SIGNIFICANCE: The better osteogenic stimulating effect of the tricalcium silicate cement on hDPSCs may be due to its relatively higher silicate content, or higher OH(-) and Ca(2+) release. Further investigations with the use of in vivo animal models are required to validate the potential augmenting osteogenic effects of the experimental discoloration-free calcium aluminosilicate cement.


Assuntos
Silicatos de Alumínio/farmacologia , Cimentos Dentários/farmacologia , Polpa Dentária/citologia , Osteogênese/efeitos dos fármacos , Animais , Compostos de Cálcio , Argila , Humanos , Silicatos , Células-Tronco
12.
Sci Rep ; 5: 17177, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26617338

RESUMO

Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide-eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components.


Assuntos
Silicatos de Alumínio , Cimentos Dentários , Polpa Dentária/citologia , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Adolescente , Adulto , Silicatos de Alumínio/farmacologia , Caspase 3/metabolismo , Diferenciação Celular , Membrana Celular/metabolismo , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Argila , Cimentos Dentários/farmacologia , Polpa Dentária/metabolismo , Humanos , Imunofenotipagem , Estresse Oxidativo , Fenótipo , Células-Tronco/metabolismo , Adulto Jovem
13.
J Endod ; 41(9): 1530-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26143609

RESUMO

INTRODUCTION: The aim of this study was to evaluate NaOCl apical extrusion by using negative apical pressure (EndoVac), sonic agitation (EndoActivator), side-vented needle (Max-i-Probe), and photon induced photoacoustic streaming (PIPS 10 mJ and PIPS 20 mJ) laser irrigation in an in vitro gel model. METHODS: Extracted mandibular and maxillary central incisors (n = 18) were prepared to size 35/.04 and 55/.04, respectively. Teeth were mounted in transparent containers with clear acrylic and suspended in a color-changing pH-sensitive gel, creating a closed system. By using a crossover design, each tooth was sequentially irrigated by using 6% NaOCl with each device following manufacturers' recommendations. Each tooth served as its own control. Pre-irrigation and post-irrigation buccal and proximal view photographs served to measure the longest distance of extrusion and were analyzed with ImageJ software. Mean results were analyzed by using Kruskal-Wallis and Dunn post hoc test (P < .05). RESULTS: There were no significant differences between EndoVac, EndoActivator, and the passive extrusion groups. The EndoVac and EndoActivator groups produced significantly less extrusion than PIPS irrigation. Max-i-Probe extrusion results were more variable than those of EndoActivator but had no significant difference. Across all irrigation systems, there were no significant differences with respect to apical preparation size. CONCLUSIONS: Under the in vitro conditions of this study, no difference was found between the 10 mJ and 20 mJ PIPS laser groups. EndoVac demonstrated significantly less potential for apical extrusion than PIPS and Max-i-Probe, whereas apical preparation size did not significantly affect extrusion of irrigant. The potential for apical extrusion of endodontic irrigants should be a consideration when selecting a system for final irrigation.


Assuntos
Tecido Periapical/efeitos dos fármacos , Irrigantes do Canal Radicular/administração & dosagem , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio , Irrigação Terapêutica/métodos , Humanos , Projetos Piloto , Preparo de Canal Radicular/instrumentação
14.
J Endod ; 41(5): 725-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25748491

RESUMO

INTRODUCTION: Recent nickel-titanium manufacturing processes have resulted in an alloy that remains in a twinned martensitic phase at operating temperature. This alloy has been shown to have increased flexibility with added tolerance to cyclic and torsional fatigue. The aim of this study was to assess the effect of repeated simulated clinical use and sterilization on cutting efficiency and flexibility of Hyflex CM rotary files. METHODS: Cutting efficiency was determined by measuring the load required to maintain a constant feed rate while instrumenting simulated canals. Flexibility was determined by using a 3-point bending test. Files were autoclaved after each use according to the manufacturer's recommendations. Files were tested through 10 simulated clinical uses. For cutting efficiency, mean data were analyzed by using multiple factor analysis of variance and the Dunnett post hoc test (P < .05). For flexibility, mean data were analyzed by using Levene's Test of Equality of Error and a general linear model (P < .05). RESULTS: No statistically significant decrease in cutting efficiency was noted in groups 2, 5, 6, and 7. A statistically significant decrease in cutting efficiency was noted in groups 3, 4, 8, 9, and 10. No statistically significant decrease in flexibility was noted in groups 2, 3, and 7. A statistically significant decrease in flexibility was noted in groups 4, 5, 6, 8, 9, 10, and 11. CONCLUSIONS: Repeated simulated clinical use and sterilization showed no effect on cutting efficiency through 1 use and no effect on flexibility through 2 uses.


Assuntos
Preparo de Canal Radicular/instrumentação , Esterilização , Animais , Bovinos , Fêmur , Teste de Materiais , Níquel , Maleabilidade , Temperatura , Titânio
15.
J Dent ; 43(5): 597-604, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25593001

RESUMO

OBJECTIVES: To evaluate the effectiveness of TRUShape® 3D Conforming Files, compared with Twisted Files, in reducing bacteria load from root canal walls, in the presence or absence of irrigant agitation. METHODS: Extracted human premolars with single oval-shaped canals were infected with Enterococcus faecalis. Teeth in Group I (N=10; NaOCl and QMix® 2in1 as respective initial and final irrigants) were subdivided into 4 subgroups: (A) TRUShape® instrumentation without irrigant activation; (B) TRUShape® instrumentation with sonic irrigant agitation; (C) Twisted Files without irrigant agitation; (D) Twisted Files with sonic irrigant agitation. To remove confounding factor (antimicrobial irrigants), teeth in Group II (N=10) were irrigated with sterile saline, using the same subgroup designations. Specimens before and after chemomechanical débridement were cultured for quantification of colony-forming units (CFUs). Data from each group were analyzed separately using two-factor ANOVA and Holm-Sidak multiple comparison (α=0.05). Canal wall bacteria were qualitatively examined using scanning electron microscopy (SEM) and light microscopy of Taylor-modified Brown and Brenn-stained demineralised sections. RESULTS: CFUs from subgroups in Group I were not significantly different (P=0.935). For Group II, both file type (P<0.001) and irrigant agitation (P<0.001) significantly affected log-reduction in CFU concentrations. The interaction of these two factors was not significant (P=0.601). Although SEM showed reduced canal wall bacteria, bacteria were present within dentinal tubules after rotary instrumentation, as revealed by light microscopy of longitudinal root sections. CONCLUSIONS: TRUShape® files removed significantly more canal wall bacteria than Twisted Files when used without an antibacterial irrigant; the latter is required to decontaminate dentinal tubules. CLINICAL SIGNIFICANCE: Root canal disinfection should not be focused only on a mechanistic approach. Rather, the rational choice of a rotary instrumentation system should be combined with the use of well-tested antimicrobial irrigants and delivery/agitation techniques to establish a clinically realistic chemomechanical débridement protocol.


Assuntos
Ligas , Instrumentos Odontológicos/microbiologia , Cavidade Pulpar/microbiologia , Preparo de Canal Radicular/instrumentação , Tratamento do Canal Radicular/instrumentação , Anti-Infecciosos/farmacologia , Carga Bacteriana , Dente Pré-Molar/microbiologia , Biguanidas/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Dentina/microbiologia , Desinfecção/instrumentação , Desinfecção/métodos , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/patogenicidade , Humanos , Polímeros/farmacologia , Irrigantes do Canal Radicular/farmacologia , Preparo de Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Rotação , Hipoclorito de Sódio/farmacologia
16.
J Endod ; 40(12): 2003-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25262034

RESUMO

INTRODUCTION: The present study examined the quality of obturation in root canals filled by an experimental non-gutta-percha-based (NGP) root filling system using warm vertical or cold lateral compaction. The quality of obturation was evaluated by comparing the volumetric percentage of gaps and voids identified from similar canals obturated with gutta-percha and an epoxy resin-based sealer using the same obturation techniques. METHODS: Forty single-rooted premolars with oval-shaped canals were cleaned, shaped, and obturated with 1 of the 4 material/obturation technique combinations (n = 10). Filled canals were scanned with micro-computed tomographic imaging. Reconstructed images were analyzed for the volumetric percentage of gaps and voids at 3 canal levels (0-4, 4-8, and 8-12 mm from the working length). Roots were sectioned at the 4-mm, 8-mm, and 12-mm levels. Scanning electron microscopic images of negative replicas of root sections were examined to quantify the circumferential percentage of interfacial gaps and the area percentage of intracanal voids. Data were analyzed with parametric or nonparametric statistical methods. RESULTS: A statistically significant difference was found for the volumetric percentage distribution of gaps and voids for "obturation technique" but not for "material." Significantly higher percentages of gaps and voids were identified in canals obturated with the NGP system using cold lateral compaction. Examination of negative replicas ascribed this difference to a higher area percentage of interfacial gaps rather than more intracanal voids. CONCLUSIONS: Using warm vertical compaction, the NGP system fulfils the objective of 3-dimensional obturation of the canal space in a manner comparable with the results achieved with gutta-percha and a root canal sealer.


Assuntos
Resinas Epóxi/normas , Materiais Restauradores do Canal Radicular/normas , Obturação do Canal Radicular/normas , Cavidade Pulpar/diagnóstico por imagem , Resinas Epóxi/química , Guta-Percha/química , Guta-Percha/normas , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Teste de Materiais , Microscopia Eletrônica de Varredura , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/métodos , Propriedades de Superfície , Temperatura , Microtomografia por Raio-X/métodos
17.
J Dent ; 42(9): 1124-34, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24769108

RESUMO

OBJECTIVES: The present study examined the quality of obturation in root canals obturated by GuttaCore, a gutta-percha-based core-carrier system with a cross-linked thermoset gutta-percha carrier, by comparing the incidence of gaps and voids identified from similar canals obturated by cold lateral compaction or warm vertical compaction. METHODS: Thirty single-rooted premolars with oval-shaped canals were shaped and cleaned, and obturated with one of the three obturation techniques (N=10): GuttaCore, warm vertical compaction or cold lateral compaction. Filled canals were scanned with micro-computed tomography (micro-CT); reconstructed images were analysed for the volumetric percentage of gaps and voids at three canal levels (0-4mm, 4-8mm and 8-12mm from working length). The roots were subsequently sectioned at the 4-mm, 8-mm and 12-mm levels for analyses of the percentage of interfacial gaps, and area percentage of interfacial and intracanal voids, using scanning electron microscopy (SEM) to examine negative replicas of root sections. Data were analysed with parametric or non-parametric statistical methods at α=0.05. RESULTS: Both micro-CT and SEM data indicated that canals obturated with GuttaCore core-carriers had the lowest incidence of interfacial gaps and voids, although the results were not significantly different from canals obturated by warm vertical compaction. Both the GuttaCore and the warm vertical compaction groups, in turn, had significantly lower incidences of gaps and voids than the cold lateral compaction group. CONCLUSIONS: Because of the similarity in obturation quality between GuttaCore and warm vertical compaction, practitioners may find the GuttaCore core-carrier technique a valuable alternative for obturation of oval-shaped canals. CLINICAL SIGNIFICANCE: The quality of obturation achieved by GuttaCore in single-rooted canals is not significantly different from that achieved by warm vertical compaction.


Assuntos
Guta-Percha/normas , Materiais Restauradores do Canal Radicular/normas , Obturação do Canal Radicular/instrumentação , Dente Pré-Molar/anatomia & histologia , Cavidade Pulpar/anatomia & histologia , Desenho de Equipamento , Guta-Percha/química , Humanos , Umidade , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Teste de Materiais , Microscopia Eletrônica de Varredura , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/métodos , Obturação do Canal Radicular/normas , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Propriedades de Superfície , Temperatura , Água/química , Microtomografia por Raio-X/métodos
18.
J Dent ; 42(5): 517-33, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24440449

RESUMO

OBJECTIVES: In tissue regeneration research, the term "bioactivity" was initially used to describe the resistance to removal of a biomaterial from host tissues after intraosseous implantation. Hydraulic calcium silicate cements (HCSCs) are putatively accepted as bioactive materials, as exemplified by the increasing number of publications reporting that these cements produce an apatite-rich surface layer after they contact simulated body fluids. METHODS: In this review, the same definitions employed for establishing in vitro and in vivo bioactivity in glass-ceramics, and the proposed mechanisms involved in these phenomena are used as blueprints for investigating whether HCSCs are bioactive. RESULTS: The literature abounds with evidence that HCSCs exhibit in vitro bioactivity; however, there is a general lack of stringent methodologies for characterizing the calcium phosphate phases precipitated on HCSCs. Although in vivo bioactivity has been demonstrated for some HCSCs, a fibrous connective tissue layer is frequently identified along the bone-cement interface that is reminiscent of the responses observed in bioinert materials, without accompanying clarifications to account for such observations. CONCLUSIONS: As bone-bonding is not predictably achieved, there is insufficient scientific evidence to substantiate that HCSCs are indeed bioactive. Objective appraisal criteria should be developed for more accurately defining the bioactivity profiles of HCSCs designed for clinical use.


Assuntos
Materiais Biocompatíveis/química , Compostos de Cálcio/química , Cimento de Silicato/química , Silicatos/química , Apatitas/química , Cimentos para Ossos/química , Osso e Ossos/anatomia & histologia , Fosfatos de Cálcio/química , Precipitação Química , Tecido Conjuntivo/anatomia & histologia , Humanos
19.
J Endod ; 39(9): 1185-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23953296

RESUMO

INTRODUCTION: Nonendodontic lesions misdiagnosed as pathoses of endodontic origin are often referenced in the literature. One of the most frequent nonodontogenic cysts of the oral cavity, the nasopalatine duct cyst (NPDC), can be misdiagnosed as endodontic in nature. METHODS: A case is presented in which a patent NPDC was originally diagnosed as a sinus tract with subsequent endodontic nonsurgical retreatment and eventual extraction before endodontic consultation. RESULTS: After surgical treatment, a histopathologic diagnosis of an NPDC was confirmed. CONCLUSIONS: If diagnosed incorrectly, inappropriate endodontic treatment of a NPDC may be initiated to include unnecessary extraction. An increased understanding of anatomy, the use of appropriate diagnostic tests to include cone-beam computed tomography imaging, and key examination techniques to distinguish endodontic lesions from nonendodontic pathoses are imperative for an accurate differential diagnosis and appropriate treatment outcome.


Assuntos
Erros de Diagnóstico , Cistos não Odontogênicos/diagnóstico , Nariz/patologia , Palato/patologia , Tomografia Computadorizada de Feixe Cônico/métodos , Fístula Dentária/diagnóstico , Humanos , Incisivo/patologia , Masculino , Tratamento do Canal Radicular/métodos , Ápice Dentário/patologia , Extração Dentária , Adulto Jovem
20.
J Endod ; 38(12): 1618-21, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23146648

RESUMO

INTRODUCTION: The purpose of this study was to determine the shaping ability of 3 nickel-titanium (NiTi) endodontic file systems by measuring canal transportation. METHODS: Seventy-two S-shaped canals in resin blocks were randomly allocated into 3 groups (n = 24): the Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel) group, the Typhoon group (Typhoon rotary files with Controlled Memory Wire; DS Dental, Johnson City, TN), and the Vortex group (ProFile Vortex rotary files with M-Wire NiTi; Dentsply Tulsa Dental Specialties, Tulsa, OK). Blocks were secured in a jig for imaging standardization and instrumentation stabilization. Gates Glidden and PathFile drills (25 mm/.02 taper) were used to prepare the glide paths. For the Typhoon and Vortex groups (25 mm/.04 taper), canals were flooded with sterile water and instrumented using a crown-down technique from sizes 40 to 20/.04 and then apically enlarged to size 30/.04. The SAF group (25 mm) was instrumented with constant sterile water irrigation in a light-pecking, transline motion. Pre- and postinstrumentation images were taken at 40× magnification and layered, and canal transportation was measured. RESULTS: After adjusting for the level and canal wall side, the mean transportation was significantly higher for the Typhoon (P < .001) and Vortex (P = .005) groups compared with the SAF group. Additionally, the mean transportation was significantly higher for the Typhoon group versus the Vortex group (P < .001). CONCLUSIONS: Under the conditions of this study, SAFs showed less canal transportation than ProFile Vortex and Typhoon files in simulated S-shaped root canals.


Assuntos
Ligas Dentárias/química , Cavidade Pulpar/anatomia & histologia , Níquel/química , Preparo de Canal Radicular/instrumentação , Titânio/química , Corantes , Desenho de Equipamento , Humanos , Azul de Metileno , Modelos Anatômicos , Fotografação , Preparo de Canal Radicular/métodos , Ápice Dentário/anatomia & histologia
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