Dentin permeability of the apical third in different groups of teeth (original) (raw)
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Evaluation of permeability of root dentin after different irrigation protocols
Srpski arhiv za celokupno lekarstvo
Introduction/Objective. This study was aimed at evaluating dentin permeability after irrigation with sodium hypochlorite (NaOCl) and final rinse with chlorhexidine (CHX), ethylenediamine tetraacetic acid (EDTA) + CHX, and new combination products: QMiX or MTAD. Methods. Roots of 60 maxillary incisors were randomly divided into five groups (n = 12) before instrumentation and irrigation with NaOCl according to the final irrigation regimen: CHX (2% CHX), EDTA + CHX (17% EDTA + 2% CHX), QMiX, MTAD, and control group (distilled water). After final irrigation, ten roots of each group were horizontally sectioned and dye penetration was evaluated in the coronal, middle, and apical thirds. Remaining samples were subjected to scanning electron microscopy. Data were analyzed with ANOVA/Tukey?s test. Results. Less dye penetration was found in CHX group compared with control as well as with QMiX and MTAD group in all thirds (p < 0.05). A significant difference between the control and EDTA + C...
Effect of cleansers and irrigation methods on primary root dentin permeability
Journal of dentistry for children (Chicago, Ill.)
The purpose of this study was to evaluate the effects of cleansers and irrigation methods on the permeability index (PI) in primary root dentin. One hundred twelve teeth were extracted and sectioned transversely, discarding their crowns. Then, the roots were distributed according to the cleansers: (1) Dakin (D); (2) Dakin+hydrogen peroxide (DHP); (3) 2% chlorhexidine gel (C); and (4) saline (S). The canals were manually instrumented. Irrigation was performed manually (MI) or ultrasonically (UI). The roots were: (1) made impermeable; (2) filled with 2% methylene blue solution; and (3) longitudinally sectioned. The halves were marked in thirds (cervical, middle, and apical), and the areas of dye penetration were measured. PI data were submitted to factorial analysis of variance and Tukey tests (P<.05). A significant effect of MI/UI, in association with cleansers, was seen on PI. For all thirds, the PI of MI was superior to UI. In the cervical third, MI achieved a high PI when assoc...
Journal of endodontics, 1994
This study evaluated the apical leakage associated with various depths of retrograde fillings placed in root apices which had been resected at one of three different angles. Leakage was assessed with a hydraulic conductance apparatus. Teeth were divided into groups corresponding to the angle of apical resection (0, 30, and 45 degrees to the long axis of the root) and apical leakage was determined following incremental increases in the depth of the retrograde filling (Ketac Silver). Increasing the depth of the retrograde filling significantly decreased apical leakage; there was also a significant increase in leakage as the amount of bevel increased. Both the permeability of resected apical dentin and microleakage around the retrograde filling material had a significant influence on apical leakage.
The purpose of this study was to investigate the influence of the type of vehicle (distilled water or propyleneglycol) on the response of apical tissues of dogs' teeth after root canal filling with mineral trioxide aggregate (MTA) at two different limits. Forty roots of incisors and premolars of two adult dogs were used. After pulpectomy, the root canals were prepared biomechanically, and the roots had the apical cemental barrier penetrated with a #15 K-file and widened to a #25 K-file. The root canals were assigned to four groups according to the vehicle used for MTA (ProRoot-MTA; Tulsa Dental, Tulsa, OK) preparation and the limit of root canal filling: group 1, filling with MTA/distilled water to the limit of the cemental canal; group 2, overfilling with MTA/distilled water; group 3, filling with MTA/propyleneglycol to the limit of the cemental canal; and group 4, overfilling with MTA/propyleneglycol. The animals were killed by anesthetic overdose 90 days after endodontic treatment, and the anatomic pieces were prepared for histomorphological analysis. The sections were stained with hematoxylin and eosin and Brown and Brenn techniques. The results showed that MTA pastes prepared with either distilled water or propyleneglycol as vehicles had similar biological behavior (p Ͼ 0.05); root fillings placed at the cemental canal limit showed better results than the overfillings (p ϭ 0.01), and MTA/propyleneglycol paste was more easily placed into the root canals than MTA/distilled water paste. (J Endod 2007;33:693-697)
Evaluation of dentin root canal permeability after instrumentation and Er:YAG laser application
Lasers in Surgery and Medicine, 2000
Background and Objectives: Smear layer removal with EDTA from root canal walls allows greater cleaning and disinfection of root canals. However, because Er:YAG laser acts on the removal of the smear layer, the objective of investigation was to analyze in vitro the effect of Er:YAG laser on dentin root canal wall permeability after endodontic instrumentation and irrigation with water or sodium hypochlorite and Er:YAG laser application. Study Design/Materials and Methods: A total of 25 extracted human maxillary incisors were divided into five groups: Group I, instrumentation with deionized distilled water as the irrigating solution; Group II, instrumentation with 1% sodium hypochlorite as the irrigating solution; Group III, instrumentation with deionized distilled water as the irrigating solution and Er:YAG laser application; Group IV, instrumentation with 1% sodium hypochlorite solution as the irrigating solution and Er:YAG laser application; Group V, instrumentation only up to #20 file with deionized distilled water as the irrigating solution and Er:YAG laser irradiation. The laser parameters were 15 Hz, 140 mJ, total energy 42 J, 300 pulses (Kavo Key Laser). Copper sulfate (10%) was used to evaluate dentin permeability. The penetration of copper ions into the dentinal tubules was observed using 1% rubeanic acid, which reveals copper ions, forming a stained compound ranging in color from deep blue to black. Transverse sections (500-m thick) were obtained with a diamond disk from the cervical, middle, and apical thirds. Results: The instrumentation of the root canal that used water as the irrigating solution followed by Er:YAG laser irradiation promoted the greatest increase in dentin permeability. The use of Er:YAG laser, 1% sodium hypochlorite + Er:YAG, and 1% sodium hypochlorite used alone showed an intermediate capacity of increasing dentin permeability. The use of water as the irrigating solution without Er:YAG laser promoted the least dentin permeability. Conclusions: The use of water as the irrigating solution after instrumentation and Er:YAG laser irradiation was an effective procedure for increasing dentin permeability.
2004 Peters - Current Challenges and Concepts in the Preparation of Root Canal Systems
Nickel-titanium rotary instruments are important adjuncts in endodontic therapy. This review attempts to identify factors that influence shaping outcomes with these files, such as preoperative root-canal anatomy and instrument tip design. Other, less significant factors include operator experience, rotational speed, and specific instrument sequence. Implications of various working length definitions and desired apical widths are correlated with clinical results.
BioMed Research International, 2015
Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm(2)) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system.
Short-term Effect of Four Root Filling Materials on the Flexural Strength of Human Root Dentin
Avicenna Journal of Dental Research, 2021
Background: This study aimed to assess the effects of calcium hydroxide, Biodentine, calcium-enriched mixture (CEM) cement, and mineral trioxide aggregate (MTA) on root dentin flexural strength after a 30-day exposure period. Methods: This in vitro experimental study evaluated 25 freshly extracted sound human incisors with no caries or restorations. The apical 5 mm and the coronal two-thirds of the crowns were cut such that all samples had 10 mm length. Dentin samples (n=20 in each group) were then exposed to 2 mm thickness of calcium hydroxide, Biodentine, CEM cement, MTA, or saline (control) in petri dishes for 30 days. Finally, dentin samples were subjected to a three-point bending test after the intervention, and the flexural strength data were analyzed using one-way ANOVA, Tukey’s test, and t test. Results: Thirty-day exposure to all four biomaterials decreased the flexural strength of root dentin (P 0.05). Conclusions: In general, all four tested biomaterials decrease the dent...
Histopathological evaluation of root canal filling materials for primary teeth
Brazilian Archives of Biology and Technology, 2010
This study aimed to assess the response of apical and periapical tissues of dogs' teeth after root canal filling with different materials. Forty roots from dogs' premolars were prepared biomechanically and assigned to 4 groups filled with: Group I: commercial calcium hydroxide and polyethylene glycol-based paste (Calen ®) thickened with zinc oxide; Group II: paste composed of iodoform, Rifocort ® and camphorated paramonochlorophenol; Group III: zinc oxide-eugenol cement; Group IV: sterile saline. After 30 days, the samples were subjected to histological processing. The histopathological findings revealed that in Groups I and IV the apical and periapical regions exhibited normal appearance, with large number of fibers and cells and no resorption of mineralized tissues. In Group II, mild inflammatory infiltrate and mild edema were observed, with discrete fibrogenesis and bone resorption. Group III showed altered periapical region and thickened periodontal ligament with presence of inflammatory cells and edema. It may be concluded that the Calen paste thickened with zinc oxide yielded the best tissue response, being the most indicated material for root canal filling of primary teeth with pulp vitality.
RESUMO www.fob.usp.br/revista or www.scielo.br/jaos he problem of finding an ideal material for filling root canals of deciduous teeth has not been solved yet. This fact led to the development of an experiment to histologically analyze the periapical tissue reaction to 3 root canal filling materials. Eighty root canals of dog deciduous anterior teeth from 6 animals, 60 days old, were used in this study. After biomechanical preparation, the root canals were filled with the following materials: slowly resorbable Maisto paste, Sealer 26 with iodoform, L&C paste (calcium hydroxide with olive oil) and as a control group, canals that were prepared but not filled. At thirty days after the treatment the animals were killed and the teeth prepared for histological analysis. The materials were ranked statistically from the best to the worst as follows: a -Maisto paste, b -Sealer 26 with iodoform, c -control group, d -L&C paste. There was significant difference (p = 0.01) only when the results of the other groups were compared with the L&C paste group. It was also observed that L&C paste was not biologically compatible and that the other materials were biocompatible but their resorption was not at the same rate as that of the deciduous teeth roots. Uniterms: Dog's deciduous tooth; Root canal filling materials; Root canal therapy. objetivo de encontrar um material ideal para obturar canais radiculares de dentes decíduos ainda não foi alcançado. Esse fato estimulou a realização de uma experimentação para analisar histologicamente a reação dos tecidos periapicais a 3 materiais obturadores de canal. Assim, oitenta canais radiculares de dentes decíduos anteriores de 6 cães, com 60 dias de idade, fora empregados neste estudo. Após o preparo biomecânico, os canais radiculares foram obturados com os seguintes materiais: pasta lentamente reabsorvível de Maisto, Sealer 26 com iodofórmio, pasta L&C (hidróxido de cálcio com óleo de oliva) e, como grupo controle, dentes cujos canais foram preparados biomecanicamente mas não obturados. Trinta dias após o tratamento os animais foram mortos e as peças processados para análise histológica. Os resultados permitiram ordenar estatisticamente os materiais do melhor para o pior da seguinte maneira: a-Pasta de Maisto, b-Sealer 26 com iodofórmio, c-grupo controle, d-Pasta L&C. Foi observado diferença significante (p=0,01) somente quando os resultados dos diferentes grupos foram comparados com o grupo da pasta L&C. Foi também observado que a pasta L&C não foi biologicamente compatível enquanto os outros materiais foram biocompatíveis, porém suas velocidades de reabsorção não foram a mesma observada com as raízes dos dentes decíduos. Unitermos: Dentes decíduos de cães; Materiais obturadores do canal radicular; Tratamento de canal. MIGUEL J A M, CUNHA D L, CALHEIROS A de A, KOO D 318 J Appl Oral Sci 2005; 13(3): 318-24