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Pulp Chamber (pulp + chamber)
Selected AbstractsSealing evaluation of the cervical base in intracoronal bleachingDENTAL TRAUMATOLOGY, Issue 6 2003Luciane Dias De Oliveira Abstract,,, Discoloration of non-vital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the cervical base efficacy in order to prevent or to minimize the leakage along the root canal filling and into the dentinal tubules. Thirty-eight extracted single-root human teeth were used, which were biomechanically prepared, filled, and divided into three experimental groups: G1, a cervical base was applied (3 mm of thickness) below the cemento-enamel junction, with resin-modified glass-ionomer cement (Vitremer); G2, the base was done with glass-ionomer cement (Vidrion R); and G3 (Control), did not receive any material as base. A mixture of sodium perborate and hydrogen peroxide 30% was placed inside the pulp chamber for 3 days, and the access opening was sealed with Cimpat. This procedure was repeated thrice. Soon after this, a paste of calcium hydroxide was inserted into the pulp chamber for 14 days. All teeth were covered with two layers of sticky wax, except the access opening, and immersed in blue India Ink for 5 days. The results did not show statistically significant differences between the three groups concerning the leakage inside the dentinal tubules. Regarding the apical direction, a statistical difference (anovaP < 0.05) was observed among the experimental group G1 and control group G3. No statistically significant difference was observed between G2 and G3 groups. Therefore, the placement of a cervical base before internal bleaching procedures is still recommended. [source] Micro-computed tomography of tooth tissue volume changes following endodontic procedures and post space preparationINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2009O. H. Ikram Abstract Aim, To compare the volume of hard tooth tissue lost after caries removal, access cavity preparation, root canal preparation, fibre post space and cast post preparation in carious premolar teeth. The null hypothesis tested was that there is no difference between the volumes of hard tooth tissue lost expressed as a percentage of the preoperative hard tooth tissue volume, after each operative procedure. Methodology, Twelve extracted human premolars with mesial or distal carious cavities penetrating into the pulp chamber were selected. Teeth were scanned using a microCT scanner. After each operative procedure the loss of hard tooth tissue volume was measured. The data were statistically analysed using one-way analysis of variance and Fisher's PLSD test with statistical significance set at , = 0.01. Results, The percentage of preoperative hard tooth tissue volume lost after caries removal was 8.3 ± 5.83, after access cavity preparation the loss of volume reached 12.7 ± 6.7% (increase of 4.4%). After root canal preparation, fibre post space and cast post preparation the hard tissue volume lost reached, 13.7 ± 6.7 (increase of 1%), 15.1 ± 6.3 (increase of 1.4%) and 19.2 ± 7.4 (increase of 4.1%) respectively. Each procedure performed after caries removal significantly increased (P < 0.01) the amount of hard tissue volume lost with the exception of the root canal preparation. Conclusions, Access cavity and post space preparation are the procedures during root canal treatment which result in the largest loss of hard tooth tissue structure. Cast post space preparation causes a larger loss of tooth structure than fibre post space preparation. This should be taken into account when planning root canal treatment and restoration of root filled teeth that are to be restored with cuspal coverage restorations. [source] Radicular peroxide penetration from carbamide peroxide gels during intracoronal bleachingINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2008O. Gökay Abstract Aim, To evaluate and compare radicular peroxide diffusion from different concentrations of carbamide peroxide bleaching gels. Methodology, Fifty maxillary premolar teeth were separated into five groups (n = 10). Standardized endodontic access cavities were prepared in the occlusal surfaces, and the root canals were prepared using a step back technique and filled using the lateral compaction technique. The gutta-percha filling was removed 4 mm short of the cemento-enamel junction (CEJ) and a 2-mm-thick glass,ionomer cement base was placed. Outer root surfaces were sealed with wax and nail polish, leaving the coronal third of the tooth and the CEJ exposed. All teeth were immersed in a plastic tube containing 2 mL of distilled water, and the experimental groups were treated with a bleaching agent of either 10%, 17% or 37% carbamide peroxide (CP) or a mixture of 30% hydrogen peroxide (HP) and sodium perborate (SP) placed into the coronal pulp chamber of teeth and left for 24 h. Peroxide penetration was measured using the ferrothiocyanate method. Statistical analysis of data was conducted by using the Kruskal,Wallis Analysis of Variance and Mann,Whitney U test. Results, Higher peroxide penetration occurred with the 30% HP-SP mixture than with the CP bleaching gels, and the 37% CP group also promoted greater peroxide penetration than the other CP groups (P < 0.05). There was no statistically significant difference between 10% and 17% CP groups (P > 0.05). Conclusion, Peroxide penetration of CP gels was significantly lower than that of a HP-SP mixture. [source] Taurodontism: a review of the condition and endodontic treatment challengesINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2008H. Jafarzadeh Abstract Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig's epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. Although permanent molar teeth are most commonly affected, this change can also be seen in both the permanent and deciduous dentition, unilaterally or bilaterally, and in any combination of teeth or quadrants. Whilst it appears most frequently as an isolated anomaly, its association with several syndromes and abnormalities has also been reported. The literature on taurodontism in the context of endodontics up to March 2007 was reviewed using PubMed, MEDLINE and Cumulative Index to Nursing & Allied Health Literature. Despite the clinical challenges in endodontic therapy, taurodontism has received little attention from clinicians. In performing root canal treatment on such teeth, one should appreciate the complexity of the root canal system, canal obliteration and configuration, and the potential for additional root canal systems. Careful exploration of the grooves between all orifices particularly with magnification, use of ultrasonic irrigation; and a modified filling technique are of particular use. [source] Influence of the pulpal components on human dentine permeability in vitroINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2005P. Puapichartdumrong Abstract Aim, To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion. Methodology, Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s. The drug diffusion test was carried out before and after removal of the retained pulpal components. Each dentine disc was inserted between two plastic chambers; enamel- and pulpal-side chambers, which were filled with 0.05 mol L,1 naproxen sodium (NA) and phosphate-buffered saline (PBS), respectively. After 10 min, the solution on the pulpal-side chamber was collected to determine the concentration of NA using a spectrophotometer. To remove the retained pulpal components and residual NA, the pulp chamber of each disc was washed out with PBS and placed in an ultrasonic cleaner. After removal of these components and the residual NA, the drug diffusion test was repeated. The inner surface of the pulp chamber was observed using scanning electron microscopy (SEM) before and after the removal of the retained pulpal components. Results, The amount of NA that diffused through dentine into the pulp was significantly higher after the pulp chamber was washed out with PBS (paired t -test, P < 0.05). SEM observation demonstrated the presence of the retained pulpal components, odontoblastic layer and some parts of subodontoblastic zone, covering the surface of predentine. These components were removed after the pulp chamber was washed out with PBS followed by cleaning in an ultrasonic cleaner. Conclusions, The presence of retained pulpal components had a significant influence on drug diffusion through dentine discs. [source] An in vitro comparison of adhesive systems to seal pulp chamber wallsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2004B. Ozturk Abstract Aim, To compare in vitro the sealing properties of five different dentine adhesive materials (Prime&Bond NT (PBNT); Prompt L-Pop (PLP); Clearfil SE Bond (CSEB); Scotchbond Multi Purpose Plus (SMPP); EBS-Multi (EBSM)) inside the pulp chamber. Methodology, Seventy-five recently extracted human molar teeth were used. The roof of the pulp chambers and roots were removed under water cooling. Pulp tissue was removed, and the canal orifices were sealed. The pulp chambers were then treated with 5% sodium hypochlorite (NaOCl) for 1 min. The teeth were randomly divided into five groups of 15 teeth each. Adhesive systems were applied to the pulp chamber walls according to the manufacturers' instructions. The samples were connected to Plexiglass plates, and a fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of seal of each specimen was measured immediately, after 24 h, 1 week and 1 month. The data were statistically analysed by repeated-measurements multivariate anova, Friedman test, Wilcoxon signed rank test, Kruskal,Wallis of one-way anova and Mann,Whitney U -tests. The pulp chamber wall with and without NaOCl and resin,dentine interfaces of specimens were observed under a scanning electron microscope (SEM). Results, The leakage values of the materials were significantly different at different measurement periods. In all groups, leakage values decreased with time (P < 0.05). PBNT and PLP had the least leakage during immediate measurements (P < 0.05). After 1 month, leakage of all adhesive systems was not significantly different (P < 0.05). SEM observation of pulp chamber walls demonstrated that the irregular dentine surface without smear layer was present in the nontreated group. However, NaOCl application removed the collagen fibrils leaving the dentine surface smooth. At resin,dentine interfaces of specimens, no hybridization zone was observed. Conclusions, None of the materials had created a perfect seal to the pulp chamber walls. PBNT and PLP had better sealing over the short term, but over the long term, there were no differences between the materials. [source] Periapical lesions and dental wear in the early MaoriINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2001J.A. Kieser Abstract Dental wear and intrabony lesions were evaluated in a sample of 225 skulls (136 male) of pre-contact New Zealand Maoris. The degree and direction of surface wear was scored according to the method of Molnar (Molnar 1971. Human tooth wear, tooth function and cultural variability. American Journal of Physical Anthropology34: 175,190) and revealed severe surface loss in both males and females with horizontal wear being the dominant pattern (62.4% male, 57.5% female). The width of coronal tissue above the pulp chamber, as well as the maximum depth and width of periapical lesions, was measured from both standard radiographs and digital images. The high prevalence of periapical pathology in the Maori underlined the extreme nature of dental wear in these people. It is postulated that this degree of tooth loss may be attributable to a change in diet from large birds to marine-dependence, the introduction of the kumara to New Zealand, dental erosion and finally, to the excessive masticatory forces exerted by a robust facial complex on normally sized teeth. Fenestrated lesions were highly prevalent (83% of skulls) and were centered mostly on the maxilla, with an even distribution among tooth classes. The finding of periapical lesions in teeth with minimal observable wear was attributed to traumatic occlusion. Copyright © 2001 John Wiley & Sons, Ltd. [source] Tooth Preparation: A Study on the Effect of Different Variables and a Comparison Between Conventional and Channeled Diamond BursJOURNAL OF PROSTHODONTICS, Issue 1 2004Daniel F. Galindo DDS Purpose: The purpose of this study was to evaluate the different variables involved in tooth cutting to characterize intrapulpal temperature generation, cutting efficiency, and bur durability when using conventional and channeled diamond burs. Materials and Methods: Forty premolars and 60 molars were selected for the study. Four diamond burs were paired according to grit size: 125- ,m grit: Brasseler Coarse (Control 1) and TDA System (Test 1) burs; and 180- ,m grit: Brasseler CRF (Control 2) and NTI Turbo Diamond (Test 2) burs. Each bur was used twice when cutting the premolar teeth, whereas it was used for 60 cuts when cutting the molar teeth. The data were analyzed to compare the correlation of bur design, grit and wear, amount of pressure, advancement rate, revolutions per minute, cutting time and rate, and proximity to the pulp chamber with intrapulpal temperature generation, cutting efficiency, and bur longevity. The mean values of test and control burs in each group were compared using an ANOVA (p < 0.05 for significant differences) for temperature generation and an ANOVA and the Tukey multiple range test (p, 0.05) for cutting efficiency and bur longevity. Results: No significant difference was found in intrapulpal temperature generation while cutting premolar and molar teeth with conventional and channeled diamond burs. In both groups, the mean temperature recorded during and after the cutting procedure was lower than the baseline temperature. For premolar teeth, no significant difference was established for control and test burs for the load required to cut into the tooth and the cutting rate. However, both test burs showed significantly fewer revolutions per minute when compared to their control counterparts. For the molar teeth, the Brasseler CRF bur required a significantly lower cutting load when compared to the NTI bur, whereas no difference was noted between the other pair of burs. The cutting rate was significantly higher for both control burs, whereas revolutions per minute (rpm) were greater for control coarser burs only. Overall, channeled burs showed a significantly lower cutting efficiency when compared to conventionally designed burs. Conclusion: Within the limitations of this study, channeled burs showed no significant advantage over conventional diamond burs when evaluating temperature generation and bur durability. Moreover, the cutting efficiency of conventional burs was greater than that of channeled burs. [source] Pulpal effects of enamel ablation with a microsecond pulsed ,,=,9.3-µm CO2 laserLASERS IN SURGERY AND MEDICINE, Issue 4 2009Michal Staninec DDS Abstract Background and Objectives In vitro studies have shown that CO2 lasers operating at the highly absorbed 9.3 and 9.6-µm wavelengths with a pulse duration in the range of 10,20-microsecond are well suited for the efficient ablation of enamel and dentin with minimal peripheral thermal damage. Even though these CO2 lasers are highly promising, they have yet to receive FDA approval. Clinical studies are necessary to determine if excessive heat deposition in the tooth may have any detrimental pulpal effects, particularly at higher ablative fluencies. The purpose of this study was to evaluate the pulpal safety of laser irradiation of tooth occlusal surfaces under the conditions required for small conservative preparations confined to enamel. Study Design/Materials and Methods Test subjects requiring removal of third molar teeth were recruited and teeth scheduled for extraction were irradiated using a pulsed CO2 laser at a wavelength of 9.3 µm operating at 25 or 50 Hz using a incident fluence of 20 J/cm2 for a total of 3,000 laser pulses (36 J) for both rates with water cooling. Two control groups were used, one with no treatment and one with a small cut made with a conventional high-speed hand-piece. No anesthetic was used for any of the procedures and tooth vitality was evaluated prior to treatment by heat, cold and electrical testing. Short term effects were observed on teeth extracted within 72 hours after treatment and long term effects were observed on teeth extracted 90 days after treatment. The pulps of the teeth were fixed with formalin immediately after extraction and subjected to histological examination. Additionally, micro-thermocouple measurements were used to estimate the potential temperature rise in the pulp chamber of extracted teeth employing the same irradiation conditions used in vivo. Results Pulpal thermocouple measurements showed the internal temperature rise in the tooth was within safe limits, 3.3±1.4°C without water cooling versus 1.7±1.6°C with water-cooling, n,=,25, P<0.05. None of the control or treatment groups showed any deleterious effects on pulpal tissues and none of the 29 test-subjects felt pain or discomfort after the procedure. Only two test-subjects felt discomfort from "cold sensitivity" during the procedure caused by the water-spray. Conclusion It appears that this CO2 laser can ablate enamel safely without harming the pulp under the rate of energy deposition employed in this study. Lasers Surg. Med. 41:256,263, 2009. © 2009 Wiley-Liss, Inc. [source] The cervical wedge-shaped lesion in teeth: a light and electron microscopic studyAUSTRALIAN DENTAL JOURNAL, Issue 3 2009TJ Daley Abstract Background:, The cervical non-carious wedged-shaped lesion is controversial in that its aetiology may involve attrition, erosion, abrasion and stress-corrosion (abfraction). This study examined the histopathology of anterior teeth with cervical wedge-shaped lesions by light and electron microscopy to elucidate their pathogenesis. Methods:, Ten undecalcified human teeth with cervical lesions were available for investigation. Patency of the dentine tubules was tested using red dye penetration from the pulp chamber. The morphology of normal and sclerotic dentine adjacent to the cervical wedge-shaped lesions was investigated by scanning electron microscopy. The numbers and diameters of dentinal tubules were measured at different levels beneath the surfaces of the lesions. Results:, The gross and microscopic features of the worn teeth were described. Red dye penetration tests showed white tracts of sclerotic tubules contrasted with red tracts of patent tubules. Numbers of tubules per square area and diameters of patent and sclerotic tubules varied at different levels within the dentine due to deposits of intratubular dentine. Conclusions:, The cervical wedge is shaped by interactions between acid wear, abrasion and dentinal sclerosis. No histopathological evidence of abfraction was found. Clinical diagnosis, conservation and restoration of non-carious cervical lesions need to take into account the extent of sclerotic dentine beneath wedge-shaped lesions. [source] Diagnosis and management of unusual dental abscesses in childrenAUSTRALIAN DENTAL JOURNAL, Issue 3 2003WK Seow Abstract Although the majority of dental abscesses in children originate from dental caries or trauma, a few are associated with unusual conditions which challenge diagnosis and management. Recent research findings have shed light on these unusual entities and greatly improved understanding of their clinical implications. These conditions include developmental abnormalities such as dens invaginatus in which there is an invagination of dental tissues into the pulp chamber and dens evaginatus in which a tubercle containing pulp is found on the external surface of a tooth crown. In addition, inherited conditions which show abnormal dentine such as dentine dysplasia, dentinogenesis imperfecta, and osteogenesis imperfecta predispose the dentition to abscess formation. Furthermore, ,spontaneous' dental abscesses are frequently encountered in familial hypophosphataemia, also known as vitamin D-resistant rickets, in which there is hypomineralization of dentine and enlargement of the pulp. In addition to developmental conditions, there are also acquired conditions which may cause unusual dental abscesses. These include pre-eruptive intracoronal resorption which was previously known as ,pre-eruptive caries' or the ,fluoride bomb'. In addition, some undiagnosed infections associated with developing teeth are now thought to be the mandibular infected buccal cysts which originate from infection of the developing dental follicles. In the present paper, these relatively unknown entities which cause unusual abscesses in children are reviewed with the aim of updating the general practitioner in their diagnosis and management. [source] Mandibular first premolar with two roots and three canalsAUSTRALIAN ENDODONTIC JOURNAL, Issue 1 2010Saravanan Poorni bds Abstract This case report presents a relatively uncommon clinical case of a mandibular premolar with two roots and three canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. Sound knowledge of root canal anatomy, appropriate assessment of the pulp chamber floor, critical interpretation of radiographs and high-magnification examinations are highly desirable to achieve the best possible outcome in complicated root canal therapy. [source] Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan populationINTERNATIONAL ENDODONTIC JOURNAL, Issue 9 2007C. M. Rwenyonyi Abstract Aim, To investigate the root and canal morphology of permanent maxillary molar teeth from a Ugandan population. Methodology, Maxillary first (n = 221) and second molar (n = 221) teeth were collected from patients attending dental clinics in Kampala. Teeth were prepared using a clearing technique: the pulp chambers were accessed and the teeth placed consecutively into 5% sodium hypochlorite, 10% nitric acid, then methyl salicylate. Indian ink was injected into the pulp chambers to demonstrate the canal system. Results, In the first molars, 95.9% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 3% of specimens and with the distobuccal root in 0.5% of teeth. In the second molars, 86% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 6.3% of specimens and with the distobuccal root in 6.8% of teeth. Apical deltas were more frequent in the mesiobuccal root when compared with distobuccal and palatal roots of both the first and second molars. A type I canal configuration (>75%) was the most frequent in all the roots of both the first and second molars. Canal intercommunications and lateral canals were more frequent in the mesiobuccal root when compared with other roots. Conclusions, The mesiobuccal root tended to have more variations in the canal system followed by the distobuccal root, whereas the palatal root had the least. The findings in root and canal morphology of this Ugandan population were different from previous studies, which may partly be attributed to racial differences. [source] Effect of placement of calcium sulphate when used for the repair of furcation perforations on the seal produced by a resin-based materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2007L. Zou Abstract Aim, To evaluate the sealing ability of calcium sulphate when used under composite resin for the repair of furcation perforations having different diameters. Methodology, Perforations of different diameter were created in the floors of pulp chambers in 60 extracted human molar teeth with either a number 3 (1 mm diameter) or 5 (1.5 mm diameter) round bur. The specimens of each group were divided into four sub-groups which were repaired with composite resin either alone or in combination with calcium sulphate that created an artificial floor (15 teeth group -1). Eight teeth without furcation perforations served as negative controls. In the leakage detection device, 1 mol L,1 glucose solution was forced under a pressure of 1.5 KPa from the crown towards the pulp chamber floor. The concentration of leaked glucose was measured at 1, 2, 4, 7, 10, 15 and 20 days using a glucose oxidase method and the data evaluated using the rank sum test. Results, The specimens with larger perforations repaired with composite resin alone had significantly more leakage (P < 0.05). Using calcium sulphate as an artificial floor significantly decreased leakage of smaller perforations (P < 0.05). In groups repaired with calcium sulphate under composite resin, leakage in smaller perforations was markedly lower than that in larger ones (P < 0.05). No significant difference was found between the specimens with 1 or 1.5 mm perforations repaired with resin alone (P > 0.05). Conclusions, Calcium sulphate significantly improved the sealing ability of 1 mm perforations repaired with composite resin but not for 1.5 mm perforations. [source] Sealing capacity of a photochromatic flowable composite as protective base in nonvital dental bleachingINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2006C. Llena Abstract Aim, To evaluate microleakage of a flowable composite used as a protective isolating base, applied with different adhesive systems. Methodology, Seventy root-filled teeth were divided into seven groups. A flowable composite base (Tetric Flow Chroma) was used with three adhesive techniques (Syntac, Excite, Excite DCS; in the three cases with and without acid etching) and in a control group without dentine conditioning or adhesive placement. A 30% hydrogen peroxide solution was applied for 24 h in the pulp chambers, followed by the placement of a dye (silver nitrate) for 4 h. Each tooth was sectioned longitudinally, and examined under 4× magnification to assess the tooth/restoration dye leakage following a four-degree scale. Percentage of dye penetration was registered. Statistical analysis was made through the Tukey and Mann,Whitney U -tests. Results, Maximum leakage (100% of specimens) was recorded in the control group without an adhesive system. In the groups subjected to acid etching, the percentage of leakage corresponded to Excite DSC (10%), followed by Syntac (20%) and Excite (30%). In the groups in which only an adhesive system was used, 50% of the teeth demonstrated dye leakage. Statistically significant differences in terms of leakage were observed between the control group and the experimental groups (P < 0.05). There were no significant differences among the experimental groups, but comparing the leakage percentages obtained between the groups in which the teeth were subjected to prior acid etching, and those in which no etching was carried out, observed differences were significant (P = 0.04). Conclusions, There were no significant differences between the adhesive systems in terms of leakage. Acid etching significantly reduced leakage. [source] Effect of bleaching agents on bonding to pulp chamber dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2005S. Timpawat Abstract Aim, To determine the effect of intracoronal bleaching agents on adhesion of bonding agents to pulp chamber dentine. Methodology, Forty extracted human maxillary anterior teeth were randomly divided into four groups of 10 teeth each. Bleaching agents were sealed in pulp chambers for 7 days, as in clinical use. Group 1 (control): distilled water, group 2: 35% hydrogen peroxide, group 3: sodium perborate mixed with water, and group 4: sodium perborate mixed with 35% hydrogen peroxide. Teeth were stored in saline at 37 °C for 7 days. After the bleaching agent was removed, teeth were leached in water for a further 7 days prior to bonding. The crown was cut vertically from mesial to distal and the labial pulp chamber dentine was prepared for bonding with Clearfil SE-Bond and filled with resin composite (Clearfil AP-X). The bonded specimens were kept moist at 37 °C for 24 h. Microtensile bond strengths were determined using a universal testing machine. Additional teeth were prepared using the same bleaching procedures to investigate the scanning electron microscopic appearance of the dentine surface. Results, Mean values (±SD) of microtensile bond strength for the experimental groups were: group 1: 5.29 ± 2.21 MPa, group 2: 5.99 ± 1.51 MPa, group 3: 9.17 ± 1.65 MPa and group 4: 3.99 ± 1.31 MPa. Dentine treated with sodium perborate in water (group 3) had significantly higher mean bond strength when compared with the other three groups (P < 0.05, Tukey's test). Mean bond strength was lowest when dentine was treated with sodium perborate plus hydrogen peroxide (group 4). Conclusions, In terms of subsequent bond strength during restoration, sodium perborate mixed with distilled water appears to be the best intracoronal bleaching agent. [source] An in vitro comparison of adhesive systems to seal pulp chamber wallsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2004B. Ozturk Abstract Aim, To compare in vitro the sealing properties of five different dentine adhesive materials (Prime&Bond NT (PBNT); Prompt L-Pop (PLP); Clearfil SE Bond (CSEB); Scotchbond Multi Purpose Plus (SMPP); EBS-Multi (EBSM)) inside the pulp chamber. Methodology, Seventy-five recently extracted human molar teeth were used. The roof of the pulp chambers and roots were removed under water cooling. Pulp tissue was removed, and the canal orifices were sealed. The pulp chambers were then treated with 5% sodium hypochlorite (NaOCl) for 1 min. The teeth were randomly divided into five groups of 15 teeth each. Adhesive systems were applied to the pulp chamber walls according to the manufacturers' instructions. The samples were connected to Plexiglass plates, and a fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of seal of each specimen was measured immediately, after 24 h, 1 week and 1 month. The data were statistically analysed by repeated-measurements multivariate anova, Friedman test, Wilcoxon signed rank test, Kruskal,Wallis of one-way anova and Mann,Whitney U -tests. The pulp chamber wall with and without NaOCl and resin,dentine interfaces of specimens were observed under a scanning electron microscope (SEM). Results, The leakage values of the materials were significantly different at different measurement periods. In all groups, leakage values decreased with time (P < 0.05). PBNT and PLP had the least leakage during immediate measurements (P < 0.05). After 1 month, leakage of all adhesive systems was not significantly different (P < 0.05). SEM observation of pulp chamber walls demonstrated that the irregular dentine surface without smear layer was present in the nontreated group. However, NaOCl application removed the collagen fibrils leaving the dentine surface smooth. At resin,dentine interfaces of specimens, no hybridization zone was observed. Conclusions, None of the materials had created a perfect seal to the pulp chamber walls. PBNT and PLP had better sealing over the short term, but over the long term, there were no differences between the materials. [source] Endodontic and periodontal treatments of a geminated mandibular first premolarINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2002S. Aryanpour Abstract Aim, To describe a rare case of gemination involving a mandibular first premolar. Summary The complex morphology of geminated teeth renders their endodontic and periodontal management difficult. Root canal and periodontal treatments were performed on a geminated mandibular first premolar with three canals. Clinical examination showed two separated crowns with united roots. Radiographically, two distinct pulp chambers with two joined and a third independent canal were seen. Conventional root canal treatment resulted in complete healing of the apical lesion. However, the occurrence of a vertical fracture led to the extraction of the mesial segment. At the follow-up visit, the distal segment was clinically healthy and continued to satisfy functional demands. Key learning points ,Failure to diagnose the initial crack along a gemination groove resulted in further propagation and finally complete vertical fracture. ,Owing to the abnormal morphology of the crown and the complexity of the root canal system in geminated teeth, treatment protocols require special attention. ,For asymptomatic cases without aesthetic or orthodontic problems and without associated pathosis, routine review and careful maintenance are required. [source] Effect of traditional and alternative intracoronal bleaching agents on microhardness of human dentineJOURNAL OF ORAL REHABILITATION, Issue 8 2004H. K. Chng summary, The purpose of this study was to compare the effect of traditional and alternative bleaching agents on microhardness of human dentine when used intracoronally. Thirty-six premolars were divided into six groups and bleaching agents were sealed into the pulp chambers as follows: group 1 , distilled water (control), group 2,30% hydrogen peroxide solution, group 3 , sodium perborate mixed with distilled water, group 4 , sodium perborate mixed with 30% hydrogen peroxide solution, group 5,35% carbamide peroxide gel, group 6,35% hydrogen peroxide gel. Access cavities were sealed and the teeth were stored in distilled water at 37°C. After 7 days, each tooth was sectioned at the cemento-enamel junction level and microhardness testing was carried out on dentine. The results showed that treatment with 35% hydrogen peroxide gel, 30% hydrogen peroxide solution and 35% carbamide peroxide gel reduced the microhardness of outer dentine to a small extent while treatment with sodium perborate mixed with water and sodium perborate mixed with 30% hydrogen peroxide solution did not significantly alter the microhardness of dentine. [source] Ablation of Systemic Phosphate-Regulating Gene Fibroblast Growth Factor 23 (Fgf23) Compromises the Dentoalveolar ComplexTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2010E.Y. Chu Abstract Fibroblast growth factor-23 (FGF23) is a hormone that modulates circulating phosphate (Pi) levels by controlling Pi reabsorption from the kidneys. When FGF23 levels are deficient, as in tumoral calcinosis patients, hyperphosphatemia ensues. We show here in a murine model that Fgf23 ablation disrupted morphology and protein expression within the dentoalveolar complex. Ectopic matrix formation in pulp chambers, odontoblast layer disruption, narrowing of periodontal ligament space, and alteration of cementum structure were observed in histological and electron microscopy sections. Because serum Pi levels are dramatically elevated in Fgf23,/,, we assayed for apoptosis and expression of members from the small integrin-binding ligand, N-linked glycoprotein (SIBLING) family, both of which are sensitive to elevated Piin vitro. Unlike X-linked hypophosphatemic (Hyp) and wild-type (WT) specimens, numerous apoptotic osteocytes and osteoblasts were detected in Fgf23,/, specimens. Further, in comparison to Hyp and WT samples, decreased bone sialoprotein and elevated dentin matrix protein-1 protein levels were observed in cementum of Fgf23,/, mice. Additional dentin-associated proteins, such as dentin sialoprotein and dentin phosphoprotein, exhibited altered localization in both Fgf23,/, and Hyp samples. Based on these results, we propose that FGF23 and (Pi) homeostasis play a significant role in maintenance of the dentoalveolar complex. Anat Rec 293:1214,1226, 2010. © 2010 Wiley-Liss, Inc. [source] Reaction of rat pulp tissue to Carisolv ,new gel',-A histocytological evaluationAUSTRALIAN DENTAL JOURNAL, Issue 1 2006T. Dammaschke Abstract Background: This study was an histological examination of pulp tissue exposed to Carisolv ,new gel' after 1 to 28 days. Methods: An occlusal cavity was prepared in 64 caries-free molar teeth of 16 Wistar rats. The roofsof the pulp chambers were perforated and Carisolv ,new gel' solution was placed onto the exposed pulps of 32 molar teeth for 20 minutes. Thirty-two contralateral molar teeth served as controls and were coated with an inert liquid containing isotonic saline solution and carmellose for 20 minutes as well. The pulps of all teeth were capped with Ca(OH)2 and the cavities were filled with a flowable composite in combination with a self-etching dentine adhesive. The animals were sacrificed after 1, 3, 7 and 28 days. Eight teeth per group and the time period were histologically examined, scored, and statistically evaluated (Wilcoxon-test). Results: The results showed no statistically significant differences between the Carisolv group and the control group (p>0.05). The observed pulp reaction was essentially the same as those reported in the past being typical for the effect of calcium hydroxide as a direct pulp capping agent. Conclusion: Compared to Ca(OH)2, Carisolv ,new gel' did not cause any different or additional pulp reaction in healthy teeth. [source] | |||||||||||||