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PubMed1989

A study of the relationship between incisor intrusion and root shortening.

Apical root shortening is one of the most common complications of orthodontic treatment. Force magnitude has been suggested as an important factor. Studies on the occurrence of root resorption show equivocal results. The aim of the present study was to evaluate the relationship between intrusion with low forces (25 gm) using utility arches in the bioprogressive technique and root shortening. Age, sex, facial type, treatment time, extraction versus nonextraction therapy, width of the symphysis, and the angle of the incisors to skeletal reference planes also were studied for their relationship to intrusion and root shortening. Root shortening was found to average 1.84 mm for maxillary incisors and 0.61 mm for mandibular incisors subjected to intrusive force. Intrusion of incisors in a population exhibiting growth was found to be one of "holding against growth" and in the upper arch to a change in angulation of the maxillary incisors. Furthermore, when extraction was a part of the orthodontic treatment, it was related to intrusion of maxillary incisors but not to intrusion of mandibular incisors. No relationship was found between the amount of root shortening and degree of intrusion achieved. However, a long treatment time was significantly correlated to root shortening. None of the other characteristics studied were related to either intrusion or root shortening. In the present study, it was found that intrusion with the utility arch type of technique is not related to amount of root shortening. The degree of root shortening was markedly higher in the maxilla than the mandible. In general, treatment time was the most significant factor for occurrence of root shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2001

A histopathological study of the role of periodontal ligament tissue in root resorption in the rat.

Whether periodontal ligament (PDL) tissue is capable of inducing root resorption was examined. The distal root of the rat molar was sectioned at the furcation and the PDL tissue removed from the root (non-PDL group, n=40). The distal root with the PDL intact was also prepared (PDL-intact group, n=40). The roots were transplanted into the dorsal skin of the rat. On the 1st, 3rd, 5th, 7th, 10th, 14th, 21st or 28th day after transplantation, the roots were removed together with surrounding dorsal subcutaneous tissue and were fixed, demineralized and embedded in paraffin. Serial sections from each block were stained with haematoxylin and eosin or by the tartrate-resistant acid phosphatase (TRAP) method to observe root-resorbing cell formation. Cyclo-oxygenase-2 (COX2) was also detected immunohistologically to examine prostaglandin E(2) production. On the 7th day after transplantation, multinucleated root-resorbing cells with TRAP were observed in the PDL-intact group. The number of TRAP-positive cells peaked on the 10th day after transplantation. COX2-positive cells were observed in PDL during the early experimental stages. No root resorption was seen in the non-PDL group. These results suggest that PDL tissue is involved in the formation of root-resorbing cells and root resorption.

Acid Phosphatase↗
PubMed2001

Periodontal healing after bonding treatment of vertical root fracture.

Vertical root fractures lead to advanced periodontal breakdown with deep periodontal pockets and vertical bone defects. The purpose of this study is to evaluate clinically the periodontal healing of root fracture treatment using adhesive resin cement. In 22 patients, 23 teeth with vertical root fractures were treated with 4-META/MMA-TBB resin cement. Eleven fractured roots were bonded through the root canal (group A) and 12 fractured roots were bonded extra-orally and replanted (group B). All teeth were then restored with full cast crowns (n=20) or coping (n=3). Mean probing depth was 6.6 mm at pre-treatment and 4.4 mm 6 months after the treatment in group A, and 7.4 mm and 4.6 mm, respectively, in group B. Bleeding scores were 100% at pre-treatment and 36.4% after 6 months in group A and 91.7% and 8.3%, respectively in group B. Radiographic bone level was 56.8% at pretreatment and 59.1% after 6 months in group A, and 18.8% and 29.2%, respectively, in group B. Two roots of group A and three roots of group B were extracted due to refracture, deterioration of periodontal inflammation, mobility, and luxation. The remaining roots (n=18) presented no discomfort to the patients and there was no deterioration of periodontal conditions over a mean period of 33 months (range 14-74 months) in group A and over a mean period of 22 months (range 6-48 months) in group B. There was no ankylosed teeth nor was any root resorption detected. The results suggested that the treatment of vertical root fracture using 4-META/MMA-TBB resin has good prognostic possibilities.

Adult↗
PubMed2003

Evaluation of root-end cavity preparation using ultrasonic retrotips.

AIM: To evaluate and compare the efficiency of root-end preparations using ultrasonic retrotips coated with diamond and zirconium nitride. METHODOLOGY: Eighty-five extracted single-rooted teeth were root filled, and then resected 3 mm from their apices. Root-end cavities were prepared with KiS (zirconium nitride-coated retrotip), CT-5 (stainless steel tip) or diamond-coated (DC) ultrasonic retrotips, and 10 teeth served as controls. Thirty teeth were used for evaluation of the time required to prepare the root-end cavity, the number of microcracks produced on the resected surface and the number of dentinal tubule openings on the root-canal wall using scanning electron microscope (SEM) images. A further 55 teeth were used for evaluation of dye penetration following filling of the root-end cavities with Super EBA. The degree of dye penetration in millimetres was measured under the microscope after 7 days of immersion in India ink. Statistical analyses were performed using the one-way ANOVA and Scheffe's F-test as the post hoc test. RESULTS: There was no significant difference in the number of microcracks and dentinal tubule openings present in the root apices prepared by the three retrotips. The time required for root-end cavity preparation using the DC retrotip was significantly less than that using the other groups (P<0.01). Positive controls showed dye penetration throughout the length of the root-end cavity, and negative controls showed no dye penetration. There was no significant difference between the three experimental groups in dye penetration. CONCLUSIONS: In this laboratory study, the time required to prepare root-end cavities using KiS retrotips was the same as that using CT-5 retrotips, and longer than that using DC retrotips. There was no significant difference in the number of microcracks or dye penetration between the three kinds of retrotips.

Analysis of Variance↗
PubMed1995

Morphological characteristics of dentitions developing excessive root resorption during orthodontic treatment.

The present study focuses on orthodontically provoked, excessive root resorption. The purpose was to identify in these cases common morphological features in radiographic diagnostic material taken before treatment. The material was submitted by 35 Danish orthodontists. The goal was to improve the future orthodontic diagnostics of the dentition in order to prevent severe root resorption during treatment. The study indicates that: (1) there is a strong connection between various dental morphological characteristics, such as invagination, length of root, and root shapes, especially taurodontism, and the tendency to root resorption during orthodontic treatment; (2) there is a connection between anomalies in the dentition, particularly ectopia and agenesis, and the tendency to root resorption during orthodontic treatment; (3) there seems to be a connection between the pattern of resorption in the primary dentition and the tendency to root resorption in the permanent dentition following orthodontic treatment; (4) girls are more susceptible to root resorption during orthodontic treatment than boys; (5) one ought to be on the lookout for connections between condylar changes, root resorptions, and anterior open bites in connection with orthodontic treatment. The observation regarding root resorption in dentitions in which invaginations and taurodontic root shapes occur has not previously been reported. Also, the findings of deviant resorption patterns in both the primary and permanent dentitions in a considerable number of patients are new observations, which ought to be incorporated into orthodontic treatment planning.

Adolescent↗
PubMed1990

Inducing gravitropic curvature of primary roots of Zea mays cv Ageotropic.

Primary roots of the mutant 'Ageotropic' cultivar of Zea mays are nonresponsive to gravity. Their root caps secrete little or no mucilage and touch the root only at the extreme apex. A gap separates the cap and root at the periphery of the cap. Applying mucilage from normal roots or substances with a consistency similar to that of mucilage to tips of mutant roots causes these roots to become strongly graviresponsive. Gravicurvature stops when these substances are removed. Caps of some mutants secrete small amounts of mucilage and are graviresponsive. These results indicate that (a) the lack of graviresponsiveness in the mutant results from disrupting the transport pathway between the cap and root, (b) movement of the growth-modifying signal from the cap to the root occurs via an apoplastic pathway, and (c) mucilage is necessary for normal communication between the root cap and root in Zea mays cv Ageotropic.

Agar↗
PubMed2005

The imaging of root canal obturation using micro-CT.

AIM: To examine the potential and accuracy of micro-computed tomography (micro-CT) for imaging of filled root canals. METHODOLOGY: The root canals of five extracted maxillary teeth were shaped manually with K-files. After irrigation and drying, the root canals were filled by lateral condensation using gutta-percha cones and AH plus (Dentsply Maillefer, Ballaigues, Switzerland) as sealer. The filled root canals were examined by micro-CT at resolutions <11 microm. Three-dimensional reconstructions of the root canal fillings were made. The roots were sectioned histologically and standard photographs of the sectioned surfaces were taken. Digitized photographic images and the corresponding micro-CT sections were correlated qualitatively by superimposition. Quantitative morphometric data were obtained with respect to the surface area of the root canal filling and the individual gutta-percha points of the histological and the micro-CT sections. Pearson correlation coefficients were calculated. RESULTS: There was a good qualitative correlation between the images from the histological and the micro-CT sections. The fillings were clearly differentiated from the root canal walls. Individual gutta-percha cones and sealer were discernable. Pearson correlation coefficients showed a highly significant correlation between the two methods (P < 0.001) with respect to the area of the complete root canal filling (r = 0.992) and the gutta-percha cones (r = 0.968). CONCLUSIONS: The micro-CT technique was a highly accurate and nondestructive method for the evaluation of root canal fillings and its constituents. Qualitative and quantitative correlation between histological and micro-CT examination of root canal fillings was high.

Dental Pulp Cavity↗
PubMed2006

Diagnostic value of computed tomography in re-treatment of root fillings in maxillary molars.

AIM: To compare the diagnostic information and radiation dose between intraoral radiography and computed tomography (CT) in re-treatment decision making concerning root fillings in maxillary molars. METHODOLOGY: Thirty-nine root-filled maxillary molars with suspected apical periodontitis were examined with two intraoral periapical radiographs and CT. Presence of periapical lesion/s per tooth and root were analysed for both techniques. In addition, in the CT images, the number of root canals, erosion, or perforation of cortical bone plates, and the distance between palatal root and cortical bone plates were evaluated. Radiation dose for CT was registered and calculated; and that of periapical radiographs used as reported previously (Ekestubbe et al. 2004). RESULTS: Periapical radiographs revealed periapical lesions in 33 teeth compared with 38 on CT images. A lesion of any root was detected more often with CT. The mesiobuccal root had two root canals in 30 teeth of which 27 of the MB2 canals were not filled, and 22 roots with an unfilled canal were associated a periapical lesion. Distances to palatal root, from the buccal and palatal cortex were measured in CT and varied between 5.0-12.0 mm and 0-4.0 mm, respectively. Based on the radiographic information, a variety of treatment alternatives were suggested. Mean effective dose of periapical radiographs was 0.02 mSv and that of CT 0.055 mSv. CONCLUSIONS: Computed tomography may give important information in re-treatment decision when considering root fillings in maxillary molars. The radiation dose should be considered individually.

Adult↗
PubMed1994

Effects of the Nd:YAG laser and combined treatments on in vitro fibroblast attachment to root surfaces.

The purpose of this in vitro study was to evaluate the effects of the Nd:YAG laser either alone or in combination with root planning or air-powder abrasive treatment on fibroblast attachment to non-diseased root surfaces. 28, 4 x 4 mm root specimens and four disc-shaped root specimens 6 mm in diameter were obtained from unerupted 3rd molars. The root segments were randomly assigned to 4 treatment groups: (1) control; (2) laser-only treated; (3) laser treated followed by root planning; (4) laser treated followed by air-powder abrasive treatment. Laser-treated root specimens were exposed for 1 min with the Nd:YAG laser calibrated at an energy setting of 75 mJ at 20 pulses/s using a 320 microns contact fiber. The contact fiber was held parallel to the root segments and the root segments were kept moist with distilled water. Following the prescribed treatments, the root specimens were incubated with fibroblast cultures and then prepared for SEM examination. Results of cell counts of fibroblasts attached to specimens within each treatment group yielded the following means and standard deviations: control groups, 181.64 +/- 44.74; lased only, 78.57 +/- 21.35; lased and root planed 125.35 +/- 26.13; and lased followed by an air-powder abrasive, 177.28 +/- 55.71. Application of ANOVA followed by the Dunn Multiple Comparison test revealed significant differences (p < 0.01) in the number of attached cells between the control and laser-only treated groups; and between the laser-only and laser/air-powder abrasive treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed2005

Root surface removal and resultant surface texture with diamond-coated ultrasonic inserts: an in vitro and SEM study.

BACKGROUND: A new diamond-coated ultrasonic insert has been developed for scaling and root planing, and it was evaluated in vitro for the amount of root surface removed and the roughness of the residual root surface as a result of instrumentation. METHODS: 48 extracted single-rooted human teeth were ground flat on one root surface and mounted (flat side up) in PVC rings of standard height and diameter with improved dental stone. Each tooth surface was treated with either a plain ultrasonic insert (PI), an ultrasonic insert with a fine grit diamond coating (DI) or sharp Gracey curettes (HI). The mounted teeth were attached to a stepper motor which drove the teeth in a horizontal, reciprocal motion at a constant rate. The thickness from the flattened bottom of the ring to the flattened tooth surface was measured before and after 10, 20, and 30 instrumentation strokes for each root surface with each of the experimental instruments. A number of treated teeth were randomly selected for examination with SEM and a profilometer. Statistical analysis (analysis of co-variance) was performed to compare the amounts of tooth structure removed among the 3 instruments and t-test was used to compare the roughness of the treated root surfaces. RESULTS: The mean depth of root structure removed was PI 10.7 microm, HI 15.0 microm, and DI 46.2 microm after 10 strokes; and PI 21.6 microm, HI 33.2 and DI 142.0 microm after 30 strokes, respectively. On average, 0.9 microm, 1.3 microm, and 4.7 microm of root surface was removed with each stroke of PI, HI and DI, respectively. PI and HI were not different from each other for all the stroke cycles, while DI was significantly different from PI and HI for all the stroke cycles (p<0.0001). Analysis with the profilometer showed that the smoothest surface was produced by the PI followed by the HI. The DI produced a surface that was significantly rougher than the surface produced by the PI or HI. CONCLUSION: These results suggest that diamond-coated ultrasonic instruments will effectively plane roots, and that caution should be used during periodontal root planing procedures. Additionally, the diamond-coated instruments will produce a rougher surface than the plain inserts or the hand curettes.

Analysis of Variance↗
PubMed2026

A novel domain of unknown function 707 protein coordinates root growth and drought tolerance.

A well-developed root system is one of the morphological mechanisms through which xerophytes adapt to drought. However, the molecular mechanisms underlying root growth are not completely known. In this work, two domain of unknown function 707 (DUF707) proteins were identified as hub genes for the response of roots to drought stress in Lespedeza potaninii, a xerophytic subshrub. We found that angiosperm DUF707 proteins can be divided into two subfamilies. LpDUF707-1 expression was strongly induced under drought stress and abscisic acid (ABA) treatment in the roots of L. potaninii, and its promoter activity in the roots was significantly induced by drought stress and mannitol treatments. The overexpression of LpDUF707-1 significantly improved root growth and drought tolerance, whereas the silencing of LpDUF707-1 inhibited root growth and reduced drought tolerance. We further revealed that the LpOBP3.1 transcription factor directly binds to the promoter region of LpDUF707-1, thereby repressing its activity. LpOBP3.1 expression was strongly suppressed under drought stress and ABA treatment in the roots of L. potaninii. The overexpression of LpOBP3.1 significantly inhibited root growth and decreased drought tolerance, whereas LpOBP3.1-RNAi lines presented the opposite pattern. Collectively, our results demonstrated that this novel module regulates root growth and drought tolerance in L. potaninii, thus providing gene targets for the development of elite crop varieties with well-developed root-mediated drought tolerance.

Drought Resistance↗
PubMed1984

Graviresponsiveness and cap dimensions of primary and secondary roots of Ricinus communis (Euphorbiaceae).

After branching from the primary root, secondary roots of castor bean (Ricinus communis) grow laterally for 15-20 mm, after which they bend downward (i.e., become positively gravitropic). During the first 10 mm of growth, the lengths of caps of secondary roots increase from 120 +/- 26 to 220 +/- 28 micrometers. Although this increase is statistically significant (P < 0.1%), the resulting secondary roots are only minimally graviresponsive. A subsequent doubling of the lengths and widths of the root caps (i.e., to 420 +/- 34 and 450 +/- 41 micrometers, respectively) is positively correlated with the onset of gravicurvature. The graviresponsiveness and dimensions of caps of positively gravitropic secondary roots are not significantly different from those of positively gravitropic primary roots. These results indicate that (i) a statistically significant increase in the length and length : width ratio of a root cap does not necessarily result in the root becoming positively gravitropic, (ii) there may be a minimum cap length and (or) width necessary for graviresponsiveness, and (iii) the degree of graviresponsiveness exhibited by a particular root may be related to the size of its root cap.

Ricinus communis↗
PubMed1994

The predominant cultivable flora of sound and carious human root surfaces.

Little detailed knowledge exists about the composition of the human root flora. Therefore, the predominant cultivable flora (PCF) was determined for samples of: (1) plaque from sound root surfaces (SRS) in eight subjects without root caries, (2) plaque from incipient root lesions (IRL) in eight subjects with root caries, and (3) carious material from advanced root lesions (ARL) in nine other subjects with root caries. Generally, one root surface was sampled per subject, and organisms-358, 512, and 389 for SRS, IRL, and ARL, respectively-were identified by standard methods. It was found that: (1) streptococci, actinomyces, and veillonellae constituted 84.2, 57.8, and 65.7% of the PCF of SRS, IRL, and ARL samples, respectively; (2) a wide variety of other Gram-positive cocci and Gram-positive and -negative rods was also present; (3) the PCF of many samples was often dominated by few organisms, the identity of which differed from sample to sample; (4) a negative and no association with root caries existed for the PCF levels of the non-mutans streptococci (non-MS) and the actinomyces; and (5) mutans streptococci (MS) and lactobacilli (L) were not always present among the PCF of IRL and ARL, respectively, and non-MS were isolated from the PCF of most lesions and actinomyces from all lesions. Our findings illustrate the complexity of the root surface flora and suggest that root caries development involves organisms other than MS and L.

Actinomyces↗
PubMed2005

Er:YAG laser in defocused mode for scaling of periodontally involved root surfaces: an in vitro pilot study.

BACKGROUND: The Er:YAG laser may be used on periodontally involved teeth in combination with conventional periodontal therapy in order to improve the efficacy of root instrumentation. The aim of this study was to compare the effect of hand instrumentation on root surfaces of periodontally involved teeth with Er:YAG laser application. METHODS: Thirty freshly extracted, non-carious, single-rooted, periodontally diseased human teeth from adult humans with advanced periodontal disease were used in this study. The teeth were divided into three groups of 10 specimens each. Group A was treated with scaling and root planing (SRP) with curets only (control). In group B, the root surfaces were scaled with curets and then lased with an Er:YAG laser (wavelength 2.94 microm). A handpiece with a water spray was used in non-contact mode (defocused) at a distance of 1 cm from root surface. Laser parameters were set at energy of 100 to 200 mJ/pulse, with 10 Hz of frequency. In group C, the root surfaces were lased only with power settings 250 to 300 mJ/pulse and 10 Hz frequency. An epon-araldite plastic embedding technique was used for light microscopic investigation. RESULTS: Histologic findings showed significant differences between the test and control sites. In control sites, after hand instrumentation, the surface was smooth, without a cementum layer, and the dentin layer presented opened tubules. Defects on the dentin layer were also present along root surfaces. In the test sites (B, C) root surfaces revealed no thermal damage; no cracking or tissue carbonization were observed. The superficial layers of lased surfaces appeared smooth and melted without alterations. CONCLUSION: Based on these findings, it appears that it may be feasible to use the Er:YAG laser for root instrumentation without prior root planing if the proper parameters are followed.

Adult↗
PubMed1990

[The study of root resorption of human deciduous teeth. I. Histological observation by light microscope].

Sixty-four human non-carious deciduous teeth were used to observe the root resorption of deciduous teeth by means of light microscope. The extent of root resorption was classified into 6 grades: Res. O, Res. i, Res. 1/4, Res. 1/2, Res. 3/4, Res. Co. In the physiological root resorption of deciduous tooth, there are numerous, large multinucleated odontoclasts and mononuclear fibroblasts or macrophages residing at the Howship's lacunae. The odontoclasts resorbed hard dental tissues, including cementum, dentin. A characteristic of active or "resorbing" odontoclasts, but not in free or inactive odontoclasts is cytoplasmic projections, or brush borders, which were found near the underlying hard dental tissues. The deciduous root resorption was found to be most advanced in the apical areas. Because of the different eruption path of the permanent successors, the position of deciduous root resorption varied. Generally, the lingual surface was resorbed more extensively than the labial surface in the deciduous anterior teeth; the resorption of the furcal area and interradicular cementum surface of the roots were more advanced in the deciduous molars. Predentin can be resorbed by odontoclasts, too. However, it seems more resistant to resorption than dentin. Resorption lacunae could be observed in the root canal and pulp chamber. This means that the internal root resorption probably occur simultaneously. Periodontal fiber attachment was observed in some Howship's lacunae of the root surface. Inflammatory changes occurred in the pulp of deciduous teeth during the shedding process, especially when the deciduous root was resorbed more than one half way. The appearance of the repairing cellular cementum and periodontal fiber attachment was clearly observed in some deciduous roots.

Child↗
PubMed2001

Periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces.

The purpose of the study was to evaluate periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces. Ten teeth with hopeless prognoses because of extensive alveolar bone loss and deep pockets extending to the apexes only on one or two surfaces, but with a healthy periodontal apparatus on the other surfaces, were selected. A mucogingival flap was elevated and the teeth were extracted carefully so as not to damage the healthy remnant of the periodontal membrane remaining on the root surfaces. Thorough extra-oral debridement was performed on the contaminated root surface and the remnant was carefully conserved. Retrofilling was also done to eliminate an endodontic cause of attachment loss. The teeth were horizontally rotated and then replanted so that the healthy root would face the connective tissue at the initially periodontally involved sites, and the root planed surfaces, which had been periodontally involved, would face the surfaces of the alveolar sockets at initially healthy sites. The teeth were splinted with adjacent teeth. Clinical parameters and radiographic examination were performed pre-operatively, and at 3 or 6 months, 1, 2, and 3 years postoperatively. One tooth was extracted 1.5 years postoperatively due to reduced support and the treatment strategy of the patient. The other nine teeth were well maintained without any discomfort for the whole maintenance period of 3 years. In all teeth, areas that previously had no pocketing but were now against denuded root surfaces maintained the previous pocket depth readings. In areas where a deep pocket was present but now had a root surface with healthy periodontium, a distinct decrease of mean pocket depth was observed at the first reexamination 3 months postoperatively. The mean radiographic alveolar bone level increased from 0.3% to 45.3% in 2 years and was thereafter maintained for the entire observation period. Loss of periodontal space and possible root resorption were observed in only one case without other ankylotic symptoms. These results suggest that the healing without ankylosis of an extensive denuded root surface may occur by mechanisms other than the maintenance of a viable periodontal ligament on the root surface.

Adult↗
PubMed2002

In vivo performance of the new non-instrumentation technology (NIT) for root canal obturation.

AIM: The aim of this in vivo study was to compare the radiographic quality of root fillings performed by the NIT-obturation method versus conventional mechanical obturation. METHODOLOGY: Sixty-six patients needing root canal treatment participated in this study. The treatments were performed by three private practitioners. The root canals were instrumented with K-Flexofiles to a master apical file between sizes 25 and 60, followed by step-back flaring up to size 70. Copious irrigation was used throughout the instrumentation procedure with NaOCl (3%). The teeth were obturated either by lateral condensation, the McSpadden technique (control) or by the new non-instrumentation technology (NIT) with and without using gutta-percha points. In the NIT method, a low pressure was created within the tooth, and AH 26 sealer was sucked into the root canal system. Radiographs of the root-filled teeth were analysed and the length of the root filling, the presence of voids and the area of any other fillings determined. RESULTS: The root canal fillings of the control group (0.1 +/- 0.1 mm) and those of the NIT/gutta-percha group (0.3 +/- 0.1 mm) were both overextended when taking the apical constriction as a reference point. Root canal fillings of the NIT/gutta-percha group were statistically (P < 0.05) significantly longer than those of the NIT without gutta-percha group. The latter showed slightly underextended root canal fillings (-0.14 +/- 0.1 mm). CONCLUSIONS: The present investigation demonstrated the performance of the NIT-obturation method in vivo. Root canals filled by the reduced-pressure-method using sealer combined with gutta-percha cones exhibited equivalent radiographic quality compared to conventionally filled canals.

Analysis of Variance↗
PubMed1998

Two canals in mesiobuccal roots of maxillary molars.

The purpose of this study was to examine extracted root canal treated maxillary molars cleared for: (i) the presence of a mesiopalatal (MP) canal in both first and second molars, (ii) the extension of MP canal from the pulp to the apical area, and (iii) the incidence of two foramina in the MB root. Seventy-two extracted maxillary molars (42 first and 30 second molars) were root canal treated by graduate students. The mesiobuccal (MB) roots of these samples were rendered transparent using a clearing technique. The results demonstrated that 52.3% of first and 40% of second molars had two canals obturated in the MB root. After clearing the same roots, the presence of MP canals rose to 80.9% and 66.6%, respectively. The MP canals were root canal treated as far as the foramen in 35.2% of first and 35% of second molars. However, after making them transparent, 91.1% and 90% showed the presence of this canal to the anatomical apex. The MB roots of the root canal treated first molars showed the presence of two foramina in 47% of cases but in 88.2% after clearing. The second molars showed 50% and 70%, respectively. The differences between root canal treated teeth before and after clearing were significantly different in almost all comparisons in both first and second molars. The only exception was when the presence of two foramina was compared before and after the clearing process in second molars (McNemar test P < 0.05).

Coloring Agents↗