Biomedical subjects

A Tamse

Publications and source records attributed to A Tamse.

At least 19 recordsLinked to original sources

PubMed2006

[Vertical root fractures in endodontically treated teeth part I: clinical and radiographic diagnosis].

A correct and quick diagnosis of endodontically treated vertically fractured teeth is important for two main reasons: (1) the differential diagnosis between the clinical and radiographic appearance of periodontal disease and endodontic failures, and (2) the delay in making the correct diagnosis will result in rapid loss of supporting bone, especially on the buccal side. Typical clinical signs in the maxillary and mandibular premolars and mesial root of the mandibular molars, which are the most susceptible roots and teeth, for fracture are a highly located sinus tract and a deep bony defect along the root facing the fracture line. In the maxillary and mandibular premolars and the mesial root of mandibular molars, typical bony radiolucencies are the halo, vertical and periodontal types. Radiolucency in the bifurcation was typical in vertical root fractures of mandibular molars.

Humans↗

PubMed2006

[Vertical root fractures in endodontically treated teeth--Part II: Etiology and prevention].

The etiologic factors for vertical fractures in endodontically treated teeth are predisposing factors, such as loss of tooth material, anatomy of the susceptible teeth, moisture loss, previous dentinal cracks, and loss of bone support; and iatrogenic factors, such as excessive removal of radicular dentin as a result of endodontic and prosthetic procedures and improper selection of dowels. Identification of susceptible teeth and roots, proper selection and cementation of dowels, and avoidance of excessive force during condensation of gutta percha and in removal of tooth structure during endodontic and prosthetic procedures, are all measures that can be taken to prevent root fractures.

Dental Restoration Failure↗

PubMed2003

Comparison of procedural errors resulting during root canal preparations completed by junior dental students in patients using an '8-step method' versus 'serial step-back technique.'.

AIM: To compare procedural errors occurring during preparation of root canals by junior dental students in patients using a new '8-step method' versus traditional 'serial step-back technique. METHODOLOGY: Junior dental students treated 291 root canals of maxillary and mandibular teeth in patients. A new '8-step method' was used to prepare 149 canals, whilst the traditional 'serial step-back technique' was used for 142 root canals. Instrumentation was carried out in both techniques using standardized stainless steel K-files and coronal flaring with Gates-Glidden reamers. In the apical one-third, a filing motion was used in the traditional technique: with the '8-step method,' reaming or filing motions were used in sizes up to 25 and only reaming in sizes larger than 25. All root canals were obturated with gutta-percha points and AH26 using a lateral condensation technique. Pre- and postoperative radiographs were made of each tooth. Procedural errors were recorded and statistically analysed using a binomic test for comparison of proportion. RESULTS: Significantly (P < (1.0001) more root canals maintained their original shape with no deviation (91%) with the'8-step method' compared to the traditional 'serial step-back technique' (61%). The procedural errors detected with the'8-step method' consisted of 10 canals with transportation (5%) and five with root perforations (2%); there were no canal obstructions. With the 'serial step-back technique: significantly (P < 0.0001) more errors occurred: 28 canals were transported (17%), 10 had root perforations (7%), and 16 canals were obstructed (6%). The differences in maintaining the original root canal shape between the two methods were significantly greater in molar versus anterior teeth. CONCLUSIONS: The new '8-step method' resulted in fewer procedural errors than the traditional 'serial step-back technique' when junior students prepared root canals in patients.

Dental Pulp Cavity↗

PubMed2003

A combined radiographic and computerized scanning method to evaluate remaining dentine thickness in mandibular incisors after various intracanal procedures.

AIM: To develop a computerized model to evaluate remaining dentine thickness after various intracanal procedures. METHODOLOGY: A three-step model was developed, in which injection of radiopaque solution into the root-canal space of 20 extracted mandibular incisors, exposure of periapical radiographs from two directions, and computerized scanning and printing of the image were combined. Following root-canal preparation and preparation of post space, evaluation of remaining dentine thickness was completed using appropriate software. RESULTS: Remaining dentine thickness was significantly affected (P < 0.01) by place (mesial-distal more than buccal-lingual), stage (root-canal preparation more than post space) and location (coronal more than middle and apical). CONCLUSIONS: This in vitro study confirmed that in an oval root-canal space, the mesial and distal aspects are mainly affected by intraradicular procedures. The three-step method is a useful tool to evaluate root-canal instrumentation as the root or tooth can remain intact during the procedure.

Contrast Media↗

PubMed2001

An evaluation of endodontically treated vertical root fractured teeth: impact of operative procedures.

Vertical root fractures of endodontically treated teeth are a frustrating complication that leads to extraction. The aim of the current survey was to evaluate the role of operative procedures in the etiology of this complication. A total of 154 endodontically treated vertical root fractured teeth were cleaned and washed after extraction and maintained in individual vials. Periapical radiographs before extraction, clinical findings and previous operative procedures were recorded. A post was observed in 95 teeth (61.7%), with 66 of these ending at the coronal third of the root. Most were screw posts of the Dentatus type (n = 64) and tapered cast posts (n = 14). A full crown was observed in 118 teeth, and 65 of these (55%) were extracted between 1 to 5 yr after final restoration. In 24 crowned teeth extraction was conducted within 1 yr after restoration and in 28 teeth after >5 years. It was concluded that post placement and root canal treatment are the major etiological factors for root fractures. Because signs and symptoms can appear years after the operative procedures in the root have been completed, coronal restorations would not interfere with the correct clinical diagnosis of vertical root fractures. Frequent recalls are recommended to diagnose vertical root fractures early, especially in susceptible teeth, such as premolars and mesial roots of mandibular molars.

Bicuspid↗

PubMed2000

Pattern of bone resorption in vertically fractured, endodontically treated teeth.

PURPOSE: To evaluate the clinical pattern of alveolar bone resorption associated with vertically fractured, endodontically treated teeth in correlation to clinical symptoms. MATERIAL AND METHODS: The pattern of bone resorption was evaluated in 66 maxillary premolars, 13 mandibular premolars, and 31 mesial roots of mandibular molars extracted during an 18-month period because of vertical root fractures. Type and duration of symptoms were recorded and correlated to the pattern of bone resorption. RESULTS: A V-shaped pattern osseous defect (dehiscence) was typical (91%) to the buccal plate rather than a U-shaped shallow, rounded, slow grade resorption in the palatal or lingual plate. Fenestration of the buccal plate was observed in 10 patients (9%). A positive correlation between type of symptoms and amount of buccal bone resorption was found (P <.0001). The resorptive defect was always facing the fracture line. CONCLUSIONS: A typical pattern of bone resorption in vertical root fracture cases as shown in this study can be helpful to the clinician in diagnosing vertical root fracture when an exploratory full flap surgical procedure is performed.

Alveolar Bone Loss↗

PubMed2000

Furcation groove of buccal root of maxillary first premolars--a morphometric study.

Furcation grooves on the palatal aspect of the buccal roots of 35 maxillary first premolars, randomly selected, were assessed and found to exist in 97% of the sample. The buccal roots were sectioned into slices, 1 mm thick, and morphometric horizontal and vertical measurements were taken by a Toolmaker Microscope. The slice with the deepest invaginations served as the reference plane. The deepest invaginations were found to be at a mean distance of 1.18 mm from the bifurcation, with a mean depth of 0.4 mm. The canal had a kidney-shaped appearance in cross-section, and the mean distance from the invagination to the canal wall was 0.81 mm. It is thus hazardous to use rotary instruments for flaring these roots and any circular-shaped post space preparation at this level is contraindicated. The outcome of such procedures might be root thinning, perforation, or vertical root fracture, thus causing a poor prognosis.

Bicuspid↗

PubMed2000

Gutta-percha softening: "Hemo-De" as a xylene substitute.

The putative hazardous nature of chloroform and xylene implies that safer substitutes should be considered. Standard cylindrical gutta-percha samples were immersed in Hemo-De, a xylene substitute, for 60 s at 37 degrees C. Weight loss of a sample, after drying, was used as a measure of its solubility. Master and accessory cone gutta-percha of three brands were compared. The highest solubility of all kinds of gutta-percha was in chloroform, which served as a positive control. The average solubility of all samples in xylene and Hemo-De was 61% and 52% of that in chloroform, respectively. DMS gutta-percha was more soluble than of Hygienic and DeTrey. Master cone gutta-percha of all brands was more soluble than that of their accessory cones. These results indicate that (a) large differences exist in the solubility of gutta-percha and (b) Hemo-De dissolved gutta-percha in a range similar to that of xylene and may be considered as a potential substitute for this organic solvent.

Chloroform↗

PubMed2000

The effect of immediate vs. delayed post space preparation on the apical seal of a root canal filling: a study in an increased-sensitivity pressure-driven system.

A 5 mm remaining length of root canal filling, after post space preparation, is commonly assumed to maintain sealing ability similar to that of the intact filling. Post spaces were prepared either immediately using hot pluggers, or later, using drills. The sealing ability of the fillings, 5 mm remaining length, were compared with each other and with an intact root canal filling control, using radioactive tracer in a pressure-driven system. When no pressure was applied, no differences could be detected between either of the groups and the control. When a pressure of 120 mm Hg was applied to the same teeth, the control group clearly maintained a better seal than each of the experimental groups, which did not significantly differ from each other. These results suggest that (a) the pressure-driven system was more sensitive than the passive leakage assay that failed to detect differences even at 14 days; (b) a remaining root canal filling of 5 mm was inferior to the intact root canal filling; and (c) the immediate post space preparation with hot pluggers did not differ from a delayed preparation with drills.

Analysis of Variance↗

PubMed2000

Residual dentin thickness in mandibular premolars prepared with gates glidden and ParaPost drills.

STATEMENT OF PROBLEM: The main factor that determines the prognosis of restored pulpless teeth is preservation of sound dentin. PURPOSE: This study evaluated the residual dentinal thickness (RDT) of mandibular premolars after preparation of post space with Gates Glidden and ParaPost drills. MATERIAL AND METHODS: Twelve extracted single canal mandibular premolars were embedded in clear polyester resin to the cementoenamel junction (CEJ) in a muffle device. Three horizontal sections were made 1, 3, and 5 mm apical to the CEJ. Mesiodistal (MD) and faciolingual (FL) axes were carefully marked and the RDT was measured for each slice. Each tooth slice was reassembled in the muffle device with orientation pins, then secured with stabilizing pins. This procedure was repeated after enlarging the root canal to K-40 file and preparing the coronal root canal space with Gates Glidden drills and ParaPost drills Nos. 3, 4, and 5. RESULTS: Residual dentinal thickness in a MD direction was 3.77 +/- 0.51 mm in the unprepared upper slice and 2.23 +/- 0.31 mm in the No. 5 ParaPost drill prepared lower slice, for a difference of 41%. The corresponding values for the FL direction were 4.35 +/- 0.51 mm and 4.08 +/- 0.46 mm, respectively (6%). CONCLUSION: The average dentinal thickness 5 mm below the CEJ in the mesial and distal directions after post space preparation approached the accepted minimal 1 mm. A conservative approach to post space preparation was advocated.

Analysis of Variance↗

PubMed1999

An evaluation of endodontically treated vertically fractured teeth.

For this survey, 92 vertically fractured endodontically treated teeth were evaluated clinically and radiographically before and after extraction. The maxillary second premolars (27.2%) and mesial roots of the mandibular molars (24%) were the most fractured teeth. In 67.4% of the teeth, a solitary buccal pocket was present; in 34.8%, a fistula frequently appeared closer to the gingival margin than to the apical area. A lateral radiolucency or a combination of lateral and periapical radiolucency was found in more than half of the cases. The general practitioners correctly diagnosed vertical root fracture in only one-third of the 92 fractured teeth in this survey.

Adolescent↗

PubMed1999

Radiographic features of vertically fractured, endodontically treated maxillary premolars.

OBJECTIVE: The purpose of this study was to evaluate the most frequent radiographic appearance of bony lesions associated with vertically fractured roots of endodontically treated maxillary premolars. STUDY DESIGN: The radiographic features of 102 endodontically treated teeth and their periradicular areas (51 with and 51 without vertically fractured roots) were evaluated and compared. RESULTS: The predominant appearance of the periradicular area in the teeth with vertically fractured roots was the "halo" lesion (57%); by contrast, in the non-vertically fractured roots group, a "periapical" radiolucent lesion was most frequently found (55%). Angular bone loss (14%) and periodontal radiolucency (14%) were also typical radiolucent lesions in the vertically fractured teeth. CONCLUSIONS: "Halo" lesion, perilateral radiolucency, and angular resorption of the crestal bone, combined with diffuse or defined but not corticated borders, indicated a high probability of vertical root fracture in maxillary premolars.

Bicuspid↗

PubMed1999

Prevalence of vertical root fractures in extracted endodontically treated teeth.

AIM: The aim of this study was to evaluate the prevalence of vertical root fractures (VRF) in extracted endodontically treated teeth and to correlate the findings to previous studies and surveys. METHODOLOGY: Root-canal-treated teeth were referred for extraction from a public dental clinic. The endodontic therapy had been completed by a variety of dentists. Each tooth was evaluated following extraction by the oral surgeon who performed the procedure: the exact aetiology for the clinical diagnosis that led to the extraction was recorded. RESULTS: The major reasons for extraction were restorative (43.5%) and endodontic (21.1%), followed by vertical root fractures (10.9%). CONCLUSIONS: The relatively high prevalence of vertical root fractures in this survey compared with previous clinical and radiographic surveys was probably related to the difficulties in making a clinical diagnosis of vertical fractures before extraction.

Adolescent↗

PubMed1998

Residual dentin thickness in mandibular premolars prepared with hand and rotatory instruments.

The residual dentin thickness in the coronal part of root canals of mandibular premolars after stepback preparation and flaring with Gates Glidden (GG) drills was assessed sequentially in a newly designed muffle device. Twelve extracted teeth were embedded in clear polyester resin, sectioned horizontally (1, 3, and 5 mm apically to the cementoenamel junction), and reassembled in the muffle device. The sequence of canal preparation was K-files to #40, then GG-2 and GG-4. After each procedure, the slices were separated and residual dentin thickness measured by a toolmaker microscope in four directions (buccal, lingual, distal, and mesial) and reassembled in the muffle device. Statistical analysis by three-way analysis of variance with repeated measures was undertaken. The difference in residual dentin thickness was highly significant with regard to instrument (control, K-40, GG-2, GG-4; p < 0.0001), slice (upper, middle, and lower; p < 0.0003), and direction (B, L, M, and D; p < 0.001). In each slice, the width of the mesial side was similar to the distal side, as was the buccal to the lingual sides. Reduction of residual dentin thickness in the mesiodistal direction, from the unprepared upper slice to the GG-4 prepared lower slice, was appreciably greater (35%) than in the buccolingual direction (5%).

Analysis of Variance↗

PubMed1998

A new muffle model system to study root canal morphology and instrumentation techniques.

A new muffle model system is presented using the principle of internal indexing. The system is composed of a metal stand, four pins, and a single Teflon mold that is used for the investment of all teeth. This system is very precise, reproducible, and versatile. The sectioned specimens can easily be stored assembled, as opposed to previous systems that rely on external indexing.

Dental Pulp Cavity↗

PubMed1998

Vertical root fractures in adjacent maxillary premolars: an endodontic-prosthetic perplexity.

Vertical root fractures in endodontically treated teeth occur frequently in teeth or roots in which their mesiodistal dimension is narrow, such as the maxillary upper premolars. Two cases of vertical root fractures in two adjacent maxillary reconstructed teeth are presented. As in many cases of vertical root fractures, the primary diagnosis was of endodontic treatment failure. The final diagnosis of the fractures was made either by the radiograph showing separation of root segments in one case, or by surgical exploration in the other. In both cases, tooth extraction was unavoidable.

Adult↗

PubMed1998

Root positioning and leakage to dye in extracted teeth using reduced pressure.

A study was conducted in vitro to assess the root apex position on leakage to dye under reduced pressure (560 mm Hg). A total of 132 extracted single-rooted teeth were randomly allocated to four groups. The teeth were prepared using a step-back technique and sealed with the cold lateral condensation technique, using gutta-percha without sealer. No significant differences (P < 0.813) were found between horizontally positioned experimental groups under reduced pressure and those in passive immersion. In the group in which the apices were in an upright position, the mean leakage was significantly different (P < 0.024) from the mean dye penetration in the group of teeth positioned horizontally under reduced pressure. Those teeth with apices upright allowed the most linear leakage (0.51 mm), whereas the groups in which the roots were horizontally positioned (with and without reduced pressure) had the least dye penetration (0.21 mm and 0.19 mm, respectively). These results show that tooth positioning has a significant effect on linear dye penetration under reduced pressure and emphasize the need to standardize factors that may influence penetration when assessing leakage study methodology.

Coloring Agents↗

PubMed1998

Comparison of apical leakage shown by four different dyes with two evaluating methods.

A study was conducted in vitro to assess and compare the extent of apical leakage of four dyes by two commonly-used evaluation methods. For the study, 120 single-rooted extracted teeth were prepared by the step-back technique and obturated by lateral condensation with gutta-percha and Roth 801 sealer. After randomly allocating the roots into six groups, they were immediately immersed in dye for 72 h, using vacuum for 30 min at 40 degrees C. Teeth were immersed in Eosin, Methylene Blue, Black India Ink and Procion Brilliant Blue and cross-sectioned in 0.7 mm thick slices. Those immersed in Black India Ink and Procion Brilliant Blue were also evaluated by the clearing process. Dye penetration was assessed using a stereomicroscope. A statistically significant greater dye penetration was measured in the cross-sectioned group compared to the clearing group using the same dyes (Black India Ink, P = 0.020, Procion Brilliant Blue, P = 0.040). In the cross-section groups, no statistical significant difference was observed in the amount of leakage comparing the four dyes. No statistically significant difference was found in the leakage pattern of Procion Brilliant Blue and Black India Ink using the clearing technique (P = 0.797). The evaluating method (cross-sections versus clearing) rather than the dye properties was the main difference between results. More research is needed to standardize dye leakage studies.

Carbon↗