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Introduction Maxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots. Methods The fracture morphology in teeth extracted from patients because of VRFs was examined from a series of horizontal cross sections. 2-dimensional fracture mechanics analysis in conjunction with the finite element technique was developed to evaluate VRF caused by canal pressure (q). As in our previous single-rooted tooth model, the apical obturation force (F) was related to q using a simple formula. Results Fracture was mostly limited to the buccal root, exhibiting some competing modes including fracture from the depression peak to the canal surface and the canal surface to the root surface, which may occur either along straight lines or curved trajectories resembling the depression outline. The analysis predicted clinical fractures well, yielding VRF force values in the upper range used by clinicians during lateral condensation of gutta-percha. Conclusions The main etiology for VRF is stress concentration resulting from the combined effect of wedgelike canal depression and the flexibility of periodontal ligament tissue joining the root and bone. This drawback can be alleviated by minimizing canal enlargement and apical condensation force during root canal therapy.

Background This study presents a series of 18 cases of cracked non-endodontically treated teeth that were diagnosed following the placement of adjacent implant-supported rehabilitation. These findings could suggest a possible cause/related events. Results Most of the cases occurred in female patients (61%), over 50 years old (78%, with an average age of 59 years). Nine (50%) of the cracked teeth were molars, 7 (39%) were mandibular premolars, and 2 (11%) were incisor teeth. Most of the cracked teeth (61%) had an amalgam restoration, 50% had deep periodontal pockets, and 78% had vital pulps. In 78% of patients, multiple implants were placed (with an average of 3 implants per patient). The time from implant loading to the diagnosis of a crack was longer than 1 year in 78% of cases. Conclusions The most common patient profile found in this series was a woman over 50 years old, having a cracked mandibular premolar tooth, which was diagnosed more than 1 year after reconstruction based on multiple adjacent implants. Additional clinical studies are warranted in order to shed light on this potential complication.

The long-term dynamics of periapical lesions in endodontically treated teeth is not fully elucidated, thus presenting a clinical dilemma regarding the need for an intervention. The aim of the study was to retrospectively evaluate the long-term dynamics of periapical lesions that were left without intervention in endodontically treated teeth.Periapical status surveys of patients treated in a public dental clinic were retrospectively evaluated for the presence of periapical lesions in endodontically treated coronally restored teeth. The dynamics of the included periapical lesions was evaluated based on the periapical index (PAI) score changes between 2 consecutive periapical surveys of at least a 4-year interval. The influence of various factors on lesion dynamics was statistically evaluated.The study cohort consisted of 74 patients with a total of 200 endodontically treated teeth having periapical lesions that fulfilled the inclusion criteria. Fifty-seven (28.5%) lesions remained unchanged, 103 (51.5%) lesions worsened (PAI score increased), and 40 (20%) lesions improved (PAI score decreased). Poor root canal filling and poor restoration were found to adversely affect the long-term dynamics of the periapical lesions (P.05). Age, sex, and the presence of a post had no statistically significant influence on lesion dynamics (P.05).Poor root canal filling and poor restoration may adversely affect the long-term dynamics of periapical lesions that are left without intervention in endodontically treated teeth. Therefore, in cases of poor root canal filling or poor restoration, further intervention may be indicated.

Introduction This study aimed to report a possible effect of the presence of an adjacent implant on the development of a vertical root fracture (VRF) in endodontically treated teeth. Methods A series of 8 cases in 7 patients with teeth diagnosed with VRF after the placement of implants in the adjacent area is described and analyzed. In addition, a comprehensive literature search with strict inclusion and exclusion criteria was undertaken to identify additional clinical studies that assessed this clinical scenario. Results The case series analysis revealed that the time from implant placement to the diagnosis of VRF was between 5 and 28 months (average = 11 months). The majority of cases occurred in female patients who received 2 or more implants. Six of the 7 patients were older than 40 years, with an average age of 54 years. The majority of teeth with VRF were premolar or mandibular molar teeth (6/8 teeth). All fractured teeth had been restored with a crown and had a post present, and the quality of the root canal filling was determined to be adequate. The systematic review revealed that implant-associated VRF has not been investigated or reported in the literature yet. Conclusions Based on a systematic review of the literature, this case series, although limited in its extent, is the first clinical report of a possible serious adverse event of implant-associated VRF in adjacent endodontically treated teeth. Additional clinical studies are indicated to shed light on this potential phenomenon.

A two-dimensional fracture mechanics analysis of vertical root fracture (VRF) in single-canal roots from apical condensation of gutta-percha (gp) is developed. The resulting analytic relation for apical load causing VRF agrees with major trends reported in in-vitro tests on roots subjected to either continuous or, the more clinically relevant, repeating vertical condensation of gp. The model explicitly exposes the role of root canal morphology and dentin fracture toughness on VRF. Ovoid and irregular canals are prone to fracture while the effect of mean root canal radius is modest. Canal taper and instrumentation details may affect VRF only marginally and indirectly. The model predicts dentinal cracks to occur following root canal instrumentation and obturation, which may pose long-term threats to tooth integrity.

Rosen E, Tsesis I, Tamse A, Bjorndal L, Taschieri S, Givol N. Medico-legal aspects of vertical root fractures in root filled teeth. International Endodontic Journal, 45, 7–11, 2012. Abstract Aim To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT). Methodology A comprehensive search in a professional liability insurance database was conducted to retrospectively identify cases of VRF following RCT. The complaints were categorized as either financial risk bearing or financial nonrisk bearing, and related demographic, prosthetic and endodontic variables were analysed. Results Seventy-seven legal cases of patients with VRFs following RCT were identified. Most of the cases were either in premolars or in mandibular molar teeth (P

Introduction Vertical root fracture (VRF) from apical condensation of gutta-percha is a common failure mode in endodontically treated teeth. Virtually all previous studies of VRF are limited to 1-canal roots. In this study, we consider experimentally and analytically VRF in roots with 2 canals. Methods The interior root morphology in mandibular molar teeth extracted from patients due to VRF or other reason was examined from a series of polished horizontal cross sections. A 2-dimensional fracture mechanics analysis was used to determine crack growth from the canal surface to the outer root surface and evaluate the apical load needed to cause VRF, F max . Results From a mechanistic viewpoint, the isthmus connecting root canals can be regarded as a natural weak plane or crack. The results expose the prime role of isthmus in reducing F max , from ≈ 50 N with no isthmus present to ≈ 10 N. Conclusions Two-canal mesial roots are much more prone to VRF than 1-canal distal roots. We suggest that VRF may occur during clinical condensation of gutta-percha in mesial roots of mandibular molars as well as other roots with canals connected by isthmus.

Vertical root fracture in an endodontically treated tooth originates from the root at any level and is considered a frustrating and vexing complication in endodontic therapy. Many times, it is difficult to achieve an accurate diagnosis and to differentiate the fracture from other clinical entities. However, usually combination of cervicaly located sinus tract combined with a narrow deep periodontal defect present is highly suggestive of a vertical root fracture. When the diagnosis of a vertical root fracture is made, usually years after all endodontic and restorative procedures have been completed, extraction of the tooth or root should be done in a timely manner to minimize the bone loss in the surrounding bone. This bone loss may compromise subsequent implant placement in the area. This chapter will emphasize the importance of achieving an accurate and timely vertical root fracture diagnosis and will describe the more typical signs, symptoms, and radiographic features that are suggestive for vertical root fracture diagnosis in the susceptible teeth and roots.

Categorization of dental fractures should take into account the origin, the location, and the direction of fracture progression. Identifying the fracture category will influence the selection of treatment options. The type of fracture category to be covered in this book will be that primarily occurring in endodontically treated teeth; the fracture is of a chronic nature and characterized as having a vertical direction over time and identified as vertical root fracture (VRF). The other two fracture types—crown-originating fractures (COFs) and trauma-related fractures—will be briefly described in this chapter to differentiate them from VRFs.

The etiology of vertical root fractures (VRFs) in endodontically treated teeth is complex because of its multifactorial nature. Since there is no single specific etiology that is pathognomonic for this complication that can be identified, prevention of vertical root fractures in endodontically treated teeth is quite difficult. There are predisposing factors as well as contributing ones. The predisposing factors are practically noncontrollable. These include the specific anatomy of the susceptible roots, biochemical changes in the root dentin in the endodontically treated tooth, and loss of healthy tooth substance as a result of caries and trauma before beginning endodontic procedures. The contributing factors are attributed to the iatrogenic risk factors associated with various dental procedures performed on the tooth. These clinical etiologies will be discussed in the first section, and a fracture mechanics perspective will be presented in the second section. This will incorporate geometry, material, and loading issues when a dentinal crack is initiated in the canal wall, which is a precursor for a future complete and incomplete fracture in the root at a later stage.

A most frustrating complication to root canal therapy is vertical root fracture (VRF) in an endodontically treated tooth. Prognosis most often is hopeless and differential diagnosis from other pathoses may be difficult at times. Nevertheless, proper diagnosis is critical to distinguish a fracture complication from clinical manifestations of periodontal and endodontic diseases. This review emphasizes the importance of the correct diagnosis of VRF, describes the more typical clinical and radiographic features of this disorder, and summarizes its prevalence and multifactorial etiology.

Objective To compare procedural errors that occur in patients during root canal preparation by senior dental students using a new ‘8-step method’ versus the traditional ‘serial step-back technique.’ Study design Senior dental students treated 221 root canals of maxillary and mandibular teeth. Instrumentation included coronal flaring with Gates-Glidden reamers and standardized stainless steel K-files in all teeth. A new 8-step method was used to prepare 67 canals using standardized stainless steel hand instruments (8-step SS) and 69 canals using the rotary Nickel Titanium instruments (8-step NiTi). The traditional serial step-back technique (step-back) was used for 85 root canals. In the apical third, reaming or filing motions were used up to sizes 25 and only reaming motion in sizes larger than 25 with the new 8-step method. A filing motion was used in the step-back for all sizes. Root canals of all groups were obturated with gutta-percha points and AH26 using a lateral condensation technique. Pre- and postoperative radiographs were taken of each tooth. Procedural errors were recorded and statistically analyzed using a binomic test for comparison of proportion. Results Procedural errors detected consisted of 2 canals with transportation (3%) with the 8-step SS, and 3 canals (4%) with transportation with 8-step NiTi. There were no canal obstructions or instrument separations. With the step-back, 20 canals were transported (24%), 7 canals had obstructions (8%), and in 1 canal instrument was separated (1%). Conclusions The new 8-step method resulted in fewer procedural errors than the traditional serial step-back technique when senior students prepared root canals in patients either by hand with standardized K-files or by rotary NiTi instrumentation.

Objective We sought to measure the residual dentin thickness (RDT) in the mesial roots of mandibular molars after instrumentation with Lightspeed and Gates-Glidden rotary instruments. Study design Thirty extracted, untreated human mesial roots of mandibular molars were separated from the distal roots and embedded in clear polyester resin. The roots were cut horizontally at 1, 4, and 7 mm short of the anatomic apex. The diameter of each mesiobuccal canal was measured by using a stereo measuring microscope at each level in the buccolingual and mesiodistal directions. The dentin thickness was measured in each level in the mesial, distal, buccal, and lingual directions. Sections were reassembled with a muffle. The canals were enlarged to the working length with Lightspeed rotary instruments, of which the average size used was a No. 50 file. The coronal third was flared with No. 2 Gates-Glidden reamers. Slices were separated again, and the RDT and canal diameters were measured. Results The minimal measured RDT after instrumentation at the 1-, 4-, and 7-mm levels was 0.70 ± 0.28 mm, 1.04 ± 0.18 mm, and 1.09 ± 0.19 mm, respectively. The average diameter of the canals after instrumentation at the 1-, 4-, and 7-mm levels was 0.50 ± 0.04 mm, 0.52 ± 0.05 mm, and 0.74 ± 0.08 mm, respectively. The canal diameter did not exceed one third of the root diameter at all levels. Conclusions Root canal preparation of mandibular mesial roots with Lightspeed instruments to No. 50 in the apical third and Gates-Glidden reamers to No. 2 in the coronal third does not significantly decrease the RDT.

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.

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.

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; p0.0001), slice (upper, middle, and lower; p0.0003), and direction (B, L, M, and D; p0.001). 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%).

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.

Tooth length determination is a crucial step in endodontic treatment. Until the late 1970s, tooth length determination was based mainly on radiographic interpretation. The advent of apex locators, which identify the difference in the electrical resistance between the root canal and the periodontal membrane, ushered in a new era for measuring tooth length. However, the accuracy of these devices has been questioned. Pertinent literature is discussed with the aim of providing information on the development of the concept, techniques, and devices for tooth length determination.

Aim To evaluate, ex vivo, the effect of maintaining apical patency on the original canal shape during preparation of curved roots by two different techniques. Methodology Forty extracted human maxillary and mandibular molars were evaluated. Occlusal surfaces were ground and roots sectioned to the level of the cemento-enamel junction to allow only one root to remain for evaluation in each tooth. Specimens were divided into four experimental groups (10 canals each): Group 1 – root canals prepared using the balanced force technique with stainless steel K-files, and patency established with size 10 K-files between each instrument; Group 2 – same as Group 1 but without the use of a patency file; Group 3 – canals instrumented with LightSpeed® instruments and patency established with size 10 K-files between each instrument; and Group 4 – same as Group 3 but without the use of a patency file. Specimens were mounted and a series of radiographs taken. Initial and post-preparation digital images were superimposed and the distance between two central axes at 1, 2 and 4 mm from the working length (WL) was measured to obtain an indication of the degree of apical transportation. Results were subjected to statistical analysis using two-way analysis of variance (anova). Results No significant differences were found in degree of apical transportation at different levels of the root canal (P > 0.05) nor in loss of WL between groups (P > 0.05). Conclusion In this laboratory study, maintaining apical patency did not influence canal transportation in the apical 4 mm.

Objective The purpose of the present study was to compare the diagnostic ability of conventional intraoral film radiography and a charged-coupled device (CCD) sensor in detecting vertical root fractures (VRF) in endodontically treated single-rooted extracted human maxillary premolars. Study design The study consisted of 60 extracted single-rooted endodontically treated maxillary premolars: 30 with clinically confirmed VRF (experimental group) and 30 with no VRF (control group). An intraoral CCD sensor and conventional Kodak Insight Film were used. Two observers evaluated the digital and conventional radiographs twice with an interval of 4 weeks. Specificity and sensitivity for each radiographic technique were calculated and subjected to statistical analysis. Kappa values were calculated for intra- and interobserver agreement. Fisher's exact test was used to evaluate detection of VRF. The overall differences in sensitivity and specificity between radiographic techniques were evaluated by McNemar test. Results The specificity of the digital system was significantly better ( P = .016) for the second observer at the first reading. There were no significant differences in sensitivity and specificity for both observers between the 2 systems for other readings ( P > .05). Conclusions No difference was found between the intraoral CCD sensor and conventional radiography in detecting vertical root fractures for single rooted maxillary premolars ex vivo.

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.

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. (J Prosthet Dent 2000;83:617-23.)

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. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:348-52)

National and international standards require that gutta-percha cones be sufficiently radiopaque to be distinguished from natural structures such as dentin and to permit evaluation of the density of the root canal filling. Discs, 1-mm thick, made from 15 commercial and experimental brands of gutta-percha cones, were tested for their compliance with the requirements. The radiopacity of 1-mm thick root dentin slabs was similarly measured with a photo-densitometer. All radiographs were made on D-speed occlusal film and replicated on E-speed film. The mean radiopacity of the gutta-percha discs on D-speed film was 7.26 mm of aluminum equivalent and 7.53 mm on E-speed film, greatly exceeding the minimal requirement of 3 mm. The difference in the values obtained with the two film types was not significant, suggesting that E-speed films may be used for the test. Dentin slabs were uniform in their radiopacity, equivalent to 1 mm of aluminum, confirming previous findings. In view of complaints of insufficient clinical performance, the present minimal requirement for radiopacity of gutta-percha cones seems too low.

The apical seal afforded by laterally condensed or thermomechanically compacted gutta-percha has been investigated. The present study measured apical leakage to a dye in roots filled by a combination of the two techniques (hybrid technique). The canals of 40 extracted teeth were endodontically prepared and separated into two equal groups. Lateral condensation with sealer was used in one group. The roots of the second one were filled using the hybrid technique. After immersion in Procion brilliant green, the roots were cleared for measuring the depth of penetration of the dye. The roots filled with the hybrid technique leaked significantly less (p

A case of a relatively rare occurrence--a draining sinus tract on the chin which originated from an abscessed lower incisor--is presented. The sequence of treatment and mode of healing are discussed, and the importance of an awareness of this phenomenon for the differential diagnosis is stressed.

A new rotatory instrument, the Engine Plugger, that is claimed to be less fragile than the McSpadden Compactor, has been introduced since the recognition of thermomechanical compaction as a valid technique for root canal filling. The purpose of this study was to test the efficacy of the apical seal afforded by the Engine Plugger in comparison with that of an established technique, lateral condensation. Eighty roots with round canals prepared to size 45 were randomly divided into two groups: one compacted with the Engine Plugger (Group 1) and the other with the lateral condensation technique (Group 2). AH-26 sealer was used in half the specimens. Four additional roots served as controls. The roots were cleared following immersion in Procion brilliant green, and the maximal depth of penetration of the dye was measured with a stereomicroscope. Severe leakage occurred in both groups when sealer was not used (mean depth: 3.17 mm in Group 1; 4.3 mm in Group 2). Addition of sealer reduced leakage significantly (p less than 0.001). There was no statistically significant difference in the depth of penetration of the dye between the two groups when AH-26 was used, although a trend in favor of the Engine Plugger method (0.15 mm versus 0.425 mm for lateral condensation) was noted.

A radiographic statistical study was performed in order to determine the presence and type of external resorption found in pulpless permanent teeth. Of 1,372 roots evaluated, 49.6% showed resorption. The degree of apical external resorption was significantly related to the presence and size of the periapical lesions in all roots. Much more resorption was found in the roots without root canal filling than in those that were filled.

Master cone adaptation is a crucial step of root canal obturation with the lateral condensation technique. In regular canals such adaptation is facilitated by the use of standardized instruments and master cones, using a “tug-back” sensation as a guide. Standardized master cones are not easily adapted to flat canals and preparation of customized master cones by the chloroform dip technique has been suggested. Thirty-four extracted roots with flat canals and fully formed apices were selected on the basis of buccolingual and mesiodistal radiographs. Roots with regular, round cross-section canals served as controls. Following a clinical-like root canal preparation, half of each group was obturated with a customized master cone, while in the other half standardized cones were used. A single cone was used with AH26 sealer. After the sealer was set, the roots were subjected to dye penetration and a clearing assay. The maximal distance to which the dye penetrated was used as a measure for the quality of the apical seal. In flat canals, customized cones provided a significantly better seal than standardized cones (p

Foramina are anatomic openings in bone and are seen radiographically as radiolucent areas. The present study investigated the prevalence of appearance of the greater palatine foramen (GPF) in bisected periapical radiographs, its location in the horizontal and vertical planes, and the prevalence of superimposition of the GPF on apices of the maxillary molars. The results showed that the GPF appeared in 37.7% of the examined periapical radiographs, and in 25.9% of the detected GPF's, they were superimposed on the apices of the second and third maxillary molars. These findings emphasize the fact that the GPF is seen rather frequently in periapical radiographs. Constant awareness of the existence of these anatomic radiolucencies will prevent a mistake in interpretation, misdiagnosis and mistreatment.