Mian K. Iqbal

A Review of Factors Influencing Treatment Planning Decisions of Single-tooth Implants versus Preserving Natural Teeth with Nonsurgical Endodontic Therapy

One of the major issues confronting the contemporary dental clinician is the treatment decision between extracting a tooth with placement of a dental implant or preserving the natural tooth by root canal treatment. The factors that dictate the correct selection of one procedure over the other for each particular case are not yet established by randomized controlled studies. The aim of this review is to evaluate key factors allowing the clinician to make clinical decisions on the basis of the best evidence and in the patients best interests. General considerations are discussed that will help the reader analyze clinical studies focused on this problem. Importantly, the major studies published to date indicate that there is no difference in long-term prognosis between single-tooth implants and restored root canal-treated teeth. Therefore, the decision to treat a tooth endodontically or to place a single-tooth implant should be based on other criteria such as prosthetic restorability of the tooth, quality of bone, esthetic demands, cost-benefit ratio, systematic factors, potential for adverse effects, and patient preferences. It can be concluded that endodontic treatment of teeth represents a feasible, practical, and economical way to preserve function in a vast array of cases and that dental implants serve as a good alternative in selected indications in which prognosis is poor.

Comparison of Apical Transportation in Four Ni-Ti Rotary Instrumentation Techniques

A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radiographically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.

Incidence and factors related to flare-ups in a graduate endodontic programme

AIM To investigate the incidence and factors related to endodontic flare-ups in nonsurgical root canal treatment (NSRCT) cases completed by graduate endodontic residents at University of Pennsylvania, USA. METHODOLOGY Residents at University of Pennsylvania enter all clinical patient records into an electronic database called PennEndo database. Analysis of records of 6580 patients treated from September 2000 to July 2005 revealed a total of 26 patients with flare-ups (0.39%). Patients were categorized to have undergone flare-up when they attended for an unscheduled visit and active treatment, and when they suffered from severe pain and or swelling after initiation or continuation of NSRCT. SAS software was used to develop a logistic regression model with flare-up as a dependent variable. Independent variables included in the model were: history of previous pain, one vs. two visit NSRCT, periapical diagnosis, tooth type, rotary versus hand instrumentation, and lateral versus vertical compaction of gutta-percha. RESULTS The odds for developing a flare-up in teeth with a periapical radiolucency were 9.64 times greater than teeth without a periapical radiolucency (P = 0.0090). There was no statistically significant difference in flare-ups between one and two visits NSRCT. The odds of developing a flare-up increased 40 fold when NSRCT was completed in three or more visits. However, this result may have been confounded by addition of an unscheduled visit in patients suffering from flare-ups. Other independent variables did not have any statistically significant correlations. CONCLUSIONS A low percentage of patients experienced flare-ups during NSRCT procedures. The presence of a periapical lesion was the single most important predictor of flare-ups during NSRCT.

The Comparison of Gutta-Percha and Resilon Penetration into Lateral Canals with Different Thermoplastic Delivery Systems

The aim of this study was to evaluate the ability of Obtura II (Obtura Spartan, Fenton, MO) and Calamus (Densply, Tulsa, OK) to fill artificially created lateral canals in simulated plastic teeth using standard gutta-percha, Flow 150 gutta-percha (Obtura Spartan, Fenton, MO), and Resilon (Resilon Research, LLC, North Branford, CT). Lateral canals were created at 2, 4, 6, 8, 10, and 12 mm from the apex in plastic teeth. The teeth were divided into eight groups. In group 1, teeth were filled with a single increment of Calamus; in group 2, canals were filled with Calamus in three increments. In group 3, Obtura II was used with a single increment of standard gutta-percha, whereas in group 4 Obtura II was used in three increments. Groups 5 and 6 were similarly filled as in the preceding groups. A multiple-comparison analysis of variance test followed by a Tukey post-hoc test were used to compare filling material penetration into the lateral canals and the experimental groups (p < 0.05). The results indicated that the flow of the filling material into lateral canals is a function of the viscoelastic properties of the filling material rather than the mechanical properties of the delivery systems. Our data also suggest that the Resilon filling material flows better into lateral canals when a single backfill technique is used.

A Comparison of Apical Transportation and Length Control between EndoSequence and Guidance Rotary Instruments

INTRODUCTION The aim of this study was to evaluate apical transportation and working length changes after instrumentation using EndoSequence (Brasseler USA, Savannah, GA) and Guidance V-taper (Guidance Endo, Albuquerque, NM) rotary files. METHODS Forty-four mesiobuccal and mesiolingual canals of extracted mandibular first and second molars were instrumented by using EndoSequence or Guidance NiTi rotary files. Group 1 (n = 22) was instrumented with EndoSequence #30/.06, #25/.06, and #20/.06 files in a crown-down technique until apical enlargement with #25/.06 was achieved at the working length. Group 2 (n = 22) was instrumented with Guidance #30/.10, #25/.08, and #20/.06 files in a crown-down method until apical enlargement with #25/.08 was reached. A double digital radiographic technique was used to measure the loss of working length and canal transportation at 0, 1, and 3 mm from the working length. Measurements were analyzed by using repeated-measures analysis of variance. RESULTS The average amount of transportation at 0, 1, and 3 mm was 0.077 mm, 0.039 mm, and 0.040 mm for the EndoSequence group and 0.066 mm, 0.046 mm, and 0.05 mm for the Guidance group, respectively. The loss of working length was 0.001 mm for the EndoSequence group and -0.002 mm for the Guidance group. CONCLUSION There was no statistically significant difference in the loss of working length or transportation at the measured level between EndoSequence and Guidance rotary files.

Preoperative Predictors of Number of Root Canals Clinically Detected in Maxillary Molars: A PennEndo Database Study

The purpose of this investigation was to evaluate the concomitant influence of several variables on the number of root canals clinically detected in maxillary molars. The study used multiple logistic regression analysis on data from 1328 patients, aged 6-82 years, who received nonsurgical root canal treatment on maxillary molars at the University of Pennsylvania from 2000-2006. The number of canals was used as the dependent variable, whereas tooth type, age, caries, referral source, restoration, and pulpal and periapical diagnosis were used as independent variables. One was 0.98 times less likely to detect more canals when the age increased by 1 year. Similarly, one was 1.4 times more likely to detect canals in teeth with caries than teeth without caries. When these independent variables were controlled, only age of the individual was significantly related to number of root canals detected.

An In Vitro Comparison of Profile GT and GTX Nickel-Titanium Rotary Instruments in Apical Transportation and Length Control in Mandibular Molar

INTRODUCTION Profile GT files have been redesigned and are now marketed as GTX nickel-titanium rotary files. METHODS A double-digital radiographic technique was used to compare apical transportation (AT) and change in working length (CWL) between Profile GT and GTX rotary files. Mesiobuccal canals of 40 extracted mandibular molars were instrumented by either rotary system. The central axes of preoperative (15 K) and master apical rotary file (30/.04) were digitally superimposed. AutoCAD was used to measure AT at 0, 1, and 3 mm from WL. The distance from the file tip to the set WL indicated any CWL. Analysis of variance test showed no significant differences between groups in AT. RESULTS CWL in GTX (-0.25 +/- 0.42) group was significantly greater than in Profile GT group (0.17 +/- 0.30). CONCLUSIONS The AT results indicate that the newly designed GTX rotary instruments are as effective as the older Profile GT instruments.

Analysis of Continuous-Wave Obturation Using a Single-cone and Hybrid Technique

This study analyzed the adaptation of gutta-percha to prepared root canal walls using two obturation techniques and determined the influence of the System-B plugger depth on filling adaptation. Fifty-six extracted human mandibular molars were instrumented using Profile NiTi rotary instruments, stratified based on curvature, then randomly distributed into two groups. Group 1 was obturated using the single-cone continuous-wave technique. Group 2 was obturated with a hybrid technique: lateral condensation followed by a continuous-wave down-pack. Based on System-B plugger penetration, teeth were divided into three subgroups: (a) < 3.5 mm, (b) 3.5 to 4.5 mm, and (c) > 4.5 mm. Roots were horizontally sectioned at 1 mm and 3 mm coronal to the apical foramen, stained, and photographed. Four evaluators scored the adaptation of gutta-percha to the prepared canal walls. In 100% (n = 56) of the samples, no statistically significant difference existed between the two obturation methods at 1-mm (x = 1.80, SD +/- 0.69) or 3-mm (x = 1.804, SD +/- 0.69) sections. Best results were obtained with a plugger depth 3.5 to 4.5 mm from the working length.

Microleakage of cavit in varnish-lined, matrix-supported endodontic access preparations

The effect of the application of a matrix band and the use of cavity varnish on the microleakage of Cavit in endodontic access preparations was investigated. Sixty human upper premolars were divided into six groups of ten specimens each. Access cavities with proximal extensions were prepared and filled with 1, Cavit only; 2, Cavit after application of varnish; 3, Cavit with the use of a matrix band; 4, Cavit with a matrix band and varnish; 5, incremental deposition of Cavit with the use of a matrix band and varnish; and 6, gutta percha stopping. The specimens were placed in 2% methylene blue dye, thermocycled, and evaluated for both proximal and occlusal linear leakage. The experimental group in which Cavit was incrementally deposited in varnish-lined and matrix-supported cavities exhibited significantly (p < 0.05) less proximal microleakage than those groups in which cavities were filled without the application of both a matrix band and a cavity varnish.

Relative frequency of teeth needing conventional and surgical endodontic treatment in patients treated at a graduate endodontic clinic--a Penn Endo database study.

OBJECTIVE The objective of this study was to identify the most commonly retreated tooth at a postgraduate endodontics program and to compare this result with teeth requiring primary root canal treatment as well as those that required further surgical endodontic treatment. STUDY DESIGN The study population consisted of 6,894 patients treated between 2000 and 2005 by endodontic postgraduate students at the University of Pennsylvania School of Dental Medicine. Data regarding tooth type and endodontic treatment rendered were obtained from the Penn Endo database. RESULTS Initial root canal treatment was most commonly done on mandibular molars. Anterior teeth were 1.411 times more likely to undergo NSRT than molars. Maxillary molars were 1.048 times more likely to undergo conventional retreatment than mandibular molars. Maxillary anterior teeth were 3.032 times more likely than mandibular molars to undergo surgical treatment. CONCLUSIONS Mandibular molars may most commonly receive initial root canal treatment but it is the anterior teeth that are more likely to undergo surgical and nonsurgical retreatment. Maxillary molars are more likely to receive surgical intervention than mandibular molars. These data call for further investigation into the reasons for such discrepancy.