Comparative micro-computed tomographic evaluation of two carrier-based obturation systems

Objectives

The aim of the study was to measure the percentage of volume of voids and gaps in the apical third of root canals obturated with two techniques using micro-computed tomography.

Materials and methods

Fifty-four single-rooted teeth were collected and root canal-prepared. The roots were randomly allocated into two groups; each group was obturated by using thermoplasticized technique with a different material (gutta-percha and Topseal for Thermafil, Resilon and RealSeal for RealSeal 1). Roots were then scanned, and volume measurements for voids and gaps in the obturated roots were carried out using specialized CT software. Percentage of gaps and voids was calculated.

Results

The present study showed that none of the root canal-filled teeth was gap free. Student t test was conducted. No significant difference was found between Thermafil and RealSeal 1 concerning percentage of voids in the apical third (P?>?0.05). Both materials showed statistically significant difference between the levels where 1 mm showed the highest volume of voids (P?<?0.05).

Conclusions

Both carrier-based techniques allowed a good sealing ability in root canals but none of the materials was gap free. Statistically significant difference between the levels was found and 1 mm showed the highest volume of voids.

Clinical relevance

This study shows the efficiency of carrier-based obturation systems in filling root canals hermetically. It compares new adhesive endodontic materials with the traditional gold standard gutta-percha. Results show the good sealing ability of both techniques making them appropriate to use in daily endodontic obturations.     

Radiopacity of dental restorative materials

Objectives

Radiopacity of dental materials enables clinician to radiographically diagnose secondary caries and marginal defects which are usually located on the proximal gingival margin. The aim of this study was to measure the radiopacity of 33 conventional resin composites, 16 flowable resin composites, and 7 glass ionomer cements and to compare the results with the radiopacity values declared by the manufacturers.

Materials and methods

From each restorative material, six 2-mm-thick disk-shaped specimens were fabricated and eight 2-mm-thick sections of teeth were made and used as reference. The material samples and tooth sections were digitally radiographed together with the aluminum stepwedge. Gray values were obtained from the radiographic images and radiopacity values were calculated and statistically analyzed. Post hoc Tukey’s honestly significant difference test was used to calculate significant differences in radiopacity values between materials and reference dentin and enamel values.

Results

The radiopacity values of all 56 restorative materials were above the dentin reference radiopacity value; however, 4 out of 33 conventional composites and 3 out of 16 flowable resin composites had significantly lower radiopacity than enamel (p?<?0.05). There were up to 1.53 mm eq Al differences between the measured and the manufacturers’ declared radiopacity values of some materials.

Conclusions

Majority of the materials exceed enamel radiopacity and would not hamper radiographic diagnosis of secondary caries. However, manufacturers’ data are not always reliable.

Clinical relevance

Materials with radiopacity lower than enamel might be misinterpreted as secondary enamel caries on radiographic images, especially when applied as initial increment on the proximal gingival margin.     

Clinical studies on core-carrier obturation: a systematic review and meta-analysis

Background

This systematic review aimed to evaluate the clinical performance of core-carrier obturation in endodontic treatment.

Methods

Keywords of “(core carrier OR Thermafil) OR (cold lateral condensation OR lateral condensation) OR (warm vertical condensation OR vertical condensation) AND (obturation OR root canal filling) AND clinical study” were searched for all obtainable publications up to year 2017 in the databases of PubMed, ScienceDirect, EMBASE, Scopus and Web of Science. The success rate, short-term postoperative pain, overfilling and adaptation of core-carrier obturation from clinical studies were selected. Reviews, laboratory studies, animal studies and irrelevant reports were excluded.

Results

1349 relevant articles were identified with 149 duplicated articles removed and 1173 irrelevant articles were excluded after screening. The titles and abstracts of the 19 identified articles were screened in the systematic review. The full texts of remaining articles were retrieved with data extracted for meta-analysis on the success rate, postoperative pain, overfilling and adaptation of obturation. The pooled success rate of core-carrier obturation was 83% (95% CI: 69%-91%). The pooled incidence of 1-day and 7-day short-term postoperative pain were 35% (95% CI: 15%-62%) and 6% (95% CI: 1-35%). The pooled proportion of teeth with overfilling and adequate adaptation of the obturation material were 31% (95% CI: 18%-50%) and 85% (95% CI: 75%-91%), respectively.

Conclusions

The success rate of endodontic treatment using core-carrier obturation was 83%. Short-term postoperative pain was not uncommon (24%). Most teeth (85%) had adequate adaptation using core-carrier obturation material, but a considerable amount of teeth (31%) had overfilling.

     

Oval-shaped canal retreatment with self-adjusting file: a micro-computed tomography study

Objectives

The aim of this study was to assess the efficacy of removing the filling material from oval-shaped canals with rotary retreatment files, with or without the additional use of self-adjusting file (SAF), using micro-computed tomography.

Materials and methods

Oval-shaped canals from 20 maxillary premolars were prepared and assigned to two groups (n?=?10), according to the obturation technique: cold lateral condensation (CLC) or vertical condensation (VC). Then, retreatment procedure was performed with retreatment rotary instruments followed by SAF. The specimens were scanned after each procedure and the volume of the filling material calculated. Median and interquartile range (IQR) percentages of the remaining filling material after each retreatment technique were statistically compared by Wilcoxon and Mann–Whitney U tests with a significance level of 5 %.

Results

The median percentage volume of the filling residue after rotary retreatment procedure was 1.59 (IQR?=?1.26) and 0.42 (IQR?=?0.86) in the CLC and VC groups, respectively (p?<?0.05). After the use of SAF, the median percentage was 1.26 (IQR?=?0.75) and 0.12 (IQR?=?0.53) in the CLC and VC groups, respectively (p?<?0.05). Statistically significant difference was also observed within the group after the additional use of SAF (p?<?0.05).

Conclusions

None of the retreatment procedures completely removed the filling material. The additional use of the SAF improved the removal of filling material after the retreatment procedure with rotary instruments.

Clinical relevance

Filling material left after retreatment procedure may harbour necrotic tissue and bacteria, which could lead to a persistent disease and reinfection of the root canal system. The additional use of self-adjusting file after the conventional retreatment procedures may improve root canal cleanliness, allowing a better action of the irrigating solution.     

Comparison between two thermoplastic root canal obturation techniques regarding extrusion of root canal filling—a retrospective in vivo study

Objectives

The aim of this study was to compare two different thermoplastic techniques—a core-carrier technique (Thermafil) and warm vertical compaction—in terms of overextension of root canal filling in vivo.

Materials and methods

Flaring of 88 teeth was conducted using Pro Files .04 as finishing files, and the teeth were obturated using Thermafil. Flaring of 74 teeth was performed using Pro Files .06 as finishing files, and the teeth were obturated using warm vertical compaction.

Results

Seventy (80 %) of the teeth obturated using Thermafil and 31 (42 %) teeth obturated using warm vertical compaction show extruded root canal filling. In contrast to Thermafil, there is a higher rate of extruded root canal filling of teeth with more than one root canal using warm vertical compaction.

Conclusion

Thermafil demonstrated a higher rate of extruded root canal filling compared to warm vertical compaction. Warm vertical compaction is a more predictable method of filling compared to Thermafil.

Clinical relevance

Root canal filling extrusion will cause irritation of the surrounding tissue and impair repair processes. In the present in vivo study, there was a higher rate of root canal filling extrusion using Thermafil compared to warm vertical compaction.     

Thermafil根管充填技术的临床评价

目的 :研究Thermafil根管充填技术的效果。方法 :选择牙髓病或根尖周病患者 60例 ,按就诊顺序随机分为 2组。即Thermafil根管充填组 (TC组 )和冷牙胶侧方加压充填组 (LC组 )。对 2组的根管充填时间、术中疼痛情况和根管充填效果进行比较。术后 3个月和 6个月进行复查 ,并拍摄X线片。结果 :以牙为单位 ,TC组适充 18颗 ,超充 11颗 ,欠充 1颗 ;在LC组中 ,适充 2 7颗 ,超充 3颗 ,无欠充 (P <0 .0 5)。TC组术中不适 4颗 ,LC组 2颗 (P >0 .0 5)。以根管为单位 ,根管充填时间Thermafil充填技术组平均 3 6.6s/根管 ,LC组平均 2 47.4s/根管 (P <0 .0 1)。结论 :Thermafil充填技术临床操作简便省时 ,但容易造成超充     

Real-time Intracanal Temperature Measurement During Different Obturation Techniques

Introduction

The purpose of this study was to assess temperature development in endodontic sealers during different obturation techniques in a closed system simulating the surrounding biological structures at body temperature.

In vitro radiographic density of dental posts measured by digital radiography

Objectives

This study evaluated the radiopacity of seven commercial root canal posts.

Methods

Digital radiographs of the seven commercial posts and of the same commercial posts and four artificial aluminum posts inserted in lower canines were obtained with a CCD-based digital sensor. The radiopacity of the posts was expressed as mm aluminum/mm material (mmAl). Subsequently, the radiographs were presented to five trained evaluators who were asked to rank their acceptability scores as not acceptable, acceptable, or excellent.

Results

Analysis of variance revealed significant differences in radiopacity among the posts (P < 0.05). The radiopacities of zirconium and titanium posts were significantly higher than those of fiber posts (P < 0.05). The minimum aluminum thickness for acceptance in the root canals was 1.2 mmAl.

Conclusions

All of the examined posts presented satisfactory radiopacity for clinical application.     

An evaluation of the Thermafil endodontic obturation technique.

The purpose of this study was to evaluate the Thermafil endodontic obturation technique and to compare it with laterally condensed gutta-percha. Thirty-seven maxillary central incisors were similarly prepared and divided into groups. Seventeen were obturated with Thermafil and 17 with lateral condensation. Three served as controls. After vacuum staining, all teeth were cleared and apical dye penetration was evaluated by two independent observers. Average leakage values were 0.24 mm and 1.32 mm for Thermafil and 0.47 mm and 1.18 mm for lateral condensation. There was no significant difference between the techniques, although a difference between evaluators was noted. Final results point to the relative subjectivity of in vitro leakage studies. When comparing the obturation times of both techniques, the Thermafil technique averaged 2 min 56 s while lateral condensation took 3 min 26 s. Statistical analysis showed no significant difference in obturation times.     

Maxillary distraction osteogenesis at Le Fort-I level induces bone apposition at infraorbital rim

Objective

The aim of this study is to evaluate whether there is any remodeling of bone at infraorbital rim following maxillary distraction osteogenesis (DO) at Le Fort-I level.

Materials and methods

Twelve adult subjects in the age range of 17–21 years with complete unilateral cleft lip and palate underwent advancement of the maxilla by DO. The effect of maxillary DO on the infraorbital rim remodeling was evaluated from lateral cephalograms recorded prior to the DO (T₀), at the end of DO (T₁), and at least 2-years after the DO (T₂) by Walker’s analysis. The ANOVA and two-tailed t test were used and probability value (P value) 0.05 was considered as statistically significant level.

Results

There was anterior movement of maxilla by 9.22?±?3.27 mm and 7.67?±?3.99 mm at the end of immediate (T₁) and long-term (T₂) follow-up of maxillary DO, respectively. The Walker’s analysis showed 1.49?±?1.22 mm and 2.31?±?1.81 mm anterior movement of the infraorbital margin (Orbitale point) at the end of T₁ and T₂, respectively (P?Conclusion The advancement of maxilla by distraction osteogenesis at Le Fort-I level induced significant bone apposition at infraorbital rim.

Clinical relevance

Patients with mild midface hypoplasia who would otherwise may be candidates for osteotomy at Le Fort-II or Le Fort-III level may benefit from maxillary distraction at Le Fort-I level.     

Relation between insertion torque and bone–implant contact percentage: an artificial bone study

Objectives

The purpose of this study was to determine the correlation between the peak insertion torque value (ITV) of a dental implant and the bone–implant contact percentage (BIC%).

Material and methods

Dental implants were inserted into specimens comprising a 2-mm-thick artificial cortical shell representing cortical bone and artificial foam bone representing cancellous bone with four densities (groups 1 to 4—0.32, 0.20, 0.16, and 0.12?g/cm³). Each specimen with an inserted implant was subjected to micro-computed tomography (micro-CT) scanning, from which the 3D BIC% values were calculated. Pearson’s correlation coefficients (r) between the ITV and BIC% were calculated.

Results

The ITVs in groups 1 to 4 were 56.2?±?4.6 (mean±standard deviation), 45.6?±?0.9, 43.3?±?4.3, and 38.5?±?3.4?N?cm, respectively, and the corresponding BIC% values were 41.5?±?0.5%, 39.0?±?1.0%, 30.8?±?1.1%, and 26.2?±?1.6%. Pearson’s correlation coefficient between the ITV and BIC% was r?=?0.797 (P?<?0.0001).

Conclusion

The initial implant stability, quantified as the ITV, was strongly positively correlated with the 3D BIC% obtained from micro-CT images.

Clinical relevance

The ITV of a dental implant can be used to predict the initial BIC%; this information may provide the clinician with important information on the optimal loading time.     

Clinical evaluation of the alar base width of patients submitted to surgically assisted maxillary expansion

Proposition

The aim of this study was to evaluate both the presence and magnitude of the modifications occurred in the alar base width, in patients submitted to surgically assisted maxillary expansion (SAME).

Methods

The alar base width of 13 patients submitted to SAME followed by alar base suture and simple V-Y suture was measured by using direct measuring with digital paquimeter during regular periods: pre-operative and 2, 6, 24, and 36 months post-operative. Data were submitted to statistical analysis by using ANOVA and Tukey’s test with level of significance of 5%.

Results

There was a statistically significant increase (P?<?0.05) of the alar base width in the comparison between the pre-operative and the 6-, 24-, and 36-month post-operative periods.

Conclusion

SAME procedure increased the alar base width even performing the alar bases sutures; however, despite the widening of 1.6 mm, the clinical result was not compromised and better than without the technique.     

An in vitro study of the quality of root fillings in teeth obturated by lateral condensation of gutta-percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of linear apical dye penetration in teeth root filled with either laterally condensed gutta-percha or Thermafil obturators, A total of 150 teeth with single roots were included in the study. All canals were prepared using a standard step-back technique with anticurvature filing. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point, was used to divide the teeth into two experimental and two control groups. A total of eight teeth were excluded because of technical difficulties, 65 were filled with Thermafil obturators, 63 were filled with laterally condensed gutta-percha whilst 14 teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. Canal obturation with Thermafil obturators (0.7 min) was significantly quicker (P > 0.001) than lateral condensation (6.4 min). Apical extrusion of sealer and gutta-percha occurred significantly more often with Thermafil obturators but there was little difference in the technical quality of the fillings and no significant difference in dye penetration. Under the conditions of this study, Thermafil obturators proved a satisfactory alternative to lateral condensation of gutta-percha.     

The evaluation of apical leakage for three endodontic fill systems

This study evaluated the apical leakage for three endodontic systems: (1) lateral condensation with Essential Dental System's epoxy adhesive: (2) Thermafil with Thermaseal adhesive; and (3) EZ-Fill Bi-directional spiral with EDS' epoxy adhesive. Five groups of 10 recently extracted single-rooted human teeth were used. Results showed that lateral condensation, and the EDS' EZ-Fill Bi-directional, and Thermafil techniques did not differ from each other, but differed from the no treatment group and the instrumented-unfilled group. In the current study, the EZ-Fill Bi-directional technique produced a tighter apical seal than either lateral condensation or Thermafil obturation techniques, but they all were not significantly different. EZ-Fill Bi-directional is a faster and more economical alternative to lateral condensation and Thermafil obturation.     

A Comparative in Vitro Study of Apical Microleakage with Five Obturation Techniques: Lateral Condensation,Soft-Core?, Obtura II?, Guttaflow? and Resilon?

Aim

A comparison was made between the root canal lateral condensation technique and other condensation techniques in which physical (temperature: Soft-Core®, Obtura II®) or chemical changes (condensation: Guttaflow®, Resilon®) may affect the dimensional stability of obturation and thus favor apical microleakage.

Materials and methods

A total of 212 single-root teeth removed for orthodontic or periodontal reasons were randomized to 5 groups of 40 teeth each. Six samples were used as positive controls, and another 6 as negative controls. The teeth were worked with the Hero 642 system, and each group was obturated using a different technique: lateral condensation, Obtura II®, Soft-Core®, Guttaflow® or Resilon®. The samples were immersed in black ink, and after 72 hours the teeth were transparentized using the technique described by Robertson. Filtration of the ink was measured under the stereoscopic microscope. Analysis of variance and post-hoc testing were used for the statistical analysis.

Results

The Soft-Core® obturated group showed significantly greater microleakage than the other groups, with no differences among the rest of the groups.

Conclusions

Under the conditions of this study, the teeth obturated with the Soft-Core® technique showed greater apical microleakage than the other systems.Key words: Apical microleakage, root canal obturation, sealing ability, transparentization     

Panel perception of facial appearance of cleft patients generated by use of a morphing technique

Objective

Perception of the facial appearance of cleft patients has, until now, been evaluated on the basis of photographs of the patients. Research based on photographs generated by use of a morphing technique has not yet been reported. The purpose of this study was to investigate female and male raters’ panel perception with regard to the following: (1) patient age, (2) attractiveness, (3) gender appearance, and (4) likeability of faces of cleft patients generated by the use of a morphing technique.

Setting

The study was conducted at the Department of Oral, Craniomaxillofacial and Facial Plastic Surgery, University Hospital of Leipzig, Germany.

Patients, participants

We used photographs of 32 adult German nonsyndromic cleft patients, mean age 18.9?±?1.3 years, and surveyed 93 students, mean age 25.3?±?3.2 years, by use of a standardized questionnaire.

Results

All respondents rated the mean age of cleft patients equally in unmorphed and morphed pictures. For all respondents, attractiveness of morphed patient pictures was rated significantly higher than for unmorphed pictures (mean 4.8?±?1.0 vs. 6.4?±?2.4; p?Conclusion Facial morphing of patient pictures is a suitable method for creation of standard cleft faces. Despite the modification of the pictures, the faces generated remain human and assessable by panel members. Perception of faces of cleft patients’ depended on raters’ gender.     

The influence of different radiopacifying agents on the radiopacity,compressive strength,setting time,and porosity of Portland cement

Objectives

The aims of this study were to evaluate the radiopacity, compressive strength, setting time, and porosity of white Portland cement (PC) with the addition of bismuth oxide (Bi₂O₃), zirconium dioxide (ZrO₂), and ytterbium trifluoride (YbF₃) after immersion at 37 °C for 7 days in distilled water or phosphate buffer saline.

Materials and methods

Specimens measuring 8 mm in diameter and 1 mm in thickness were fabricated from PC with the addition of 10, 20, and 30 wt% Bi₂O_3, ZrO₂ or YbF₃. ProRoot MTA (Dentsply, Tulsa, OK, USA) and pure PC were used as controls. For radiopacity assessments, specimens were radiographed alongside a tooth slices and an aluminum stepwedge on Extraspeed occlusal dental films (Insight Kodak, Rochester, New York). Mean optical density of each specimen was calculated and used to express radiopacity of the material as an equivalent thickness of aluminum. Compressive strength was measured by using 4-mm diameter and 6-mm high specimens and Universal testing machine. High-pressure mercury intrusion porosimeter (Carlo Erba Porosimeter 2000) was employed to measure the porosity of the specimens. The setting time was measured by using a needle of 100 g in weight. The morphology of specimens was evaluated using a scanning electron microscope (TESCAN Mira3 XMU, USA Inc.). Data were analyzed by one-way ANOVA and post hoc Tukey test (P?<?0.05).

Results

The PC with the addition of at least 10 wt% Bi₂O₃ and 20 wt% ZrO₂ or YbF₃ demonstrated greater radiopacity value than the recommended 3 mmAl cut-off. ZrO₂ and YbF₃ increased the compressive strength of PC, but it was not statistically significant (P?>?0.05), while Bi₂O₃ decreased it (P?<?0.05). All radiopacifiers significantly increased the porosity of the experimental cements (P?<?0.05). Bi₂O₃ extended the setting time of PC (P?<?0.05), whilst ZrO₂ and YbF₃ did not significantly affect it (P?>?0.05).

Conclusions

ZrO₂ and YbF₃ may be used as a suitable alternative to replace Bi₂O₃ in MTA without influencing its physical properties.     

The long-term sealing ability of AH 26 and AH plus used with three gutta-percha obturation techniques.

OBJECTIVE: To evaluate and compare the sealability of root fillings in extracted teeth by using AH 26 and AH Plus in conjunction with three different obturation techniques. METHOD AND MATERIALS: Root canals of 940 single-rooted teeth were prepared according to the crown-down/stepback technique (using both 2.5% NaOCl and File-Eze) before lateral condensation and hybrid condensation of gutta percha or obturation with Thermafil. Teeth were immersed in India ink for 90 hours after storage for 1 day, 1 week, 2 weeks, 1 month, and 6 months. The roots were split longitudinally, and the extent of dye penetration was measured using a stereomicroscope. Statistical analysis was performed using Kruskal-Wallis test and Mann-Whitney U test. RESULTS: There were no statistically significant differences in apical leakage within the AH 26 and the AH Plus groups, nor between the two sealer groups, at any observation period. Coronal leakage was significantly higher for Thermafil compared to hybrid condensation at 1 day, 1 week, and 2 weeks both for AH 26 and AH Plus. Coronal leakage was higher only for Thermafil compared to lateral condensation at 1 week for AH 26 and for lateral condensation compared to hybrid condensation at 1 week for AH Plus. CONCLUSION: Both AH 26 and AH Plus, when used with an identical gutta-percha obturation technique, resulted in comparable sealability at all evaluation times and in comparable coronal sealability at 1 and 6 months.     

Position of lower wisdom teeth and their relation to the alveolar nerve in orthodontic patients treated with and without extraction of premolars: a longitudinal study

Objectives

The present longitudinal study aimed to compare changes in the lower third molar position and nerve involvement in orthodontically treated patients with and without premolar extractions.

Materials and methods

The sample consisted of pretreatment and posttreatment panoramic radiographs of 349 orthodontically treated patients subdivided into a non-extraction group (n?=?263) and an extraction group (n?=?86). Patients did not present dental agenesis in the lower jaw. The mandibular third molar position was assessed by classifying the teeth according to Pell and Gregory, Winter, and two new classifications. The relation between third molars and the mandibular canal was assessed based on Whaites’ classification. The development of third molars was evaluated based on Demirjian’s classification. Data were analyzed using frequency analysis, Mann–Whitney U test, Fisher’s exact test, and chi-square testing.

Results

There was a significant difference (p?p?Conclusions Orthodontic treatment without premolar extractions shows significantly more eruption problems of wisdom teeth than those with premolar extractions. Third molars in the non-extraction group were more frequently found in close relationship to the mandibular nerve compared to the extraction group.

Clinical relevance

Orthodontists should be aware of the effect of orthodontic treatment on the development of the lower third molars.