Evaluation of root-end cavity preparation using ultrasonic retrotips

Comparative Evaluation of Sealing Ability of Different Type of MTA as Root-End Filling Materials Using Dye Penetration Technique - An In Vitro Study

Introduction

The main goal of the root-end filling material is to create a hermetic seal to protect against microbes and their by-products. Excellent biocompatibility and sealing ability are characteristics of MTA developed by Torabinejad et al. This study aimed to compare the sealing ability of different type MTA as root-end filling material using dye penetration technique.

Material and Method

One-twenty (N = 120) extracted human maxillary anterior teeth were decontaminated, cleaned, and decoronated. Endodontic treatment and root-end resection were done. Then root-end cavity was prepared and filled with tested materials (N = 30). A calibrated stereomicroscope was used to evaluate linear measurement. All data were tabulated and statistically analyzed with a level of significance set at P < .05.

Result

This order of increasing microleaks was observed: MTA Angelus < MTA Plus < PRO-Root MTA < Control group. There was a statistically significant difference in mean microleakage in MTA Angelus and MTA Plus groups (P = 0.040). MTA Angelus shows the least microleakage among all the bioceramic material groups.

Conclusion

Although the sealing ability of MTA Angelus is superior to MTA Plus, PRO-Root MTA. MTA Plus, PRO-Root MTA could be considered an acceptable alternative to MTA Angelus in peri-radicular surgeries.

The effect of ultrasonic access cavity preparation on dentinal inner walls: a micro-CT study on cadaveric samples

OBJECTIVE

The objective of this study is to evaluate the occurrence of coronal dentinal micro-cracks after access cavity refinement using high-speed burs and ultrasonic tips by means of micro-computed tomography (micro-CT) analysis.

METHODS

In this study, 18 mandibular cadaveric incisors were divided into two groups according to the protocol of the preparation of the conventional access cavity. The diamond bur 802 # 12 was used until the perforation of the pulp roof. Then, the Endo-Z bur was used for the group #1 and the ultrasonic tip Start-X # 1 for the group #2 to finish and refine the access cavity. The preparation time of each access cavity has been recorded. The teeth underwent a micro-CT scan before and after the preparation of the access cavity. Fisher's exact test, the Chi-square test, the Kolmogorov-Smirnov test, the Mann-Whitney test, and the Student's test were used for statistical evaluation.

RESULTS

The percentage of teeth with new micro-cracks is not significantly different between the two groups (-p-value < 0.5). The number of newly formed micro-cracks and extension size were not significantly different between the two groups. The direction of extension of the micro- cracks was occluso-apical. The average duration of the access cavity is significantly smaller with the Endo-Z system (-p- value < 0.001). The roughness of walls surfaces has no statistically difference between the two groups.

CONCLUSION

The use of ultrasound, although slower, is considered safe in the creation of dentinal micro-cracks, in the preparation of the access cavity.

Comparison of crack formation induced by ultrasonic tips and burs during root-end preparation: a systematic review and meta-analysis

Introduction The main objective of root canal treatment is to achieve apical seal. Crack formation during root-end preparation promotes bacterial penetration, thereby leading to failure. This systematic review aims to examine the literature and summarise studies that compare the crack formation induced by ultrasonic tips and burs during root-end preparation.Methods This systematic review and meta-analysis were reported and conducted according to the PRISMA guidelines. The online databases PubMed, Scopus, and Google Scholar were used for data search. In vitro and ex vivo studies conducted up to March 2021 in the English language were included in the review. The risk of bias in the present study was assessed using a customised tool. A random-effects model was used for meta-analysis, χ² values and I² values were used to assess statistical heterogeneity. Meta-analysis was performed using RevMan software Version 5.4.Results A total of 317 records were found from all of the databases and one article was added following hand-searching. Twelve articles were included in the study after the application of the eligibility criteria of which ten articles were included for the meta-analysis. Nine studies showed a medium risk of bias while three studies showed a high risk of bias. The analysis of the crack formation showed a statistically significant difference between the ultrasonic tip and the bur (P = 0.0002). The odds ratio was 2.72 (1.60, 4.65) with a confidence interval of 95% suggesting higher odds of crack formation in the ultrasonic group.Conclusion This review concludes that ultrasonic root-end preparation resulted in higher crack formation than burs.

Sealing ability of two root-end filling materials at different retro-preparation lengths

PURPOSE

The aim of the present study was to evaluate the sealing performance, expressed as microleakage (ML), of two root-end filling materials when used at different retro-preparation lengths.

METHODS

Fifty single-rooted human teeth were collected for the study. The teeth were cut at the cement-enamel junction and endodontic treatment was performed. Each root was cut at 3 mm from the apex and then stored in wet condition. The teeth were divided into three groups according to the retro-preparation length: control group (no retro-preparation); group 1 (retro-preparation of 3 mm); group 2 (retro-preparation of 9 mm). The teeth were equally allocated to either Biodentine or Super EBA treatment group. The teeth were immersed in 3% methylene blue dye solution for 24 h. The samples were split longitudinally and the depth of dye penetration was examined through light microscopy.

RESULTS

No significant statistical differences were found at different retro-preparation lengths (P > 0.05). Differences were found between materials (P > 0.05).

CONCLUSION

Biodentine showed significantly lower ML when compared to Super-EBA and no statistical significative differences were observed when samples were retro-prepared at 3 mm or 9 mm.

Effects of ultrasonic refinement on endodontic access cavity walls: A microcomputed tomography analysis

Objectives

The present study aimed in assessing the coronal defects after access cavity finishing and refinement by micro.

Methods

Access cavities on thirty molars were prepared using a diamond bur. To finish and refine the access cavity, the Endo-Z was used in group 1 (n=15) and Start X 1 in group 2. Preparation time was recorded. A micro-CT scan was done before and after access preparation. Formation and location of the new defects were registered, the extension of defects calculated and the direction of the extension registered, preparation time and surface roughness determined (P < 0.05).

Results

Preparation time was significantly higher with ultrasonics (P <0.001). Internal walls showed smoother surfaces for Endo-Z group. Newly counts and extension length of defects weren't significantly different between groups (P > .05).

Conclusion

Ultrasonic tips induced new cracks. Both instruments caused the extension of cracks. Ultrasonic tips requires more time and results in significantly rougher surfaces.

The Effect of Root End Cavity Preparation Using Er,Cr:YSGG Laser, Ultrasonic Retrotip, and Bur on the Apical Microleakage of Retrograde Cavity Filled with MTA Plus

Aim:

The sealing ability of the retrograde material is greatly affected by the technique used for root end preparation. Advances in retrograde preparation techniques such as lasers has shown to provide an efficient outcome. The study was to evaluate and compare the effect of various techniques of retrograde cavity preparation on apical microleakage.

Materials and Methods:

Forty-five single rooted teeth were decoronated. Biomechanical preparation was carried out up to size F2 ProTaper system and obturated. Glass–ionomer cement was used as an access restorative material. The apical root resection was done at 3 mm from the apex at angulation of 90° to the long axis of the root. The allocation of the samples was done into three groups of 15 each. Group A: Retrograde cavities prepared using conventional round bur; Group B: Retrograde cavities prepared using ultrasonic retro preparation diamond tip; and Group C: Retrograde cavities prepared using “Erbium, chromium: yttrium, scandium, gallium, garnet” (Er,Cr:YSGG). The retrograde cavities hence prepared were filled with MTA Plus. Nail varnish was used to coat the samples except at the apical end. Samples were immersed in methylene blue for 24h. Stereomicroscope was used for examination of the sectioned teeth. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey test.

Results:

Results showed very highly significant difference between laser and bur (P value = 0.001).

Conclusion:

Retrograde preparation with Er,Cr:YSGG showed significantly less microleakage when compared to the use of ultrasonic retrotip and burs.

Evaluation of Root-End Preparation with Two Different Endodontic Microsurgery Ultrasonic Tips

The aim of this study is to compare root-end preparation performed with two different ultrasonic tips-CVDentus and NSK-and respective time requirements. After root-end resection, 32 teeth were randomly divided in two groups, according to the ultrasonic tip used for root-end preparation. Preparation time was recorded. Photomicrographs were taken to assess the following parameters: root surface microcracking, marginal integrity and presence of debris. One ultrasonic tip from each group was analyzed through scanning electron microscopy before and after root-end preparation. The significance level was set at α = 0.05. Incidence of microcracks in both groups was 12.5%. Solely intracanal microcracking was found, consistently positioned within the widest side of the remaining dentine. No statistically significant differences were verified between both experimental groups regarding marginal integrity (p = 0.102) and preparation time (p = 0.780), whereas statistical differences (p = 0.003) were found concerning the presence of debris (the minimum registered score was mostly verified in CVDentus group). NSK tips showed major morphological changes, with extensive surface wear and noticeable loss of particles, which was not verified on CVDentus tips. Our findings suggest significant differences regarding root-end preparation walls quality, with CVDentus tips showing better results. Concerning microcracking, as well as preparation time and marginal integrity, both ultrasonic tips showed similar results. Qualitative analysis exposed NSK tips major morphological changes and wear after use, which was not verified on CVDentus tips.

Evaluation of surface integrity of root end cavities prepared using conventional and piezoelectric devices: A scanning electron microscopy study

Introduction

An array of factors control the success of endodontic surgery. One of them is the technique used to prepare the root end cavities which is conventionally being done with burs. In past decades, ultrasonic instruments have been introduced for the same. Studies comparing these instruments on root surface integrity are scarce. Thus, an in-vitro Scanning Electron Microscopy study was designed to evaluate the surface integrity of root end cavities prepared using conventional and piezoelectric devices.

Methodology

Twelve single-rooted human intact mandibular premolar teeth were endodontically treated and included in the study. They were divided into two groups. In the first group, 3 mm root-end cavities were prepared using conventional retro preparation burs and in the second group, 3 mm root-end cavities were prepared using piezoelectric retro-tips. The specimens were coded for blind evaluation and analysed under scanning electron microscope at 100x, 500x and 1000x magnification for smear layer and debris. Gutmann's scoring criteria was followed to score the specimens. Statistical analysis was carried out using Shapiro Wilk test and the independent sample t-test was used to check mean differences between variables.

Results

It was noted that significant statistical differences existed in mean debris and smear layer scores (p< 0.001) between the two groups. In the piezoelectric group, significantly lower debris layer and smear layer was found, compared to the conventional bur group.

Conclusion

Root-end cavities prepared using piezo retrotips produced cleaner, well-centered and more conservative surface with minimal debris & smear layer, compared to root-end cavities prepared using conventional burs.

Effect of ultrasonic root-end cavity preparation on dentinal microcrack formation: A micro-computed tomography study

Background:

Root-end preparation during surgical endodontics may produce dentinal microcrack formation and/or propagation, leading to vertical root fractures.

Aim:

This study aimed to evaluate and compare the microcrack formation and propagation during ultrasonic root-end cavity preparation, with diamond- and zirconium nitride-coated tips using micro-computed tomography (CT).

Methodology:

Twenty-eight extracted, mature, free-of-defect, mandibular premolars were decoronated and micro-CT scanned for the presence of preexisting microcracks. Samples were prepared till F4, were obturated, and were re-scanned to determine an increase in the number of microcracks. After 3 mm of root-end resection, the samples were randomly divided for ultrasonic root-end preparation into Group 1 (n = 12): preparation was done with ProUltra Surg tip, Group 2 (n = 12): preparation was done with KiS tip, and Group 3 (n = 4): no preparation was done. The samples were rescanned, and data collected were analyzed using ANOVA and Student's t-test. The level of significance was set at 5%.

Results:

Preexisting microcracks were observed in few samples. The mean percentage number increase of microcracks after root-end preparation in ProUltra Surg group was 1.25 and in KiS group, it was 0.5. The difference in mean percentage increase for the number of microcracks after root-end cavity preparation using ProUltra Surg tip and KiS tip was 0.75. However, this difference was not statistically significant (P = 0.34).

Conclusion:

Both diamond- and zirconium nitride-coated ultrasonic tips resulted in more number of dentinal crack formation and propagation when preexisting cracks were present.

A comparison of Er, Cr: YSGG laser with ultrasonic preparation on the seal of retrograde cavities

BACKGROUND AND AIM

The aim of this in vitro study was to compare Er, Cr: YSGG laser with ultrasonic preparation on the seal of retrograde cavities.

MATERIALS AND METHODS

Twenty-eight maxillary anterior teeth were used in this study. After removing the crowns, the canals were prepared with the step-back technique and filled with guttapercha. Three millimeters below the apex; each root was cut with a fissure diamond bur. The root surfaces were then covered with nail polish and three millimeters deep retrograde class I cavities were prepared, using Er, Cr: YSGG laser (group L=12 roots) or ultrasonic retro-tip (group U=12 roots). Four roots were arranged for negative and positive control groups. Retrograde cavities were then filled with mineral trioxide aggregate (MTA) and teeth were placed in 2% methylene blue dye for 72 hours. The amount of dye penetration in sagittal sections of each tooth was measured with a stereomicroscope. An independent sample t-test was used for statistical analysis.

RESULTS

Cavities prepared with the Er, Cr: YSGG laser (1.61 + 0.81) showed significantly less micro-leakage than those prepared with the ultrasound (2.55+ 1.84) (P value =0.02).

CONCLUSIONS

Under the conditions of this research, the use of Er, Cr: YSGG laser for retrograde cavity preparation causes significantly less apical leakage and may increase the success rate of endodontic surgeries.

Effects of ultrasonic root-end cavity preparation with different surgical-tips and at different power-settings on glucose-leakage of root-end filling material

Aim:

The aim of this in vitro study was to evaluate the effects of different ultrasonic surgical-tips and power-settings on micro-leakage of root-end filling material.

Materials and Methods:

The root canals were instrumented using rotary-files and were filled with tapered gutta-percha and root canal sealer using a single-cone technique. The apical 3 mm of each root was resected and the roots were divided into six experimental groups; negative and positive control groups. Root-end cavities were prepared with diamond-coated, zirconum-nitride-coated and stainless-steel ultrasonic retro-tips at half-power and high-power settings. The time required to prepare the root-end cavities for each group was recorded. Root-end cavities were filled with Super-EBA. Leakage values of all samples evaluated with glucose penetration method on 7, 14, 21 and 28^th days. The results were statistically analyzed with Kruskal-Wallis and Hollander-Wolfe tests.

Results:

The mean time required to prepare retro cavities using diamond-coated surgical tip at high-power setting was significantly less than other groups (P < 0.01). There were no statistically significant differences in the glucose penetration between the groups at first and second weeks (P > 0.01). Diamond-coated surgical tip showed the least leakage at high-power setting at 3^rd and 4^th weeks (P < 0.01).

Conclusions:

Under the conditions of this study, cavity preparation time was the shortest and the leakage of the root-end filling was the least when diamond-coated retro-tip used at high-power setting.

Evaluation of two different root-end cavity preparation techniques: A scanning electron microscope study

OBJECTIVE

In this study, we aimed to evaluate and compare the dentinal walls of root-end cavities for the presence of cracks after cavity preparation using US retrotips and Er: YAG laser.

MATERIALS AND METHODS

Fifty single-rooted teeth were prepared by Protaper NiTi rotary system and obturated by lateral condensation. Three milimeters of root-end was resected. Twenty teeth were prepared with US retrotip (Group 1), 20 teeth with Er: YAG laser (Group 2), and 10 teeth without retropreparation (control group). The root-end surfaces were examined under a scanning electron microscope (SEM). Then the cracks of the resected root surfaces were evaluated on microphotographs.

RESULTS

No statistically significant difference was detected between US Group and Laser Group for complete, incomplete, intradentinal, and total number of cracks (P = 0.47, P = 0.80, P = 0.69, P = 0.869, respectively).

CONCLUSION

Statistical analysis revealed no significant effect of retropreparation technique on the development of apical cracks (P > 0.05).

Coronal microleakage of two root-end filling materials using a polymicrobial marker

The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 +/-14.8 days) followed by AH Plus and MTA (66.1 +/- 18.7), Diaket and amalgam (60.0 +/- 23.1), AH Plus and amalgam (56.9 +/- 22.1), and Ketac Endo and MTA (42.1 +/- 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 +/- 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05).

Effect of Waterlase laser retrograde root-end cavity preparation on the integrity of root apices of extracted teeth as demonstrated by light microscopy

Most endodontists use ultrasonic instruments for retrograde root-end cavity preparations even though they have been found to produce cracks. In this laboratory study, thirty-six randomly chosen roots had root-end cavity preparations made with the Waterlase laser and only one questionable intra-canal crack was found. It was concluded that the Waterlase laser when used to make endodontic root-end cavity preparations produces either no cracks, or a very low percentage (2.8%) of cracks.

Endodontic surgery with ultrasonic retrotips: One-year follow-up

OBJECTIVE

The purpose of this prospective clinical study was to monitor the outcome of ultrasonic root-end preparation, in relation to tooth type and location, presence of post restoration and type of retrotip.

STUDY DESIGN

Teeth treated surgically showed a periradicular lesion of strictly endodontic origin. Fifty teeth were included in the study, according to specific selection criteria. Cases were followed for a period of 1 year and then classified in 3 groups (success, uncertain healing, and failure) according to radiographic and clinical criteria.

RESULTS

Of the 46 teeth evaluated at 1-year follow-up, 42 teeth (91.3%) successfully healed, 1 tooth had uncertain healing, and 3 failed. We found no statistically significant differences in treatment results related to the type of tooth, tooth location, post restoration, and type of retrotip.

CONCLUSION

Adherence to a strict endodontic surgical protocol and the use of contemporary techniques and materials can lead to a predictable outcome.

SEM analysis of the integrity of resected root apices of cadaver and extracted teeth after ultrasonic root-end preparation at different intensities

AIM

To compare the integrity of root apices of cadaver and extracted teeth after resection, ultrasonic root-end cavity preparation at medium and low ultrasonic power settings and retrieval.

METHODOLOGY

Root canal treatment, perpendicular root-end resection and root-end preparation were performed on single-rooted anterior and premolar teeth (49 teeth in situ in maxillary and mandibular jaws from cadavers and 45 extracted teeth). Apical root-end cavities were prepared with the S12/90 degrees D tip and the Suni-Max ultrasonic unit (Satelec, Merignac, France) at the intensity prescribed by the manufacturer (power 7 at power mode S) (34 cadaver teeth, 30 extracted teeth) and at a lower intensity (power 4 at power mode S) (15 cadaver teeth, 15 extracted teeth). After ultrasonic preparation the cadaver teeth were retrieved from the jaws. Exaflex impressions (GC Corporation, Tokyo, Japan) were made of the root apices after resection, root-end preparation and retrieval. These impressions were processed for SEM analysis, and the recordings evaluated for cracks and marginal chipping.

RESULTS

In general, extracted teeth showed significantly more cracks and chipping than cadaver teeth. Lowering the ultrasonic power from medium to low intensity resulted in equal scores for cracks on extracted teeth and for chipping on cadaver teeth, in higher scores for cracks on cadavers and in lower scores for chipping on extracted teeth. Complete cracks and cracks originating from the root surface occurred only in extracted teeth.

CONCLUSIONS

The number of cracks and degree of chipping caused by ultrasonic root-end preparation was higher on extracted teeth than on cadaver teeth. Lowering the ultrasonic power from medium to low intensity cannot be recommended as it resulted in more cracks and equal chipping on cadaver teeth. Investigation of techniques and materials should be conducted in situ and not on extracted teeth.

Effects of ultrasonic root end preparation on resected root surfaces: SEM evaluation

OBJECTIVE

The purpose of this study was to investigate the in vitro effect of ultrasonic retrotips on root end surfaces.

STUDY DESIGN

Root end resection was performed on 45 single-root teeth endodontically treated after extraction. Setting the ultrasonic device at full power, a retrograde cavity was made by a stainless steel tip in 9 specimens (SS-FP). In another 9 samples a diamond tip was used (D-FP). Setting the intensity of the ultrasonic device at half power, 9 specimens were treated using stainless steel tips (SS-HP) and 9 using diamond tip (D-HP). Nine teeth were only apically resected and used as controls. Histologic serial sections were examined by scanning electron microsope to assess the number of root-face cracking, the marginal quality, and the crack type.

RESULTS

No significant difference between diamond and stainless steel groups was found at a given power setting. Significant differences were found between SS-FP and SS-HP group for both the number of cracks and the marginal quality.