Efficacy of Rotary and Hand Instrument in removing Gutta-percha and Sealer from Root Canals of Endodontically Treated Teeth

AIM

One of the common dental procedures employed these days in patients with irreversible pulpitis is root canal therapy. In retreatment cases, it is necessary for complete removal of obturate gutta-percha (GP) from obturate root canal system. Various methods and techniques are available these days for this purpose. This study was aimed to assess the efficacy of D-RaCe files, ProTaper retreatment files, Mtwo retreatment files, and manual Hedstrom files (H-files) in removing filling materials from the root canals of the endodontically treated teeth.

MATERIALS AND METHODS

The present study included comparative evaluation of efficacy of nickel-titanium (NiTi) retreatment instruments and H-files in removing GP and sealer from root canals. All the samples were randomly and broadly divided into four study groups based on the instrumentation technique for removing the root canal fillings. Evaluation of the results was done based on operating time and remaining root canal filling material. Stereomicroscopic evaluation of the samples was done at 8* magnification.

RESULTS

All the results were assessed and analyzed by Statistical Package for the Social Sciences (SPSS) software. Least quantity of filling material was left by ProTaper retreatment files. When put together in decreasing order, the efficacy of different study groups, in terms of mean time taken for retreatment, was found to be as follows: D-RaCe > ProTaper Retreatment > Mtwo Retreatment > H-file.

CONCLUSION

No single technique can completely remove obturating fillings from the root canals of endodontically treated teeth. However, rotary instruments are better in comparison with hand instruments for removing the GP from obturate root canals.

CLINICAL SIGNIFICANCE

ProTaper retreatment files and D-RaCe files are recommended over other instrument systems in terms of quality for managing retreatment root canal cases.

ÖGRO survey on radiotherapy capacity in Austria : Status quo and estimation of future demands

BACKGROUND

A comprehensive evaluation of the current national and regional radiotherapy capacity in Austria with an estimation of demands for 2020 and 2030 was performed by the Austrian Society for Radiation Oncology, Radiobiology and Medical Radiophysics (ÖGRO).

MATERIALS AND METHODS

All Austrian centers provided data on the number of megavoltage (MV) units, treatment series, fractions, percentage of retreatments and complex treatment techniques as well as the daily operating hours for the year 2014. In addition, waiting times until the beginning of radiotherapy were prospectively recorded over the first quarter of 2015. National and international epidemiological prediction data were used to estimate future demands.

RESULTS

For a population of 8.51 million, 43 MV units were at disposal. In 14 radiooncological centers, a total of 19,940 series with a mean number of 464 patients per MV unit/year and a mean fraction number of 20 (range 16-24) per case were recorded. The average re-irradiation ratio was 14%. The survey on waiting times until start of treatment showed provision shortages in 40% of centers with a mean waiting time of 13.6 days (range 0.5-29.3 days) and a mean maximum waiting time of 98.2 days. Of all centers, 21% had no or only a limited ability to deliver complex treatment techniques. Predictions for 2020 and 2030 indicate an increased need in the overall number of MV units to a total of 63 and 71, respectively.

CONCLUSION

This ÖGRO survey revealed major regional differences in radiooncological capacity. Considering epidemiological developments, an aggravation of the situation can be expected shortly. This analysis serves as a basis for improved public regional health care planning.

Use of biological mesh in trans-anal treatment for recurrent recto-urethral fistula

PURPOSE

To report the author's experience on a mini-invasive technique using bioprosthetic plug and a rectal wall flap advancement in the treatment of recurrent recto-urethral fistula.

MATERIALS AND METHODS

Between 2013 and 2015, seven patients with recurrent recto-urethral fistula were referred to the Pederzoli Hospital, Peschiera del Garda, Verona, Italy. Intraoperatively all patients were found to have a rectal wall lesion and were treated with urinary and fecal diversion. For the persistence of the fistula, all the patients underwent a mini-invasive treatment consisting on placement of a bioprosthetic plug in the fistula covered by an endorectal advancement flap through a trans-anal and trans-urethral combined technique.

RESULTS

Median operative time was 48 min with a median blood loss of 30 ml. Median hospital stay was 3 days (IQR 1-3). No case of fistula recurrence or plug migration was described. None of the patients experienced fecal or urinary incontinence. All patients obtained complete fistula healing.

CONCLUSIONS

Recurrent recto-urethral fistula is a challenging postsurgical complication for surgeons and urologists, and its best treatment is still unknown. Our method seems to be feasible and effective for the treatment of complex recto-urethral fistula.

Healing of apical periodontitis through modern endodontic retreatment techniques

The presence of apical periodontitis in teeth which have undergone initial root canal treatment is largely attributed to bacteria residing in or invading from the apical root canal space. Bacteria-associated apical periodontitis will not heal spontaneously, nor will systemic antibiotics eradicate the infection. Only endodontic retreatment, endodontic surgery, or extraction will control the bacterial etiology. Modern retreatment is an effective means of addressing apical periodontitis. A mandibular premolar with apical periodontitis, apical root resorption, and overfilled gutta percha was retreated with post removal, retrieval of gutta percha from beyond the apex, ultrasonic irrigation and disinfection, and placement of a collagen internal matrix to facilitate a well-controlled MTA apical fill. The magnification and illumination imparted by the operating microscope was integral to achievement of treatment objectives. The patient's symptoms were resolved and complete osseous healing occurred. During treatment planning, clinicians should consider the capability of modern endodontic techniques to overcome technical challenges, often allowing the natural dentition to be preserved and restored to function days after retreatment.

Retrieval technique for the Branemark Novum protocol: replacement of a lost implant

In the past, the Branemark Novum protocol for the immediate functional loading of a mandibular fixed implant supported prosthesis provided an effective alternative for select patients. However, the manufacturer has discontinued this design, and only a few selected prosthetic-related replacement components are currently available. This clinical report presents the loss of an implant associated with a discontinued system. To take advantage of all of the preexisting components, it proposes a rescue procedure that allows continuous use of the original fixed restoration during the restoration of the tripod support at the implant level.

Double-barrel entanglement of intracranial Enterprise stents resulting from undetected incomplete stent apposition

OBJECTIVE

Although intracranial stents have expanded the spectrum of aneurysms amenable to coiling, closed cell design variants can be prone to incomplete stent apposition around tightly curved arterial bends. A case is presented illustrating the technical ramifications of this phenomenon during subsequent treatment.

CLINICAL PRESENTATION

A 49-year-old woman who had previously undergone Enterprise (closed cell design) stent mediated coiling of a wide necked ophthalmic carotid artery aneurysm was noted to harbor residual central filling on follow-up imaging, and was scheduled for additional embolization.

INTERVENTION

During retreatment, performed with a second concentrically placed Enterprise and further coil packing using the jailing technique, the proximal portion of the second Enterprise stent failed to expand as expected. C-arm cone beam CT (CBCT) revealed the second stent to have been navigated into and out of the orphaned lumen created by the incompletely apposed first Enterprise stent at the carotid siphon. This stent entanglement resulted in the formation of a trapped proximal double-barrel lumen in the curved segment and resolution to a single barrel lumen in the distal straight segment of the parent vessel facing the aneurysm neck.

CONCLUSION

Caution is urged when navigating around curved vessel segments through previously deployed intracranial stents, which may be incompletely apposed to the vessel wall, to avoid deleterious and potentially catastrophic entanglement. CBCT imaging may be helpful in delineating the spatial relationship of previously deployed intracranial stents during subsequent endovascular navigation.

Use of standard hypodermic needles for accessing laparoscopic adjustable gastric band ports

BACKGROUND

Laparoscopic adjustable gastric banding is a common and successful method of surgically treating morbid obesity. A recipient will have to attend their surgeon's rooms a number of times to optimally adjust the amount of fluid in the band and hence the amount of restriction. Manufacturers suggest that the ports should be accessed with special non-coring needles that may not always be available in regional or remote centers, and this could create a safety risk in cases where urgent band deflation is required.

METHODS

Ports of two different brands were repeatedly accessed over 100 times in the same location while containing fluid under pressure, using a standard beveled 21 g hypodermic needle (SN) and a 20 g Huber tipped non-coring needle (NCN). The path the needles types took through the port septum was also examined.

RESULTS

There was no leakage of fluid from any of the ports tested. Neither SN nor NCN passed through the port septum down their axis, but rather in a direction closer to that of their beveled surface.

CONCLUSIONS

There is no more risk of "coring" the septum with a SN than with a NCN. SN can be used safely and routinely to access laparoscopic adjustable gastric band ports.

Lasers and soft tissue: 'loose' soft tissue surgery

Oral soft tissue is composed of collagen, water, pigmented connective tissue, blood and lymphatic vessels. In that each may be considered target chromophores, all commercially available laser wavelengths in dentistry will interact with these component elements to a greater or lesser extent. What is of prime importance is that consideration is given to the predominant chromophore in any target tissue and the laser wavelength matched to achieve maximum absorption of light energy. Laser surgery can offer haemostasis, fewer post-operative complications and greater patient acceptance. This article examines the common 'loose' soft tissue management procedures in general dental practice and how the use of lasers can enable the clinician to deliver responsible care.

Efficacy of Two Rotary NiTi Instruments in the Removal of Gutta-Percha During Root Canal Retreatment

The aim of this study was to evaluate the efficacy of ProTaper and K3 in the removal of gutta-percha during root canal retreatment in comparison with hand Hedstrom files. Time of gutta-percha removal and amount of apically extruded debris were also evaluated. Sixty extracted single-rooted anterior teeth and premolars were instrumented and obturated with laterally condensed gutta-percha technique. The teeth were cleared and randomly divided into three groups of 20 teeth each. The roots were split longitudinally, digital images were created using a scanner, and the areas of remaining filling material were traced using Ulead Photoimpact7 then calculated using SigmaScan software. The results indicated that the two rotary nickel-titanium instruments left significantly less remaining filling material than hand instruments (p < 0.001). The ProTaper and K3 required significantly less time for filling material removal than hand instruments (p < 0.001). There was no statistically significant difference among the three techniques regarding the amount of apically extruded debris (p = 0.159). In conclusion, ProTaper and K3 were found to be effective and faster in removing gutta-percha.

A simple method for re-dilatation of an acute tracheostoma stenosis

Tracheostomy or laryngectomy stomas may sometimes re-stenose, resulting in respiratory distress for the patient unless the stoma is rapidly re-dilated and an adequate airway re-established. This article describes a simple and effective method for the acute re-dilatation of a tracheostoma stenosis, using an aural speculum, prior to the insertion of a patent airway tube. This technique has been successfully used in our department since 1995 and, in our experience, causes significantly less distress to our patients when compared with other means employed previously.

Ex vivo study of the efficacy of H-files and rotary Ni-Ti instruments to remove gutta-percha and four types of sealer

AIM

To compare the efficacy of ProFile rotary Nickel-Titanium (Ni-Ti) instruments and Hedstroem-files (H-files) combined with Gates-Glidden (GG) drills during removal of gutta-percha root fillings used in combination with one of the four representative sealers.

METHODOLOGY

Forty-eight single-rooted human teeth, with fully formed apices and straight root canals were used. The root canals were accessed and instrumented using a stepback technique with H-files. They were randomly assigned to four groups and subsequently filled with a combination of lateral and vertical condensation of gutta-percha and one of the following sealers: Roth 811, AH26, Endion and Roekoseal. The root fillings were removed 1 year later, using either H-files in combination with GG drills or the ProFile Ni-Ti system. Teeth were then grooved longitudinally and split. The amount of gutta-percha and sealer remaining on the root canal walls was traced and scored visually with the aid of a stereomicroscope. The scores were analysed and statistically compared with the Kruskal-Wallis test between the ProFile and H-file groups, as well as among the four sealer subgroups. Two samples from each group were studied under the scanning electron microscope to enhance inspection of canal walls and remaining material.

RESULTS

Sealer remnants were observed with both techniques mainly in the middle and apical third of the root canal. The ProFile system and the H-files were associated with similar amounts of remaining filling material (P > 0.05). In the cervical third of the root canal all sealer remnants were removed with both techniques. In the middle and apical third AH26 was associated with a statistically significant greater quantity of remnants on the root canal walls with both removal techniques (P < 0.05). Endion, Roth 811 and Roekoseal were associated with approximately the same amount of filling material in the middle third of the root canal (P > 0.05), whereas in the apical third Endion was associated with significantly more remnants of filling material than the other two sealers with either ProFile or H-files (P < 0.05).

CONCLUSIONS

None of the methods used for the removal of root fillings was totally effective, especially in the apical third of the root canal.

In Vitro Evaluation of the Ability of Three Apex Locators to Determine the Working Length During Retreatment

The purpose of this in vitro study was to evaluate the accuracy of three apex locators in determining the working length during the retreatment process. Twenty extracted single-rooted human teeth with mature apices were used in this study. The root canal length of each tooth was measured placing a #15 file until the tip was visible at the apical foramen. The direct visual measurement was reduced by 0.5 mm and recorded. The root canals were instrumented and filled to the direct visual measurement using lateral compaction technique. After 7 days the teeth were retreated using three apex locators: ProPex, NovApex, and Root ZX, for determining the retreatment working length. Afterward, comparison between the visual working length and the retreatment working length were made. ProPex, NovApex, and Root ZX were accurate within 0.5 mm 80, 85, and 95% of the time, and within 1 mm 95, 95, and 100%, respectively. No significant differences were detected between the three apex locators (p > 0.05).

Efficacy, cleaning ability and safety of different rotary NiTi instruments in root canal retreatment

AIM

To evaluate the efficacy, cleaning ability and safety of three different rotary nickel-titanium instruments with and without a solvent (eucalyptol) versus hand files in the removal of gutta-percha root fillings.

METHODOLOGY

Eighty extracted single-rooted anterior teeth were enlarged to size 35 and obturated with laterally condensed gutta-percha using AHPlus as the sealer. Removal of gutta-percha was performed with the following devices and techniques: FlexMaster, GT Rotary, ProTaper and Hedström files. All techniques were used with and without the solvent eucalyptol. The following data were recorded: time taken to reach the calculated working length and time required for the removal of gutta-percha. The teeth were split longitudinally and photographed. Cleanliness of the root canal walls was scored using the projected slides with a total magnification of approximately 70x. Statistical analysis was performed using the two-way anova (P < 0.001) for the analysis of working time.

RESULTS

The technique that reached the working length most rapidly was that using ProTaper instruments and eucalyptol (+E), followed by FlexMaster + E, ProTaper, FlexMaster, Hedström files + E, GT Rotary + E, Hedström files, and GT Rotary. No significant differences were found for retreatment with or without a solvent in all groups. ProTaper and FlexMaster worked significantly more rapidly than Hedström files and GT Rotary (anova, P < 0.001). Time for complete removal of gutta-percha was again shortest with ProTaper + E, followed by FlexMaster + E, ProTaper, FlexMaster, GT Rotary + E, Hedström files + E, Hedström files, and GT Rotary. ProTaper and FlexMaster again worked significantly faster than the other techniques (anova, P < 0.001). There was no visible filling material extruded apically. Root canal cleanliness proved best following the use of FlexMaster + E, and Hedström files + E, followed by ProTaper + E, and GT Rotary + E.

CONCLUSION

Under the experimental conditions, FlexMaster and ProTaper NiTi instruments proved to be efficient and time-saving devices for the removal of gutta-percha. The use of eucalyptol as a solvent shortened the time to reach the working length and to remove the gutta-percha, but this was not significant.

The operating microscope and ultrasonics; a perfect marriage

Ultrasonic instruments for endodontic, endo-restorative, and microrestorative procedures are underutilized by restorative dentists. These ultrasonic instruments are useful with traditional visualization (unaided vision or loupes). However, their true worth can best be appreciated in conjunction with microscopic visualization. It is imperative that the reader understand that some of the utilizations described in this article are not recommended unless accompanied by the operating microscope and some level of training.

Efficacy, cleaning ability and safety of different devices for gutta-percha removal in root canal retreatment

The purpose of this study was to evaluate the efficacy, cleaning ability and safety of five different devices and techniques to remove gutta-percha root canal fillings. One hundred and twenty extracted single-rooted anterior and premolar teeth were enlarged to ISO size 35 and obturated with laterally condensed gutta-percha using AH 26 as the sealer. Removal of gutta-percha was performed with the following devices and techniques: (a) Gates-Glidden and Hedstrom files, (b) only Hedstrom files, (c) Hedstrom files and chloroform, (d) the Endotec and Hedstrom files, and (e) the XGP drill and Hedstrom files. The following data were recorded: time taken to reach the desired working length, time required for the removal of the gutta-percha, and the amount of material extruded apically. The teeth were split longitudinally and photographed. Cleanliness of the root canal walls was scored using the projected slides with a total magnification of approximately 70x. The fastest technique to reach the working length was using the XGP drill (e), followed by the Gates-Glidden drills (a), Hedstrom files and chloroform (c), and the Endotec device (d). The use of Hedstrom files (b) without any additional support proved to be most time-consuming. Differences were statistically significant (U-test, P > 0.05) between the rotary devices and the manual techniques. Time for complete removal of gutta-percha was again shortest with the XGP drills (e), followed by the Gates-Glidden burs (a), the Endotec device (d), Hedstrom files with chloroform (c), and Hedstrom files alone (b). The XGP burs and the Gates-Glidden drills worked significantly faster than the other techniques. The amount of debris and filling material extruded apically in most cases did not exceed 0.1 mg. No significant differences could be detected between the groups (U-test, P > 0.05). Root canal cleanliness proved best following the use of Hedstrom files without additional support (b) and the Gates-Glidden drills (a), followed by Hedstrom files in combination with chloroform (c), the XGP-gutta-percha remover (e), and the Endotec device (d). When using the XGP two instrument fractures occurred in the apical parts of the root canals preventing further instrumentation to the apical foramen. When using the Gates-Glidden burs four instrument fractures occurred, but all fragments could be removed with forceps immediately. The results suggest that the XGP gutta-percha remover and the Gates-Glidden drills are efficient and time saving devices to remove gutta-percha but include a certain risk of instrument breakage and may leave some filling material inside the root canal. The best root canal cleanliness was achieved with Hedstrom files alone which, on the other hand, were shown to be the most time-consuming.