High-speed Bur Research Articles

Image-guided intrathecal baclofen pump catheter implantation: a technical note and case series.

OBJECTIVE Medically refractory spasticity and dystonia are often alleviated with intrathecal baclofen (ITB) administration through an indwelling catheter inserted in the lumbar spine. In patients with cerebral palsy, however, there is a high incidence of concomitant neuromuscular scoliosis. ITB placement may be technically challenging in those who have severe spinal deformity or who have undergone prior instrumented thoracolumbar fusion. Although prior reports have described drilling through the lumbar fusion mass with a high-speed bur, as well as IT catheter implantation at the foramen magnum or cervical spine, these approaches have notable limitations. To the authors' knowledge, this is the first report of ITB placement using cone beam CT (CBCT) image guidance to facilitate percutaneous IT catheterization. METHODS Data were prospectively collected on patients treated between November 2012 and June 2014. In the interventional radiology suite, general anesthesia was induced and the patient was positioned prone. Imaging was performed to identify the optimal trajectory. Percutaneous puncture was performed at an entry site with image-guided placement of a sheathed needle. CBCT provided real-time 2D projections and 3D reconstructions for detailed volumetric imaging. A biopsy drill was passed through the sheath, and subsequently a Tuohy needle was advanced intrathecally. The catheter was threaded cephalad under fluoroscopic visualization. After tip localization and CSF flow were confirmed, the stylet was replaced, the external catheter tubing was wrapped sterilely in a dressing, and the patient was transported to the operating room. After lateral decubitus positioning of the patient, the IT catheter was exposed and connected to the distal abdominal tubing with typical pump placement. RESULTS Of 15 patients with Gross Motor Function Classification System Levels IV and V cerebral palsy and instrumented thoracolumbar fusion, 8 had predominantly spasticity, and 7 had mixed spasticity and dystonia. The mean age of patients was 20.1 years (range 13-27 years). Nine patients underwent initial catheter and pump placement, and 6 underwent catheter replacement. The procedure was technically successful, with accurate spinal catheter placement in all patients. The median hospital stay was 4 days (IQR 3-5 days). One patient had an early postoperative urinary tract infection. With a mean follow-up of 25.8 months (median 26, range 18-38 months), no CSF leakage or catheter failure occurred. One late infection due to Pseudomonas aeruginosa (requiring pump explantation) occurred at 4 months, probably secondary to recurrent urinary tract infections. CONCLUSIONS Image-guided CBCT navigation resulted in accurate percutaneous placement of the IT catheter for ITB pumps in patients with prior instrumented thoracolumbar fusion. The multimodality approach is an alternate technique that may be used for IT catheter insertion in patients with complex lumbar spine anatomy, extending the potential to provide safe, durable ITB therapy in this population.

Comparison of marginal microleakage of flowable composite restorations in primary canine teeth prepared with high-speed diamond bur, Er:YAG laser and Er,Cr:YSGG laser.

Adhesive restorations have become highly popular in pediatric dentistry, and novel methods of cavity preparation with minimal patient discomfort including Er:YAG and Er,Cr:YSGG laser preparations have greatly advanced. This study aimed to compare the microleakage of composite restorations of class V cavities prepared in primary canine teeth with high-speed bur and Er:YAG and Er,Cr:YSGG lasers. This in vitro study was conducted on 30 class V cavities prepared on the buccal surfaces of primary canine teeth in three groups (n = 10) of bur preparation, Er:YAG laser and Er,Cr:YSGG laser. The cavities were etched, bonded and restored with Grandio flowable composite according to the manufacturer's instructions. After thermocycling, the teeth were immersed in 1% methylene blue dye for 24 hours to detect microleakage. The teeth were evaluated under a stereomicroscope at ×32 magnification to assess the depth of penetration of methylene blue. The data were analyzed using SPSS version 19 and non-parametric Kruskal-Wallis and Mann Whitney tests. Non-parametric Kruskal-Wallis test showed no significant difference in dye penetration among the three groups (P > 0.05). Pairwise comparisons of occlusal and gingival margins by nonparametric Mann Whitney test revealed no significant difference in microleakage either (P > 0.05). Use of Er:YAG and Er,Cr:YSGG lasers can decrease microleakage to the level of bur preparation. Bur and laser cavity preparations are not significantly different in terms of microleakage at the enamel or dentin margins. Thus, considering the advantages of laser, it may serve as a suitable alternative to bur preparation in pediatric dentistry.

Evaluation of Enamel Surface Roughness after Various Finishing Techniques for Debonding of Orthodontic Brackets.

The aim of this study was to evaluate the surface roughness of enamel after debonding with various types of burs. The buccal surfaces of 20 mandibular incisors for each group of bur were subjected to profilometer analysis, and three parameters of surface irregularity were recorded. After bracket debonding, adhesive remnants were removed by tungsten carbide burs in low-speed, high-speed, and stainbuster settings. The samples were evaluated at pre-treatment (on sound enamel) (T1) and post-treatment (T2) by a profilometer. The specimens were measured twice, and the mean values were recorded. The results were analyzed in intra-group comparisons with paired t-tests and in inter-group comparisons with one-way ANOVA and Tukey's HSD test. All resin removal techniques significantly increased enamel surface roughness (p<0.05). According to one-way ANOVA, there were significant differences in the effect of enamel surface roughness between all methods (p<0.05). The high-speed bur caused the maximum roughness values and the stainbuster bur caused the minimum roughness values in all the parameters (Ra, Rz, and Rq). The three types of burs used for finishing methods revealed significant differences in the enamel surface after debonding. However, the stainbuster bur created smoother surfaces than the other applied methods.

Accidental High-Speed Hand Piece Bur Buried During Surgery of Mandibular Third Molar: A Rare Case Report

Surgical extraction of the mandibular or maxillary third molar is a routine surgical procedure in the department of oral and maxillofacial surgery. But despite of adequate effort to perform these surgeries carefully, it can result in a number of complications. Sometimes accidental surgical instruments can be buried during the surgical procedures. But, this is a very rare complication reported in the literature. The present article reports one of the rare case of non-symptomatic accidental buried of high-speed handpiece bur into the bone. It is the responsibility of the dental practitioner to always check the surgical instrument for breakage signs and should be prepared to solve any possible emergency of this type. Retained instrument fragments should be studied carefully prior to attempt of removal.

Surgical Simulation of Endoscopic Endonasal Anterior Skull Base Surgery using 3D Head Model and Cone Beam CT

Endoscopic endonasal anterior skull base surgery is currently applied for the treatment of olfactory neuroblastoma, and other skull base lesions. In the surgical approach to the anterior skull base, one of the important step is extended frontal sinus surgery, including modified endoscopic Lothrop procedure (MELP). Surgical simulation using artificial three dimensional (3D) models is known to a useful training method to learn the surgical steps and to gain the surgical skills. In this study, we investigated the usefulness of a 3D head model with the detailed CT information in the surgical simulation for extended frontal sinus surgeries and anterior skull base resections. 3D head models (KEZLEX, Ohno, Japan) were used as a surgical simulator. This model is exactly reconstructed and made as a human head including sinonasal structure and anterior/posterior skull base by 3D printer. In this model, we made the first olfactory nerve with a steel wire at the skull base as the posterior limit of the frontal sinus flour to the skull base. In addition, the head model was examined for surgical anatomy by using the cone-beam CT (Accuitomo, Morita, Japan). Then, endoscopic endonasal surgery was performed using a high speed bur (M5, Medtronic, Japan) for the bone resection guided with a navigation system (Fusion, Medtronic, Japan). MELP was performed according to the surgical steps of the outside-in frontal drill-out technique. In results, MELP and the anterior skull base resection including crista galli were successfully performed for 3D model with CT and the navigation. These findings suggest that surgical simulation using artificial 3D head model and cone beam CT combined with a navigation system is useful in the surgical training for endoscopic endonasal anterior skull base surgery.

Effects of antimicrobial photodynamic therapy and surgical endodontic treatment on the bacterial load reduction and periapical lesion healing. Three years follow up

Besides the advances in endodontics, there are situations in which surgery is necessary to retain a tooth that otherwise would be extracted. This study analyzes the microbial reduction after conventional periapical surgery followed by antimicrobial photodynamic therapy (aPDT) in 3 years follows up. Twenty-eight teeth needing periapical surgery were enrolled in this study. Microbiological samples were taken after: (1) accessing the lesion, (2) surgical procedure, and (3) aPDT. The teeth received a full mucoperiosteal flap, osteotomy with a high-speed bur, manual curettage of lesion and of the root, root-end resection and retrograde cavities prepared using ultrasonic retro-tips. After the conventional procedure the cavities received an aqueous solution of methylene blue (60 μM, 3 min) and were irradiated with a diode laser λ=660 nm (6 min, 15 J). After aPDT, a retrograde filling with mineral trioxide aggregate, flap re-positioning, and sutures conventionally ended the procedure. In all the cases, a periapical X-ray exam was taken before and after the surgical procedure. The microbiological samples showed an overall significant reduction, surgical procedure achieved a mean reduction of about 3.5 log while aPDT achieved a 5 log reduction. After 36 months of follow up the patients had, in average a reduction of 78% of the periapical lesion area. It appears that surgical endodontic treatment associated with antimicrobial photodynamic therapy highly improves the microbial reduction compared to the traditional technique and this could directly affect the treatment prognosis and periapical lesion healing.

Effect of different orthodontic adhesive removal techniques on sound, demineralized and remineralized enamel

The aim of this in vitro study was to determine the effect of four different orthodontic adhesive removal techniques on sound, demineralized and remineralized enamel. Composite resin adhesive was bonded to 100 teeth which were divided into four groups with each comprising five sound teeth and 20 teeth with demineralized and remineralized lesions adjacent to the adhesive. Adhesive was removed with either: (1) slow speed bur (SS); (2) high speed bur (HS); (3) aluminium oxide disc (DC); or (4) ultrasonic scaler (US). Damage to the enamel was assessed using white light profilometry, digital photography and scanning electron microscopy. The least to greatest mean depth of damage with the four different adhesive removal techniques to sound enamel was DC = SS < US = HS and to demineralized and remineralized enamel were DC < HS < US = SS. Sound enamel experienced the least amount of damage. Remineralization prior to adhesive removal significantly reduced the amount of damage produced by all techniques compared with demineralized enamel. Discs were the least damaging to demineralized and remineralized enamel compared with the other removal techniques. When demineralization was present discs were found to be the least damaging adhesive removal technique and remineralization further reduced the amount of enamel damage.

Er:YAG laser or high-speed bur for cavity preparation in adolescents

Objectives. The aim was to evaluate the effect on cavity preparation time, the pulse changes and the patient's subjective experience during removal of healthy tooth substance with high-speed bur and Er:YAG laser. Materials and methods. Thirty-five (13 male, 22 female) 14–18-year-olds participated. After local anaesthesia, Er:YAG laser and high-speed diamond bur were used for a 2 mm deep cavity preparation on the middle of the buccal surface on contra-lateral healthy maxillary first premolars. The cavity preparation time and the pulse were measured during the treatment. Subjective experience was evaluated using a VAS-scale and a questionnaire. Wilcoxon Signed Rank test and Chi-2-test were used for statistical analyses. Results. The mean (SD) cavity preparation time was 3.7-times longer (p < 0.001) for the laser [59 (41) s] than for the high-speed bur [16 (4) s]. The mean pulse change during preparation differed (p < 0.05) between the bur (+2.2%) and laser (−4.4%). The smell was worse when laser was used (p < 0.01); 65.7% expressed less discomfort and 57.1% experienced a lower sound level when laser was used. Laser was preferred for future treatment in 62.9% of the adolescents. Conclusion. Laser ablation caused unpleasant smell and longer cavity preparation time, but was preferred by a majority of the adolescents.

Clinical application of Draf IIb frontal sinusotomy and it's modified procedures

To summarize the follow-up outcomes of Draf IIb frontal sinusotomy and it's modified procedures, and to discuss the surgical indications and prognostic factors. Thirty-two patients treated between 2004 and 2010 were enrolled in this study. There were 15 patients for recurrent frontal inverted papilloma (IP), 6 for mucocele, 4 for recurrent frontal sinusitis, 3 for osteoma, 2 for meningoencephalocele with cerebrospinal fluid rhinorrhea, 1 for meningoencephalocele alone and 1 for acute frontal sinusitis. All patients underwent preoperative paranasal sinus computed tomography (CT) scans. Patients with tumor accepted magnetic resonance imaging (MRI). The patients with meningoencephalocele and cerebrospinal fluid rhinorrhea received magnetic resonance cisternography (MRC). The Draf IIb frontal sinusotomy and it's modified Draf IIb-1-3 procedures were applied endoscopically under general anesthesia mainly by high speed bur and power system. The postoperative CT scan was obtained as a base line for follow-up 1 week after the operation. Postoperative follow-up was performed under endoscope. Among 19 cases of Draf IIb, 12 were recurrent IP of frontal sinus, 4 were mucocele, 2 were recurrent frontal sinusitis and 1 were osteoma. Five cases received Draf IIb-1, 2 for each recurrent IP of frontal sinus and recurrent frontal sinusitis and 1 for osteoma. Six cases received Draf IIb-2, 3 for meningoencephalocele, 1 for each IP, acute frontal sinusitis and osteoma. Two cases received Draf IIb-3 were mucocele. The follow-up ranged from 8 to 73 months. Twenty-two cases of the frontal nepostium were widely opened, 7 were stenosis and 3 were closed. Revision surgery was seen in 2 cases with IP. All of them had no complications. The Draf IIb frontal sinusotomy and it's modified procedures are suitable for complex frontal sinus disease, which can be selected according to pathological and anatomical features, and have a good prospect for clinical application.

Effect of acid fruit juices combined with electric or sonic toothbrushing on root dentin permeability: an in vitro study

The purpose of this in vitro study was to quantify the alterations on human root dentin permeability after exposure to different acid fruit juices and to evaluate the effect of toothbrushing with electric or sonic toothbrush after acid exposure. The root dentin of 50 extracted third molars was exposed with a high speed bur. Crowns were sectioned above the cementoenamel junction and root fragments were used to prepare dentin specimens. Specimens were randomly assigned to 5 groups according to the fruit juice (kiwifruit, starfruit, green apple, pineapple and acerolla). Each specimen was connected to a hydraulic pressure apparatus to measure root dentin permeability using fluid filtration method after the following sequential steps: I) conditioning with 37% phosphoric acid for 30 s, II) root scaling, III) exposure to acid fruit juices for 5 min and IV) electric or sonic toothbrushing without dentifrice for 3 min. Data were analyzed statistically by the Wilcoxon and Mann-Whitney tests at 5% significance level. All fruit juices promoted a significant increase of dentin permeability while toothbrushing decreased it significantly (p<0.05). It may be concluded that all acid fruit juices increased root dentin permeability, while toothbrushing without dentifrice after acid exposure decreased the permeability. The toothbrush mechanism (electric or sonic) had no influence on the decrease of root dentin permeability.

Efficacy of Two Methods for Restorative Materials’ Removal in Primary Teeth

This in vitro study aimed to compare the time required for removal, the presence of residues of restorative material, tooth structure loss and dental surface morphology after removal of composite resin and amalgam restorations from occlusal cavities in primary molars using conventional high-speed bur and CVDentus® ultrasonic diamond tips. A total of 37 primary molars were allocated into four groups: Group 1 (n=9)-amalgam restorations removed using high-speed bur; Group 2 (n=10)-amalgam restorations removed using ultrasonic tip; Group 3 (n=8)- composite resin restorations removed using high-speed bur; Group 4 (n=10)-composite resin restorations removed using ultrasonic tip. After being restored, teeth were sectioned and analyzed through stereoscopic microscope images before and after restoration removal. The structural loss was analyzed by software of image analysis, and an examiner assessed for the presence of residues. Scanning electron microscopy was used to evaluate the morphology. Time and structural loss values were compared using ANOVA, and the percentages of samples with residues using Fisher test. There was no statistically significant difference in the tooth structure loss among different methods and restorative materials, as well as in the presence of residues of restorative material. However, diamond burs were faster than the ultrasonic method for both materials. Differences in dental morphology were observed between the methods of restoration removal, but not related to the restorative material. Both conventional high-speed bur and ultrasonic diamond tip methods remove similar amounts of tooth structure, but the removal performed with diamond tips in ultrasonic devices is slower. This study shows that both ultrasonic and conventional high-speed bur methods for removing restorations generate similar loss of sound dental tissue, but the former is slower.

The influence of grain size coating and shaft angulation of different diamond tips on dental cutting

Objectives:To evaluate the influence of the grain size coating and shaft angulation of ultrasonic and high-speed diamond burs on the dental cutting effectiveness.Materials and Methods:For the grain size evaluation, cavities were prepared on 40 incisors using high-speed (1092 and 1093F KG Sorensen®) and ultrasonic tips (8.2142 and 6.2142-CVDentus®). For the shaft angulation evaluation, cavities were prepared on 40 incisors using uniangulated (T1-CVDentus®) and biangulated (T1-A CVDentus®) ultrasonic tips. The cavities were bisected and examined at ×50 magnification. The width and depth of cavities were measured by Leica QWin software. Kruskal–Wallis non-parametric test was used for analysis.Results:The grain size did not affect the cutting effectiveness, but the high-speed burs promoted deeper and wider cavities than the ultrasonic tips. The shaft angulation did not affect the cutting effectiveness; both the angulated and biangulated tips had greater cutting efficiency in dentin than in enamel.Conclusions:Ultrasonic tips promoted more conservative preparations and seemed promising for cavity preparation.

Ultrasonic Chemical Vapor Deposition–coated Tip versus High- and Low-speed Carbide Burs for Apicoectomy: Time Required for Resection and Scanning Electron Microscopy Analysis of the Root-end Surfaces

This study compared ultrasonic chemical vapor deposition (CVD)-coated tip (CVDentus #8.1117-1; Clorovale Diamantes Ind. e Com. Ltda Epp, São José dos Campos, SP, Brazil) versus high-speed (#FG700L) and low-speed (#699) carbide burs for apicoectomy, evaluating the time required for resection and analyzing the root-end surfaces by scanning electron microscopy. Thirty extracted human premolars had the canals instrumented and obturated and were randomly assigned to 3 groups ( n = 10), according to the instrument used for root-end resection. The time required for resection of the apical 2 mm of each root was recorded. The resected apical segments were dried, sputter coated with gold, and examined with a scanning electron microscope at ×350 magnification. A four-point (0–3) scoring system was used to evaluate the apical surface smoothness. The results were analyzed statistically by the Kruskal-Wallis test, and two-by-two comparisons analyses were performed using the Miller test. The significance level was set at 5%. Root-end resection with the high-speed bur was significantly faster (p < 0.05) compared with the low-speed bur and CVD tip. The carbide burs produced significantly smoother root-end surfaces than the CVD tip (p < 0.05). The low-speed bur produced the smoothest root-end surfaces, whereas the roughest and most irregular root ends (p < 0.05) were obtained with the CVD tip. However, no statistically significant difference (p > 0.05) was found between the high- and low-speed burs regarding the surface roughness of the resected root ends (p > 0.05). In conclusion, under the tested conditions, ultrasonic root-end resection took a longer time and resulted in rougher surfaces compared with the use of carbide burs at both high and low speed.

Ultrasonic versus high-speed cavity preparation: Analysis of increases in pulpal temperature and time to complete preparation

The use of ultrasonic tips has become an alternative for cavity preparation. However, there are concerns about this type of device, particularly with respect to intrapulpal temperatures and cavity preparation time. The purpose of this study was to analyze pulpal temperature increases generated by an ultrasonic cavity preparation with chemical vapor deposition (CVD) tips, in comparison to preparation with a high-speed handpiece with a diamond rotary cutting instrument. The time required to complete the cavity preparation with each system was also evaluated. Thermocouples were positioned in the pulp chamber of 20 extracted human third molars. Slot-type cavities (3 x 3 x 2 mm) were prepared on the buccal and the lingual surfaces of each tooth. The test groups were: high-speed cavity preparation with diamond rotary cutting instruments (n=20) and ultrasonic cavity preparation with CVD points (n=20). During cavity preparation, the increases in pulpal temperature, and the time required for the preparation, were recorded and analyzed by Student's t test for paired samples (alpha=.05). The average pulpal temperature increases were 4.3 degrees C for the high-speed preparation and 3.8 degrees C for the ultrasonic preparation, which were statistically similar (P=.052). However, significant differences were found (P<.001) for the time expended (3.3 minutes for the high-speed bur and 13.77 minutes for the ultrasound device). The intrapulpal temperatures produced during cavity preparation by ultrasonic tips versus high-speed bur preparation were similar. However, the use of the ultrasonic device required 4 times longer for the completion of a cavity preparation.

Influence of Pulse Repetition Rate on Temperature Rise and Working Time During Composite Filling Removal with the Er:YAG Laser

The purpose of this study was to assess the efficacy of Er:YAG laser energy for composite resin removal and the influence of pulse repetition rate on the thermal alterations occurring during laser ablation. Composite resin filling was placed in cavities (1.0 mm deep) prepared in bovine teeth and the specimens were randomly assigned to five groups according to the technique used for composite filling removal. In group I (controls), the restorations were removed using a high-speed diamond bur. In the other groups, the composite fillings were removed using an Er:YAG laser with different pulse repetition rates: group 2-2 Hz; group 3-4 Hz; group 4-6 Hz; and group 5-10 Hz. The time required for complete removal of the restorative material and the temperature changes were recorded. Temperature rise during composite resin removal with the Er:YAG laser occurred in the substrate underneath the restoration and was directly proportional to the increase in pulse repetition rate. None of the groups had a temperature increase during composite filling removal of more than 5.6 degrees C, which is considered the critical point above which irreversible thermal damage to the pulp may result. Regarding the time for composite filling removal, all the laser-ablated groups (except for group 5 [10 Hz]) required more time than the control group for complete elimination of the material from the cavity walls. Under the tested conditions, Er:YAG laser irradiation was efficient for composite resin ablation and did not cause a temperature increase above the limit considered safe for the pulp. Among the tested pulse repetition rates, 6 Hz produced minimal temperature change compared to the control group (high-speed bur), and allowed composite filling removal within a time period that is acceptable for clinical conditions.

Adhesive interfaces of enamel and dentin prepared by air-abrasion at different distances

The purpose of this study was to analyse, by scanning electron microscopy (SEM), the morphology of enamel and dentin/adhesive interfaces in cavities prepared by air-abrasion at different working distances. Thirty sound third human molars were selected and, on both their buccal and lingual surfaces, class V cavities were prepared by air-abrasion, at 2-, 4-, 6-, 8- and 10-mm working distances, or high-speed bur (control group). After preparation, all cavities were etched with 35% phosphoric acid gel and restored with Single Bond/Filtek Z-250. Buccal and lingual surfaces were separated and restorations sectioned in a buccolingual direction, providing two sections of each cavity, which were analysed by scanning electron microscopy. It was observed that the distances of 6 and 8 mm promoted more homogeneous dentin/adhesive interfaces, with tags formation, and more uniform for enamel, which were similar to the control group. It may be concluded that the air-abrasion working distance can influence the morphology of enamel and dentin/adhesive interfaces, and the intermediate distances provided better adhesive interfaces.

Modern Surgical Treatment of Primary Aneurysmal Bone Cyst of the Spine in Children and Adolescents

Aneurysmal bone cyst (ABC) is a benign but locally aggressive tumor-like condition. Treating children with spinal involvement poses special hazards due to the proximity of the lesion to the spinal cord and the need to preserve spinal stability and balance after surgery. Twelve children with ABC treated between 1990 and 2002 at a tertiary pediatric musculoskeletal tumor center using modern surgical techniques and technology were retrospectively reviewed. A surgical technique using a four-step approach of intralesional curettage, high-speed bur, electrocautery, and bone grafting was found to have a significantly reduced rate of recurrence (0/8 cases) compared with traditional intralesional curettage and bone grafting (4/4 cases) (P < 0.002). Short-segment spinal fusion with instrumentation was also done in five cases immediately after excision of the ABC under the same anesthesia and was a nonsignificant marker for reduced rate of recurrence (P < 0.08), likely secondary to wide exposure. Overall, at last follow-up, all 12 patients were alive and well with no evidence of disease and no significant spinal deformity. The four-step approach to treatment of ABC of the spine with appropriate spinal instrumentation and fusion is recommended for successful treatment of this aggressive lesion.

Influence of air abrasion preparation on microleakage in glass ionomer cement restorations

The aim of this study was to assess microleakage in class V cavities prepared by air abrasion or high-speed dental bur and restored with different glass ionomer cements. Sixty bovine incisors were equally divided into 6 groups: I, II and III (preparation by high-speed) and IV, V and VI (preparation by air abrasion). Groups I and IV were restored with Fuji IX; groups II and V with Ketac Molar; and groups III and VI with Vitremer. After 24 h (37 degrees C), specimens were thermocycled, isolated with nail varnish, immersed in a 0.2% Rhodamine B solution for 24 hours, sectioned longitudinally and analyzed for microleakage using an optical microscope connected to a digital camera and a computer. The images were digitized and a software allowed the quantitative evaluation of microleakage in millimeters. Data were analyzed by Wilcoxon and Kruskal-Wallis tests. It was observed that there were significant differences (p < 0.05) between incisal (enamel) and cervical (dentine/cementum) margins, mainly for Ketac Molar; there was no difference (p > 0.05) between preparation methods, except for group II (high-speed/Ketac Molar) that showed higher infiltration; regarding the materials, Ketac Molar demonstrated the highest microleakage values (p < 0.05), and only Vitremer sealed completely both margins of restorations. It was concluded that air abrasion preparation did not influence microleakage in class V restorations with the employed glass ionomer cements.

The use of ballclip attachments with an implant-supported primary-secondary bar overdenture.

The use of ballclip attachments with an implant-supported primary-secondary bar overdenture.

Comparative study of dentine permeability after apicectomy and surface treatment with 9.6 microm TEA CO2 and Er:YAG laser irradiation.

Failure of apicectomies is generally attributed to dentine surface permeability as well as to the lack of an adequate marginal sealing of the retrofilling material, which allows the percolation of microorganisms and their products from the root canal system to the periodontal region, thus compromising periapical healing. The purpose of this study was to evaluate dentine and the marginal permeability after apicectomy and surface treatment with 9.6 micro m TEA CO(2) or Er:YAG 2.94 micro m laser irradiation. Sixty-five single rooted human endodontically treated teeth were divided into five experimental groups: group I (control), apicectomy with high speed bur; group II, similar procedure to that of group I, followed by dentinal surface treatment with 9.6 micro m CO(2) laser; group III, similar procedure to group I followed by dentinal surface treatment with Er:YAG laser 2.94 micro m; group IV, apicectomy and surface treatment with CO(2) 9.6 micro m laser; and group V, apicectomy and surface treatment with Er:YAG laser 2.94 micro m. The analysis of methylene blue dye infiltration through the dentinal surface and the retrofilling material demonstrated that the samples from the groups that were irradiated with the lasers showed significantly lower infiltration indexes than the ones from the control group. These results were compatible with the structural morphological changes evidenced through SEM analysis. Samples from groups II and IV (9.6 micro m CO(2)) showed clean smooth surfaces, fusion, and recrystallized dentine distributed homogeneously throughout the irradiated area sealing the dentinal tubules. Samples from groups III and V (Er:YAG 2.94 micro m) also presented clean surfaces, without smear layer, but roughly compatible to the ablationed dentine and without evidence of dentinal tubules. Through the conditions of this study, the Er:YAG 2.94 micro m and the 9.6 micro m CO(2) laser used for root canal resection and dentine surface treatment showed a reduction of permeability to methylene blue dye.