Low-speed Drilling Research Articles

Diagnosis and Successful Medical Management of a Colonic, Urate Enterolith in an Argentine Black and White Tegu (Salvator merianae)

A 5-yr-old female Argentine black and white tegu (Salvator merianae) was presented for a lack of fecal output, anorexia, and lethargy. Several weeks prior the tegu underwent a rapid diet change to whole rodents. Computed tomography revealed a mineral-dense calculus in the distal colon, causing gastrointestinal obstruction. Because of poor response to enteric fluid therapy alone, transcloacal enterolith removal was elected. Under sedation and neuraxial anesthesia, saline-infusion cloacoscopy was performed and the calculus visualized and destructed using a dental burr on a low-speed dental handpiece and grasping forceps. Recovery from the procedure was unremarkable. Fluid therapy and oral lactulose therapy were prescribed postoperatively. The tegu began to defecate several days later. Transcloacal calculus destruction with a low-speed drill under cloacoscopic guidance should be considered a noninvasive option for management of colonic and cloacal calculi in larger lizard species.

Study on bone volume harvested from the implant sites with different methods

To compare the volume of autogenous bone particles harvested utilizing different techniques and various implant systems during implant surgery, and to determine the advantageous method to collect autogenous bone particles. Homogeneous epoxy resin simulated jaw bone model was enrolled. Bicon, Bego implant systems and Straumann tissue level implant systems were utilized. The two techniques were investigated. One method was low-speed drilling (50 r/min) without water irrigating, and the other one was drilling with cold water irrigating to the ideal depth, then closing the water and drilling out with low speed (50 r/min). The bone particles in the drill groove and implant beds were collected. The volumes of the bone harvested were compared between the different techniques and also among the three implant systems, then they were compared with the volume of the bone harvested by the special bone drill. The sample size of each sub-group was 10. The bone particles were weighed by electronic balance after drying. The harvested bone volume between the latch reamers and hand reamers of Bicon system with the first method was not significantly different. When the same size implant bed was prepared, the volume of the bone particles produced during the implant surgery with low-speed drill without water was significantly higher than that with the other method no matter Bicon [3.5 mm×10 mm hole for example (28.42±6.04) mg vs. (6.30±2.51) mg, P<0.001] or Bego system [2.8 mm×10 mm hole for example (28.95±5.39) mg vs. (4.61±3.39) mg, P<0.001] was used, and the ratio of bone volume between the first method and the second one was approximately 3.3 to 7.0 times. When using the second method to prepare the similar size implant bed, the bone volume was not significant different among Bicon, Bego and Straumann implant systems [Bicon (9.90±3.42) mg, Bego (8.70±4.09) mg, and Straumann (10.56±5.66) mg, P=0.69]. When preparing a 5 mm-diameter-10 mm-length hole with Bicon implant system and a 4.7 mm-diameter-10 mm-length with Bego implant system, the bone quantity harvested from each group was less than that harvested by special bone drill from Neo Biotech [Bicon (82.54±12.26) mg, Bego (85.07±12.64) mg vs. Neo Biotech (96.78±13.19) mg, P<0.05]. More autogenous bone can be harvested from implant beds by preparing with low-speed rolling without water than the method with water irrigation. When utilizing the same preparing method, the implant system has no impact on the volume of the bone harvested.

The effect of antimicrobial photodynamic therapy mediated by papain gel on infected dentin in primary teeth: a clinical trial with microbiological evaluation

Antimicrobial photodynamic therapy (aPDT) has been used for treatment of dental caries. Papacarie™ is a gel composed of papain and chloramine employed for the partial removal of carious tissue, effective against bacteria; however, some studies report that this antibacterial action is not quite so evident. The aim of this study is to evaluate the clinical effect of the substance PapaMBlue followed by laser irradiation on infected dentin in dental caries lesion in primary teeth. Thirty-two primary molars with deep occlusal dental caries were selected and divided in two groups: G1—caries removal with a low-speed drill—and G2—application of aPDT with PapacarieMBlue. After treatment, all the teeth were restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at 3, 6, and 12 months. Dentin samples before and after treatment were analyzed microbiologically. A reduction in the bacterial count was found in both groups and the inter-group difference was non-significant (p = 0.41022). It is possible to conclude that there was a microbial reduction with the two treatments proposed; however, PapaMBlue is minimally invasive, maintains healthy tissue integrity, and is easy to use in Pediatric Dentistry and Public Health. NCT02734420 on 10 March 2016

An experimental comparative study of drilling efficiency and temperature elevation with unmodified and modified medical drills in pig tibia bone

BackgroundThere are no medical drill specifications capable of achieving bone drilling in a short time under low-thrust and low-speed drilling. Gekkou-drill® is an industrial drill that enables drilling with low cutting resistance by its characteristic point design. Our aims were to develop Gekkou-modified drills by processing to the points of currently available medical drills and to verify whether these modified drills enable less invasive drilling procedure for bone tissue in thermal exposure compared with unmodified medical drills. Materials and methodsTwo commercially available 3.2-mm drills were compared before and after Gekkou modification. Drilling of pig tibias was performed at speeds of 300, 800, and 1,500 rpm and a uniform thrust force of 10 N. Temperature at the entry point for bone drilling was measured using a digital thermometer system. The feed rates were calculated using cortical thickness and monitoring data of the digital force gauge. ResultsTwo unmodified drills could not penetrate the cortical bone on the near side at 300 rpm, even after 5 min of drilling. The maximum temperatures with modified drills were 54.6 °C and 46.2 °C at 300 rpm. At medium to high speeds, those were statistically significantly lower than with unmodified drills (58.5 °C vs. 90.5 °C at 800 rpm, 62.6 °C vs. 80.8 °C and 73.9 °C vs. 104.6 °C at 1,500 rpm). The feed rates for modified drills were 4.9–6.9 times as high as unmodified drills at 800 rpm, and 3.4 to 4.5 times at 1,500 rpm. On the other hand, the feed rates of modified drills at 300 rpm were equal to or higher than those of unmodified drills at 1500 rpm. ConclusionGekkou-modified drills clearly suppressed the temperature rise and increased the feed rate compared with conventional drills. Furthermore, it was notable that these modified drills had higher performance even at conditions of low thrust and low speed.

Comparison of Proliferation and Differentiation of Human Osteoblast-like Cells Harvested During Implant Osteotomy Preparation Using Two Different Drilling Protocols.

Autogenous bone grafts are considered a "gold standard." The success of autografts mainly depends on their ability to promote an osteogenic response. The aim of this study was to collect autogenous bone during implant osteotomy preparation using two different drilling protocols and to evaluate and compare the proliferation and differentiation ability of the collected bone particles. Autogenous bone particles were harvested from 20 patients during implant osteotomy preparation using two different drilling protocols: (1) standard drilling protocol with saline irrigation (according to the manufacturer's recommendation) and (2) low-speed drilling protocol without saline irrigation (speed < 200 rpm). Bone samples collected were cultured in growth medium, and after 2 to 3 weeks, cells that grew out from bone grafts were cultured in the normal medium as well as in osteogenic medium for days 0, 4, 7, and 20. Scanning electron microscopy, alizarin red/toluidine blue staining, DNA, ALP, and calcium content measurements were performed. Repeated measures analysis of variance (ANOVA) with Bonferroni's test was employed to analyze the data of this study. The total DNA content was significantly higher for the low-speed drilling samples compared with the standard drilling on day 4 (P < .05), day 7 (P < .01), and day 20 (P < .001) in the normal medium and on day 7 (P < .01) and day 20 (P < .01) in the osteogenic medium. Besides, calcium measurements and mineralized matrix formation observed with alizarin red/toluidine blue staining were significantly higher for the low-speed drilling group compared with the standard drilling group. Osteogenic efficacy (differentiation and proliferation) of autogenous bone particles collected using low-speed drilling was superior compared with standard drilling samples.

Simulation Analysis of RuT450 Drilling Force Based on LS-DYNA Gun Drilling

Cutting force is one of the most important parameters in the machining process, it significantly influenced machining precision of the workpiece, power consumed in the machining process, wear of the cutting tools and so on. There are many factors that affect the cutting force, such as the performance of the workpiece material, cutting speed, usage of the cutting fluid, etc. Single factor variable method was used in this paper, RuT450 was used as workpiece, welded cemented carbide gun drill was used as cutting force and LS-DYNA was used as simulation platform to established the cutting simulation model to analyzed the impact of the cutting speed and feed rate to the drilling force. Simulation results show that, at the low speed drilling stage, drilling force increases with the increase of the feed rate and decreases with the increase of the rotation feed, from the stress cloud it could be seen that the equivalent stress near the drill tip reached the maximum in the drilling process.

Biological drilling: Implant site preparation in a conservative manner and obtaining autogenous bone grafts

Background/Aim: The drilling process for insertion of an implant should be as conservative as possible, as not to damage the future implant bed. If this drilling is conservative additional bone can be obtained to be used afterwards, during the same surgery, as bone graft particulate if needed. The objective of this study was to evaluate the efficiency of a biological low-speed drilling and to analyse the bone obtained in order to ascertain viability and vitality of the contained bone cells. Also, the bone obtained from the low-speed drilling was compared with bone obtained with high speed drilling and irrigation, collected through a filter in aspiration system. Material and Methods: In this pilot study, samples of biological drilling (low speed without irrigation) were collected in five patients undergoing implant surgery. In the same patients a high speed drilling with irrigation was also used. Bone of the drilling was collected through a filter in the aspiration system. Subsequently the samples were analysed by conventional histology and cultivated in order to observe cell growth. Results: The samples of bone obtained by biological drilling showed live cells in the conventional optical microscopy and cell growth after cultivation. The bone obtained with drilling at high revolutions showed no living cells and no cell growth after cultivation. Conclusions: The biological drilling at low speed offered two advantages compared to drilling at high speed with irrigation. The first of these is the perfect control of the drilling depth as the marks of the burs are visible during drilling; the second is possibility of collection of a large number of viable particulate bone grafts without increasing time and complexity of the surgery, which allows immediate augmentation of bone if needed.

Effect of the Combination of Low-Speed Drilling and Cooled Irrigation Fluid on Intraosseous Heat Generation During Guided Surgical Implant Site Preparation: An In Vitro Study.

Investigating the effect of the combination of low-speed drilling and cooled irrigation fluid on intraosseous temperature rise during guided and freehand implant surgery. Bovine ribs were used as bone specimens. Grouping determinants were as follows: drill diameter (2.0, 2.5, 3.0, and 3.5 mm), irrigation fluid temperature (10°C, 15°C, and 20°C), and surgical method (guided and freehand). Drilling speed was 800 rpm. Results were compared with previous ones using 1200 rpm. Temperature measurements were conducted using K-type thermocouples. No mean temperature change exceeded 1.0°C if irrigation fluid cooled to 10°C was used, regardless of the drill diameter or the surgical method, with the highest elevation being 2.10°C. No significant reduction was measured when comparing groups using 15°C and 20°C irrigation fluids, regardless of both drill diameter and surgical method. The use of irrigation fluid being cooled to 10°C combined with low-speed drilling (800 rpm) seems to be a safe method for implant site preparation and drilling through a drilling guide in terms of temperature control.

Comparison of the Bone Harvesting Capacity of an Intraoral Bone Harvesting Device and Three Different Implant Drills.

The aim of the present study was to compare bone-collecting capacity of bone harvesting device and minimally irrigated low-speed drilling using three implant systems. One bone harvesting device and three commercially available drill systems were compared using the osteotomies on bovine rib bones. The amount of the collected bone particle and particle size (<500 μm: small, 500–1000 μm: medium, and >1000 μm: large) were measured. Total wet (1.535 ± 0.232 mL) and dry volume (1.147 ± 0.425 mL) of the bone particles from bone harvesting device were significantly greater than three drill systems (wet volume: 1.225 ± 0.187–1.27 ± 0.29 mL and dry volume: 0.688 ± 0.163–0.74 ± 0.311 mL) (P < 0.05). In all groups, the amount of large sized particles in wet and dry state was the greatest compared to that of medium and small particles. The dry weight of the bone particles showed the same tendency to volumetric measurement. In conclusion, total bone particles and large sized particles (>1000 μm) were harvested significantly greater by bone harvesting device than minimally irrigated low-speed drilling. The composition of particle size in all harvesting methods was similar to each other.

Endodontic Treatment of Primary Molars with Antibiotic Paste: A Report of 38 Cases.

This study presents 38 cases of primary molars with necrotic pulps treated with antibiotics-based paste. The technique consisted of necrotic tissue removal of the pulp chamber, using spoons excavators and low speed drills. Pulp cavity was washed with saline solution and dried with sterile cotton balls. Then an antibiotic paste composed of chloramphenicol, tetracycline, zinc oxide and eugenol - CTZ paste - was inserted at the entrance of root canals. Patients were evaluated clinically and radiographically at different times. The criteria that defined clinical success were the lack of periapical abscess and mobility compatible with chronological age. Radiographic assessments consisted in absence of radiolucency in the region of root bifurcation and pathological bone resorption. There were 100% and 93% of clinical and radiographic success, respectively. The results suggest that the CTZ paste is an optional therapy for pulp of primary molars.

The effect of low-speed drilling without irrigation on heat generation: an experimental study.

ObjectivesIn this study we evaluated heat generation during the low-speed drilling procedure without irrigation.Materials and MethodsTen artificial bone blocks that were similar to human D1 bone were used in this study. The baseline temperature was 37.0℃. We drilled into 5 artificial bone blocks 60 times at the speed of 50 rpm without irrigation. As a control group, we drilled into an additional 5 artificial bone blocks 60 times at the speed of 1,500 rpm with irrigation. The temperature changes during diameter 2 mm drilling were measured using thermocouples.ResultsThe mean maximum temperatures during drilling were 40.9℃ in the test group and 39.7℃ in the control group. Even though a statistically significant difference existed between the two groups, the low-speed drilling did not produce overheating.ConclusionThese findings suggest that low-speed drilling without irrigation may not lead to overheating during drilling.

3D micro-CT analysis of void formations and push-out bonding strength of resin cements used for fiber post cementation.

PURPOSETo investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (µCT) and regional push-out bonding strength.MATERIALS AND METHODSTwenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using µCT scanner at resolution of 13.7 µm. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the µCT analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (α=.05).RESULTSOverall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation (44.86 ± 22.71). Multilink N showed the least void surface (3.51 ± 2.24 mm2) and volume (0.01 ± 0.01 mm3). Regional push-out bond strength of the cements was not different (P>.05).CONCLUSIONµCT proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.

Effect of Diamond Coating on Drilling Force and Temperature during High Speed Micro Drilling of Bone

Bone drilling commonly exists in clinical practice and the heat and force generated by the drilling process has a huge impact on the surgery effect and the recovery of patients. High speed drilling, proved to have less injury and be more efficient when compared to the traditional low speed drilling, is considered to be the development direction of bone drilling-related surgeries. In order to make a further study of the controlling of the heat and force during the bone drilling process, the experiment designed to examine the influence of the diamond coating has been conducted and the result indicates that the diamond coating generally has little influence on the drilling force, however, it can increase the drilling temperature to a certain extent which indicates that the diamond coating is not suitable to apply to bone drills under the conditions of the conducted experiments. The result of this research could be of some help to the development of new kinds of medical drills.

Bacterial Contamination Levels of Autogenous Bone Particles Collected by 3 Different Techniques for Harvesting Intraoral Bone Grafts

The aim of this study was to compare levels of bacterial contamination of autogenous bone collected when using low-speed drilling, a back-action chisel, and a bone filter. Bone tissue samples were taken from 31 patients who underwent surgical extraction of their third lower molars. Before surgical removal of the molar, bone particles were collected by a low-speed drill or a back-action chisel. Then, a stringent aspiration protocol was applied during the ostectomy to collect particulate bone by a bone filter. Processing of samples commenced immediately by incubation in an anaerobic or a CO2-rich atmosphere. The number of colony-forming units (CFUs) was determined at 48 hours of culture. No significant difference in the number of CFUs per milliliter was observed between the low-speed drilling group and the back-action chisel group in the anaerobic or CO2-rich condition (P = .34). However, significantly more micro-organisms were found in the bone filter group than in the low-speed drilling group or the back-action chisel group in the anaerobic and CO2-rich conditions (P < .001). Particulate bone harvested with low-speed drilling or a back-action chisel is safer for use as an autograft than are bone particles collected with a bone filter. These results suggest that bone obtained from low-speed drilling is safe and straightforward to harvest and could be the method of choice for collecting particulate bone. Further research is needed to lower the bacterial contamination levels of autogenous bone particles used as graft material.

Use of Spongostan™ for Prevention of Cranial Subdural Adhesions Following Craniotomy in an Experimental Rabbit Model.

Spongostan™ is a sterile, water-insoluble, porcine gelatin absorbable sponge, which is widely used as a hemostatic material. The aim of this study is to test the anti-fibrotic capacity of Spongostan™, using a craniotomy model in an experimental rabbit model. Eighteen rabbits were divided into two groups: Each group consisted of 9 rabbits, duratomy plus Spongostan™ (group 1), and duratomy without Spongostan™ (group 2). Right parietal bone was removed via trephine and low speed drill and dura was opened. On the group 1 rabbits, an appropriate piece of Spongostan™ was meticulously placed under dural layer. On group 2 rabbits, same procedures were repeated without Spongostan™. Histological sections were taken from each group and evaluated for degree of fibrosis and collagen fibers. There was marked increase in number of fibroblasts and collagen fibers in group 2 rabbits, however most of the rabbits in Spongostan™ group demonstrate scarce histopathological findings for fibrosis. We conclude that an appropriately placed subdural Spongostan™ over cerebral tissue may prevent postoperative surgical adhesions after neurosurgical operations.

Implant-Guided Vertical Bone Augmentation Around Extra-Short Implants for the Management of Severe Bone Atrophy

The purpose of this study is to describe the conservative treatment of severe vertical bone atrophy by combining the insertion of extra-short implants and implant-guided bone augmentation. For that, a low-speed drilling protocol was selected to facilitate the collection of bone particles and to maintain graft osteogenic properties. Extra-short implants were incompletely inserted because of the severe atrophy, and the denuded implant surface was covered by autologous bone particles held together by the adhesive properties of plasma rich in growth factors. The surgical site was then covered with resorbable fibrin membrane, and the flap was repositioned and sutured. Eight patients with a mean residual bone height of 4.19 ± 0.97 mm were treated according to the described treatment protocol. The distance between the implant shoulder and the bony crest was 1.77 ± 0.18, 2.16 ± 0.23, and 1.97 ± 0.26 mm at the mesial, central, and distal aspects, respectively. Vertical bone augmentation resulted in the coverage of 85% of exposed surface by stimulating 1.6 ± 0.5 mm of supra-alveolar bone growth. All 10 extra-short implants placed were successfully osseointegrated. After a mean of 5 ± 1.6 months, provisional screw-retained prostheses were placed. Within the limitations of this study, we conclude that the minimally invasive approach described may successfully rehabilitate extreme vertical bone atrophy in the posterior mandible.

Proliferation and osteogenic differentiation of osteoblast-like cells obtained from two techniques for harvesting intraoral bone grafts

The aims of our study were to verify the presence of viable osteoblasts in samples of bone tissue obtained by drilling or from cortico-cancellous bone blocks and to assess their growth and differentiation capacities. Bone tissue samples were processed independently and cultured in Dulbecco's modified Eagle medium, in a CO2 incubator at 37°C. The proliferative capacity of osteoblasts was determined by spectrophotometry (MTT) at 24 and 48h of culture. Cell cycle was analysed by flow cytometry. Cell differentiation was studied by red alizarin staining of nodules formed in mineralisation medium and by analysis of alkaline phosphatase activity. In comparison to bone block-derived osteoblasts, the proliferative capacity was greater at 24 and 48h of culture (P < 0.001) in the drilling-derived osteoblasts, which showed significantly increased G2/M (P = 0.014) and S (P < 0.001) phases in the cell cycle study. The number of mineralised nodules was proportional to the incubation time, with no differences between the two types of sample, which also did not significantly differ in alkaline phosphatase activity. Superior autograft material is obtained by harvesting particulate bone from low-speed drilling fragments than from a cortico-cancellous bone block. These results suggest that bone obtained from low-speed drilling is a simple and effective alternative to the classic procedure for obtaining bone tissue.

Injury-to-surgery interval does not affect the occurrence of osteonecrosis of the femoral head: A prospective study in a canine model of femoral neck fractures

SummaryBackgroundIt is controversial whether an early reduction and internal fixation can reduce the occurrence of femoral neck fracture-induced osteonecrosis of the femoral head (ONFH). This prospective study was designed to reflect the relationship between injury-to-surgery interval (ISI) and traumatic ONFH based on a canine model of femoral neck fractures.Material/MethodsTwenty-four dogs were equally divided randomly into 3 groups. A lateral L-shape approach centered left great trochanter was used for exposure of the femoral neck. A low-speed drill was used for making displaced fractures in the narrow femoral neck, with the femoral head kept in situ with ligamentum teres intact. In Group A, the fracture was immediately reduced and fixed with 3 parallel pins; while the operation was done 3 days later in Group B, and 3 weeks later in Group C. Another 2 dogs had their fractures untreated. Postoperatively, all dogs were fed separately and received regular x-ray examination. Left femoral heads were harvested for histological examination with a postoperative follow-up of 3.5 months.ResultsThe canine model of femoral neck fractures could be achieved successfully. Radiological signs of post-fracture ONFH could not be detected at intervals of 2 weeks, 4 weeks, 1 month and 2 months. Histologically, there were 2 cases with ONFH in Group A, 1 case in Group B, and 2 cases in Group C. The difference had no statistical significance. For untreated fractures, obvious ONFH could be found radiologically.ConclusionsA shorter ISI may not reduce the incidence of fracture-induced ONFH, which suggests that intrinsic factors play an important role in the occurrence of ONFH.

Estudio histológico comparativo de la reparación ósea entre hueso alveolar y extra-alveolar en los cerdos sometidos a osteotomía con alta y baja velocidad, con refrigeración líquida

IntroductionTaking into account the bone repair process in pigs has shown a greater similarity among the histological variables studied compared to other biological models, the present study has as its aim to evaluate the histological bone repair process of osteotomy performed on alveolar and extra-alveolar bones, using drilling tools with liquid refrigeration. Material and methodEighteen Large White pigs weighing between 20 and 25 Kg were divided into three groups of six animals in order to evaluate the osteotomy repairs with low and high speed in the alveolar bone and threes in the extra-alveolar area, study periods of 7, 14 and 28 days. ResultsIt was observed that in the alveolar bone at the postoperative times of 14 and 28 days, the best repair results were in the osteotomy performed with low speed, while in the 7 day postoperative period, the results with high speed were slightly better, in alveolar areas as well as extra-alveolar areas. There no statistically significant differences between the alveolar and extra-alveolar bone repair process. ConclusionsThe repair process, by means of microscopic analysis in the alveolar and extra-alveolar areas, are similar with better results observed in osteotomies performed with low speed drills in the 14 and 28 day study periods, and at 7 days postoperative the results with high speed drills and refrigeration were slightly better. Research works using pigs as an animal model are perfectly viable.

Combined Electric and Acoustic Stimulation: Successful Treatment Option for Partial Deafness

Combined Electric and Acoustic Stimulation: Successful Treatment Option for Partial Deafness