Simplified Drilling Research Articles

Cooling Efficiency of Sleeveless 3D-Printed Surgical Guides with Different Cylinder Designs.

Background and Objectives: Surgical guides might impede the flow of coolant to the implant drills during the preparation of the implant bed, potentially contributing to increased temperatures during bone drilling. The objective of this experimental study was to assess the cooling efficiency of various guiding cylinder designs for sleeveless surgical guides used in guided surgery. Materials and Methods: In this experimental study, surgical guides with three different guiding cylinder designs were printed. One group had solid cylinders (control) and two test groups (cylinders with pores and cylinders with windows). Forty customized polyurethane blocks with type III bone characteristics were fitted into the guide and fixed in a vise, and implant bed preparations were completed using a simplified drilling protocol with and without irrigation. An infrared thermographic camera was used to record the temperature changes during drilling at the coronal, middle, and apical areas. ANOVA test and Games-Howell post hoc test were used to determine significant thermal differences among groups. Results: A significant thermal increase was observed at the coronal area in the group without irrigation (39.69 ± 8.82) (p < 0.05). The lowest thermal increase was recorded at the surgical guides with windows (21.451 ± 0.703 °C) compared to solid (25.005 ± 0.586 °C) and porous surgical guides (25.630 ± 1.004) (p < 0.05). In the middle and apical areas, there were no differences between solid and porous cylinders (p > 0.05). Conclusions: 3D-printed sleeveless surgical guides with window openings at the guiding cylinders reduce the temperature elevation at the cortical bone in guided implant surgery.

Infrared thermography comparison of heat generation between simplified and conventional implant site preparation techniques

ABSTRACT&#x0D; Introduction: The predictability of osseointegration depends on a non-traumatic surgical technique that maintains cell viability. It is known that during the drilling osteotomy for implant placement occurs heat generation, being able to influence osseointegration due to thermal damage. The objective of this research was to evaluate and compare the heat generated by the drills during the preparation of surgical sites for implant placement between two different techniques: simplified (Simplified Drilling, SD) and conventional, in an in vitro model.&#x0D; Material and methods: Fifty implant site preparations were performed in segments of bovine ribs, divided into two groups, with the respective drill sequences: control group, conventional preparation, Ø2.0mm spear drill and Ø2.15mm, Ø2.85mm, Ø3.35mm, Ø3.85mm twist drills; SD group, Ø2.15mm and Ø3.85mm twist drills. The measurement of the temperature variation generated by each drill in each group was performed by an infrared thermal camera at three points in the bovine rib segment.&#x0D; Results: The temperature variations at one and thirteen millimeters below the drilling site were, respectively, 0.51±0.64°C and 0.46±0.59°C for the control group, and 0.62±0.76°C and 0.5±0.86°C for the SD group. No statistically significant differences were found between the control and SD groups in relation to heat generation in any of the evaluated points; p=0.288 and p=0.584, respectively for analyzes one and thirteen millimeters below the drilling site.&#x0D; Discussion: The technique of implant site preparation can be simplified, using only two drills in this modality, without showing significant differences in relation to heat generation when compared to the conventional preparation technique.

Simulation and experimental investigations of ultrasonic-assisted drilling with Micro-PDC bit

Ultrasonic-assisted drilling (UAD) technology is a new drilling technology, which combines polycrystalline diamond compact (PDC) bits and performs better than conventional PDC drilling in improving the rock-breaking efficiency during deep hard formations. In this study, a series of simulations and laboratory tests were conducted to explore the dynamic rock-breaking mechanism of UAD with a PDC bit and the influence of different input parameters on the force and energy distribution. First, the UAD process was analyzed using a simplified drilling system model, and the relationship between the axial and tangential forces was investigated using a single PDC cutter cutting model. Then, a finite element analysis model that considers rock heterogeneity was used for the analysis. The drilling process, element damage situation, and broken form of the borehole bottom of conventional drilling (CD) and UAD were compared, and the impact of amplitude, frequency, and rotary speed on the weight on bit (WOB), torque, cutting force, and energy consumption were evaluated. Finally, laboratory experiments on PDC micro-drilling for different drilling conditions were conducted to verify the effectiveness of UAD. The results indicate that during rock-breaking using UAD, the PDC cutter periodically penetrated and broke away from the rock with ultra-high frequency, causing a large amount of damage to the rock. The frequency and amplitude significantly influenced the UAD: when the vibration frequency was between 25 and 35 kHz, the force state of the PDC cutter greatly improved compared with that of CD, and the effect of ultrasonic load reached the maximum at 33 kHz; when the amplitude was between 10 and 50 μm, WOB and torque decreased significantly and the effect of ultrasonic load improved with increase in amplitude, but the rotary speed had little effect on the torque and WOB of UAD. During the laboratory experiments, the drilling efficiency and rate of penetration (ROP) improved on using UAD. When the WOB was 100–200 N and the rotary speed was 300–400 rpm, the efficiency of ultrasonic rotary drilling to improve the ROP increased by 14.7–23.4%.

Effects of a simplified drilling protocol at 50 rpm on heat generation under water-free conditions: an in vitro study.

In recent years, guided implant surgery has been widely used for the convenience of patients and surgeons. Further streamlining the surgical procedure would make implant surgery more convenient. Low-speed water-free conditions are often used in guided implant surgery. Therefore, in this study, we attempted to confirm once again whether drilling was safe at a low speed without water. The main purpose of this study was to evaluate whether a simplified drilling protocol that omits some intermediate steps in the drilling process was safe from the viewpoint of heat generation. D1 density artificial bone blocks were drilled under 50 rpm, 10 N·cm water-free conditions, and the surface temperature was measured using a digital infrared camera. First, drilling was performed with the sequential drilling method, which is the most widely used technique. Second, for each drill diameter, the temperature change was measured while performing simplified drilling with omission of the previous 1, 2, or 3 steps. In sequential drilling, the heat generated during drilling at all diameters was less than the critical temperature of osteonecrosis (47°C) except for the ⌀2 drill. Statistical significance was observed in all groups when comparing sequential and simplified drilling in the ⌀3.2, ⌀3.8, and ⌀4.3 drills (P<0.001). However, in the simplified drilling procedures, the temperature was below the osteonecrosis threshold temperature (47°C) except for the ⌀4.3 drill with the omission of the previous 3 steps (⌀3.0, ⌀3.2, and ⌀3.8). In general, drilling under low-speed, water-free conditions has shown stable results in terms of heat generation. Simplified drilling showed statistically significantly greater heat generation than sequential drilling. However, most of the diameters and omitted steps seem to be clinically acceptable, so it will be useful if an appropriate selection is made according to the patient's clinical condition.

Resonance Frequency Analysis to Evaluate the Effect of Different Drilling Techniques on Implant Stability at Different Time Intervals: A Randomized Clinical Trial.

To evaluate the effect of different drilling techniques on implant stability at different time intervals. Patients were randomly allotted into three groups based on drilling technique for osteotomy: conventional drilling technique; simplified drilling technique; or modified conventional drilling technique. In 30 patients (n = 10 each group), a total of 44 implants were placed. In the conventional drilling technique, drills with increasing diameters were used. In the simplified drilling technique, only pilot and final-diameter drills were used. In the modified conventional drilling technique, all the drills were used in sequential order in the clockwise direction except the last drill, which was used in the counterclockwise direction. Implant stability quotient was recorded immediately after placing implants and at 1 and 3 months. Statistical analysis was performed with two-way analysis of variance (ANOVA) and Student t test. Two-way ANOVA showed that drilling technique (P < .001) and time (P = .002) did have a statistically significant effect on implant stability quotient. The modified conventional drilling technique showed a drop in secondary implant stability at 1 month that was negligible compared to the other techniques. After 1 month, there was a significant increase in implant stability quotient with the modified conventional drilling technique compared to the conventional drilling technique (P = .001). The least crestal bone loss during 3 months of follow-up was with the modified conventional drilling technique (0.37 ± 0.06). Secondary stability increased with the modified conventional drilling technique in 3 months and showed a negligible drop at 1 month. This novel drilling technique had an early shift from a decrease to an increase in stability pattern, along with the least crestal bone loss at 3 months.

Welding distortion investigation of rotary drill rig pipe with radial loading transition bars

Cylindrical drilling pipe is an essential component of the rotary drilling rig, and its fabrication accuracy will significantly affect the machine performance and service reliability. The paper investigates the fabrication distortion of drilling pipes during the welding processing. Given the effects of welding distortion induced by material heterogeneity and pipe diameters, the welding deformation of simplified drilling pipe components with a single long bar was first studied to clarify the mechanism of dimensional variation and determine the inherent strain by the Thermal Elastic-Plastic (TEP) method. The deduced inherent strain results were employed to estimate the welding distortion of complex welding drilling pipe structures. To mitigate the welding distortion of the drilling pipe, the influence of the welding sequence on the local deformation is examined in the hoop direction. Moreover, the discrepancy of distortion under each welding pass was demonstrated. Different welding strategies (rotate and symmetry) for the next welded bar are employed according to the pipe rolling action after one welding. The distortion results show an optimization welding sequence by the characteristics distribution of welding distortion.

A retrospective case series report on a novel aggressively threaded and tapered implant

Background: Firm primary implant stability is considered as one determinant of success with implant therapy. A novel tapered implant with aggressive threading aiming at high primary stability, also in low bone densities, using a simplified drilling protocol has recently been developed. Aim/Hypothesis: To retrospectively evaluate the primary stability, clinical and radiographic performance of 25 tapered and aggressively threaded implants in 15 consecutive patients after one year of follow-up. Materials and Methods: The study comprised of the first 15 consecutive patients (13 female, 2 male) treated with 25 implants (Proactive Edge, Neoss AB, Gothenburg, Sweden) using a one-stage protocol and loaded for at least one year (Figures 1 and 2). Five implants had been placed in the mandible and 20 in the maxilla for seven single tooth replacements, seven partial bridges and one full bridge. Insertion torque/time curves were registered during placement with an Elcomed drilling unit (W&H Austria GmbH, Bürmoos, Austria). RFA measurements were taken after implant placement using a PenguinRFA instrument (IDSAB, Gothenburg, Sweden). The implants were either restored immediately (n = 5) or after 6 to 8 weeks of healing (n = 20). Marginal bone levels were evaluated in baseline and one-year intraoral radiographs. Results: All implants achieved firm primary stability as assessed with insertion torque (42.6 + 17.0 Ncm, range 13-80 Ncm) and RFA (76.9 + 3.7 ISQ, range 66-84 ISQ) measurements. Thirteen of the implants (all 3.5 mm in diameter) could be placed after the use of one spiral drill only. The remaining implants (4.0 mm, n = 10, 5.0 mm, n = 2) were placed after using two spiral drills. No implant was lost during the one-year of follow-up. The mean marginal bone resorption was 0.5 + 0.6 mm after one year. Conclusions and Clinical Implications: The present case series report showed that the novel implant and simplified drilling protocol resulted in firm primary implant stability. Promising clinical and radiographic outcomes were seen after one year. However, clinical studies including more patients and implants are needed. Keywords: dental implants, primary stability, clinical follow-up, case series Figure 1: The Neoss Proactive Edge implant in different diameters, Figure 2: Postoperative (left) and one-year (right) intraoral radiograph of one implant used for a maxillary molar replacement.

Effect of Simplifying Drilling Technique on Heat Generation During Osteotomy Preparation for Dental Implant

To test the hypothesis that there would be no difference in heat production by reducing the number of drills during the implant site preparation relative to conventional drilling sequence. A total of 120 implant site preparations with 3 different diameters (3.6, 4.3, and 4.6 mm) were performed on bovine ribs. Within the same diameter group, half of the preparations were performed by a simplified drilling procedure (pilot drill + final diameter drill) and other half using the conventional drilling protocol (pilot drill followed by graduated series of drills to widen the site). Heat production by different drilling techniques was evaluated by measuring the bone temperature using k-type thermocouple and a sensitive thermometer before and after each drill. Mean for maximum temperature increase during site preparation of the 3.6, 4.3, and 4.6-mm implants was 2.45, 2.60, and 2.95° when the site was prepared by the simplified procedure, whereas it was 2.85, 3.10, and 3.60° for the sites prepared by the conventional technique, respectively. No significant difference in temperature increase was found when implants of the 3 different diameters were prepared either by the conventional or simplified drilling procedure. The simplified drilling technique produced similar amount of heat comparable to the conventional technique that proved the initial hypothesis.

Bone Healing Around Dental Implants: Simplified vs Conventional Drilling Protocols at Speed of 400 rpm.

This study evaluated whether simplified drilling protocols would provide comparable histologic and histomorphometric results to conventional drilling protocols at a low rotational speed. A total of 48 alumina-blasted and acid-etched Ti-6Al-4V implants with two diameters (3.75 and 4.2 mm, n = 24 per group) were bilaterally placed in the tibiae of 12 dogs, under a low-speed protocol (400 rpm). Within the same diameter group, half of the implants were inserted after a simplified drilling procedure (pilot drill + final diameter drill), and the other half were placed using the conventional drilling procedure. After 3 and 5 weeks, the animals were euthanized, and the retrieved bone-implant samples were subjected to nondecalcified histologic sectioning. Histomorphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) analysis were performed. Histology showed that new bone was formed around implants, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, when all independent variables were collapsed over drilling technique, no differences were detected for BIC and BAFO; when drilling technique was analyzed as a function of time, the conventional groups reached statistically higher BIC and BAFO at 3 weeks, but comparable values between techniques were observed at 5 weeks; 4.2-mm implants obtained statistically higher BAFO relative to 3.75-mm implants. Based on the present methodology, the conventional technique improved bone formation at 3 weeks, and narrower implants were associated with less bone formation.

Effect of the Drilling Technique on Heat Generation During Osteotomy Preparation for Wide-Diameter Implants.

To test the hypothesis that there would be no difference in heat generation by reducing the number of drills during the implant site preparation relative to conventional drilling sequence. A total of 80 implant site preparations with 2 different diameters (5.6 and 6.2 mm) were performed on bovine ribs. Within the same diameter group, half of the preparations were performed by a simplified drilling procedure (pilot drill + final diameter drill) and the other half using the conventional drilling protocol, where multiple drills of increasing diameter were utilized. Heat production by different drilling techniques was evaluated by measuring the bone temperature using K-type thermocouple and a sensitive thermometer before and after each drill. Mean for maximum temperature increase during site preparation of the 5.6- and 6.2-mm implants was 2.20°C, and it was 2.55°C when the site was prepared by the simplified procedure, whereas it was 2.80°C and 2.95°C for the sites prepared by the conventional technique, respectively. No significant difference in temperature increase was found when implants of the 2 chosen diameters were prepared either by the conventional or simplified drilling procedure. The simplified drilling protocol produces similar amount of heat comparable to the conventional technique, which proved the initial hypothesis.

A study on simplified procedure of enhanced designed implant drill

Purpose : The objective of this research was to develop a more simplified drilling procedure with an enhanced implant drill. Materials and Methods : The drill enhanced design factors enabled implantation of Dia. 5.0mm fixture with only 2 times drilling which is more simplified drilling procedure. The enhanced drill was designed with 2 flutes, 2-phase or 3-phase formed drill tip and 25 degrees of helix angle. The proposed drilling procedure (2 times) was compared with a general drilling process (4 times) in terms of temperature changes, cutting time and ISQ value. Results : The simplified drilling procedure indicated less heat than a conventional drilling procedure (p&lt;0.05). The enhanced drill showed significantly shorter drilling time than a conventional drill (p&lt;0.05). On the other hand, higher insertion torque and ISQ value were observed on the the suggested drilling procedure than the conventional drilling procedure (p&lt;0.05). Conclusion : A simplified drilling procedure with the newly designed drill could provide higher effectiveness and safety of dental implant operations under properly controlled external conditions, such as irrigation and RPM of drilling.

Effect of low speed drilling on osseointegration using simplified drilling procedures

Our aim was to find out whether simplified drilling protocols would provide biological responses comparable to those of conventional drilling protocols at the low rotational speed of 400rpm. Seventy-eight root form endosseous implants with diameters of 3.75, 4.2, and 5mm were placed into canine tibias and allowed to heal for 3 and 5 weeks. After the dogs had been killed, the samples of implanted bone were retrieved and processed for non-decalcified histological sectioning. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) analyses were made on the histological sections. Implants treated by the simplified protocol resulted in BIC and BAFO values comparable to those obtained with the conventional drilling protocol, and there were no significant differences in the technique or diameter of the drilling. The results suggest that the simplified procedure gives biological outcomes comparable to those of the conventional procedure.

Letter to the Editor: Re: Simplified Drilling Technique Does Not Decrease Dental Implant Osseointegration: A Preliminary Report

Letter to the Editor: Re: Simplified Drilling Technique Does Not Decrease Dental Implant Osseointegration: A Preliminary Report

Simplified Drilling Technique Does Not Decrease Dental Implant Osseointegration: A Preliminary Report

To date, some experimental studies have addressed the effect of bone drilling technique and sequence on dental implant osseointegration. In the present study, the authors hypothesize that there would be no differences in osseointegration when reducing the number of drills for osteotomy compared to the conventional drilling protocols. Seventy-two implants (diameters 3.75 mm and 4.2 mm; n = 36 for each diameter) were bilaterally placed in the tibia of 18 beagles for 1, 3, and 5 weeks. Half of the implants of each diameter were placed using a simplified drilling procedure (pilot and final drill), and the other half were placed using a conventional drilling procedure (all drills in sequence). The retrieved samples were subjected to histologic and histomorphometric evaluation. Histology showed that new bone formed around the implant, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, the simplified group presented significantly higher bone-to-implant contact and bone area fraction occupancy compared to the conventional group after 1 week; however, no differences were detected at 3 and 5 weeks. Bone responses to the implant with the simplified protocol can be comparable to the conventional protocol.

The Effect of Simplifying Dental Implant Drilling Sequence on Osseointegration: An Experimental Study in Dogs

Objectives. To test the hypothesis that there would be no differences in osseointegration by reducing the number of drills for site preparation relative to conventional drilling sequence. Methods. Seventy-two implants were bilaterally placed in the tibia of 18 beagle dogs and remained for 1, 3, and 5 weeks. Thirty-six implants were 3.75 mm in diameter and the other 36 were 4.2 mm. Half of the implants of each diameter were placed under a simplified technique (pilot drill + final diameter drill) and the other half were placed under conventional drilling where multiple drills of increasing diameter were utilized. After euthanisation, the bone-implant samples were processed and referred to histological analysis. Bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) were assessed. Statistical analyses were performed by GLM ANOVA at 95% level of significance considering implant diameter, time in vivo, and drilling procedure as independent variables and BIC and BAFO as the dependent variables. Results. Both techniques led to implant integration. No differences in BIC and BAFO were observed between drilling procedures as time elapsed in vivo. Conclusions. The simplified drilling protocol presented comparable osseointegration outcomes to the conventional protocol, which proved the initial hypothesis.

Feasibility Study of Boreholes Hand Drilling in Senegal—Identification of Potentially Favorable Areas

Drilling techniques commonly used in Africa are rather well suited for areas where geologic formations are hard and groundwater is not located at higher depths. Thus, for a large number of people living in rural areas, access to improved drinking water sources is often limited, due to the high cost of drilled boreholes that is closely linked to geographical, geological and hydrogeological factors. The analysis of various contexts has revealed that, in order to improve access to safe drinking water for underserved communities and populations, it is possible to consider less costly alternative solutions, compared to current options for water supply which are still expensive. In this paper, a simplified drilling technology at a very low cost has been demonstrated: “the manual or hand drilling”, which is a practical solution for less than 40-m deep water points in alluvial terrains or low resistance rock formations. The feasibility study of manual drilling in Senegal has revealed that, even if it is not practical in all geological formations of the country, manual drilling remains an alternative solution for reducing costs and improving accessibility to drinking water in several areas in Senegal, particularly in the Senegal River Valley, along the northern coast, in Fatick and Casamance coastal zones. This study was used to set up map of areas suitable for manual drilling boreholes; it aims to strengthen the local private sector capacity to meet growing drinking water needs in rural areas.

Symbolic computation of normal form for Hopf bifurcation in a retarded functional differential equation with unknown parameters

Based on the normal form theory for retarded functional differential equations by Faria and Magalhães, a symbolic computation scheme together with the Maple program implementation is developed to compute the normal form of a Hopf bifurcation for retarded functional differential equations with unknown parameters. Not operating as the usual way of computing the center manifold first and normal form later, the scheme features computing them simultaneously. Great efforts are made to package this task into one Maple program with an input interface provided for defining different systems. The applicability of the Maple program is demonstrated via three kinds of delayed dynamic systems such as a delayed Liénard equation, a simplified drilling model and a delayed three-neuron model. The effectiveness of Maple program is also validated through the numerical simulations of those three systems.

Research on Preventing Deflection Mechanism of the Auger Mining Machine

Auger mining machine which is used in thin coal seam gets coal by drilling. Its drilling distance always is dozens of meters. Because of the long Drilling distance, the deflection of the drilling tool was produced by deviating force . In order to improve auger mining machine’s preventing deflection character and scope of application, the research on preventing deflection mechanism of auger mining machine combining theoretical analysis and experimental research was carried out on the basis of a simplified drilling tool structure. The studies we have performed showed that: increasing the drilling assembly bending rigidity or the drill pipe weight can prevent deflection; reducing the distance between the drilling stabilizer and drill is another method to reduce amount of deflection.