Generated heat at implant site during gradual and single-drill protocols among Indian patients.

Excessive heat generation during bone drilling for dental implant placement is a known risk factor for bone necrosis and delayed healing. Therefore, it is of interest to evaluate the maximum change in temperature during and after preparation of the implant site for an implant diameter of 4.2 using gradual drilling and single drilling protocols. Hence, 26 artificial bone blocks with d1 density were divided into two groups where the group I had 13 sites prepared using a single drill and for group II bone blocks, 13 implant sites were prepared with the gradual drill protocol using 5 drills. The drill was done at room temperature with 1500 rpm using constant saline irrigation of 50ml/min. The maximum change in temperature was assessed using an intraoral camera. The data collected were statistically evaluated and results were formulated. Data shows that temperature change was significantly higher in group II where a gradual drill protocol was done compared to group I with a single drill protocol for placing the dental implant of diameter 4.2.Considering its limitations, the present in-vitro assessment concludes that a single drill protocol for preparing an osteotomy site for placing a dental implant of diameter 4.2 generates lesser heat than conventional gradual drilling protocols.

Does implant drill design influence the accuracy of dental implant placement using static computer-assisted implant surgery? An in vitro study.

BACKGROUND: The purpose of this in vitro study was to compare the accuracy of implant placement in model surgeries according to the design of the drills (straight drills or step drills) used to finalize the implant bed during pilot-guided static computer-assisted implant surgery (sCAIS). METHODS: Model surgeries were carried out on resin models randomly assigned to three study groups. Virtual planning software (coDiagnostiX 10.6, Dental Wings, Montreal, Canada) was used to plan the implant positions. In Groups 1 and 2, pilot-guided sCAIS was performed. Straight drills were used in Group 1, and step drills were used in Group 2 to finalize the implant beds. In Group 3, fully guided sCAIS was performed using a universal fully guided kit (RealGUIDE Full Surgical Kit 3DIEMME, RealGUIDE, Cantù, Como, Italy). A total of 90 dental implants (Callus Pro, Callus Implant Solutions GmbH, Nuremberg, Germany) were placed (six implants per model, five models per study group). The primary outcome variables (angular deviation, coronal global deviation, and apical global deviation) were calculated for all implants based on the comparison of the preoperative surgical plan with the postoperative scans. RESULTS: Group 2 (coronal global deviation, 0.78 ± 0.29 mm; apical global deviation, 1.02 ± 0.56 mm) showed significantly lower values of both global deviation variables than Group 1 (coronal global deviation, 0.95 ± 0.20 mm; apical global deviation, 1.42 ± 0.49 mm). However, there was no significant difference in angular deviation between Groups 1 and 2 (7.56 ± 2.92° and 6.44 ± 2.84°). Group 3 produced significantly lower values of all three primary outcome variables (angular deviation, 2.36 ± 0.90°; coronal global deviation, 0.59 ± 0.28 mm; apical global deviation, 0.90 ± 0.29 mm) than Group 1 and significantly lower angular deviation and coronal global deviation values than Group 2. CONCLUSIONS: The design of the drills used to finalize implant osteotomies during pilot-guided sCAIS influences dental implant placement accuracy. Using step drills instead of straight drills for final osteotomies decreases deviation from the surgical plan. The fully guided approach performed better than the pilot-guided sCAIS.

Temperature Changes during Implant Osteotomy Preparations in Fresh Human Cadaver Tibiae, Comparing Straight with Tapered Drills.

The success of osseointegration depends on many factors. With temperatures beyond a 47 °C threshold over 1 min, bone survival may be impaired. The purpose of the study was to evaluate, in fresh human cadaver tibiae, the temperature changes during osteotomy preparations using two straight and two tapered implant systems' drills, external irrigation, and varying revolutions per minute (RPM). The tibiae from a fresh female cadaver were harvested bilaterally. Two tapered and two straight design drills were assessed. Two-hundred and forty osteotomies were prepared at 6 mm depth following the drill sequence of the manufacturers' protocol for each drilling speed. Difference in temperature (ΔΤ) was calculated by subtracting the baseline from the maximum temperature (ΔT = Tmax - Tbase). Drill design and drill diameter, as independent variables or synergistically, had a significant effect on ΔΤ. Tapered drills: As the drill diameter increased, ΔΤ increased at all RPM. Straight drills: As the drill diameter increased, ΔΤ remained constant or slightly decreased at all RPM. Drill diameter and design had a significant effect on ΔΤ in human tibiae, which never exceeded the critical threshold of 47 °C. Tapered drills caused significantly greater heat production compared to straight drills.

Influence of bone density, drill diameter, drilling speed, and irrigation on temperature changes during implant osteotomies: an in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants. MATERIALS AND METHODS: Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation). RESULTS: In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p < 0.001) and at 800 rpm with irrigation (p = 0.001). CONCLUSIONS: Maximum temperature attained was always below the critical threshold that can cause osteonecrosis, showing that both external irrigation with higher drilling speeds and no irrigation with lower speeds were effective methods to avoid excessive heat generation. CLINICAL RELEVANCE: Despite being always below the critical temperature, bone type, drill diameter, drilling speed, and irrigation must be considered temperature-influencing factors during implant osteotomies.

Comparative Analysis of the Chemical Composition and Microstructure Conformation Between Different Dental Implant Bone Drills.

BACKGROUND: Hardness is considered an important parameter for evaluating the clinical performance of dental implant bone drills. It is connected to the chemical composition, microstructure conformation and manufacture of the surgical drills. METHODS: Microstructure of five dental implant drills using scanning electronic microscopy (SEM) integrated with energy dispersive X-ray spectrometry. Vickers microhardness was measured using a CV 2000 microhardness tester with an indentation force of 500 g. RESULTS: Composition of the implant drills was typical of martensitic stainless steel (MSS). The drills contained 13%-17% of Cr; Mo, Si and Mn were present as minor ligands. The examined bone drills showed different external surface conformation and hardness in relation to the different industrial production processes. A rougher external surface and a higher hardness value are characteristics of the surgical bone drills produced by hot forming; the implant drills produced by machining showed mailing lines on their external surface and a lower hardness. CONCLUSIONS: Different compositions and treatments were used by the manufacturers to improve the hardness of the external layer of the dental implant drills making them prone to a diverse heat generation during the implant site preparation.

Improved Dental Implant Drill Durability and Performance Using Heat and Wear Resistant Protective Coatings.

The dental implant drilling procedure is an essential step for implant surgery, and frictional heat in bone during drilling is a key factor affecting the success of an implant. The aim of this study was to increase the dental implant drill lifetime and performance by using heat- and wear-resistant protective coatings to decrease the alveolar bone temperature caused by the dental implant drilling procedure. Commercially obtained stainless steel drills were coated with titanium aluminum nitride, diamond-like carbon, titanium boron nitride, and boron nitride coatings via magnetron-sputter deposition. Drilling was performed on bovine femoral cortical bone under the conditions mimicking clinical practice. Tests were performed under water-assisted cooling and under the conditions when no cooling was applied. Coated drill performances and durabilities were compared with those of three commonly used commercial drills with surfaces made from zirconia, black diamond. and stainless steel. Protective coatings with boron nitride, titanium boron nitride, and diamond-like carbon have significantly improved drill performance and durability. In particular, boron nitride-coated drills have performed within safe bone temperature limits for 50 drillings even when no cooling is applied. Titanium aluminium nitride coated drills did not show any improvement over commercially obtained stainless steel drills. Surface modification using heat- and wear-resistant coatings is an easy and highly effective way to improve implant drill performance and durability, which can improve the surgical procedure and the postsurgical healing period. The noteworthy success of different types of coatings is novel and likely to be applicable to various other medical systems.

Avaliação funcional do desenho de três brocas de preparo para colocação do implante dentário / Functional evaluation of three different drill designs for dental implant osteotomy: an in vitro study

Objetivos: avaliar o desempenho de furação de brocas. Material e métodos: três sistemas de implantes brasileiros foram testados: A (FGM, Joinville); B (Neodent, Curitiba); e C (SIN, São Paulo). A força de furação foi mantida constante e igual a 35 N. A rotação das brocas foi de 800 rpm e os corpos-de-prova foram mantidos em temperatura de 36°C ± 2°C, sendo a água destilada como fluido refrigerante. Dados sobre a temperatura e torque de furação foram adquiridos, e o desgaste das brocas foi avaliado por MEV. Os testes Anova e Tukey (α=5%) foram utilizados na análise estatística. Resultados: as brocas são eficazes, não ultrapassando a temperatura de limite biológico (47°C). Conclusão: de acordo com os ensaios realizados, a broca do grupo A reúne características que a habilitam como broca de perfuração única no preparo do leito do implante dentário. A análise em MEV mostrou que os grupos A e B mantiveram os gumes de corte bem defi nidos e sem desgaste aparente.

Objectives: to evaluate the osteotomy performance of implant drills. Material and methods: three different Brazilian dental implant systems were tested: A (FGM, Joinville), B (Neodent, Curitiba), and C (SIN, São Paulo). Drilling force was kept at 35 N. Drill rotation was set at 800 RPM and samples were kept at 36 ± 2°C under water coolant. Data regarding temperature and torque were acquired and drill wear evaluated under SEM. The Anova and Tukey tests (α=5%) were applied for statistical analyses. Results: all drills were effi cient and remained below the biologic limit level (47°C). Conclusion: according to the tests, drills of the A group had characteristics for a single osteotomy at the bone bed for implant placement. The SEM analysis demonstrated that groups A and B still had sharp, well-defi ned cutting edges with no visible wear.

Effects of implant drill wear, irrigation, and drill materials on heat generation in osteotomy sites.

This study evaluated the effects of drill wear on bone temperature during osteotomy preparation with 3 types of drills and compared heat production between drills. The drills used in this study were titanium nitride-coated metal, tungsten carbide carbon-coated metal, and zirconia ceramic drills. An osteotomy 11 mm in depth was formed in bovine scapular bone following the manufacturer's recommended drill sequences. Drilling was performed without irrigation and repeated 20 times; temperature was measured every 5 times. Next, 200 rounds of drilling during irrigation were performed for each drill, with temperature change monitored until round 200. Analysis of variance statistics were used for analyses of the measured data. Drilling without irrigation showed significant thermal increase at all time points compared to drilling with irrigation (P < .001). No significant difference was found between drill materials. Under irrigation, the frequency of previous drilling had minimal effects on thermal change. The repeated-measures analysis of variance revealed major thermal change at the initial time point (P < .0001), and the multiple comparison tests revealed a significant difference in temperature between the initial drills that had been used 50 or fewer times and those that had been used more than 50 times, irrespective of the drill material. The results of this study indicate that the initial drill should be changed in osteotomy preparation with irrigation after they have been used 50 times. Irrigation may be a more critical factor for the control of temperature elevation than is the drill material.

Drilling- and withdrawing-related thermal changes during implant site osteotomies.

BACKGROUND: Intrabony temperature increase is not only dependent on shearing energy and mechanical friction between bone and surgical drill but is also related to heat capacity and thermal conductivity of the surrounding bone and the applied surgical instrument. Thus time of occurrence of the highest temperature rise can be expected after the shearing process of the osteotomy, potentially affecting the process of osseointegration. PURPOSE: The aim of this study was to evaluate temperature changes during the shearing and withdrawing processes during osteotomies. MATERIALS AND METHODS: An overall 160 automated intermittent osteotomies (10/16 mm drilling depth) with 2 mm diameter twist drills and 3.5 mm diameter conical drills and different irrigation methods (without/external/internal/combined) were performed on standardized bone specimens. The drilling cycles were operated by a computer-controlled surgical system, while a linear motion potentiometer and multichannel temperature sensors in various intrabony levels ensured the real-time documentation of temperature changes during the shearing and withdrawing processes. RESULTS: The highest temperature changes were invariably recorded during the process of withdrawal. Significantly lower temperature changes (p < .02) could be recorded at maximum drilling depths during the shearing process regardless of drilling depth, diameter or irrigation method. During coolant supply, 2 mm diameter twist drills showed higher temperatures (10 mm, p < .01/16 mm, p < .03) compared with 3.5 mm diameter conical implant drills. Internal (10 mm, p < .01) or combined irrigation (16 mm, p < .01) was associated with significantly lower temperatures compared with external irrigation by the use of conical implant drills. CONCLUSIONS: Considering that heat generation during osteotomies is a multifactorial scenario, this study could demonstrate that the highest temperature rise during implant osteotomies occurs during the withdrawing process and that the time of occurrence is influenced by predominant factors such as osteotomy depth and mode of irrigation.

Heat generated by dental implant drills during osteotomy-a review: heat generated by dental implant drills.

STATEMENT OF PROBLEM: Osseointegration is the more stable situation and results in a high success rate of dental implants. Heat generation during rotary cutting is one of the important factors influencing the development of osseointegration. PURPOSE: To assess the various factors related to implant drills responsible for heat generation during osteotomy. MATERIALS AND METHODS: To identify suitable literature, an electronic search was performed using Medline and Pubmed database. Articles published in between 1960 to February 2013 were searched. The search is focused on heat generated by dental implant drills during osteotomy. Various factors related to implant drill such effect of number of blades; drill design, drill fatigue, drill speed and force applied during osteotomies which were responsible for heat generation were reviewed. Titles and abstracts were screened, and literature that fulfilled the inclusion criteria was selected for a full-text reading. RESULTS: The initial literature search resulted in 299 articles out of which only 70 articles fulfils the inclusion criteria and were included in this systematic review. Many factors related to implant drill responsible for heat generation were found. Successful preparation of an implant cavity with minimal damage to the surrounding bone depends on the avoidance of excessive temperature generation during surgical drilling. CONCLUSION: The relationship between heat generated and implant drilling osteotomy is multifactorial in nature and its complexity has not been fully studied. Lack of scientific knowledge regarding this issue still exists. Further studies should be conducted to determine the various factors which generate less heat while osteotomy such as ideal ratio of force and speed in vivo, exact time to replace a drill, ideal drill design, irrigation system, drill-bone contact area.