Effects of implant drilling parameters for pilot and twist drills on temperature rise in bone analog and alveolar bones
Introduction
The insertion of dental implants is one of the available dental procedures for replacing missing teeth. It has many advantages: (1) the biting force after the operation may recover to the original level; (2) it reduces the resorption of alveolar bones; (3) there is no abrasion against the neighboring natural teeth; and (4) a natural appearance is retained after the operation. Albrektsson et al. [1] reported that the success rate for installing dental implants depends on the initial recovery of alveolar bones, which is improved with the mitigation of drilling injuries. In general, surgical drills for installing artificial tooth roots include round burs, pilot drills, twist drills, countersinks, and taps. In addition to the usual mechanical injuries to alveolar bones caused by drilling during surgery, the excessive temperature rise from drilling may lead alveolar bone necrosis, which is a major factor affecting the initial recovery [2].
Research on issues of surgical drilling began in 1964, when conducted drilling experiments on canine mandibles found that increasing the rotation speed of the drill can improve the bone recovery [3]; the explanatory mechanisms for this, however, were not proposed. Matthews and Hirsch [4] conducted drilling experiments on human femurs with temperature measurements, and suggested that the bone temperature rise is affected more by the force loaded during the drilling process than by the rotation speed. In 1981, Krause et al. [5] experimented on bovine cortical bones with drill rotation speeds in the range of 20,000–100,000 rpm, and concluded that increasing the drilling feed rate can effectively decrease the temperature of cortical bones. Eriksson and Alberksson [2] found that osteonecrosis occurred if the bone temperature was maintained above 47 °C for at least one minute. Since then, reducing bone temperature rise during drilling has become important for bone surgeries. The effects of the drilling feed force on the temperature rise of bovine cortical bones was discussed by some researchers [6], [7], [8], [9]; they indicated that increasing the drilling feed force shortened the friction time between the drill and the bone, thereby reducing heat generation and the bone temperature rise during drilling. Benington et al. [10] conducted drilling experiments on the cortical bones of bovine mandibles using drill bits with different geometrical shapes and concluded that different geometrical parameters of the drill bits directly affected the bone temperature rise. The effects of drills with two cutting edges compared to those with three cutting edges on the bone temperature rise were compared and it was found that three cutting edges effectively decreased heat generation during drilling [11]. Tu et al. [12] constructed a three-dimensional finite element model and experiment to simulate the bone temperature rise during a drilling process. Their results indicate that, for a constant drill feed rate, the drill bit with a higher rotation speed can cause a noticeable increase in bone temperature as well as the size of the thermally affected zone. The drilling equipment in seven implant systems confirmed that both the design parameters and the mechanical properties of drill bits could affect the drilling efficiency and the drill's durability, which in turn affected the temperature distribution in alveolar bones [13], [14]. Although various parameters have been studied, it has been reported that heat generation after bone drilling is of particular importance when determining its effect on surrounding bone and the resulting thermal osteonecrosis [15], [16], [17], [18], [19], [20], [21]. These parameters include drill design, drilling parameters and the cooling system. In summary, reducing the temperature rise in alveolar bones during dental implant surgery improves the initial recovery of alveolar bones and improves the success rate of implants.
An ideal experiment for determining the bone temperature during drilling is difficult because bone is a complex and anisotropic biological tissue. To develop a mathematic model to investigate the effects of complex parameters would thus be an effective approach. In this study, a three dimensional (3D) elasto-plastic dynamic finite element analysis (FEA) was combined with experimental validation to investigate the influences of different rotation speeds and feed rates for pilot drills and twist drills on the temperature elevation of alveolar bones during drilling.
Section snippets
Drilling experiment
The drills used for installing dental implants during the experiment were pilot drills and twist drills developed and designed by the Metal Industries Research and Development Centre (MIRDC). The diameter of the pilot drill bit was 2.0 mm, and the twist drill bits had tapering diameters of 2.2–2.8 mm, 2.9–3.5 mm and 3.7–4.3 mm (Fig. 1); all of the drill bits were made of SUS420 stainless steel, and their surfaces were coated with a 2–4 µm thick layer of titanium nitride.
The artificial bones
Model validation
For validation of the model, the measurement results in temperature were used to validate the dynamic finite element model. The experiment was performed using a 2-mm diameter pilot drill, at a feed rate of 0.5 mm/s, drill speed (rotational speed) of 1200 rpm, drilling depth of 6 mm, cortex thickness of 2.0 mm. The measuring position was x = 0.5 mm from the drill hole edge and 2.0 mm in depth. Fig. 4(A) compares the bone temperature obtained from the DFEM and the experiment, showing that the peak bone
Conclusions
In this study, the effects of drilling parameters on the bone temperature elevation in the drilling process of installing dental implants were investigated by primarily using a three dimensional (3D) elasto-plastic dynamic finite element model (DFEM). The parameters for the pilot drills and twist drills discussed in the text included three feed rates and three rotation speeds. In summary, the following conclusions are drawn:
- 1.
For both pilot drills and twist drills, when the rotation speed was
Conflict of interest
The authors declare that there is no conflict of interest regarding the publication of this paper.
Acknowledgments
This study is a part of a scientific project with funding supported by E-Da Hospital (Grant no. EDAHI-102001) and Ministry of Science and Technology, ROC (Grant no. NSC 102-2221-E-020-012). All authors express great acknowledgments.
References (24)
- et al.
Temperature threshold levels for heat-induced bone tissue injury: a vital-microscopic study in the rabbit
J Prosthet Dent
(1983) - et al.
A study of the effects of high-speed rotary instruments on bone repair in dogs
Oral Surg Oral Med Oral Pathol
(1964) - et al.
Temperature elevations in orthopaedic cutting operations
J Biomech
(1982) - et al.
Effect of drill speed on bone temperature
Int J Oral Maxillofac Surg
(1996) - et al.
Temperature changes in bovine mandibular bone during implant site preparation: an assessment using infrared thermography
J Dent
(1996) - et al.
Heat production by 3 implant drill systems after repeated drilling and sterilization
J Oral Maxillofac Surg
(2006) - et al.
An in vitro study of temperature changes in type 4 bone during implant placement: bone condensing versus bone drilling
Oral Surg Oral Med Oral Pathol Oral Radiol Endod
(2011) - et al.
Influence of orthopaedic drilling parameters on temperature and histopathology of bovine tibia: an in vitro study
Med Eng Phys
(2011) - et al.
Cortical bone drilling and thermal osteonecrosis
Clin Biomech
(2012) - et al.
Temperature effects in the drilling of human and bovine bone
J Mater Process Technol
(1999)
An experimental investigation on thermal exposure during bone drilling
Med Eng Phys
Influence of drill parameters on bone temperature and necrosis: A FEM modelling and in vitro experiments
Comput Mater Sci
Cited by (13)
Heat generation during implant site preparation and its effects on osseointegration: A review
2023, Materials Today: ProceedingsCitation Excerpt :In past 2 decades, dental implant procedures have increased significantly due to various research in dentistry. Dental implant surgery is the process of replacing a missing tooth proving to be advantageous in dentistry [1–4]. In the control and diagnosis of oral disease, significant progress has been made.
An evaluation of fluid distribution at the implant site during implant placement by using a computational fluid dynamics model
2019, Journal of Prosthetic DentistryCitation Excerpt :Drill speed is another important determinant of heat generation at the implant drilling site. An inverse relationship between the drilling speed and heat production has been reported,5,6 whereas some others have reported the opposite conclusion.15,17,31 However, despite this controversy, for dental implant site preparation, the drill speed in clinical practice is more dependent on the implant system chosen and is always limited to 1200 rpm.16
Assessment of thermal necrosis risk regions for different bone qualities as a function of drilling parameters
2018, Computer Methods and Programs in BiomedicineCitation Excerpt :A heat transfer finite element model which based on the thermo-mechanical theory for predicting the heat generation and temperature distribution was developed by Davidson and James [15]. Tu and Chen et al. [16–18] constructed such a model and experimentally validated it for evaluating the thermal affected zone during bone drilling. The relationship between the risk region of thermal necrosis and parameters such as bone quality, feed force, feed rate, rotation speed, and drill-bit diameter should be clinically verified.
Modelling and experimental validation for thrust force and heat generation during bone drilling
2023, International Journal on Interactive Design and ManufacturingExperimental temperature evaluation during a robotized bone drilling process
2023, Biotechnology and Biotechnological Equipment
- 1
Equal contributor.