Purchase and Use of Dental Implant Handpieces
At present, with the popularization of dental implantation technology, how to choose a suitable implanter becomes the first issue to be considered in developing dental implantation technology. In the early days of dental implantation technology in China, because there were not many companies engaged in the distribution of implant systems and supporting tools at that time, the companies that distributed a certain brand of implant system often provided users with an implanter selected by the company or the brand implant system. Dental implant handpieces from the same manufacturer. This often gives users the idea that after selecting a certain planting system, they must choose a planting handpiece that is compatible with the system. Due to the actual work, this method often leads to two phenomena: first, the matching implanter is relatively expensive due to lack of competition; or the implanter can only be used for the implants of the system and cannot be applied to the current market Most (or all) mainstream growing systems. At present, with the popularization of dental implant technology and the huge development prospects of the domestic market, many international manufacturers have gradually entered the Chinese market, which has provided consumers with more choices in the choice of affordable and more suitable handpieces.
So, can a certain brand of planting handpiece be applicable to most (or all) mainstream planting systems on the market today? The answer is yes. In addition, manufacturers are constantly improving, according to some clinical needs, on the basis of meeting their basic functions, adding some special functions. Therefore, before developing dental implantation technology, understand the structure and function of some implanters before buying affordable and convenient implanters among many domestic products. Let’s talk about our experience on the structure of the implanter combined with clinical application experience.
First, the basic steps of bone implant implantation and its basic requirements for implant function
The implantation process of bone implants generally includes pioneer drill positioning, 2-4 stepwise reaming, shoulder table molding, tapping, and implant implants. This step can summarize the basic requirements for clinical implant function:
The maximum speed of the decelerated handpiece after deceleration should reach 2000 rpm. Although many implant systems require steps 1 and 2 to be performed below 800-1000 rpm, our application feels that if the speed is too low, the ball drill and the pioneer drill enter the bone. More difficult; in addition, as will be mentioned below, the initial speed of the bone drill usually decreases when the bone is drilled, and the decline is 1/4 — 1/3, so we use the initial speed of 2000rpm in the first two steps During the drilling process, it can only reach about 1200rpm. In general, the faster the speed, the easier it is to drill into the bone, but too fast, it can generate heat and cause bone burns. On the basis of not causing bone burns, the faster the bone drill is, the easier it is to operate.
When expanding the implant socket, when the bone drill enters, only the edge of the front end of the drill pin contacts the bone. This contact area is small and easy to enter, so it does not need too high speed at this time. In the implant socket forming step, 800 rpm is used. That is, this speed reduces the heat production to a greater extent, thereby ensuring that the cell viability of the finally formed bone wound can be protected to the greatest extent. In order to facilitate operation, most implanters can preset two programs, one maximum speed is set to 2000 rpm, and the other maximum speed is set to 800 rpm. It is best to directly switch between the two programs by foot control, which can greatly speed up the surgical process. .
When tapping and screwing implants at low speeds, most implant systems require a rotation speed of about 15 rpm for tapping and screwing the implants. The torque should be increased step by step, and the maximum torque should be over 50 Ncm. It has reverse rotation function, so that it can be reversely rotated out when tapping.
Each step and jump of each function should be operated by foot switch.
Structure of dental implant handpiece
In the past, there were two types of dental implants: electric and pneumatic. However, because electric is more convenient and applicable, it is difficult to see pneumatic dental implants in the market, so this article only introduces electric. The electric dental implanter usually consists of a host, a motor, a handpiece, a water pump and a foot control.
(1) Host
In all electric dental implanters, the speed control, cooling water pump, function adjustment and status display are located on the host. The foot control is also connected with the host to complete the control function. The main unit is powered by standard circuits (110V or 220V AC) and provides kinetic energy for the motor.
Control Panel Although the items on the control panel of various planters are different, the basic items are similar. The following are the main items.
- The function corresponding to the planting operation step can be selected by the assistant through the panel or directly jumped by foot control. This function should be able to be preset and adjusted on the panel;
- Display This display is used to display the operating status of the planter. If the maximum speed of the motor is 40,000 rpm and a 20: 1 reduction gear is used, then the 20: 1 function on the panel must be selected. The speed displayed on the screen is 2,000rpm. It should be noted that this selection switch does not increase or decrease the actual speed of the motor. The output of the motor is still its maximum speed of 40,000rpm, which is decelerated to 2,000rpm by the handpiece. The speed only shows the numerical calculation result after the maximum speed of the motor is decelerated by the deceleration handpiece. At this time, if you further adjust the speed, you need to reduce the motor speed through the rheostat on the panel or the foot control.
- Some hosts of the motor wiring socket can have two motor interfaces. The advantage is that two different speed-down handpieces can be connected at the same time. Under the same function of the host, different speeds can be selected, which reduces intraoperative replacement. In addition, if a motor fails during the operation, a backup can be provided.
(2) Motor (motor) and handpiece
The motor is connected to the host through the connection line and is powered by the latter. This type of motor is often called a micro motor because of its small size, and is usually designed with different maximum speeds to match the power provided by the host. The most commonly used maximum speed designs are 20,000rpm, 30,000rpm, and 40,000rpm. In clinical practice, handpieces with different reduction ratios need to be equipped according to the speed and torque requirements. For surgical operations such as osteotomy, it is easier to operate at higher speeds, and because of the high speed, you do not need too much torque. At this time, 1: 1 handpieces are often used. A handpiece that can reduce its motor speed is called a speed-reducing handpiece. Generally speaking, while the handpiece is decelerating, the torque is increased by the same proportion. The preparation of planting nests requires low speed and high torque, so this type of handpiece is generally used. According to its deceleration effect, the corresponding logo is engraved on the handle of the handpiece. For example, a 20: 1 handpiece indicates that it can reduce the motor speed by 20 times. Clinically, dental implant handpieces usually use 16: 1 or 20: 1 handpieces. Different motors with different maximum speeds and handpieces with different reduction ratios usually have an optimal speed power range, that is, the maximum power can be generated in this speed range. This phenomenon is similar to automobile gears, each gear corresponds to a speed range that can exert its maximum power. The higher the gear, the higher the required speed range. When the car is running at a lower speed in a higher gear, the power is insufficient. At this time, you need to reverse the gear, or go to the gear after accelerating in the lower gear to ensure sufficient power. The same phenomenon exists in the matching of handpieces and motors. For example, when a handpiece with a certain reduction ratio cannot reach a certain speed, there may be insufficient power. You need to increase the speed or use a handpiece with a larger reduction ratio to ensure sufficient power. For example, on a 20,000rpm motor, when a 20: 1 handpiece is used, the power when the speed reaches 1000rpm is greater than when the speed is lower than 800rpm. When the speed is lower than 800rpm, the power and speed will be significantly lost. When the same handpiece is used on a 30,000rpm motor, the optimal power range is 850-1500rpm.
Under the premise of the same output power, at this time, the motor with a maximum speed limit of 20,000 rpm generates a large torque when drilling the bone at low speed, and even at the same speed, its torque is greater than 30,000 rpm and 40,000 rpm, but 20,000 When using a 20: 1 reduction ratio handpiece with a rpm motor, it is often felt that the speed is too low and it is difficult to drill into the bone, especially in step 1 and step 2. In actual operation, we generally operate at 2,000 in steps 1 and 2. This is mainly considered when the compact bone plate is drilled, the motor speed can be lost 1 / 4-1 / 3, especially at low speeds and drill pins. In the case of insufficient sharpness, the surgeon often drills into the bone by increasing the pressure. At this time, the speed may be lowered. In this way, for a motor with a maximum speed of 20,000rpm, the application of a deceleration handpiece when the power is full may reduce the speed to 750rpm or even lower, it can not reach the speed required when drilling into dense bone plates, nor can it reach the optimal speed power range of the handpiece; the same reduction handpiece uses a 40,000rpm motor, and the maximum speed after deceleration of the handpiece reaches 2000rpm when drilling into a compact bone plate, the speed loss is 1/4 to 1/3, and it can reach more than 1,000 rpm. It can still be in the optimal speed power range of the handpiece, and it is easier to drill into the bone. If the actual operation requires a rotation speed of about 1000 rpm, it is best to choose a motor with a maximum speed of 30,000 rpm or 40,000 rpm. Theoretically, if most of the steps in the actual operation need to be performed at a speed lower than about 1000 rpm (for example, 800 rpm), then a 20,000 motor can be used to achieve the required torque. A 30,000 rpm or 40,000 rpm motor can also be operated at ﹤ 800 rpm. To achieve the required torque, but you should replace the handpiece with a larger reduction ratio. However, in actual operation, we use a motor with a maximum speed of 40,000rpm, the maximum output power of the host is 95W, and the maximum torque of the motor is 7Ncm (note that this torque refers to the motor. After the handpiece is decelerated, the increase in torque at the drill bit is proportional to the deceleration ratio. ), 20: 1 reduction ratio handpiece, has been able to fully meet the clinical needs, no phenomenon of insufficient torque is found, from our application experience, when buying planting handpieces, should choose the handpiece that can reach a higher speed.
Handpieces that increase the maximum speed of the motor are usually called speed-increasing handpieces. Because the increase in speed is directly proportional to the decrease in power, the speed-increasing handpiece is generally not used when implanting bone implants, but only in early foliar implants. When using such handpieces.
Speed-up or speed-down handpieces are more expensive than ordinary handpieces. The larger the speed-up and speed-down ratio, the more expensive. In general, 20: 1 or 16: 1 handpieces are usually selected.
Practical precautions:
When drilling a bone, the speed usually decreases. The decrease is related to the pressure applied to the inner drill, the diameter of the bone drill, and the sharpness of the drill bit. When this speed decreases less than 1/3 of the initial speed, it will not cause handpiece damage. However, if this decline is exceeded, it means that the drilling resistance is too large, which may cause damage to the handpiece.
Before drilling into the bone, the drill pin should be started to increase the speed to reach the optimal speed and power state of the handpiece before drilling into the bone.
(Three) Water Pump
In dental implant surgery, it is required not to generate heat as much as possible to avoid thermal burns to bone tissue. Therefore, most dental implant handpieces on the market in recent years are equipped with water pumps to ensure that the entire bone drilling process is performed under sufficient running water cooling. The water pump powers a separate motor. Some handpieces can change the water injection volume by adjusting the speed of the motor, but in our application, we feel that using a constant speed water pump can meet the clinical needs. It is important to pay attention to the power of this motor when purchasing. Because there are often interruptions in clinical operation, this motor is required to start at the same time as the bone drill at each intermittent restart to ensure sufficient water cooling during bone drilling. Due to the insufficient power of the pump motor, some implanters sometimes cannot start with the bone drill motor at the same time when restarting, and the bone is drilled without water to cause thermal burns. In addition, the water supply method of the water pump is usually to press the water pipe on the wheel shaft of the water pump, and the water in the water pipe is squeezed forward when the shaft rotates. Due to the different types of disposable water supply pipes on the market, different water pipes are pressed on the shaft. There may be a certain difference in power, so the motor power of the water pump should have a certain margin to avoid starting difficulties when using non-supporting water pipes of this type of planting handpiece. When buying, you can tighten the water pipe by hand, add a certain extra load to the pump wheel shaft, and repeatedly check whether it can restart, you can understand the power status of the motor.
(4) Foot control device
Foot control has now become the basic configuration of dental implant handpieces. Its basic functions are: 1. Turn the pump on and off; 2. Jump between preset programs; 3. Adjust the rotation direction of the motor;
(5) Other functions
The basic configuration and functions of the universal dental implanter are introduced above. These configurations and functions can meet the operation requirements of mainstream clinical implant systems. At present, various manufacturers continue to improve and continuously add new functions to the implanter to meet some specific requirements in clinical or scientific research. For example, the actual torque when drilling a bone can be displayed on the panel in real time; the entire operating steps and parameters (such as the torque used when the implant is inserted) of each case are automatically recorded in the computer chip, which is for future analysis and clinical summary provided useful information. These new features are usually more expensive than general-purpose models, and you should choose according to your needs when purchasing such planters.
