Periozone Blog

Minimally Invasive Dental Implant Surgery

As we enter a new decade in time, we are also entering an exciting and interesting time in the practice if dentistry.  Since the advent of osseointegration in the 1960’s dental implants have become ideal treatment for patients missing single and multiple teeth and over the past few decades implant dentistry has made significant progress in its reach to the patients.  It will not be an overstatement to say that dental implants have become a part of everyday dentistry.  What seemed to be a complicated procedure to many a few years ago has now become more simple and easier due to the fact of advancing technology and emergence science.  One of the main reasons for most dentists who were skeptical initially to get on board is the proof of this treatment over time in establishing form and function and more importantly the high success rate.  At the present time most if not all general practitioners are involved with some form of restorative work with dental implants but only a few are involved with the surgical aspect of implant placement.  The reason for this could be the surgical protocol.  To put this in perspective let me explain the recommended initial protocols and the changes that have happened over time.

Dental implant surgery as it is practiced widely even today was formulated in 1966 and recommended by P.I. Branemark, Adell and Albrektsson in 1977 and 1981.  The original protocol recommended a 2 stage surgery which involved reflection of a surgical flap to access the bone followed by sequential osteotomy to place the implant and primary closure over the implant for 4 – 6 months to allow for osseointegration.  It was theorized at the time that implant must be protected from the oral bacterial flora and other deleterious forces of the mouth in order to have successful osseointegration and must be exposed back to the oral cavity only after the 4-6 month period.  This protocol was later challenged by another research group in Switzerland led by A. Schroeder in 1976.  This group investigated the possibility of a one stage surgical technique and a one piece implant that placed and left exposed in the mouth with a tissue healing component.  This approach showed similar results as the 2 stage surgery at the time and has consistently shown similar results over time and most implant surgeons have now moved to a one stage protocol with most systems available in the market today.  

Flapless Implant Surgery

            As the one stage implant surgery became more predictable, there was an interest in pushing the surgical part another step and placing the implant with a flapless approach.  In my opinion flapless surgery can be divided into 3 categories: 1. Traditional Approach, 2. Model Based Approach and 3. Computer Assisted Approach.

Traditional Approach:  This approach involves more surgical experience and is generally followed by implant surgeons in the posterior quadrants of the mouth on a relatively common basis on preference.  It involves a reasonable understanding of the bone and soft tissue profile of the area and includes use of an initial tissue punch and sequential drilling to widen the osteotomy and placement of the implant.  This particular situation is one where the use of a surgical guide may or may not be required based on the location and the number of implants. 

 Model Based Approach:  This approach involves the use of models of the case with ridge mapping information transferred to the model.  Ridge mapping involves the use of a calibrated probe with a stopper to measure the thickness of the tissue along the edentulous site on a bucco-lingual manner including the crest.  This is done after the patient is anesthetized in the area and a minimum of 4 – 8 areas are measured along the ridge from buccal to lingual.  The information of each reading in the location is then transferred to the model in the form of dots on the model corresponding to the same location.  It is then sectioned with or without the use of pins (similar to that of sectioning a model for crown and bridge) and the ridge form can be evaluated or assessed.  Based on this information, a surgical guide can then be fabricated.  The surgical guide is then used to follow the steps of implant site preparation and placement through the flap.

Computer Based Approach:  This is the newest method and probably the most efficient approach to placing multiple implants in a flapless approach with greater predictability and precision, as to the exact location of the implants.  This method involves the use of a radiographic guide and a CT scan of the patient with the radiographic guide in order to generate a 3D model of the edentulous site in the computer.  At this point, with the help of an implant planning software, a virtual implant is placed with the anticipated future restoration, in terms of angulation, length, width and location of the implant.  The information is then sent to the company which will make a stereolithographic surgical guide milled from the information obtained from the planning software.  Since this whole process is automated there is less room for human error in the transfer of information, although the human input and guidance is required all along the procedure from start to finish.  A guide generated in this manner allows the implant surgeon to place the implant within a 5 degree error.  Since the planning allows for implants to be placed with such little error it is even possible to plan on the final abutment and the prosthesis at the same time.  At this point in time, although the surgical placement is predictable with the computer gee rated surgical guide, the restorative aspect being done at the same time can be quite challenging and calls for meticulous steps to be followed in order for it to happen at the same time.  The computer generated guide is usually received in the dental office within 1-3 weeks of the planning and can vary depending on the company and the lab involved in the process.