A guide drill is a round-shaped or pointed drill used to mark the site of an osteotomy by making an initial entry into cortical bone. An osteotomy is a procedure that involves the removal and/or reshaping of existing bone. Osteotomies can be performed at many locations throughout the body, but in dentistry, it is often used to correct bone issues in the mandible. An osteotomy can also be performed to correct the placement of an ill-fitting implant or prosthesis. Prior to the reshaping or removal of bone, a guide drill is used to create a small hole in the bone at the surgical site. This serves to identify the location of the procedure but also prevents the splitting of the bone due to a more aggressive drilling or cutting approach. Without the use of guide drills, bone cracking and splitting has been frequently reported resulting in damage to the bone that would have held the implant.
A guide pin can refer to one of two things:
- A device placed within a dental implant osteotomy to assist in determining the location and angulation of the site relative to adjacent teeth, implants, or other landmarks
- Extended occlusal or abutment screws used during prosthesis fabrication in the laboratory
For use in an osteotomy, the guide pin will show the surgeon if the alignment of the pilot hole is correct for the implant that will be placed. Using it correctly will prevent incorrect angulation and the need to re-drill the hole. The guide pin will also help to ensure blood vessels, nerves, or other oral structures are not damaged in the implant preparation stages as it will show the trajectory of the hole being drilled. In prosthesis fabrication, a guide pin is used to attach the prosthesis to the implant fixture. These types of guide pins are threaded and are made to work with specific implant systems.
Guided bone regeneration (GBR)
Guided bone regeneration, or GBR, is a bone regenerative technique that uses physical means such as barrier membranes to seal off an anatomic site where bone is to be regenerated. The goal is to direct bone formation and prevent other tissues, including connective tissue, from interfering with osteogenesis. Guided bone regeneration is often used to increase the alveolar ridge where there has been bone resorption. Without GBR procedures, stable implant placement would not be possible for many patients as their remaining bone would not support an implant. There are two different approaches for guided bone regeneration. The first is known as the simultaneous approach where the placement of the implant and GBR take place at the same time. The second is the staged approach in which GBR is performed prior to implant placement. Regardless of the approach, the use of barrier membranes is essential to the success of the GBR process.
A guided sleeve, also known as a guided cylinder, is a round metal cylinder usually five millimeters in length and available in various diameters, which is incorporated into a surgical or stereolithographic guide to precisely position the drill and subsequently the dental implant during surgery. Guided sleeves often come as part of a guided drilling set and allow for the accurate placement of a dental implant. The length of the guided cylinder helps in placing the implant at the right depth in the bone and ensures the drill follows the correct path and angulation through the bone for successful implant placement. The use of guided sleeves in oral surgeries and implant procedures ensures a much higher rate of accuracy than if the practitioner were to perform the surgery free hand. Recent studies have shown that the use of longer sleeves and drill keys also play a crucial role in achieving the highest level of accuracy.
Guided Tissue Regeneration (GTR)
GTR, or guided tissue regeneration, is a type of dental surgical procedure that uses barrier membranes to direct the growth of new bone and gingival tissue. It is employed at sites with insufficient volumes or dimensions of bone or gingiva for proper function, esthetics, or prosthetic restoration. Guided tissue regeneration uses a membrane at the surgical site to prevent soft tissue cells from growing into and over the new bone. This allows the bone to integrate without interference from other cells or pathogens that might otherwise disrupt the process. Bone grafts are often needed for implant patients who have insufficient bone for the process. The graft will provide new bone for the support, strength, and anchorage of the implant once it is placed. This gives the implant greater stability and an increased longevity. The use of GTR following a bone grafting procedure enhances the new bone’s ability to heal and create a strong foundation for the implant.