Crestal vs. Basal implants

Crestal vs. Basal implants

Criteria Crestal (Axial / Screw)Implants Basal Implants Shape and structure Root form - designed to imitate roots of a tooth The implants look like an inverted T Endosseous section Screw shaped with machined / sandblasted / HA coated surfaces. Flat / blade like surfaces with spaces permitting bone in growth. Technique Insertion thro’ crestal bone and communication with oral cavity much more than basal implants Insertion thro’ lateral aspect of basal bone. Load bearing area of implant has no communication with the oral cavity. Bone requirement Vertical bone – both crestal and rarely a small portion of basal bone. Basal bone is what is needed. Horizontal aspects of the bone are fully utilized along with the inner and outer cortices. Armamentarium A large set of instruments are necessary for procedures Instrumentation relatively a lot simpler Bone grafting procedures Essential in cases of deficiency in bone height. Grafting procedures give unpredictable results Not essential. Bone displacement Considerable bone substance displacement / loss occurs and varies with size and length of implant. Crestal bone is more susceptible to resorption Displace upto 60% less bone substance. Bone integrity and perfusion are barely impaired. Basal bone - highly resistant to resorption Mucosal penetration diameter Larger. Chances of peri implantitis, vertical bone loss, crater like bone loss and infections are relatively high Smaller (1.9 – 2.3mm. only). The whole vertical implant part is polished – hence,  chances  of problems seen as in the case of crestal implants relatively very low. Anatomy – proximity to Maxillary Sinus & Inf.Alveolar Nerve Very important consideration and technique is to be modified accordingly. Bone augmentation essential in most cases. Overcoming unfavorably placed MS and IAN is possible Abutment angulations Two piece implants have to have pre-angulated abutments. KOS single piece implants provide angulated as well as bendable abutment provisions. All BOI implants have bendable abutments. Loading Two piece implants often require delayed loading & two surgical phases at times Immediate loading Healing Prolonged healing time – clinically significant Bone healing time not clinically significant Masticatory forces Act in the vertical direction along the sides of the screw structure Transferred to the basal plate deep into the cortical bone areas which are able to accept large loads and have great capacity for regeneration. Resterilization of implant including abutments  Impossible Possible after pre-cleaning Applications in destructive periodontitis & after multiple extractions of teeth Placement nearly impossible and success is unpredictable. Placement of implants very much possible and results are excellent. Smoking patients Failure rate is nearly 100% Best option for smoking patients Controlled diabetic patients Crestal implants always run a risk of failure in cases where there are blood sugar variations Blood sugar variations may not affect the survival of the implant at all. Click here for Appointment