DENTAL IMPLANT THAT INCREASES BONE SUPPORT

Abstract

This describes an implant design that increases the amount of bone around the implant by increasing its length in order to place a longer implant without the need for a sinus elevation surgery in the posterior maxillary region where bone stock is not sufficient by employing the principles of displacement procedures in implantology which rely on regeneration of patient's own bone and have been used for years in the dentistry for orthodontic procedures. The implant system we have designed has a pressure adaptor (4) that protrudes and advances through the apical part of the implant. Pressure adaptor (4) is advanced within the bone until desired length of implant and bone is achieved. This procedure forms significant amount of bone around the implant within the floor of maxillary sinus. Floor of maxillary sinus is elevated. New bone is formed without the need for an additional surgery. This implant system can also be used for distraction osteogenesis in sinus floor or other anatomic spaces by a unique application different from distractor implants.

Description

Dental implants are biocompatible functional devices that are placed into bones for substituting an extracted tooth or providing support to fixed or mobile prostheses. The goal of implant design is to provide sufficient initial stability and accomplish osteointegration as early as possible after implantation. Implants are kept load-free for 3 to 6 months following primary surgery. During this period, new regular bone that will stand against the occlusive loads is formed around the implant (osteointegration); so the implant becomes stable enough to resist functional forces created during mastication. Following this stage, prosthetic restoration is done onto the implant to obtain a functional implant.

Magnitude of mechanical stress on alveolar bone depends on the diameter and length of the implant; proper placement of implants with respect to the direction of the forces applied; the number of implants and distribution of the forces. Increasing length of the implant increases its load-bearing surface. Increased length is also crucial for primary stability. Implant should resist shearing and torque forces when abutment is mounted. Increased length also reduces the stress applied on the neck of the implant. Implant body design, screw geometry and surface characteristics are continuously being improved to strengthen the implant-tissue interface, and to attain ideal load transfer; eventually to increase the success and survival of the implant.

High number of anatomic spaces and important nerves in the oral region limits the length of the implants to be used and mandates a detailed examination. If occlusive forces are increased, larger and longer implants should be used. However, confined width and length of the bone restricts the use of implants with appropriate length and width. This negatively affects the long-term success of the implant.

Sagging of the sinus floor, insufficient height and quality of bone are common problems in the patients that have remained toothless for a long time particularly in the posterior maxillary region, and it is rarely possible to place an implant of sufficient length in proper position. Even if the implant can be placed, this situation causes the implant to have bone support with poor quality. We have inspired from the displacement technique that is based on regeneration of the patient's own bone and widely used in the dentistry for orthodontic procedures to place a long implant to the maxillary posterior region without the need for sinus lifting where bone distance is particularly insufficient; and by using this technique in implantology we aimed to increase the amount of bone around the implant by increasing its length.

Throughout the normal development of the root of the teeth, increased root length is associated with increased length of alveolar bone. This physiologic and remarkably slow mechanism allows growth of roots to sufficient length without jeopardizing important structures such as maxillary sinus or inferior alveolar nerve. In a similar manner, the implant we have designed can be gradually lengthened to allow the use of an implant of sufficient length in areas with insufficient bone length.

The implant system we have designed consists of 5 parts (FIG. 1, 2, 3, 4, 5). In the implant system, there is a pressure adaptor (4) that protrudes and advances through the apical part of the implant body (1). Following insertion of implant system into the posterior maxillary area and attainment of osteointegration (FIG. 6), driving screw (2) is used to force the pressure adaptor (4) of the implant system into the floor of the sinus (FIG. 7). Force applied within physiologic limits initiates remodeling around the terminal part of the pressure adaptor (4) similar to the behavior of the bones of the teeth that are exposed to orthodontic forces. This process is carried on until a desired implant and bone length is achieved. Implant system also contains a leak-proof element (5) that prevents leakage between pressure adaptor and the implant body. A screw cap (3) is mounted on the implant body to prevent immigration of bacteria and foreign bodies from the oral cavity. These all lead to significant bone formation around the implant system within the maxillary sinus floor. Floor of maxillary sinus is elevated (FIG. 7). New bone is formed without the need for an additional surgical procedure.

Our newly developed implant system provides new bone formation by bone remodeling (FIG. 6, 7). Unlike the implant distractors that make use of distraction osteogenesis by forming fracture on the bone and make use of flexible fracture callus to form new bone, this implant system make use of remodeling without creating a fracture. Bone formation through remodeling is much slower. This implant system offers a higher patient acceptance as it requires no additional surgery and is less traumatic compared to distractors.

However, by unique application different from the other distractors, this implant system can also be used for distraction osteogenesis in maxillary sinus or other anatomic spaces (FIG. 8, 9). Unlike other distractor implants which require osteotomy at the middle part of the implant, in this system only a minimal fracture is formed at the cortical bone above the apical part of the implant as presented in FIG. 8 to form callus and consequently new bone in a way similar to distraction osteogenesis. For this procedure, driving screw (2) is advanced and pressure adaptor (4) forces fractured part through the anatomic space fairly faster compared to remodeling (FIG. 9). In the distractor implants osteotomy line is at the middle part of the implant.

Claims

1. This device is a dental implant used to form new bone and to increase the bone support at the apex of the implant system when placed in the sinus floor or in other anatomic spaces or areas adjacent to anatomic spaces by making use of principles of remodeling and distraction osteogenesis; and it consists of implant body (1), pressure adaptor (4) that are in direct contact with the bone and driving screw (2), implant cap (3), and leak-proof element (5) that are not in direct contact with the bone.

2. Mentioned in claim 1 is a dental implant capable of increasing the bone support and characterized by new bone formation using the remodeling principle without causing a fracture after placement, by exertion of propulsive forces apically through the apex of the implant body (1) via pressure adaptor (4) similar to rooting of the teeth.

3. Mentioned in claim 1 is a dental implant that increases the bone support and is characterized by formation of a small fracture at the cortical bone of the anatomic spaces that is equal to the apical diameter of the pressure adaptor (4) before placement and production of a distraction callus at this area using principles of distraction osteogenesis by means of compression forces on the free fragment of bone exerted via the pressure adaptor (4) that moves the fragment towards the anatomic space.

4. Mentioned in claim 1 is the implant body (1) characterized by its fixed position in the bone and it reside within the intact bone where no fracture is formed.

5. Mentioned in claim 1 is the implant body (1) characterized by its open end at the apical direction which allows pressure adaptor (4) to protrude from the implant body (1) and exert compression forces on the bone in the apical direction.

6. Mentioned in claim 1 is the pressure adaptor (4) characterized by stimulation of new bone formation by protruding through the apical end of the implant body (1) that has a fixed position in the bone and exertion of compression forces apically through the apical end of the implant system.

7. Mentioned in claim 1 is the driving screw (2) characterized by its design that propels the pressure adaptor (4) through the apical end of the implant body (1) without causing any rotational movement.