**Abstract**

The research and development of new implant models modifying the micro and macro design has increased significantly in the last decades. With the advancement of knowledge about the biological behavior of these materials when implanted in living tissue, a great search for morphological changes at macrogeometric, microgeometric and even nanogeometric levels was started, to accelerate the process of osseointegration of implants, reducing the time for the rehabilitation treatment. This chapter will seek to demonstrate, through scientific evidence, the potential effect of the morphological characteristics of implants on osseointegration. Modifications in the surface treatment of implants will be discussed to improve the osseointegration process in terms of quality and time reduction, changes in the surgical technique used for the osteotomy of the implant installation site, and macrogeometric changes in the shape of the implant body.

**Keywords:** implant design, implant microgeometry, implant macrogeometry, rapid osseointegration, titanium implants

## **1. Introduction**

Dental implants have become a predictable and safe form of treatment for the replacement of missing teeth. Surely, implants have revolutionized dentistry practice in worldwide, enabling the rehabilitation of patients who have lost single teeth to patients with loss of all teeth. Thus, various types of treatments made possible by improving the quality of life and patient satisfaction. Among these treatments that had the greatest representation, we can mention: the cases of totally edentulous people, who could receive implants to improve the fixation of removable dentures or even receive fixed dentures; patients with partial losses with a lack of posterior pillars (teeth) who had to wear removable dentures and could receive fixed dentures; and patients who had unit losses where it was possible to rehabilitate them without wearing out natural healthy teeth.

Since its diffusion by Branemark in the 60s [1, 2], dental implants have been the object of many studies and, consequently, have undergone several changes. However, the base material for its manufacture, titanium, continues to be used due to its

excellent biological and mechanical characteristics. Surgical techniques have also undergone several advances and modifications. Initially, a waiting time for the beginning of the rehabilitation procedures of 6 months was recommended, with implants installed in the bone tissue and covered by mucosa during this waiting period for osseointegration. With the advancement of knowledge, it was proposed that for implants installed in the mandible, the waiting time could be less than in the maxilla, due to the difference in density between the two anatomical sectors. However, Gehrke and Tavares da Silva Neto [3], showed in a clinical study that the evolution of osseointegration is the same in the 2 types of bone (maxilla and mandible) and that the implants could be loaded in both arches with the same waiting time, as long as these sites who received implants were in adequate condition. On the other hand, new techniques aiming to speed up the treatment time and provide greater comfort to patients, such as post-extraction implants (immediate), immediate loading on the implants, implants with simultaneous bone regeneration, among others, were proposals and studied and, currently, are widely used.

Different changes at nano-, micro- and macro-structural levels have been researched and proposed with the aim of improving and/or accelerating the processes involved in the osseointegration of dental implants. Such possibilities became possible with the evolution of scientific knowledge about the events involved in the healing process of peri-implant tissues after implant insertion. In this sense, several types of surface treatment have been proposed in order to promote a physical–chemical stimulation capable of accelerating the initial phases of bone neoformation on the implant [4, 5]. Among the main methods used to produce surface roughness of implants are the addition processes (e.g., titanium plasma spray, hydroxyapatite coating) and subtraction processes (e.g., acid etching, microparticle blasting, laser). Among all of them, the most used procedure currently by most of the world industry is the subtraction methods, as they have shown good results and are less costly. On the other hand, the addition of ions (e.g., Calcium, Magnesium, hydroxyapatite) on these surfaces at nano- and/or micrometric levels has shown good results for the osseointegration.

Initially, the implants had a cylindrical macrogeometry, being later proposed implants with macrogeometry with conical designs. Tapered shaped implants had advantages over cylindrical ones, especially regarding the surgical process, where they were shown to generate less trauma to the bone tissue resulting from the drilling process used for this type of implant. In addition to this change in the body of the implant body, changes in the shape of the turns, which were initially triangular and with little depth, received other shapes, such as trapezoidal, square, and with greater depth and distance in the thread pitch. Also, changes in the cervical portion of the implants, which are in contact with the cortical bone, have been proposed. Among these changes, we can mention the presence of smooth (polished) surfaces, treated (rough) surfaces and the presence of micro-turns. Regarding the prosthetic connections, the implants had several alterations, being proposed different models of fittings, always with the intention of improving the stability of the rehabilitation in the long term. **Figure 1** shows different types of implants and designs proposed in recent decades.

More recently, with scientific evidence that the installation of implants with less compression of the bone tissue could benefit and accelerate the osseointegration process, new macrogeometric models of implants were proposed. In this sense, it was shown that the presence of free spaces of bone tissue or the presence of uncompressed fragments can facilitate the cellular work of phagocytosis and bone matrix neoformation, as shown schematically in the **Figure 2**. This type of condition, creating a space

*Characteristics of Implant Systems That Can Accelerate and Improve the Osseointegration Process DOI: http://dx.doi.org/10.5772/intechopen.99937*

**Figure 1.**

*Available dental implants with different design and connections. (courtesy of Implacil De Bortoli company, Brazil).*

#### **Figure 2.**

*Schematic image depicting the installation of an implant in a conventional technique (left) causing bone compression over an extensive area, and the implant insertion with spaces between the bone and the implant (right) decreasing bone compression area.*

between the bone tissue and the implant, is achieved through a modification in the surgical technique, that is, in the relationship between the diameter of the last reamer used and the diameter of the implant to be inserted into the bone. Thus, in this chapter we will describe and discuss some advances resulting from these changes in the structure of dental implants during the last decades.
