**1. Introduction**

Edentulism is a state of oral health that consists of the loss of teeth. Although the causes of tooth loss are diverse, dental cavity and periodontal disease are the main causes. Despite the decrease in edentulism in developed countries, edentulism continues to have a high prevalence affecting multiple functions such as chewing, nutrition, speech, self-esteem and quality of life [1].

After tooth loss, the physiological stimuli that give mechanical and cellular maintenance to the alveolar bone disappear. As a consequence, there is a reduction in the quantity and quality of bone, which we define as bone atrophy. The International Journal of Oral & Maxillofacial Implants defines alveolar atrophy as "decrease in the volume of the alveolar process occurring after tooth loss, drecased fuction and/or localized overloading from an improperly fitting removable partial or complete denture" [2].

Conventional full arch rehabilitation treatments achieved stability, support and retention at the expense of remaining teeth or residual bone anatomy. However, when a patient has edentulism and bone atrophy, conventional rehabilitative treatment does not meet the treatment goals, expectations, and comfort for the patient.

Dental implants are biocompatible alloplastic devices that are inserted into a residual bone ridge. The use of osseointegrated endosteal implants was introduced in North America in 1982 thanks to the research of Dr. Branemar. His results established the guidelines for contemporary implantology [3].

To replace missing teeth there are different prosthodontic options. Which include implant-supported crowns (ISCs), implant-supported fixed dental prostheses (IFDPs), implant-supported removable dental prostheses (IRDPs), tooth-supported fixed dental prostheses (TFDPs), and removable partial dentures (RPDs). In patients with several missing teeth, implant-supported fixed dental prostheses (IFDPs) have shown excellent results in the short and medium term, positively impacting quality of life [4].

The objective of this chapter was to describe the key and current aspects in fullarch rehabilitation with dental implants. The purpose is to guide professionals in the diagnosis and rehabilitation treatment of the full arch with dental implants in the patient with edentulism.

## **2. Diagnosis of the patient with bone atrophy, selection of the patient**

As mentioned, dental extraction induces a series of physiological changes in the hard and soft tissue of the dental socket. These local alterations arise as a natural healing process that aims to achieve a secondary closure of the wound and the dental socket. The healing phases of an alveolus include an inflammatory phase, a proliferation phase, and a remodeling phase. After multiple tooth extractions with or without the use of dentures, people may suffer from extensive vertical and horizontal reduction in their alveolar bone process. A reduction of up to 50% of the original bone table can be expected, being greater in the buccal aspect than in its lingual/palatal counterpart [5]. This process of bone resorption continues and determines the morphological configuration of the alveolar process and the severity of the bone atrophy of the jaws. Occasionally, bone resorption is so severe that the alveolar process may be non-existent, compromising important anatomical structures such as the maxillary sinus, the piriformis notch, the nasopalatine nerve, the inferior alveolar nerve, among others (**Figure 1**).

Currently there are multiple classifications that describe alveolar bone atrophy. The two most used are the Seibert classification and the Cawood and howell classification. The Seibert's nomenclature divides alveolar bone loss into three types: Class 1: Loss of vestibule/lingual tissue with normal bone crest height, Class 2: Loss of apical/ coronal tissue with normal vestibule/lingual dimension, Class 3: Loss combined horizontal and vertical bone [6].

The Cawood and Howell classification evaluates the post-extraction socket and the edentulous crest for a subsequent restoration treatment, it is divided as follows: Class I: toothed, Class II: post-extraction, Class III: convex shaped process, with width and height adequate, Class IV: sharp edge with adequate height, insufficient width of alveolar process, Class V: flat shape with loss of alveolar process, Class VI: loss of basal bone [7].

Regardless of the degree and severity of bone atrophy, the patient's selection for full arch rehabilitation treatment with dental implants depends on his or her expectations. During the consultation, it is essential to carry out an adequate questioning and understand the reason for our patient's consultation. Esthetic, functional and personal needs. In general, when a patient requires a complete rehabilitative treatment, he has undergone multiple treatments throughout his life, his mentality towards treatment, although in most cases it is "philosophical", sometimes we could have demanding patients with "hysterical" mentality.

*A Review of Current Concepts in Full Arch Rehabilitation with Dental Implants DOI: http://dx.doi.org/10.5772/intechopen.99704*

#### **Figure 1.**

*Different degrees of bone atrophy. The first patient presents a mild/moderate maxillary atrophy, however, he presents a severe mandibular atrophy at the level of the inferior alveolar nerve. The second patient presented severe maxillary atrophy with loss of the premaxilla. The atrophy extends posteriorly to the floor of the maxillary sinus, making it impossible to place conventional implants. In the mandible it presents a mild/moderate atrophy in the posterior sector.*

Understanding the attitude of patients and their expectations is important for the success of full arch rehabilitation and to offer the best rehabilitative treatment [8].

In general, indications for a full arch rehabilitative treatment with dental implants include:


There are few contraindications to dental implant treatment, most are relative and not absolute.

• Uncontrolled systemic disease: Systemic compromises such as cancer, radiotherapy, chemotherapy, autoimmune diseases, HIV, bisphosphonates and bone diseases could contraindicate treatment if the patient does not have a pharmacological control with adequate response to treatment. However, when these conditions are medically controlled and performed with established protocols, they can have a high success rate and are not an absolute contraindication to dental implant treatment [12–14].

