**2. Bone augmentation**

Bone augmentation procedures usually involve bone block grafts, guided bone regeneration, ridge expansion/splitting, sinus floor elevation, and distraction osteogenesis. In addition, socket preservation is often used for the protection of the existing bone. Despite the availability of these techniques, guided bone regeneration has been widely used for implant site development [15]. This is attributed to its predictability, easiness while handling, and lessinvasive nature than other advanced bone augmentation techniques [16]. Another advantage of this procedure is that it can be performed prior to or simultaneously with implant placement [17]. The results of horizontal bone augmentation are more reliable than those of vertical bone augmentation. Achieving bone gain in the vertical dimension is more difficult than that in the horizontal dimension [18].

Using a bone graft does not always guarantee clinical success. There are many major and minor factors that affect clinical success [19].

Major factors:

The success of dental implants is assessed by criteria such as implant survival, stability of prosthetic treatment, radiological bone loss, and presence of peri-implant infection [5]. The accepted general consensus for the success of dental implants in recent years is that both functional and esthetic results are satisfactory [6]. There are risk factors that should be considered for the success of an accomplished outcome. Some of these factors include age, sex, general health status, habits, the region where the implant is placed, the number of implants, and the

For dental implant indications, the presence of adequate bone and the relationship between both jaws are important. Studies have reported that a non-ideal three-dimensional implant placement may cause peri-implantitis, esthetic and functional failure, and may even result in removal of the implant [8]. To achieve optimal esthetics and function, the position of implant in the alveolar crest has to be in a biologically correct and prosthetically driven location [9]. When the implant is placed in an inappropriate position, for example, a bone-directed position, the use of pink porcelain and/or angulated abutments would be inevitable. Besides, nonaxial masticatory forces will increase the risk of complications, such as screw loosening or fracture and chipping on implant-supported restoration [10]. Insufficient alveolar ridges may require bone augmentation procedures to achieve optimal bone volume before implant placement. These applications ensure that the implant is placed in the correct position and that an

The amount and location of bone resorption are important factors in the selection of the augmentation technique. In addition, the relationship between the jaws in radiological and clinical evaluations should be considered in the sagittal, frontal, and transverse planes [12]. Alveolar bone augmentation procedures include applications for increasing residual crest width and/ or height using grafts and/or biomaterials or for optimizing bone contours with repair of bone defects [13]. In an attempt to correct bone defects, many techniques have been extensively described for bone augmentation and grafting materials. Although autografts remain the "gold standard," the use of biomaterials in orthopedics and dentistry is increasing [14].

Bone augmentation procedures usually involve bone block grafts, guided bone regeneration, ridge expansion/splitting, sinus floor elevation, and distraction osteogenesis. In addition, socket preservation is often used for the protection of the existing bone. Despite the availability of these techniques, guided bone regeneration has been widely used for implant site development [15]. This is attributed to its predictability, easiness while handling, and lessinvasive nature than other advanced bone augmentation techniques [16]. Another advantage of this procedure is that it can be performed prior to or simultaneously with implant placement [17]. The results of horizontal bone augmentation are more reliable than those of vertical bone augmentation. Achieving bone gain in the vertical dimension is more difficult than that

Using a bone graft does not always guarantee clinical success. There are many major and

condition of the bone [7].

142 Tissue Regeneration

**2. Bone augmentation**

in the horizontal dimension [18].

minor factors that affect clinical success [19].

appropriate restoration can be performed [11].


Minor factors:

