Clinical Assessment of Bone Quality at Implant Site using CBCT and Hounsfield Unit

ABSTRACT

Objectives:

The current research was done to assess the bone quality at implant site using CBCT.

Materials and Methods:

The present study was conducted on 50 partially edentulous patients of both genders. All subjects had their chests scanned using a Kodac machine set to 120 kVp, 12 mA, and a 17-second exposure time. Using Hounsfield units, bone quality was classified as D1, D2, D3, D4, and D5 (HU).

Result:

Out of 50 patients, 27 were males and 23 were females. The average HU was 786.1 at the anterior maxilla, 1174.3 at the anterior mandible, 332.1 at the posterior maxilla, and 742.4 at the posterior mandible. The variation was considerable (P-0.01).

Conclusion:

The anterior mandible, anterior maxilla, posterior mandible, and posterior maxilla were found to have the highest densities. Based on Hounsfield units, CBCT is helpful in determining the bone density at the implant site.

INTRODUCTION

The oral rehabilitation of patients who are partially or completely edentulous now frequently involves the placement of dental implants. Bone density appears to play a significant role in both the predictability of oral implant outcomes as well as primary implant stability.[1]

A frequently used imaging technique in dentistry is CBCT. Multislice computed tomography (MSCT) systems were replaced by cone beam computed tomography (CBCT) systems for dental planning and treatment. Because isotropic voxels are used in CBCT, measurements are exact and are thought of as 1: 1.[2] High-quality 3D images can be obtained using CBCT for relatively little money and radiation exposure.[3]

Hounsfield units (HU), a measure of bone density that conveys important details about the bone, are a unit used in CT scans to accurately assess anatomical structures in three dimensions. The value of air on the Hounsfield scale is −1000 (black on the grayscale), while the value of bone ranges from +700 for spongy bone. The amount of bone determines the dental implant’s primary stability.[4]

The Lekholmu and Zarb classification, which is based on the amount of cortical and trabecular bone visible in preoperative panoramic and cephalometric radiographs, has been the most widely used classification for determining jawbone density. Computed tomography (CT) can be used to objectively quantify direct bone density measurements that are expressed in Hounsfield units, according to T Misch (HU). In accordance with a calibrated scale of grey levels, HU represent the relative density of bodily tissues. They categorized bone density into four categories, Q1 to Q4, based on the proportion of cortical to spongy bone. Cone beam computed tomography is a helpful diagnostic tool, particularly for evaluating implant sites. It provides information in three dimensions about the implant site.[5] Hounsfield units are used to quantify the grey values (GVs) that can be found in 3D CT images. This implies that during image reconstruction, a Hounsfield unit value based on the content of each image voxel must be established. In terms of water, Hounsfield units are defined as linear transformations of a material’s measured X-ray attenuation coefficients.[3]

One of the key elements influencing implant therapy success has been hypothesized to be bone quality. An important component of pre-surgical implant planning should be the evaluation of radiological bone quality. The 3D nature of the surgical site has pushed dental CBCT use in pre-surgical planning.[3]

The current research was done to assess the quality of bone at implant site using CBCT technique.

MATERIALS AND METHODS

The department of Prosthodontics, Oral medicine and radiology, was the site of the current study. The study was done after obtaining approval from institutional ethic committee and informed consent from participants. There were 50 patients with partial dentures, in both genders. All patients received written information about the study and their written consent. The institutional ethical committee gave its approval for the study.

Names, ages, genders, and other information were recorded. All underwent CBCT, which was captured using a Kodac machine set to 120 kVp, 12 mA, and a 17-second exposure time. Sagittal, axial, and coronal planes, among others were all obtained. Every image was examined by an oral radiologist. Using Hounsfield units, bone quality was classified as D1, D2, D3, D4, and D5. Results were statistically analyzed using P 0.05 as the threshold for significance.

RESULTS

Out of 50 patients, there were 27 men and 23 women. The mean HU was 786.1 at the anterior maxilla, 1174.3 at the anterior mandible, 332.1 at the posterior maxilla, and 742.4 at the posterior mandible. The distinction was substantial (P-0.01) [Table 1].

Table 1.

Bone densities in HU in different jaw regions

Area	Mean (HU)	P
Anterior maxilla	786.1	0.01
Anterior mandible	1174.3
Posterior maxilla	332.1
Posterior Mandible	742.4

DISCUSSION

Due to its ability to provide 3D views of the area of interest, computed tomography (CT) has developed into an indispensable diagnostic tool and is now regarded as the gold standard in implant dentistry.[6] CBCT is now a crucial diagnostic tool for designing dental implant procedures.[7] The goal of the current study was to use CBCT technology to evaluate the quality of bone at the implant site.

Digital OPG and CBCT are important for evaluating osseointegration in implants, according to Chopra et al.[6] Rezallah et al. demonstrate that CBCT with X-resin can provide precise measurements not only for the bone but also for the soft tissue in various situations with the least amount of radiation and expense.[8] Morar et al. came to the conclusion that, prior to the placement of dental implants, an objective evaluation of the site-specific bone density may offer useful clinical information for the choice of implant size and the planning of a patient-specific drilling protocol.[4] CBCT measurements of bone level revealed that there was bone loss around every dental implant, according to Yamany, who used it successfully to assess bone loss around dental implants.[7]

We found that, CBCT is helpful in determining the bone density at the implant site. Further studies are needed to validate the results.

CONCLUSION

The anterior mandible, anterior maxilla, posterior mandible, and posterior maxilla had the highest densities. Based on Hounsfield units, CBCT is helpful in determining the bone density at the implant site.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.