# A Study Comparing the Efficacy of “The All-on-Four Implants” in the Maxillary and the Mandibular Arches

## TL;DR

This study compares how well dental implants called 'all-on-four' work in the upper and lower jaws, finding better results in the lower jaw.

## Contribution

The study provides a comparative evaluation of the 'all-on-four' implant technique's effectiveness in maxillary and mandibular arches.

## Key findings

- Mandibular implants showed lower crestal bone loss and pocket depths compared to maxillary implants.
- Gingival health and implant stability were better in mandibular implants over a 24-month follow-up.
- Mandibular implants stabilized faster than maxillary implants from 12 to 24 months.

## Abstract

Introduction

The “all-on-four” technique of dental implants has been in popular use for the past few years due to its ease of rehabilitation of teeth. This technique employed four simultaneous implants over the upper maxillary and lower mandibular arches to suit the needs of the patient as a prosthesis. However, the comparative utility of this technique of implants between the maxillary and the mandibular arches has not been thoroughly evaluated. Hence, this study bridged that gap and compared the impact of this technique in the upper and lower jaw arches.

Aim and objectives

The main aim of this study was to comparatively assess the impact and compatibility of the “all-on-four” technique in both the maxillary and the mandibular arches after the implant procedure. The objectives of this study were to compare and assess the mean pocket depths as well as the mean crestal bone losses in both the maxillary and mandibular arches after the implant procedure. Also, this study compared and assessed the implant stability quotients as well as the gingival indices in both the maxillary and mandibular arches after the implant procedure.

Methodology

This was a prospective study done on 90 patients who were followed up to 24 months after the procedure, with intervals ranging from 3 months, 6 months, 12 months, 18 months, and 24 months after the completion of the procedure. Muco-periosteal flaps were raised from one molar to the contralateral molar, accompanied by vertical releasing incisions after a thorough assessment using orthopantomographs and cone beams. This was then followed by impressions and placement of guiding wires using abutment devices. Then the implants were aligned to guide them and position them at four quadrants in each arch. During the follow-up of this procedure, the averages of the pocket depths (mm), crestal bone loss (mm), and implant stability quotients, as well as the gingival indices, were compared between the upper and lower arches after the placement of implants.

Results

The values of mean crestal bone loss (mm) and mean pocket depths (mm) were higher in maxillary implants compared to the mandibular implants, and the aforementioned values became stabilized in mandibular implants from 12 to 24 months of follow-up, compared to the maxillary implants. The gingival indices were healthier in mandibular implants compared to their maxillary counterparts. The implant stability quotient values were higher in mandibular implants compared to the maxillary implants.

Conclusions

In this study, the mandibular implants were found to be better adapted to the “all-on-four” procedural technique. The stability quotients of the mandibular implants were also much better compared to their maxillary counterparts, thereby suggesting the possibility that the lower jaw arch is a more promising site for this technique than the upper jaw arch.