# Alveolar Ridge Preservation Using Three-Dimensional Root Replicas of Polycaprolactone: A Radiological and Histological Evaluation of a Case Report

## TL;DR

This case report evaluates a 3D-printed biodegradable scaffold for preserving alveolar bone after tooth extraction, showing successful bone regeneration in one case and mixed results in another.

## Contribution

The study introduces a 3D-printed PCL scaffold with a PCL–PEG coating for alveolar ridge preservation, evaluated through radiological and histological methods.

## Key findings

- In one case, the scaffold supported new bone formation with lamellar and Haversian structures.
- The scaffold in the other case was not osseointegrated and was covered with lax connective tissue.
- One dental implant achieved high insertion torque and successful rehabilitation.

## Abstract

Background and Clinical Significance: To describe the effectiveness of alveolar ridge preservation under the radiological and histological analysis of a customized resorbable scaffold three-dimensionally printed with polycaprolactone (PCL) reinforced with a coating of a copolymer of polycaprolactone-block-polyethylene glycol (PCL–PEG) by electrospray. Case Presentation: A 62-year-old male with vertical root fractures of teeth #14 and #15. From the cone beam CT (CBCT) image, the scaffold root replicas were designed with the shape of the roots and printed with PCL coated with PCL–PEG by electrospray. The scaffold was inserted into the alveolar bone and maintained with a tension-free flap closure. After six months, a CBCT of the surgical site and histological analysis of a bone sample at the dental implant installation site were performed. After 6 months, the wound in tooth #14 was closed, clinically proving no adverse reaction or complications. The histological analysis of the bone sample showed new bone formation with lamellar structure, Haversian canal structure, and osteocyte spaces. However, the scaffold in tooth #15 was exposed and not osseointegrated, and it was covered with membranous tissue. Histologically, the sample showed tissue compatible with lax connective tissue with mixed inflammatory infiltrate. In tooth #14, the dental implant presented an insertion torque >35 Ncm and was rehabilitated three months after its installation. Conclusions: Three-dimensional printed PCL scaffolds showed the ability to regenerate vital and functional bone with osseointegration capability for maxillary bone regeneration and oral rehabilitation based on dental implants. A case of inadequate scaffold osseointegration accompanied by lax connective tissue formation is shown.