Pubblicazioni

Abstract

Aim: To compare soft tissue dimensional changes and relative differences in soft and hard tissue volumes 4 months after single-tooth extraction and three different treatment modalities: spontaneous healing (SH) and alveolar ridge preservation by means of a deproteinized bovine bone mineral and a collagen matrix, with (IMPL/DBBM/CM) or without (DBBM/CM) immediate implant placement.

Materials and methods: STL files from study casts obtained at baseline and after 4 months were matched to calculate buccal soft tissue linear and volumetric changes. DICOM files from CBCTs were superimposed to STL files allowing the evaluation of soft tissue thickness at baseline and 4 months.

Results: Mean horizontal reduction accounted for 1.46 ± 0.20 (SH), 0.85 ± 0.38 (DBBM-CM) and 0.84 ± 0.30 IMPL/DBBM-CM, with no statistical differences. Soft tissue thickness had a significant mean increase of 0.95 for SH group, compared to a non-significant mean decrease for DBBM-CM (0.20) and IMPL/DBBM-CM groups (0.07).

Conclusion: A preservation technique with DBBM-CM, with or without immediate implant placement, did not reduce the horizontal linear and volumetric changes at the buccal soft tissue profile significantly at 4 months after tooth extraction when compared to spontaneous healing. This is due to a significant increase in soft tissue thickness in spontaneously healing sites.

Trial registration: ClinicalTrials.gov NCT03422458.

Keywords: STL file; alveolar ridge preservation; immediate implant placement; soft tissue changes; tooth extraction.

Abstract

Aim: To radiographically evaluate the effect of immediate implant placement plus alveolar ridge preservation (ARP) with a deproteneized bovine bone mineral and a collagen matrix (IMPL/DBBM/CM) as compared to ARP (DBBM/CM) or spontaneous healing (SH) on vertical and horizontal bone dimensional changes after 4 months of healing.

Materials and methods: Thirty patients requiring extraction of one single-rooted tooth or premolar were randomly assigned to IMPL/DBBM/CM, ARP DBBM/CM or SH. Cone-beam computed tomography (CBCT) scans, performed before tooth extraction and after 4 months, were superimposed in order to assess changes in ridge height at the buccal and lingual aspect and in ridge width at 1 mm, 3 mm and 5 mm apical to the bone crest. Kruskal-Wallis test was applied for comparison of differences between groups.

Results: No statistically significant differences between the groups were observed for the vertical bone resorption of the buccal and the lingual side, while significant differences were found between SH group (-3.37 ± 1.55 mm; -43.2 ± 25.1%) and both DBBM/CM (-1.56 ± 0.76 mm; -19.2 ± 9.1%) and IMPL/DBBM/CM (-1.29 ± 0.38 mm; -14.9 ± 4.9%) groups in the horizontal dimension at the most coronal aspect.

Conclusion: Ridge preservation techniques using DBBM and CM reduce the horizontal bone morphological changes that occur, mostly in the coronal portion of the buccal bone plate following tooth extraction, when compared to spontaneous healing. This is true regardless of whether immediate implant placement is performed or not.

Trial registration: ClinicalTrials.gov NCT03422458.

Keywords: CBCT; alveolar ridge preservation; immediate implant placement; radiographic changes; tooth extraction.

Abstract

Purpose: The aim of the present study was to analyze the alveolar bone morphology of the upper first and second molars. This analysis aims to evaluate the morphology of a hypothetical postextractive site in the upper molar area to diagnose the possibility of immediate postextraction implant placement.

Materials and methods: Cone-beam CT scans of 100 patients were examined. The measurements were made using a dedicated 3D software. Reference points were identified to allow clear and repeatable measurements.

Results: The mean available height was 7.43 ± 3.40 mm for the upper first molars and 7.07 ± 3.09 mm for the upper second molars. The interradicular septum was present in first molars in 74% of cases and 44% of cases in upper second molars.

Conclusions: In most cases, the alveolar sites of the upper first and second molars do not present ideal conditions for immediate implant insertion in a correct position. The primary stabilization of a standard-sized dental implant is often difficult because of the minimum apical bone available. In particular, the interradicular septum, which often represents the ideal fixture position, is rarely adequately represented. Preoperative cone-beam scan and the knowledge of anatomical measurements from the present analysis are fundamental before planning immediate postextractive implants in the upper molar area.

Abstract

Purpose: The aim of the present radiological study was to analyze the alveolar bone morphology of the lower molars in physiological conditions. The main goal is to describe the bone anatomy of a hypothetically postextractive site in lower molar area.

Materials and methods: Computed tomography scans of 100 patients were examined. Axial, paraxial, and Panorex sections were analyzed using a dedicated software. Precise reference points were encoded to make the bone measurements clear and repeatable.

Results: The total number of dental sites examined was 235. The mean available bone height was 13.32 ± 3.23 mm in first molars and 11.76 ± 2.82 mm in second molars. The inter-radicular septum was present in 86% out of cases in first molar sites and in 52% in second molar sites. The lingual cortex mean width, at the most coronal point, measured 1.41 ± 0.52 mm in first molar alveoli and 1.67 ± 0.66 mm in second molar alveoli.

Conclusions: Proper clinical conditions, for scheduling a postextraction immediate implant placement surgery, involve the presence of 4 bone walls showing and sufficient height and width. The accurate knowledge of alveolus bone morphology of mandibular molars, prior extraction, could be an important guide to avoid potential failures due to nonideal anatomical features to fixture stabilization.