Tactile sense of the surgeon in determining bone density when placing dental implant

Small blood stem cells for enhancing early osseointegration formation on dental implants: a human phase I safety study

Background

Small blood stem cells (SB cells), isolated from human peripheral blood, demonstrated the ability to benefit bone regeneration and osseointegration. The primary goal of our study is to examine the safety and tolerability of SB cells in dental implantation for human patients with severe bone defects.

Methods

Nine patients were enrolled and divided into three groups with SB cell treatment doses of 1 × 10⁵, 1 × 10⁶, and 1 × 10⁷ SB cells, and then evaluated by computed tomography (CT) scans to assess bone mineral density (BMD) by Hounsfield units (HU) scoring. Testing was conducted before treatment and on weeks 4, 6, 8, and 12 post dental implantation. Blood and comprehensive chemistry panel testing were also performed.

Results

No severe adverse effects were observed for up to 6-month trial. Grade 1 leukocytosis, anemia, and elevated liver function were observed, but related with the patient’s condition or the implant treatment itself and not the transplantation of SB cells. The levels of cytokines and chemokines were detected by a multiplex immunological assay. Elevated levels of eotaxin, FGF2, MCP-1, MDC, and IL17a were found among patients who received SB cell treatment. This observation suggested SB cells triggered cytokines and chemokines for local tissue repair. To ensure the efficacy of SB cells in dental implantation, the BMD and maximum stresses via stress analysis model were measured through CT scanning. All patients who suffered from severe bone defect showed improvement from D3 level to D1 or D2 level. The HU score acceleration can be observed by week 2 after guided bone regeneration (GBR) and prior to dental implantation.

Conclusions

This phase I study shows that treatment of SB cells for dental implantation is well tolerated with no major adverse effects. The use of SB cells for accelerating the osseointegration in high-risk dental implant patients warrants further phase II studies.

Trial registration

Taiwan Clinical Trial Registry (SB-GBR001) and clinical trial registry of the United States (NCT04451486).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02461-z.

Ultralow Dose MSCT Imaging in Dental Implantology

INTRODUCTION

The Council Directive 2013/59 Euratom has a clear commitment for keeping medical radiation exposure as low as reasonably achievable and demands a regular review and use of diagnostic reference levels.

METHODS

In dental implantology, the range of effective doses for cone beam computed tomography (CBCT) shows a broad overlap with multislice computed tomography (MSCT). More recently, ultralow dose imaging with new generations of MSCT scanners may impart radiation doses equal to or lower than CBCT. Dose reductions in MSCT have been further facilitated by the introduction of iterative image reconstruction technology (IRT), which provides substantial noise reduction over the current standard of filtered backward projection (FBP).

AIM

The aim of this article is to review the available literature on ultralow dose CT imaging and IRTs in dental implantology imaging and to summarize their influence on spatial and contrast resolution, image noise, tissue density measurements, and validity of linear measurements of the jaws.

CONCLUSION

Application of ultralow dose MSCT with IRT technology in dental implantology offers the potential for very large dose reductions compared with standard dose imaging. Yet, evaluation of various diagnostic tasks related to dental implantology is still needed to confirm the results obtained with various IRTs and ultra-low doses so far.

Histomorphometric Analysis of Bone Density in Relation to Tactile Sense of the Surgeon During Dental Implant Placement

Introduction:

A correct diagnosis and optimal treatment planning is essential for success in implant dentistry. Proper diagnosis of bone quality is an important part of the diagnostic procedure.

Objective:

The purpose of this study was to correlate the tactile sense of the surgeon in the assessment of bone density to the histomorphometric analysis of bone quality.

Methods:

In this study, 56 bone samples from 33 patients were harvested from implant sites with trephine drills. The samples were analyzed with Image J software. In the samples following parameters were measured: BV/TV, superficial cortical plate thickness, the number and thickness of haversian canals in cortical bone and the number, thickness and distance of trabecules in cancellous bone. The clinical hardness of bone during drilling was evaluated by surgeon according to Misch. GEE analysis with exchangeable correlation structure and linear model was used to evaluate the relationship between the tactile sense of the surgeon and histomorphometric parameters and all analysis was adjusted for two confounding variables: gender and location.

Results:

There were 51.79% implants in D2 samples and 48.21% in D3. Bone classification according to Misch was significantly correlated to distance of trabecules in cancellous bone (P-value=0.05), and shown marginally significant correlation with mean superficial cortical bone thickness (P-value =0.07) and number of haversian canals (P-value =0.005) in cortical bone.

Discussion:

There were differences between our results and others. The authors believed that these differences mainly are because of confounding factors, that in this study were eliminated. The clinical finding during surgery can approximately explain the histologic properties of bone.

Conclusion:

It is concluded that tactile sense of the surgeon can exhibit the histologic properties of the bone, and we are able to estimate the healing prognosis of the bone in implant placement.

Effect of Microthread Design on Marginal Bone Level Around Dental Implants Placed in Fresh Extraction Sockets

PURPOSE

This study was designed to compare radiographically the effect of microthread on the coronal portion of the fixture on marginal bone level (MBL) around immediately placed dental implants in human subjects.

MATERIAL AND METHODS

Forty-one roughened surface screw type Dentium oral implants (Dentium) were inserted in fresh extraction sockets of the anterior segment of maxilla of 30 patients. The implants were selected randomly using either microthread design on coronal portion of the fixture (Implantium) (test group) or without microthread thread design (Superline) (control group). MBL was measured using digital subtraction radiography technique after 3, 6, and 12 months.

RESULTS

At month 3, the microthread groups have been associated with more marginal bone loss than the control group (P = 0.04). At months 6 and 12, both groups had comparable bone levels (P = 0.21).

CONCLUSION

The microthread design of the implant collar could not have a positive effect in maintaining the MBL around implants placed in fresh extraction socket in anterior maxilla.