Immunomodulatory differences between mesenchymal stem cells from different oral tissues

Mesenchymal stem cells (MSCs) have recently been identified as having potentially therapeutic immunomodulatory properties. MSCs isolated from different oral tissues have similar morphology and immunophenotypes, however, direct comparisons of their gene expression and immunomodulatory properties have not been conducted. We isolated alveolar bone-derived MSCs (aBMSCs), dental pulp stem cells (DPSCs) and gingiva-derived MSCs (GMSCs) from the same patients and compared their immunophenotypes and transcriptomes. Additionally, we compared their production of soluble immunomodulatory cytokines as well as their immunoregulatory properties in coculture with THP-1 human monocytic cells. RNA sequencing revealed distinct gene expression in DPSCs while aBMSCs and GMSCs had less differentially expressed genes. DPSCs also had significantly less secretion of osteopontin compared to aBMSCs and GMSCs. Finally, DPSCs did not exhibit an immunosuppresive effect on THP-1 cells to the same degree as aBMSCs and GMSCs. These findings demonstrate that MSCs from different oral tissues have distinct transcriptomes and immunoregulatory properties.

Dual Digitally Guided Crown Lengthening in Esthetic Area Compromised by Disharmonic Implant Crown

INTRODUCTION

A disharmonious smile results from excessive gingival exposure or gingival margin misalignment is a frequent finding in patients. The most common cause is altered passive eruption; however, in the case presented here, the esthetics of the smile is compromised also due to an inadequate implant placement and crown fabrication.

CASE PRESENTATION

This case presented a combination of altered passive eruption and a buccally as well as deeply placed implant crown (#10) that led to disproportionate dimensions of an upper lateral incisor. Dual digitally guided crown lengthening surgical procedure for teeth #5 to #12 was performed aiming a better harmony of the smile. Treatment also included placement of tooth veneers and re-made of implant crown. A pleasant smile with appropriate colors and proportions was achieved. All esthetic and periodontal health parameters were maintained throughout the follow-up period (1 year).

CONCLUSION

The use of dual digitally guided crown lengthening help to accomplish precision and stability of esthetic outcome, as it guides for both, bone and soft tissue removal. Particularly, in challenging cases with high esthetic demand and complicated factors present, such as the case presented here, the digital approach provides tools to attain excellent treatment outcome.

Biological and Technical Complications of Splinted or Nonsplinted Dental Implants: A Decision Tree for Selection

PURPOSE

To present an in-depth review on splinting versus nonsplinting the restorations of adjacent dental implants, in addition to discussing biological and technical complications associated with either choice; and to provide the clinician with a decision tree that serves in everyday judgments when it comes to addressing this issue.

MATERIALS AND METHODS

A comprehensive literature review was performed for articles comparing success of splinted versus nonsplinted dental implants.

RESULTS

There is no evidence to suggest that implementing either prosthetic design results in higher implant survival. Both designs tend to have their own set of complications, but there is compelling evidence to suggest that splinted restorations generally have less technical complications.

CONCLUSION

Either splinting or nonsplinting are valid options for restoring adjacent implants, but each tend to face different biological and technical complications. Knowing which patients are more likely to face particular complications is strategic to provide patients with successful restorations.

Dental implants and grafting success remain high despite large variations in maxillary sinus mucosal thickening

Background

Although mucosal thickening is the most common radiographic finding observed regarding sinus pathology, the knowledge regarding its clinical significance on the outcomes of dental implants and grafting in the maxillary sinuses is still limited. We hypothesized that mucosal thickening would not alter the predictability for sinus floor augmentation and dental implant placement. The purpose of this retrospective study was to evaluate the outcomes of dental implant placement in sinus-augmented areas with preexisting sinus mucosal thickening.

Methods

This study involved the review of cone-beam computed tomographic (CBCT) scans taken on patients that underwent both maxillary sinus elevation with grafting and implant placement at the University of Michigan School of Dentistry from 2004 to 2014. Cases with documented radiographic and clinical follow-up were included. The data analyses revealed the following.

Results

A total of 29 CBCT scans met the inclusion criteria for evaluation, and 93.1% of them had maxillary sinus mucosal/tissue thickening. Specifically, 6.9% of cases exhibited no thickening, 6.9% had minimal thickening (1–2 mm), 20.7% of cases had moderate thickening (2–5 mm), and 65.5% had severe thickening (>5 mm). We propose these categorical measurements of tissue thickening as a new “mucosal thickening index.” The tissue thickening did not vary based on gender, age, or smoking status, nor did it relate to the underlying alveolar ridge height. However, patients with a history of periodontal diseases demonstrated a significant association with mucosal thickening (p = 0.0043). These data indicate that there is high implant and grafting success rate (100%) in the maxillary sinus despite large and varied physiologic sinus mucosal/tissue thickening.

Conclusions

Based on study findings, this research will help guide dental practitioners regarding cases that exhibit mucosal thickening. These data support the concept that physiologic mucosal thickening in varied ranges is not associated with implant or grafting failure in the maxillary sinus.

Incidental Findings From Cone-Beam Computed Tomography During Implant Therapy

INTRODUCTION

This report reviews relevant literature on foreign bodies identified with cone-beam computed tomography (CBCT) and documents a rare case of a foreign body that was serendipitously identified during routine implant treatment planning.

CASE PRESENTATION

The literature shows a frequent occurrence of incidental findings with CBCT. This case documents incidental findings in the maxillary sinus and external auditory canal that were identified during routine CBCT used for implant treatment planning. The finding in the maxillary sinus was diagnosed as a mucous retention pseudocyst that did not require treatment. The finding in the external auditory canal was diagnosed as a foreign body (remnant of a cotton swab). Removal of the foreign body was prompted because of its presumed association with chronic headaches that were unresolved. Removal of the foreign body alleviated the chronic headaches, and implant placement proceeded uneventfully.

CONCLUSIONS

This review and case underscore the importance of a thorough review of the entire tomographic image volume. Using advanced technology for treatment creates new responsibilities and places more liability on providers not to overlook findings that may be significant to the patient's health.