The dynamics of closure following excisional mid-palatal mucoperiosteal wound in a rat model

Early Implant Failure in Patients Using Antihypertensive Medications: A Retrospective Cohort Study

INTRODUCTION AND AIMS

Antihypertensive medications increase osteoblasts differentiation and bone mineral formation. Osseointegration of dental implants depends on new bone formation and remodelling. Consequently, improved osseointegration may be speculated in patients receiving antihypertensive drugs. Aim - Asses the effect of antihypertensive medications on osseointegration of dental implants.

METHODS

Retrospective cohort study. All individuals (792) who received at least one dental implant during a 6-year period at a single medical centre. The cohort was divided into three groups: normotensive (74.8% - 593) patients (NT group), hypertensive (23.4% - 185) patients using antihypertensive medications (HTN +med group), and hypertensive patients not using (1.8% - 14) antihypertensive medications (HTN -med group). Interventions-Installation of dental implants by experienced oral and maxillofacial surgeons with or without bone augmentation. Main measures - Early implant failure (EIF) (≤12 months from loading) reflects lack of new bone formation or excessive bone turnover during osseointegration.

RESULTS

The study included 792 individuals, 14 in the HTN-med group, 185 in the HTN +med group and 593 in the NT group. At the patient level, the HTN -med group were most likely (P = .041) to experience EIF 28.60% (4/14 patients). Due to the small sample of the HTN -med group, an additional analysis was carried out excluding this group. EIF of 9.70% (18/185 patients) in the HTN +med group was significantly (P = .047) lower than the NT group 14.50% (86/593 patients). 2971 implants were inserted in all study groups, 71.4% (2123) in the NT group, 26.4% (784) in the HTN +med group and 2.2% (64) in the HTN -med group. Collectively, EIF was recorded for 114 (3.84%) implants. In the HTN -med group, EIF of 6.25% (4 implants), was significantly (P < .001) higher than the two other groups. The EIF rate of the HTN +med group was 2.29% (18 implants) which was significantly less than that of the NT group 4.33% (92 implants). Controlling modifying parameters, using antihypertensive medication yielded lower EIF with marginal significance (P = .059) and OR = 0.618.

CONCLUSION

Based on statistically significant lower EIF rate found in the HTN +med group, antihypertensive medications may decrease the EIF rate of dental implants.

CLINICAL RELEVANCE

Clinicians should be encouraged to treat hypertensive patients with implant-supported prostheses, provided patient compliance regarding medications intake is good.

Harvest of epithelialized gingival grafts without application of hemostatic sutures: A randomized clinical trial using laser speckle contrast imaging

BACKGROUND

This randomized controlled trial with two parallel arms and a 1:1 allocation ratio aimed to compare early microvascular healing (primary outcome), surgical times, and patient-reported outcomes (PROM) after harvesting palatal epithelialized gingival grafts (EGG), where hemostasis was achieved with sutures and hemostatic sponges (control) or with a sutureless approach (test).

METHODS

From a total of 33 patients, 34 EGG were harvested. Thirty-two were randomized to the test/control group (n = 16) and two were excluded. Early palatal microvascular healing was assessed at 7, 14, and 30 days with laser speckle contrast imaging (LSCI). Postoperative bleeding, pain, discomfort, and analgesic consumption were assessed over 2 weeks with a dedicated questionnaire.

RESULTS

A faster onset and resolution of postharvest hyperemia was observed in the test group where peak blood flow was reached at 7 days. No significant blood flow differences were observed between the groups at any of the evaluated timepoints. The mean surgical time was 13 min shorter in the test (p = 0.00). No significant differences were observed for postoperative bleeding and analgesic consumption at any timepoint.

CONCLUSIONS

The tested approach represents a viable alternative to the standard one, providing no relevant differences in microvascular, clinical, and patient-related results, but with significantly shorter surgical times.

Clinical and histological comparison of healing by steel scalpel, diode laser, and radiofrequency in palatal wound: An animal study

Background

Wound healing following periodontal soft tissue procedures can differ owing to different techniques, the feasibility of which can be determined through detailed macroscopic and microscopic observations.

Aims

This study aimed to clinically and histologically evaluate palatal wound healing in rats by secondary intention after excision using a steel scalpel, diode laser, and radiofrequency.

Materials and Methods

An excision was made in the edentulous anterior maxilla of 42 4-month-old male Wistar rats weighing 289-428 g. Part of the connective tissue was left in the surgical area to observe the dynamics of secondary intention wound healing. Three experimental groups were established: the steel scalpel, an 810-nm diode laser at a power output of 1.5 W in continuous mode, and a monopolar radiofrequency in a fully rectified waveform at 15 W. Clinical and histological analyses were performed on days 2, 4, and 7. Hemostasis, changes in body weight, defect size, epithelial gap, and inflammatory infiltration were evaluated.

Results

The epithelial gap closed completely in all groups on day 7. Bleeding occurred significantly more in the scalpel group (P < 0.001). No significant changes were observed in body weight between the groups. Macroscopically, the mean wound area decreased over time in all groups. Wound healing was significantly slower in the laser group on day 2 and in the radiofrequency group on days 4 and 7 (P < 0.001). Microscopically, the laser created the cleanest wound area, with minimal inflammatory infiltration and no thermal injury. More damage occurred in the connective tissue of the radiofrequency group. Wound healing was observed on day 7 in all groups.

Conclusions

Palatal wound healing with secondary intention yielded different outcomes in a rat model when different techniques were used. However, almost complete healing was observed in all wounds, which highlights the importance of the soft tissue left in the surgical area. Wound healing in periodontal soft tissue procedures is not compromised by different techniques, as long as the clinician has sufficient knowledge and experience.

Green Synthesis of Gold Nanoparticles with Curcumin or Açai in the Tissue Repair of Palatal Wounds

This study aimed to evaluate and compare the effects of treatment with gold nanoparticles (GNPs) reduced with Curcumin (Curcuma longa L.) or Açai (Euterpe oleracea) to a standard commercial treatment of the pharmacological type (Omcilon®) and an electrophysical agent (photobiomodulation) in the palatal wounds of rats. As for the in vitro assay, a cell viability test was performed to assess the toxicity of the synthesized nanoparticles. In vivo assay: 60 Wistar rats were divided into five groups (n = 12): I. Palatal Wound (PW); II. PW + Photobiomodulation (PBM); III. PW + Omcilon®; IV. PW + GNPs-Cur (0.025 mg/mL); V. PW + GNPs-Açai (0.025 mg/mL). Animals were first anesthetized, and circular lesions in the palatine mucosa were induced using a 4 mm-diameter punch. The first treatment session started 24 h after the injury and occurred daily for 5 days. The animals were euthanized, and the palatal mucosa tissue was removed for histological, biochemical, and molecular analysis. GNPs-Açai were able to significantly reduce pro-inflammatory cytokines and increase anti-inflammatory ones, reduce oxidant markers, and reduce inflammatory infiltrate while increasing the collagen area and contraction rate of the wound, along with an improved visual qualification. The present study demonstrated that the proposed therapies of GNPs synthesized greenly, thus associating their effects with those of plants, favor the tissue repair process in palatal wounds.

Wound healing dynamics, morbidity, and complications of palatal soft-tissue harvesting

Palatal-tissue harvesting is a routinely performed procedure in periodontal and peri-implant plastic surgery. Over the years, several surgical approaches have been attempted with the aim of obtaining autogenous soft-tissue grafts while minimizing patient morbidity, which is considered the most common drawback of palatal harvesting. At the same time, treatment errors during the procedure may increase not only postoperative discomfort or pain but also the risk of developing other complications, such as injury to the greater palatine artery, prolonged bleeding, wound/flap sloughing, necrosis, infection, and inadequate graft size or quality. This chapter described treatment errors and complications of palatal harvesting techniques, together with approaches for reducing patient morbidity and accelerating donor site wound healing. The role of biologic agents, photobiomodulation therapy, local and systemic factors, and genes implicated in palatal wound healing are also discussed.

Single-cell transcriptomic analysis of oral masticatory and lining mucosa-derived mesenchymal stromal cells

AIM

To reveal the heterogeneity of ex vivo-cultured human mesenchymal stromal cells derived from either masticatory or lining oral mucosa.

MATERIALS AND METHODS

Cells were retrieved from the lamina propria of the hard palate and alveolar mucosa of three individuals. The analysis of transcriptomic-level differences was accomplished using single-cell RNA sequencing.

RESULTS

Cluster analysis clearly distinguished between cells from the masticatory and lining oral mucosa, and revealed 11 distinct cell sub-populations, annotated as fibroblasts, smooth muscle cells or mesenchymal stem cells. Interestingly, cells presenting a mesenchymal stem cell-like gene expression pattern were predominantly found in masticatory mucosa. Although cells of masticatory mucosa origin were highly enriched for biological processes associated with wound healing, those from the lining oral mucosa were highly enriched for biological processes associated with the regulation of epithelial cells.

CONCLUSIONS

Our previous work had shown that cells from the lining and masticatory oral mucosae are phenotypically heterogeneous. Here, we extend these findings to show that these changes are not the result of differences in averages but rather represent two distinct cell populations, with mesenchymal stem cells more common in masticatory mucosa. These features may contribute to specific physiological functions and have relevance for potential therapeutic interventions.

The Impact of Corticosteroid Administration at Different Time Points on Mucosal Wound Healing in Rats: An Experimental Pilot In Vivo Study

Simple Summary

The objective of this pilot study was to evaluate the impact of corticosteroid (CS) administration at different time points on palatal wound healing in rats. Thirty-six young male rats were divided into three groups. The test groups were treated by CS in the early (1–4 days) and late (5–9 days) stages after palatal wounding, while the control group was left for spontaneous healing. Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Abstract

Background: Conflicting results were found regarding the effect of corticosteroid (CS) administration upon wound healing. The objective of this pilot study was to evaluate the impact of CS administration at different time points on palatal wound healing in rats. Methods: A 4.2 mm diameter punch created a secondary healing excisional palatal defect in thirty-six (36) Wistar-derived, two-month-old male rats weighing 250–270 g. We evaluated the effect of CS by comparing wound healing between three equal groups: 12 rats who were not exposed to CS and two additional groups in which 1 mg/kg dexamethasone (1 mg/kg) was administered daily, early (1–4 days) and late (5–9 days) after injury. The dynamics of the healing process were evaluated weekly in 4 sacrificed rats from each group for three weeks. The wound area was assessed both macroscopically and microscopically; the inflammation score was assessed microscopically. Results: The initial wound area in all the rats was 13.85 mm². At the end of the study, it decreased to 4.11 ± 0.88 mm², 7.32 ± 2.11 mm², and 8.87 ± 3.01 mm² in control, early, and late CS administration groups, respectively (p = 0.075). Inflammation scores showed a tendency to decrease in the third week in all groups, with no statistical differences. Conclusions: Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Age-Related Palatal Wound Healing: An Experimental In Vivo Study

We assessed age-related excisional palatal mucoperiosteal wound closure in rats. A 4.2 mm diameter punch was used to create a secondary healing defect in the palate of Wistar rats. Study group-21, 18-month-old vs. control 21, 2-month-old males. The 2-dimensional area, maximum length and width of the soft tissue defect served as clinical outcome parameters. The dynamics of the initial three healing weeks were assessed. Semi-quantitative histomorphometric analysis of inflammation and myofibroblasts served for the evaluation of the inflammatory and proliferative wound healing phases. Complete wound closure was faster in the old rats. A dimensional related wound closure was observed in the young rats versus a symmetrical wound closure in the old rats. Inflammatory response was significantly delayed and of lower intensity in the old rats. Myofibroblastic response, representing the proliferative stage, was delayed and of lower intensity in the old rats, albeit not statistically significant. Reduced initial tissue damage due to decreased and delayed inflammatory response in the old rats ultimately led to faster clinical wound healing compared to the young rats, despite a statistically non-significant lower proliferative response in the old rats.