3D-printed PMMA implant for gingival smile treatment through the VISTA technique: A report of a new approach.

BACKGROUND: A gingival display higher than 3 mm is considered a characteristic of a gingival smile (GS). Several etiological factors have been associated to GS and for this reason various treatments have been proposed according to its etiology. The aim of this study is to present a case with an alternative technique to treat GS with minimally invasive vestibular incision subperiosteal tunnel access (VISTA) and polymethyl methacrylate (PMMA) implants for lip repositioning. METHODS AND RESULTS: The patient, a 25-year-old woman diagnosed with excessive gingival exposure, had previously done botulinum toxin (BoNT) injections and did not like the result. She had a major subnasal depression and the upper lip would lodge in there during spontaneous smile. She was informed about all options of treatment and agreed to a lip repositioning installing a customized PMMA implant. CONCLUSION: This is the first study to our knowledge to present a case with use of a PMMA implant associated with the VISTA approach for lip repositioning and gingival smile correction. The results are encouraging, and the patient was satisfied with results accomplished by this technique. KEY POINTS: Why is this case new information? This is a new and innovative surgical approach for gingival smile with PMMA implants through a minimally invasive technique (VISTA). What are the keys to successful management of this case? Well-defined presurgical planning and the presence of the upper lip lodging in the subnasal depression during spontaneous smile. What are the primary limitations to success in this case? Cases with vertical maxillary excess and those in which osteotomy/osteoplasty is indicated. It is a technique-sensitive treatment dependent on the clinician's experience.

Development of double emulsion nanoparticles for the encapsulation of bovine serum albumin.

In the present work, a double emulsion was developed for the encapsulation of Bovine Serum Albumin (BSA) as a model protein for the future encapsulation of viral proteins. The first emulsion polydispersity index (PDI) was studied with increasing concentrations of poly (ε-caprolactone) (PCL) as stabilizer (from 16% w/v to 5% w/v) and polyvinyl alcohol (PVA) as the surfactant in the second emulsion at 1.5% w/v. Results suggest that at decreasing concentrations of PCL the PDI of the emulsion also decrease, indicating that viscosity of the emulsion is crucial in the homogeneity of the resultant size distribution of the nanoparticles. When PVA concentration in the second emulsion was increased from 1.5% w/v to 2.5% w/v the PDI also increased. To study the relationship between the structure of the surfactant in the second emulsion and the resultant BSA encapsulation, emulsions were prepared with Pluronic F68 and PVA both at 1.5% w/v and PCL in the first emulsion at 5% w/v. Results indicated that Pluronic F68 was a better stabilizer because at the same experimental conditions encapsulation of BSA was 1.5 higher than PVA. FTIR studies confirmed the presence of BSA in the nanoparticles. SEM and TEM microscopies showed a size distribution of 300nm-500nm size of nanoparticles. Circular dichroism studies demonstrated that the secondary structure of the protein was conserved after the encapsulation into the nanoparticles.

Adjunct effect of the antimicrobial photodynamic therapy to an association of non-surgical and surgical periodontal treatment in modulation of gene expression: a human study.

BACKGROUND: This study has evaluated the effect of antimicrobial photodynamic therapy (aPDT) used in conjunction with non-surgical and surgical periodontal treatment (PT) in modulating gene expression during periodontal wound healing. METHODS: Fifteen patients with chronic periodontitis, presenting bilaterally lower molars with class III furcation lesions and scheduled for extraction, were selected. In initial therapy, scaling and root planing (SRP) was performed in the Control Group (CG), while SRP+aPDT were performed in the Test Group (TG). 45days later, flap surgery plus SRP, and flap surgery plus SRP+aPDT were performed in the CG and TG, respectively. At 21days post-surgery, the newly formed granulation tissue was collected, and Real-time PCR evaluated the expression of the genes: tumor necrosis factor-α, interleukin-1ß, interleukin-4, interleukin-10, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2), osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and bone sialoprotein. RESULTS: There were statistically significant differences between the groups in relation to mRNA levels for MMP-2 (TG=3.26±0.89; CG=4.23±0.97; p=0.01), TIMP-2/MMP-2 ratio (TG=0.91±0.34; CG=0.73±0.32; p=0.04), OPG (TG=0.84±0.45; CG=0.30±0.26; p=0.001), and OPG/RANKL ratio (TG=0.60±0.86; CG=0.23±0.16; p=0.04), favoring the TG. CONCLUSION: The present data suggest that the aPDT associated to nonsurgical and surgical periodontal therapy may modulate the extracellular matrix and bone remodeling by up regulating the TIMP- 2/MMP-2 and OPG/RANKL mRNA ratio, but the clinical relevance needs to be evaluated in further studies.

Effects of antimicrobial photodynamic therapy on transforming growth factor-ß1 levels in the gingival crevicular fluid.

BACKGROUND AND OBJECTIVE: Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive therapy to scaling and root planing (SRP). The transforming growth factor-ß1 (TGF-ß) has been considered as an anti-inflammatory cytokine, and its levels in the gingival crevicular fluid (GCF) could monitor the periodontal repair. This study evaluated the adjunct effect of aPDT compared with SRP, analyzing the TGF-ß levels in GCF after nonsurgical and surgical therapy in chronic periodontitis patients. METHODS: Fifteen patients, presenting bilaterally lower molars with class III furcation lesions, were selected. Each pair of teeth was randomly assigned to a control group (CG) or test group (TG). Initially, SRP was performed in the CG, and SRP + aPDT in the TG. Forty-five days later, flap surgery plus SRP, and flap surgery plus SRP + aPDT were performed in CG and TG, respectively. GCF was collected and an enzyme-linked immunosorbent assay (ELISA) test was conducted to determine the amount and concentration of TGF-ß in the GCF at baseline, 45 days post-initial therapy, and 21 days after surgery. RESULTS: Statistically significant differences between groups were found in relation to GCF volume 21 days after the surgical procedures (p=0.03) and TGF-ß concentration in GCF 45 days post-initial therapy (p=0.04), favoring the TG. CONCLUSIONS: There was an additional effect of the aPDT protocol compared with SRP for the TGF-ß concentration in GCF 45 days after nonsurgical therapy, and for the GCF volume 21 days after surgical therapy.

Comparison between micro- and macrosurgical techniques for the treatment of localized gingival recessions using coronally positioned flaps and enamel matrix derivative.

BACKGROUND: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). METHODS: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. RESULTS: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. CONCLUSIONS: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT.

Potential of bioactive glass particles of different size ranges to affect bone formation in interproximal periodontal defects in dogs.

BACKGROUND: The aim of this study was to compare the potential of bioactive glass particles of different size ranges to affect bone formation in periodontal defects, using the guided tissue regeneration model in dogs. METHODS: In six dogs, 2-wall intrabony periodontal defects were surgically created and chronified on the mesial surfaces of mandibular third premolars and first molars bilaterally. After 1 month, each defect was randomly assigned to treatment with bioabsorbable membrane in association with bioactive glass with particle sizes between 300 and 355 microm (group 1) or between 90 and 710 microm (group 2), membrane alone (group 3), or negative control (group 4). The dogs were sacrificed 12 weeks after surgeries, and histomorphometric measurements were made of the areas of newly formed bone, new mineralized bone, and bioactive glass particle remnants. RESULTS: With regard to the area of bioactive glass particle remnants, there was a statistically significant difference between groups 1 and 2, favoring group 1. There were greater areas of mineralized bone in groups 1 and 2 compared to groups 3 and 4 (P <0.05). CONCLUSION: The bioactive glass particles of small size range underwent faster resorption and substitution by new bone than the larger particles, and the use of bioactive glass particles favored the formation of mineralized bone.

Comparison between two surgical techniques for root coverage with an acellular dermal matrix graft.

AIM: The aim of this randomized, controlled, clinical study was to compare two surgical techniques with the acellular dermal matrix graft (ADMG) to evaluate which technique could provide better root coverage. MATERIAL AND METHODS: Fifteen patients with bilateral Miller Class I gingival recession areas were selected. In each patient, one recession area was randomly assigned to the control group, while the contra-lateral recession area was assigned to the test group. The ADMG was used in both groups. The control group was treated with a broader flap and vertical-releasing incisions, and the test group was treated with the proposed surgical technique, without releasing incisions. The clinical parameters evaluated before the surgeries and after 12 months were: gingival recession height, probing depth, relative clinical attachment level and the width and thickness of keratinized tissue. RESULTS: There were no statistically significant differences between the groups for all parameters at baseline. After 12 months, there was a statistically significant reduction in recession height in both groups, and there was no statistically significant difference between the techniques with regard to root coverage. CONCLUSIONS: Both surgical techniques provided significant reduction in gingival recession height after 12 months, and similar results in relation to root coverage.

Comparison of two surgical procedures for use of the acellular dermal matrix graft in the treatment of gingival recessions: a randomized controlled clinical study.

BACKGROUND: The aim of this randomized, controlled, clinical investigation was to compare two surgical techniques for root coverage with the acellular dermal matrix graft to evaluate which technique provided better root coverage, a better esthetic result, and less postoperative discomfort. METHODS: Fifteen patients with bilateral Miller Class I or II gingival recessions were selected. Fifteen pairs of recessions were treated and assigned randomly to the test group, and the contralateral recessions were assigned to the control group. The control group was treated with a broader flap and vertical releasing incisions; the test group was treated with the proposed surgical technique, without vertical releasing incisions. The clinical parameters evaluated were probing depth, relative clinical attachment level, gingival recession (GR), width of keratinized tissue, thickness of keratinized tissue, esthetic result, and pain evaluation. The measurements were taken before the surgeries and after 6 months. RESULTS: At baseline, all parameters were similar for both groups. At 6 months, a statistically significant greater reduction in GR favored the control group. The percentage of root coverage was 68.98% and 84.81% for the test and control groups, respectively. The esthetic result was equivalent between the groups, and all patients tolerated both procedures well. CONCLUSIONS: Both techniques provided significant root coverage, good esthetic results, and similar levels of postoperative discomfort. However, the control technique had statistically significantly better results for root coverage of localized gingival recessions.