Topical sodium alendronate combined or not with photodynamic therapy as an adjunct to scaling and root planing: Histochemical and immunohistochemical study in rats.

OBJECTIVE: The purpose of this study was to evaluate influence of topical sodium alendronate (ALN), photodynamic therapy (aPDT), or a combination thereof as adjuvant to scaling and root planing (SRP) in the treatment of experimental periodontitis in rats. BACKGROUND: Therapeutic protocols to control periodontitis progression that aim to equalize bacterial action and load with tissue immune response are well addressed in current scientific research. METHODS: Experimental periodontitis was induced in 96 rats with a ligature around the mandibular left first molar. After 7 days, ligature was removed and animals were treated according to the following experimental groups (n = 8): control-SRP plus saline solution; ALN-SRP plus ALN; aPDT-SRP plus methylene blue irrigation, followed by low-level laser therapy (LLLT); and ALN/aPDT-SRP plus ALN and methylene blue irrigation followed by LLLT. The animals were euthanized at 7, 15, and 30 days after treatments. Collagen maturation (picrosirius red staining) and immunohistochemical analyses (TRAP, RANKL and osteoprotegerin [OPG]) were performed. Data were submitted to statistical analysis (P < .05). RESULTS: At 7 days, group ALN presented a significantly higher number of TRAP-positive cells and percentage of immature collagen fibers than group ALN/aPDT, while group ALN/aPDT presented a significantly higher percentage of mature collagen fibers than group ALN. At 30 days, group ALN presented significantly lower percentage of immature collagen fibers and higher percentage of mature collagen fibers than control. CONCLUSION: It can be concluded that topical use of ALN coadjutant to SRP, alone or combined with aPDT, enhanced collagen maturation and reduced osteoclastogenesis during the healing of experimental periodontitis.

Effects of the prebiotic mannan oligosaccharide on the experimental periodontitis in rats.

AIM: To evaluate the effect of the prebiotic (PREB) mannan oligosaccharide (MOS) on the progression of the experimental periodontitis (EP) and intestinal morphology in rats. MATERIALS AND METHODS: Forty rats were randomly allocated into groups (n = 10): C (control), PREB, EP and EP-PREB. Groups PREB and EP-PREB received MOS incorporated into the feed daily. After 30 days, groups EP and EP-PREB received a cotton ligature around their mandibular first molars, kept for 14 days. Morphometrical, histomorphometrical, microcomputed tomography, gene expression analyses and immunohistochemistry were performed. Data were statistically analysed (p < 0.05). RESULTS: Group EP-PREB showed less interproximal bone loss, area without bone in the furcation and bone porosity, and greater bone mineral density than group EP (p < 0.05). It was also observed a significant decrease in IL-10 and IFN-γ gene expression, besides a decrease in TNF-α and IL-1ß and an increase in TGF-ß immunolabeling score for group EP-PREB. Group EP-PREB also presented villous height and crept depth values similar to group C, while group EP presented reduced values (p < 0.05). CONCLUSION: It can be concluded that the oral administration of MOS promotes a protective effect against alveolar bone loss caused by EP in rats, modifying histologic and immune-inflammatory parameters, in addition to protecting the intestine.

Influence of periodontal tissue thickness on buccal plate remodelling on immediate implants with xenograft.

AIM: To evaluate the influence of gingival thickness and bone grafting on buccal bone plate remodelling after immediate implant placement in sockets with thin buccal bone, using a flapless approach. MATERIALS AND METHODS: The gingiva of eight dogs was thinned at one side of the mandible, mandibular premolars were extracted without flaps, and four implants were installed on each side at 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). After 12 weeks the dogs were sacrificed and the samples were processed for histological analysis. RESULTS: All animals exhibited a thin buccal bone initially. In all the experimental groups the buccal gap was filled with newly formed bone and the buccal bone level was slightly apical to the implant shoulder. There were no statistically significant differences among the groups for the histomorphometric parameters. CONCLUSIONS: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The gingival thickness or the addition of a biomaterial in the gap did not influence the results.

The influence of the periodontal biotype on peri-implant tissues around immediate implants with and without xenografts. Clinical and micro-computerized tomographic study in small Beagle dogs.

OBJECTIVE: Soft tissues and buccal bone plate remodeling after immediate implantation in sockets with thin buccal bone, using the flapless approach with or without bone graft into the buccal gap, was compared between sites with thin and normal gingiva. MATERIAL AND METHODS: Eight dogs had the gingiva of one side of the mandible thinned, the mandibular premolars were extracted without flaps, and 4 implants were installed in each side, positioned 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). Buccal bone thickness (BBT), thickness of keratinized tissue (TKT), alveolar thickness (AT), gingival recession (GR), and probing depth (PD) were clinically evaluated. Within 12 weeks the dogs were sacrificed and the samples were analyzed by micro-computerized tomography. RESULTS: A thin BBT was observed in all the dogs. The presurgical procedures reduced TKT in the test group, with minimal changes of the AT. There were no statistically significant differences among the groups for the clinical parameters and the tomographic analysis showed similar linear and tri-dimensional bone reduction in all the groups. CONCLUSION: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The decrease in gingival thickness or the addition of a biomaterial in the gap did not influence the results.

Digital smile design for gummy smile correction.

Some tools can be used as an aid to the surgical planning for gummy smile correction, such as digital smile design (DSD), which allows to determine patterns of harmony and eventual asymmetries between teeth and gums. This work aims to report a gummy smile correction using DSD as reverse planning. The clinical examination revealed the presence of gummy smile and extensive bone exostosis in the premolar region. DSD was performed in the upper arch, determining the amount of gingiva to be removed, thus providing more safety and precision to the procedure. The surgery was performed by performing using an internal bevel incisions, detachment of a full thickness flap, and osteotomy and osteoplasty. After 6 months of preservation, there was an increase in the clinical crown of the teeth, with smile harmony, less exposure of the gingiva in the smile and a high level of patient aesthetic satisfaction.

Comparative study of two surgical techniques for root coverage of large recessions in heavy smokers.

Reduced root coverage due to diminished periodontal vascularity can be expected in heavy smokers. The aim of this study was to evaluate the root coverage obtained for large gingival recessions in heavy smokers using two different surgical techniques. Twenty heavy smokers were selected. Each patient had large, bilateral Miller class I or II gingival recessions (Control Group (CG): 3.30 ± 1.29; Test Group (TG): 3.45 ± 0.80) on nonmolar teeth. Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized mucosa height (KMH), and keratinized mucosa thickness (KMT) were determined at baseline and after 12 months. One side received a coronally positioned flap (CPF), while the contralateral side received the extended flap technique (EFT), both procedures carried out in conjunction with a subepithelial connective tissue graft (SCTG). Saliva samples to measure cotinine levels were taken at baseline and after 12 months as an indicator of the level of exposure to nicotine. Intergroup and intragroup analysis showed no statistical differences for the evaluated clinical parameters. Patients maintained the same exposure to smoke during the evaluation period. Both techniques resulted in low root coverage (CPF: 48.60%; EFT: 54.28%), but both techniques were effective in decreasing the gingival recessions (P ≤ 0.01). The variables smoke exposure, root coverage, and the thickness and height of keratinized tissue were subjected to linear regression. Regardless of the surgical technique used, heavy smoking strongly limits root coverage, especially for large recessions.

Treatment of gingival recessions in heavy smokers using two surgical techniques: a controlled clinical trial.

Smokers have small root coverage which is associated with bad vascularity of periodontal tissues. This study evaluated a technique that can increase the blood supply to the periodontal tissues compared with a traditional technique. Twenty heavy smokers (10 males and 10 females) with two bilateral Miller class I gingival recessions received coronally positioned flaps in one side (Control group)and extended flap technique in the other side (Test group). Clinical measurements (probing pocket depth, clinical attachment level, bleeding on probing, gingival recession height, gingival recession width, amount of keratinized tissue, and width and height of the papillae adjacent to the recession) were determined at baseline, 3 and 6 months postoperatively. Salivary cotinina samples were taken as an indicator of the nicotine exposure level. No statistically significant differences (p>0.05) were detected for the clinical measurements or smoke exposure. Both techniques promoted low root coverage (Control group: 43.18% and Test group: 44.52%). In conclusion, no difference was found in root coverage between the techniques. Root coverage is possible and uneventful even, if rather low, in heavy smoker patients with low plaque and bleeding indices.

In vitro evaluation of acellular dermal matrix as a three-dimensional scaffold for gingival fibroblasts seeding.

BACKGROUND: Tissue engineering principles could improve the incorporation of acellular dermal matrix (ADM). The aim of this study is to verify if ADM is a suitable three-dimensional matrix for gingival fibroblasts and cancerous cells ingrowth, and also if cultured medium conditioned in ADM affect cellular behavior. METHODS: Canine gingival fibroblasts (CGF), human gingival fibroblasts (HGF), and murine melanoma cell line (B16F10) were seeded on ADM for up to 14 days. The following parameters were assessed: morphology and distribution of CGF, HGF, and B16F10; CGF and HGF viability; and the effect of ADM conditioned medium (CM) on CGF viability. RESULTS: Epifluorescence revealed that CGF were unevenly distributed on the ADM surface, showing no increase in cell number over the periods of study; HGF formed a monolayer on the ADM surface in a higher number at 14 days (P <0.05); B16F10 exhibited an increase in cell number within 7 days (P <0.05), and were mainly arranged in cell aggregates on the ADM, forming a continuous layer at 14 days. A higher percentage of cells on the ADM surface (P <0.05) compared to inside was observed for all cell types. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) values indicated higher cell viability in samples cultured with HGF compared to CGF (P = 0.024). A significantly lower cell viability for CGF grown in CM compared to cells grown in non-CM was observed at 48 and 72 hours (P <0.05). CONCLUSIONS: ADM is not suitable as a three-dimensional matrix for gingival fibroblasts ingrowth. Gingival fibroblasts and highly proliferative cells as B16F10 can only be superficially located on ADM, and CGF are negatively affected by culture medium conditioned in ADM, reducing its viability.

Treatment of gingival recessions in heavy smokers using two surgical techniques: a controlled clinical trial

Smokers have small root coverage which is associated with bad vascularity of periodontal tissues. This study evaluated a technique that can increase the blood supply to the periodontal tissues compared with a traditional technique. Twenty heavy smokers (10 males and 10 females) with two bilateral Miller class I gingival recessions received coronally positioned flaps in one side (Control group)and extended flap technique in the other side (Test group). Clinical measurements (probing pocket depth, clinical attachment level, bleeding on probing, gingival recession height, gingival recession width, amount of keratinized tissue, and width and height of the papillae adjacent to the recession) were determined at baseline, 3 and 6 months postoperatively. Salivary cotinina samples were taken as an indicator of the nicotine exposure level. No statistically significant differences (p>0.05) were detected for the clinical measurements or smoke exposure. Both techniques promoted low root coverage (Control group: 43.18 percent and Test group: 44.52 percent). In conclusion, no difference was found in root coverage between the techniques. Root coverage is possible and uneventful even, if rather low, in heavy smoker patients with low plaque and bleeding indices.

Fumantes apresentam resultados ruins no recobrimento radicular, o que pode estar relacionado à má vascularização dos tecidos periodontais. O objetivo deste estudo foi avaliar uma técnica que pode aumentar a nutrição do tecido periodontal, comparando com uma técnica tradicional.Vinte fumantes pesados (10 homens e 10 mulheres) apresentando duas retrações bilaterais classe I de Miller receberam recobrimento radicular pela técnica de retalho posicionado coronalmente de um lado e pela técnica do retalho estendido no outro lado. Medidas clínicas (profundidade de sondagem, nível clínico de inserção, sangramento a sondagem, altura e largura da retração gengival, quantidade de tecido queratinizado, altura e largura das papilas dos dentes adjacentes a retração gengival)foram realizadas no início do estudo, 3 e 6 meses de pós-operatório. Amostras salivares foram feitas para detectar cotinina, um indicador do nível de exposição ao fumo. Não foram detectadas diferenças estatisticamente significantes (p>0,05) para os parâmetros clínicos ou exposição ao fumo. Ambas as técnicas tiveram baixo recobrimento radicular (controle: 43,18 por cento e teste: 44,52 por cento). Nenhuma diferença estatisticamente significante foi encontrada para o recobrimento radicular entre as técnicas. Em pacientes fumantes pesados com baixo índice de placa e de sangramento gengival o recobrimento radicular é possível e comum, no entanto, o recobrimento é parcial.