BMP-2 and asporin expression regulate 5-aza-dC-mediated osteoblast/cementoblast differentiation of periodontal dental ligament mesenchymal progenitor cells.

Periodontal dental ligament (PDL) is composed of heterogeneous population of mesenchymal progenitor cells. The mechanisms that regulate the differentiation of these cells towards osteoblast/cementoblast phenotype are not fully understood. Some studies have demonstrated that is possible to change the pattern of cell differentiation via epigenetic mechanisms. The proposal of this study was to investigate whether 5-aza-2'-deoxycytidine (5-aza-dC) treatment would stimulate the osteoblast/cementoblast differentiation of periodontal ligament mesenchymal progenitor cells (PDL-CD105+ enriched cells), characterized as low osteoblast potential, through bone morphogenetic protein-2 (BMP-2) modulation. PDL-CD105+ cells from a single donor were cloned and characterized in two populations as high osteoblast/cementoblast potential (HOP) and low osteoblast/cementoblast potential (LOP) by mineralization in vitro and expression of osteogenic gene markers, such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN), bone morphogenetic protein 2 (BMP-2) and asporin (ASPN). Next, two LOP clones (L1 and L2) were pretreated with 5-aza-dC (10 µM) for 48 h, cultured under osteogenic condition and evaluated for mineralized matrix in vitro, transcription modulation of osteogenic gene markers, methylated and hydroxymethylated DNA levels of BMP-2 and ASPN and intracellular/extracellular expression of BMP-2 protein. LOP clones showed high expression of ASPN transcripts associated with low mRNA levels of BMP-2, RUNX2, ALP, and OCN. 5-aza-dC treatment raised hydroxymethylated DNA levels of BMP-2 and increased the expression of BMP-2 transcripts in both LOP clones. However, BMP-2 protein (intracellular and secreted forms) was detected only in L1 cell clones, in which it was observed an increased expression of osteoblast/cementoblast markers (RUNX2, ALP, OCN) associated with higher mineralization in vitro. In L2 cell clones, 5-aza-dC increased gene expression of ASPN, with no great change in for osteoblast/cementoblast differentiation potential. These data show that 5-aza-dC improves osteoblast/cementoblast differentiation of PDL-CD105+ cells via BMP-2 secretion, and this effect depends on low levels of ASPN expression.

Polycaprolactone scaffolds as a biomaterial for cementoblast delivery: An in vitro study.

OBJECTIVE: To define the potential of polycaprolactone (PCL) scaffold for cementoblast delivery. BACKGROUND: Dental cementum is critical for tooth attachment and position, and its regenerative capabilities remain unpredictable. METHODS: PCL scaffolds were manufactured by the electrospinning technique at 10% and 20% (w/v) and seeded with cementoblasts (OCCM-30). Scaffolds were characterized for their morphology and biological performance by scanning electron microscopy (SEM), confocal and conventional histology, cytocompatibility (PrestoBlue assay), gene expression (type I collagen - Col1; bone sialoprotein - Bsp; runt-related transcription factor 2 - Runx-2; alkaline phosphatase - Alpl; osteopontin - Opn; osteocalcin - Ocn, osterix - Osx), and the potential to induce extracellular matrix deposition and mineralization in vitro. RESULTS: Overall, data analysis showed that PCL scaffolds allowed cell adhesion and proliferation, modulated the expression of key markers of cementoblasts, and led to enhanced extracellular matrix deposition and calcium deposition as compared to the control group. CONCLUSION: Altogether, our findings allow concluding that PCL scaffolds are a viable tool to culture OCCM-30 cells, leading to an increased potential to promote mineralization in vitro. Further studies should be designed in order to define the clinical relevance of cementoblast-loaded PCL scaffolds to promote new cementum formation.

Childhood Hypophosphatasia Associated with a Novel Biallelic ALPL Variant at the TNSALP Dimer Interface.

The goal of this study was to perform a clinical and molecular investigation in an eight-year-old female child diagnosed with hypophosphatasia (HPP). The proband and her family were evaluated by medical and dental histories, biochemical analyses, radiographic imaging, and genetic analysis of the tissue-nonspecific alkaline phosphatase (ALPL) gene. A bioinformatic analysis was performed to predict the structural and functional impact of the point mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) molecule and to define their potential contribution to the phenotype. We identified a novel combination of heterozygous ALPL missense variants in the proband, p.Ala33Val and p.Asn47His, compatible with an autosomal recessive mode of inheritance and resulting in skeletal and dental phenotypes. Computational modeling showed that the affected Asn47 residue is located in the coil structure close to the N-terminal α-helix, whereas the affected Ala33 residue is localized in the N-terminal α-helix. Both affected residues are located close to the homodimer interface, suggesting they may impair TNSALP dimer formation and stability. Clinical and biochemical follow-up revealed improvements after six years of ERT. Reporting this novel combination of ALPL variants in childhood HPP provides new insights into genotype-phenotype associations for HPP and specific sites within the TNSALP molecule potentially related to a childhood-onset HPP and skeletal and dental manifestations. Beneficial effects of ERT are implicated in skeletal and dental tissues.

Comparative proteomic analysis of dental cementum from deciduous and permanent teeth.

BACKGROUND AND OBJECTIVES: Dental cementum (DC) is a mineralized tissue covering tooth roots that plays a critical role in dental attachment. Differences in deciduous vs. permanent tooth DC have not been explored. We hypothesized that proteomic analysis of DC matrix would identify compositional differences in deciduous (DecDC) vs. permanent (PermDC) cementum that might reflect physiological or pathological differences, such as root resorption that is physiological in deciduous teeth but can be pathological in the permanent dentition. METHODS: Protein extracts from deciduous (n = 25) and permanent (n = 12) teeth were pooled (five pools of DecDC, five teeth each; four pools of PermDC, three teeth each). Samples were denatured, and proteins were extracted, reduced, alkylated, digested, and analyzed by liquid chromatography-mass spectrometry (LC-MS/MS). The beta-binomial statistical test was applied to normalized spectrum counts with 5% significance level to determine differentially expressed proteins. Immunohistochemistry was used to validate selected proteins. RESULTS: A total of 510 proteins were identified: 123 (24.1%) exclusive to DecDC; 128 (25.1%) exclusive to PermDC; 259 (50.8%) commonly expressed in both DecDC and PermDC. Out of 60 differentially expressed proteins, 17 (28.3%) were detected in DecDC, including myeloperoxidase (MPO), whereas 43 (71.7%) were detected in PermDC, including decorin (DCN) and osteocalcin (BGLAP). Overall, Gene Ontology (GO) analysis indicated that all expressed proteins were related to GO biological processes that included localization and response to stress, and the GO molecular function of differentially expressed proteins was enriched in cell adhesion, molecular binding, cytoskeletal protein binding, structural molecular activity, and macromolecular complex binding. Immunohistochemistry confirmed the trends for selected differentially expressed proteins in human teeth. CONCLUSIONS: Clear differences were found between the proteomes of DecDC and PermDC. These findings may lead to new insights into developmental differences between DecDC and PermDC, as well as to a better understanding of physiological/pathological events such as root resorption.

Novel LRAP-binding partner revealing the plasminogen activation system as a regulator of cementoblast differentiation and mineral nodule formation in vitro.

Amelogenin isoforms, including full-length amelogenin (AMEL) and leucine-rich amelogenin peptide (LRAP), are major components of the enamel matrix, and are considered as signaling molecules in epithelial-mesenchymal interactions regulating tooth development and periodontal regeneration. Nevertheless, the molecular mechanisms involved are still poorly understood. The aim of the present study was to identify novel binding partners for amelogenin isoforms in the cementoblast (OCCM-30), using an affinity purification assay (GST pull-down) followed by mass spectrometry and immunoblotting. Protein-protein interaction analysis for AMEL and LRAP evidenced the plasminogen activation system (PAS) as a potential player regulating OCCM-30 response to amelogenin isoforms. For functional assays, PAS was either activated (plasmin) or inhibited (ε-aminocaproic acid [aminocaproic]) in OCCM-30 cells and the cell morphology, mineral nodule formation, and gene expression were assessed. PAS inhibition (EACA 100 mM) dramatically decreased mineral nodule formation and expression of OCCM-30 differentiation markers, including osteocalcin (Bglap), bone sialoprotein (Ibsp), osteopontin (Spp1), tissue-nonspecific alkaline phosphatase (Alpl) and collagen type I (Col1a1), and had no effect on runt-related transcription factor 2 (Runx2) and Osterix (Osx) mRNA levels. PAS activation (plasmin 5 µg/µl) significantly increased Col1a1 and decreased Bglap mRNA levels (p < .05). Together, our findings shed new light on the potential role of plasminogen signaling pathway in the control of the amelogenin isoform-mediated response in cementoblasts and provide new insights into the development of targeted therapies.

Local IL-10 level as a predictive factor in generalized aggressive periodontitis treatment response.

Generalized aggressive periodontitis (GAgP) presents a reduced response to non-surgical therapy. However, it is not clear if the initial clinical, microbiological or immunological characteristics are impacting the worse response to treatment. This study aimed to identify the predictive value of clinical, microbiological and immunological patterns on the clinical response to therapy in GAgP patients. Twenty-four GAgP patients were selected, and gingival crevicular fluid (GCF) and subgingival biofilm were collected. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia levels were evaluated by qPCR, and IL-1ß and IL-10 concentration by ELISA. Twelve patients were treated with SRP (scaling and root planning), and twelve with SRP plus 375 mg amoxicillin and 250 mg metronidazole (8/8 hours, 7 days) (SRP + AM). The clinical changes (Probing Pocket Depth [PPD] reduction and Clinical Attachment Level [CAL] gain) 6 months post-treatment were correlated to the initial clinical, inflammatory and microbiological variables using stepwise logistic regression (α = 5%). CAL gain at 6 months was 1.16 ± 0.77 for SRP and 1.74 ± 0.57 mm for SRP + AM (P > .05). PPD reduction was 1.96 ± 0.82 for SRP and 2.45 ± 0.77 mm for SRP + AM (P < .05). In the SRP group, IL-10 showed a predictive value for clinical response. The higher the IL-10 concentration at baseline, the higher the reduction in PPD at 6 months (P = .01, r = .68). However, when antimicrobials were administered, no significant influence was detected (P > .05). It can be concluded that the IL-10 levels in GFC act as a predictor of clinical response to GAgP. Moreover, the intake of antimicrobials appears to overlap the influence of the inflammatory response on clinical response to treatment. Clinical trial registration number: NCT03933501.

Clinical and molecular analysis in Papillon-Lefèvre syndrome.

Papillon-Lefèvre syndrome (PLS; MIM#245000) is a rare recessive autosomal disorder characterized by palmar and plantar hyperkeratosis, and aggressively progressing periodontitis leading to premature loss of deciduous and permanent teeth. PLS is caused by loss-of-function mutations in the CTSC gene, which encodes cathepsin C. PLS clinical expressivity is highly variable and no consistent genotype-phenotype correlation has been demonstrated yet. Here we report the clinical and genetic features of five PLS patients presenting a severe periodontal breakdown in primary and permanent dentition, hyperkeratosis over palms and soles, and recurrent sinusitis and/or tonsillitis. Mutation analysis revealed two novel homozygous recessive mutations (c.947T>C and c.1010G>C) and one previous described homozygous recessive mutation (c.901G>A), with parents carrying them in heterozygous, in three families (four patients). The fourth family presented with the CTSC c.628C>T mutation in heterozygous, which was inherited maternally. Patient carrying the CTSC c.628C>T mutation featured classical PLS phenotype, but no PLS clinical characteristics were found in his carrier mother. All mutations were found to affect directly (c.901G>A, c.947T>C, and c.1010G>C) or indirectly (c.628C>T, which induces a premature termination) the heavy chain of the cathepsin C, the region responsible for activation of the lysosomal protease. Together, these findings indicate that both homozygous and heterozygous mutations in the cathepsin C heavy chain domain may lead to classical PLS phenotype, suggesting roles for epistasis or gene-environment interactions on determination of PLS phenotypes.

Does enamel matrix derivative application improve clinical outcomes after semilunar flap surgery? A randomized clinical trial.

OBJECTIVES: To evaluate the treatment of gingival recessions by semilunar coronally positioned flap plus enamel matrix derivative (SCPF + EMD). MATERIALS AND METHODS: Thirty patients with class I localized gingival recession were included. They were randomly allocated in two groups: SCPF + EMD and SCPF. Recession height (RH), recession width (RW), width of keratinized tissue (WKT), thickness of keratinized tissue (TKT), probing depth (PD), and clinical attachment level (CAL) were measured at baseline, 6 and 12 months post-surgery. Patient/professional evaluation of esthetics and root sensitivity was performed. RESULTS: After 12 months, mean root coverage was 1.98 ± 0.33 mm for SCPF + EMD (90.86 ± 14.69%) and 1.85 ± 0.41 mm (79.76 ± 17.44%) for SCPF (p > 0.05). The esthetic evaluation by the patient showed preference for SCPF + EMD. According to the professional evaluation (QCE), the use of EMD decreases the appearance of postoperative scar tissue line. There was a significant reduction in root hypersensitivity with no further complaints by the patients. CONCLUSIONS: The addition of EMD provides significantly better esthetics to SCPF, according to patient and professional assessments. SCPF + EMD is effective but not superior to SCPF for root coverage, after 12 months. CLINICAL RELEVANCE: Previous clinical trials showed that the combination of EMD with coronally advanced flaps may enhance the outcome of root coverage. There is a lack of studies testing the combination of EMD with SCPF. The combination SCPF + EMD provides better esthetics when compared to the SCPF and is effective, but not superior, to SCPF for root coverage, after 12 months. TRIAL REGISTRATION: NCT02459704.

Leucine-Rich Amelogenin Peptide (LRAP) Uptake by Cementoblast Requires Flotillin-1 Mediated Endocytosis.

Basic, pre-clinical, and clinical studies have documented the potential of amelogenin, and its variants, to affect cell response and tissue regeneration. However, the mechanisms are unclear. Thus, the aim of the present study was to identify, in cementoblasts, novel binding partners for an alternatively spliced amelogenin form (Leucine-Rich Amelogenin Peptide-LRAP), which is supposed to act as a signaling molecule in epithelial-mesenchymal interactions. LRAP-binding protein complexes from immortalized murine cementoblasts (OCCM-30) were achieved by capture affinity assay (GST pull down) and proteins present in these complexes were identified by mass spectrometry and immunoblotting. Flotillin-1, which functions as a platform for signal transduction, vesicle trafficking, endocytosis, and exocytosis, was identified and confirmed by co-precipitation and co-localization assays as a protein-binding partner for LRAP in OCCM-30 cells. In addition, we found that exogenously added GST-LRAP recombinant protein was internalized by OCCM-30 cells, predominantly localized in the perinuclear region and, that inhibition of flotillin1-dependent functions by small interference RNA (siRNA) methodology significantly affected LRAP uptake and its biological properties on OCCM-30 cells, including LRAP effect on the expression of genes encoding osteocalcin (Ocn), bone sialoprotein (Bsp), and runt-related transcription factor 2 (RunX2). In conclusion, LRAP uptake by cementoblast involves flotillin-assisted endocytosis, which suggests an involvement of LRAP in lipid-raft-dependent signaling pathways which are mediated by flotillin-1. J. Cell. Physiol. 232: 556-565, 2017. © 2016 Wiley Periodicals, Inc.

EEF1D modulates proliferation and epithelial-mesenchymal transition in oral squamous cell carcinoma.

EEF1D (eukaryotic translation elongation factor 1δ) is a subunit of the elongation factor 1 complex of proteins that mediates the elongation process during protein synthesis via enzymatic delivery of aminoacyl-tRNAs to the ribosome. Although the functions of EEF1D in the translation process are recognized, EEF1D expression was found to be unbalanced in tumours. In the present study, we demonstrate the overexpression of EEF1D in OSCC (oral squamous cell carcinoma), and revealed that EEF1D and protein interaction partners promote the activation of cyclin D1 and vimentin proteins. EEF1D knockdown in OSCC reduced cell proliferation and induced EMT (epithelial-mesenchymal transition) phenotypes, including cell invasion. Taken together, these results define EEF1D as a critical inducer of OSCC proliferation and EMT.

Full-mouth ultrasonic debridement associated with povidone iodine rinsing in GAgP treatment: a randomised clinical trial.

OBJECTIVE: This study evaluated the clinical, immunological and microbiological results of full-mouth ultrasonic debridement (FMUD) with 10 % povidone iodine (PVPI) as the cooling liquid in the treatment of generalised aggressive periodontitis (GAgP). MATERIAL AND METHODS: Twenty-eight patients presenting GAgP were randomly assigned to one of the following groups for evaluation: FMUD + SS (n = 14)--single session of FMUD with 0.9 % saline solution as cooling agent and FMUD + PVPI (n = 14)--single session of FMUD with PVPI solution as cooling agent. Probing depth (PD), relative clinical attachment level (RCAL), relative position of gingival margin, plaque index (FMPI) and bleeding score (FMBS), immunological (interleukin-10 and interleukin-1ß concentrations in gingival crevicular fluid) and microbiological (Aa and Pg amounts) parameters were evaluated at baseline, first, third and sixth months after treatment. RESULTS: The two groups presented reduction of FMPI and FMBS and had statistically significant PD reductions, RCAL gains and gingival recession (p < 0.05). Both therapies reduced Pg levels in deep and in moderate pockets (p < 0.05). FMUD + PVPI reduced Aa levels in deep pockets. However, no inter-group differences in clinical, immunological and microbiological parameters were observed (p > 0.05). CONCLUSIONS: It could be concluded that 10 % PVPI used as an irrigant solution in FMUD decreased Aa levels in deep pockets but had no additional benefits when compared with saline solution irrigation in terms of clinical, microbiological and immunological results. CLINICAL RELEVANCE: The FMUD is a valid option for the treatment of GAgP, but the use of 10 % PVPI did not improve the results of the periodontal therapy.

Enamel matrix protein derivative and/or synthetic bone substitute for the treatment of mandibular class II buccal furcation defects. A 12-month randomized clinical trial.

OBJECTIVE: This study aims to clinically evaluate the treatment of mandibular class II furcation defects with enamel matrix derivative (EMD) and/or a bone substitute graft made of ß-tricalcium phosphate/hydroxyapatite (ßTCP/HA). MATERIALS AND METHODS: Forty-one patients, presenting a mandibular class II buccal furcation defect, probing pocket depth (PPD) ≥4 mm and bleeding on probing, were included. They were randomly assigned to the groups: 1-EMD (n = 13); 2-ßTCP/HA (n = 14); 3-EMD + ßTCP/HA (n = 14). Plaque index (PI), gingival index (GI), relative gingival margin position (RGMP), relative vertical and horizontal attachment level (RVCAL and RHCAL), and PPD were evaluated at baseline and 6 and 12 months. The mean horizontal clinical attachment level gain was considered the primary outcome variable. RESULTS: No significant intragroup differences were observed for RGMP, but significant changes were observed for RVCAL, RHCAL, and PPD for all groups (p < 0.05). After 12 months, the mean horizontal clinical attachment level gain was 2.77 ± 0.93 mm for EMD, 2.64 ± 0.93 mm for ßTCP/HA, and 2.93 ± 0.83 mm for EMD + ßTCP/HA, with no significant differences among the groups. At the end of the study, 85.3 % of the sites were partially closed; however, no complete closure was observed. CONCLUSION: EMD + ßTCP/HA does not provide a significant advantage when compared to the isolated approaches. All three tested treatments promote significant improvements and partial closure of class II buccal furcation defects. Based on its potential to induce periodontal regeneration, EMD may be considered an attractive option for this type of defect, but complete closure remains an unrealistic goal. CLINICAL RELEVANCE: The partial closure of buccal furcation defects can be achieved after the three tested approaches. However, the combined treatment does not provide a significant benefit when compared to the isolated approaches.

Current perspective of the impact of smoking on the progression and treatment of periodontitis.

This literature review provides an overview of the current scenario regarding the impact of smoking on the progression and treatment of periodontitis; clinical, microbiological and immunological data from studies from our and other groups are presented. In general, preclinical and clinical data are unanimous in demonstrating that smokers present increased susceptibility, greater severity and faster progression of periodontal disease compared with nonsmokers. The evidence further demonstrates that smokers lose more teeth and have a less favorable response to therapy than do nonsmokers. Although it is well established that smoking significantly impacts on the onset, progression and outcome of periodontal disease, the mechanisms involved remain unclear. More importantly, some of the reported deleterious effects of smoking on periodontal tissues have been reported to be reversible upon participation in smoking-cessation programs. Therefore, clinicians should strongly advise smokers to enroll in cessation strategies, even temporarily, in order to improve the overall outcome.

Periodontal clinical and microbiological characteristics in healthy versus generalized aggressive periodontitis families.

AIM: Generalized aggressive periodontitis (GAP) is a severe and multifactorial disease in which a familial aggregation and a specific microbiological profile have been suggested. Thus, this case-control study evaluated the clinical and subgingival microbial profile of GAP subjects and their families compared to healthy families. METHODS: Fifteen families with parents presenting periodontal health and 15 with parents with a history of GAP were selected. Each family should have at least one child between 6 and 12 years old. Plaque index (PI), gingival index (GI), and periodontal probing depth (PPD), as well as Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans (Aa) amounts (by qPCR), were assessed from all subjects. RESULTS: Children of GAP families showed a higher PI, GI, and PPD when compared to children of healthy families (p ≤ 0.05). A higher frequency of detection and amounts of Aa was observed in GAP children compared to children of healthy families (p ≤ 0.05). Moreover, a significant association between Aa amounts and gingival bleeding was observed in children (p ≤ 0.05, r = 0.37). CONCLUSION: Children from GAP families have worst clinical conditions, i.e. higher levels of PI, GI, and PPD, a more pathogenic microbiological profile, and the amount of Aa are associated with a higher marginal inflammation.

Salivary carriage of periodontal pathogens in generalized aggressive periodontitis families.

BACKGROUND: Generalized aggressive periodontitis (GAP) is a multifactorial disease that shows a specific microbial profile and a familial aggregation. AIM: This study evaluated the salivary microbial profile of families with a history of GAP and compared them with healthy families. DESIGN: Fifteen families with parents presenting periodontal health and 15 with parents with a history of GAP were selected. Each family had a child aged 6-12 years. Stimulated saliva was collected from all subjects, and Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), and Aggregatibacter actinomycetemcomitans (Aa) amounts were determined. RESULTS: Children of GAP families showed higher detection of Aa (90%) than children of healthy families (45%) (P < 0.05). Parents with GAP showed a Pg salivary concentration statistically higher than that of healthy parents (P < 0.05).Children of GAP families, however, exhibited similar Pg concentration than healthy children (P > 0.05). Tf amounts did not differ either in parents or in children (P > 0.05) The infection risk calculation indicates that children who have one parent who is positive for Aa have 16.3 times (95% CI 3.1-87.2) more risk of being infected with Aa (P < 0.05) than children from an Aa-negative family. CONCLUSION: It may be concluded that children of parents with aggressive periodontitis have higher levels and higher risk of Aa infection.

Disparate effects of sclerostin deletion on alveolar bone and cellular cementum in mice.

BACKGROUND: Cellular cementum (CC) includes cementocytes, cells suspected to regulate CC formation or resorption as osteocytes do in bone. Sclerostin (SOST) is a secreted negative regulator of Wnt/ß-catenin signaling expressed by osteocytes and cementocytes. Osteocyte SOST expression reduces bone formation. We investigated the functional importance of SOST in CC compared with alveolar bone (AB) using a Sost knockout (Sost-/-) mouse model to better understand the role of cementocytes in CC. METHODS: Mandibles and femurs of Sost-/- and wild-type (WT) mice were analyzed at 42 and 120 days postnatal (dpn). Maxillary first molars were bilaterally extracted at 42 dpn and both AB healing (maxillary molar sockets) and CC apposition (mandibular first molars) were examined at 21 days post-procedure. Analyses included micro-computed tomography, histology, and immunohistochemistry. RESULTS: Femur cortical and trabecular bone and mandibular bone volumes were similarly increased in Sost-/- versus WT mice at 42 and/or 120 dpn. In contrast to previous reports, CC was not increased by Sost-/- at either age. We conducted challenge experiments on AB and CC to explore tissue-specific responses. Post-extraction AB healing was improved by Sost deletion. In contrast, experimentally-induced apposition in molars failed to stimulate increased CC formation in Sost-/- versus WT mice. Wnt pathway markers AXIN2 and DKK1, which were increased in Sost-/- versus WT AB osteocytes, were unchanged in cementocytes. CONCLUSIONS: These data indicate CC is less responsive than AB to SOST deletion. Within the study limitations, these results do not support cementocytes as critical for directing increased CC formation. PLAIN LANGUAGE SUMMARY: Sclerostin is a protein known to inhibit bone formation, and removing sclerostin leads to more bone formation. Cementum is the thin layer that covers the surface of the tooth's root. Previous studies suggest that inhibiting sclerostin can similarly increase the amount of cementum. We wanted to compare the response of cementum and bone when sclerostin is absent to understand similarities and differences between these two tissues. In this study, we removed the Sost gene (the gene which produces sclerostin) in mice. We found that mice without sclerostin have more bone in their legs and jaws. Moreover, mice without sclerostin also healed better after tooth removal compared with normal mice. Surprisingly, unlike previous studies, we found that the amount of cementum was not different in mice without sclerostin compared with normal mice. Additionally, we challenged the cementum by taking out the opposing tooth to cause the first mandibular molar to move up by building more cementum. Even with this challenge, we found no difference in the amount of cementum in mice lacking sclerostin compared with normal mice. Therefore, we conclude here that cementum is less sensitive to the absence of sclerostin compared with bone.

Photodynamic therapy in the treatment of class II furcation: a randomized controlled clinical trial.

AIM: To investigate the effect of photodynamic therapy (PDT) as adjunct to mechanical therapy in furcations. MATERIALS AND METHODS: A double-blind, parallel, randomized controlled clinical trial was conducted in subjects presenting class II furcations. The subjects were randomly allocated to a test (PDT; n = 16) or control group (non-activated laser/only photosensitizer; n = 21). At baseline, 3 and 6 months, clinical, microbiological and cytokine pattern evaluation was performed. Clinical attachment level was defined as the primary outcome variable. RESULTS: Clinical parameters improved after both therapies (p < 0.05) with no differences between groups at any time point (p > 0.05). At 6 months, real-time PCR evaluation showed a decrease in Porphyromonas gingivalis and Tannerella forsythia only in the PDT group (p < 0.05) with no inter-group differences. Regarding cytokines, IL-4 and IL-10 levels increased in both groups at 6 months. GM-CSF, IL-8, IL-1ß and IL-6 levels decreased only in the PDT group after 3 months (p < 0.05). At 3 months, inter-group analyses showed that GM-CSF, IFN-γ, IL-6 and IL-8 levels were lower in the PDT group. At 6 months, lower IL-1ß levels were also observed in the PDT group (p < 0.05). CONCLUSION: Photodynamic therapy did not promote clinical benefits for class II furcations; however, advantages in local levels of cytokines and a reduction in periodontopathogens were demonstrated.

Parathyroid hormone (1-34) compensates the negative effect of smoking around implants.

OBJECTIVES: This study aimed to investigate the effect of Recombinant Human Parathyroid Hormone (PTH 1-34) on attenuating the influence of cigarette smoke on bone around titanium implants. MATERIAL AND METHODS: Forty-eight female Wistar rats were used. At the beginning of the study, 15 animals were randomly assigned to Group 1 (control) and received subcutaneous injections of saline solution, three-times/week, after implant placement. The other animals received intermittent cigarette smoke inhalation (CSI), 60 days prior and 60 days after implant placement ( Al 2 O 3 -blasted titanium implants - 4.0 × 2.2 mm). After surgery, these animals were randomly assigned to: Group 2 - subcutaneous injections of saline solution, three-times/week (n = 16) and Group 3 - intermittent doses of PTH (1-34) (40 µg/Kg), three-times/week (n = 17). Animals were sacrificed 60 days after surgery, and degree of bone-to-implant contact (BIC), bone area (BA) within the limits of the threads and proportion of mineralized tissue (PMT) adjacent to the implants (500 µm wide zone) were separately obtained in cortical and cancellous bone. RESULTS: Data analysis confirmed that CSI negatively affects bone around implants, as observed for BIC in cortical zone (Cohen's d (d) = -1.26) and for PMT in both zones (d = -6.09 and d = -4.46 for cortical and cancellous zones, respectively). In addition, in the presence of CSI, PTH (1-34) promoted the highest BIC in both regions and BA and PMT in cancellous bone (P < 0.05). The histometric parameter that was not influenced by both PTH and CSI (1-34) was BA in cortical bone (P > 0.05). CONCLUSION: In the presence of cigarette smoke, a factor related to poor bone healing and low bone density, PTH (1-34) increased bone volume around implants.

One stage, full-mouth, ultrasonic debridement in the treatment of severe chronic periodontitis in smokers: a preliminary, blind and randomized clinical trial.

OBJECTIVE: The aim of this clinical trial was to assess the performance of a full-mouth ultrasonic debridement protocol in the treatment of severe chronic periodontitis in comparison with scaling and root planing in a quadrant-wise procedure in smokers. MATERIALS AND METHODS: The trial consisted of 30 participants presenting with periodontitis divided into 3 groups: Group FMUD - full-mouth ultrasonic debridement, i.e., one session of 45 minutes of ultrasonic instrumentation for smokers (n = 10), Group SRP- scaling and root planing performed in a quadrant-wise manner for smokers (n = 10), and Group Control - SRP for nonsmokers (n = 10), treated following the same protocol as the SRP group. The parameters evaluated were: plaque/bleeding on probing indices, probing pocket depth, relative recession, and relative probing attachment level at baseline, 45, 90 and 180 days after therapy. RESULTS: Full-mouth ultrasonic debridement and scaling and root planing resulted in comparable gain of attachment 6 months after therapy. Both groups exhibited probing pocket depth reduction at all experimental periods as compared to baseline. Smokers, however, had less probing pocket depth reduction and relative probing attachment level gain compared to non-smokers, despite the mechanical protocol used (p < 0.05). Moreover, at 180 days, nonsmokers presented with fewer sites requiring re-treatment (probing pocket depth > 5 mm and bleeding on probing) than smokers (p < 0.05). CONCLUSIONS: Full-mouth ultrasonic debridement and scaling and root planing result in comparable clinical outcomes for the treatment of smokers with severe chronic periodontitis. Despite the non-surgical technique used, smokers had a less favorable clinical response than non-smokers.

Connective tissue graft plus resin-modified glass ionomer restoration for the treatment of gingival recession associated with non-carious cervical lesions: microbiological and immunological results.

OBJECTIVES: It was previously reported the clinical results of placing subgingival resin-modified glass ionomer restoration for treatment of gingival recession associated with non-carious cervical lesions. The aim of this study was to evaluate the influence of this treatment on the subgingival biofilm and gingival crevicular fluid (GCF) inflammatory markers. MATERIALS AND METHODS: Thirty-four patients presenting the combined defect were selected. The defects were treated with either connective tissue graft plus modified glass ionomer restoration (CTG+R) or with connective tissue graft only (CTG). Evaluation included bleeding on probing and probing depth, 5 different bacteria targets in the subgingival plaque assessed at baseline, 45, and 180 days post treatments, and 9 inflammatory mediators were also assessed in the GCF. RESULTS: The levels of each target bacterium were similar during the entire period of evaluation (p > 0.05), both within and between groups. The highest levels among the studied species were observed for the bacterium associated with periodontal health. Additionally, the levels of all cyto/chemokines analyzed were not statistically different between groups (p > 0.05). CONCLUSION: Within the limits of the present study, it can be concluded that the presence of subgingival restoration may not interfere with the subgingival microflora and with GCF inflammatory markers analyzed. CLINICAL RELEVANCE: This approach usually leads to the placement of a subgingival restoration. There is a lack of information about the microbiological and immunological effects of this procedure. The results suggest that this combined approach may be considered as a treatment option for the lesion included in this study.