Dosage Effects of an 810 nm Diode Laser on the Proliferation and Growth Factor Expression of Human Gingival Fibroblasts.

Introduction: A substantial amount of evidence supports the positive effect of photobiomodulation on the proliferation and differentiation of various cell types. Several laser wavelengths have been used for wound healing improvement, and their actual outcome depends on the settings utilized during irradiation. However, the heterogeneous wavelengths and laser settings applied in the existing literature make it difficult to draw solid conclusions and comparison of different studies. The aim of the present study is to evaluate and compare the effects of various doses of laser energy, provided by an 810 nm diode, on human gingival fibroblasts in terms of proliferation and expression of growth factors with a pivotal role in wound healing. Methods: Human gingival fibroblasts were cultured on plastic tissue culture and irradiated with 2, 4, 6 or 12 J/cm2. The effects of the low-level laser therapy (LLLT) using an 810 nm diode laser on growth factor expression (EGF, TGF and VEGF) were evaluated by qPCR at 72 hours and 7 days after irradiation. Cell proliferation was evaluated at 24, 48 and 72 hours after LLLT using MTT assay. Results: Energy density of 12 J/cm2 provoked irradiated gingival fibroblasts to demonstrate significantly higher proliferation as well as higher gene expression of Col1, VEGF and EGF. LLLT positive effects were obvious up to 7 days post-irradiation. Conclusion: LLLT with 810 nm presents beneficial effects on proliferation, collagen production and growth factor expression in human gingival fibroblast cells. The application of 12 J/cm2 can be suggested as the optimal energy density for the enhancement of the wound healing process.

Low Level Laser Therapy With an 810-nm Diode Laser Affects the Proliferation and Differentiation of Premature Osteoblasts and Human Gingival Fibroblasts In Vitro.

Introduction: Photomodulation is a promising strategy for optimizing tissue healing, but its photomodulatory effects on the synergistic cellular metabolism of gingival and bony tissues remain largely unknown. The aim of the present study was to evaluate the photomodulatory effects of a diode laser (810 nm) on osteoblasts, HGFs and their co-cultures in vitro. Methods: Primary cultures of HGFs, cultures of immature osteoblastic cells (MG63) and their co-cultures were irradiated with a diode laser (810 nm), 15 J/cm2. Cell cultures were examined for cellular proliferation (MTT assay), viability (FDA/PI staining) after 24, 48 and 72 hours and cell differentiation (qPCR of collagen type 1a - COL1a and alkaline phosphatase expressions - ALP) after 7 days. Results: Photomodulation with an 810-nm diode laser increased cell proliferation at all time points. COL1a gene expression increased both in HGF and co-cultures. ALP expression was up-regulated in osteoblastic cultures, but co-cultures with fibroblasts negated this response. Conclusion: The 810-nm diode laser positively affected cell proliferation and viability in all experimental groups. The statistically significant increased COL1a gene expression at 7 days after irradiation both in the irradiated HGF and co-cultures suggests that low-level laser therapy (LLLT) stimulated extracellular matrix (ECM) formation signaling in both cell types.

Immunomodulatory effects of Nd:YAG (1064 nm) and diode laser (810 nm) wavelengths to LPS-challenged human gingival fibroblasts.

OBJECTIVE: Human gingival fibroblasts (hGFs) are involved in inflammatory responses to bacteria by recognizing pathogen-associated molecular patterns. In search of host modulation strategies to increase LPS tolerance, Low level laser therapy (LLLT) has been suggested as an alternative treatment that reduces periodontal tissue inflammation. In this study, we investigate whether 810 nm (diode) and 1064 nm (Nd:YAG) laser wavelengths, modulate pro-inflammatory responses to LPS challenges in hGFs. DESIGN: Primary hGFs were challenged with Porphyromonas gingivalis LPS and irradiated with either Diode (810 nm) or with Nd:YAG (1064 nm) lasers. Cell cultures were examined for cell proliferation by MTT assay and IL-6 and IL-8 expression by qPCR at 24, 48 and 72 h. IL-6 and IL-8 protein levels were detected via ELISA. RESULTS: Naïve hGF populations irradiated with both Diode 810 nm and Nd:YAG 1064 nm lasers demonstrated cellular proliferation (p < 0.05), but LLLT did not affect cellular viability in LPS-challenged cells. IL-6 and IL-8 gene expression levels revealed significant anti-inflammatory effects of irradiation with both examined wavelengths on hGFs challenged with P. gingivalis LPS. Protein levels of these cytokines were increased by LPS challenge. Treatment with LLLT inhibited this increase for both wavelengths evaluated in the study at a statistically significant level particularly for the first 48 h. CONCLUSIONS: The present study demonstrates a modulatory effect of LLLT using both 810 nm diode and Nd:YAG 1064 nm lasers in gingival fibroblasts by decreasing the production of IL-6, IL-8 in response to LPS.

A randomized controlled clinical trial on the effectiveness of three different mouthrinses (chlorhexidine with or without alcohol and C31G), adjunct to periodontal surgery, in early wound healing.

OBJECTIVES: The use of chlorhexidine (CHX) with or without alcohol has been recommended for a number of clinical applications. On the other hand, there is a plethora of widely subscribed antiseptics, such as agent C31G (alkyl dimethyl glycine/alkyl dimethyl amine oxide), which has not yet been evaluated postsurgically. The effectiveness of three different mouthrinses (CHX with and without alcohol, C31G) in plaque control and early wound healing was compared postoperatively. MATERIALS AND METHODS: In this, randomized, double-blind, controlled clinical trial 42 patients were allocated to three groups assigned to 2 weeks rinsing after non-regenerative periodontal flap surgery with or without osseous surgery with C31G (group A), alcohol-free CHX 0.12% (group B) or alcohol-based CHX 0.12% (group C). At days 7 and 14, plaque and early wound healing indices were recorded. At day 14, total bacterial counts were estimated utilizing real-time quantitative polymerase chain reaction (qPCR). Statistics included linear and generalized linear mixed models. RESULTS: At day 7, healing response was not significantly different among groups. At day 14, group A revealed the highest while group C demonstrated the lowest plaque index values (B vs A, odds ratio-OR = 0.18, p = 0.012; C vs A, OR = 0.01, p < 0.001; C vs B, OR = 0.06, p < 0.001). Group C demonstrated the lowest bacterial counts levels at day 14 (38.470 × 106, 48.190 × 106, and 3.020 × 106 for groups A, B, and C, respectively). At day 14, healing was significantly better in group C compared to B (p = 0.007). Group A showed no significant differences compared to other groups. CONCLUSIONS: (1) The presence of alcohol may increase the effectiveness of CHX in early wound healing, (2) C31G might be an alternative solution prescribed during early postoperative period after non-regenerative periodontal flap surgery. CLINICAL RELEVANCE: The present study found that active agent C31G displayed no significant differences to CHX formulations regarding periodontal wound healing improvement and might be used alternatively after non-regenerative periodontal flap surgery. In addition, an alcohol based 0.12% CHX mouthwash was more effective than an alcohol-free 0.12% CHX and C31G mouthrinse on plaque control in the absence of mechanical oral hygiene.

Osteostimulative calcium phosphosilicate biomaterials partially restore the cytocompatibility of decontaminated titanium surfaces in a peri-implantitis model.

Bacterial peri-implant biofilms, and the chemotherapeutics for their removal alter titanium surface cytocompatibility. In this study we aimed to assess the adjunctive use of an osteostimulative biomaterial utilizing a peri-implantitis model under the hypothesis that it will increase cell migration towards treated titanium surfaces. Acid-etched titanium surfaces were inoculated with a multi-species biofilm model and treated with 1.5% NaOCl in a previously characterized in vitro peri-implantitis model. Cell migration of MG63 cells towards the treated titanium surface (CTRL) was significantly reduced following inoculation with biofilm and chemotherapeutic treatment as compared to sterile controls. Addition of a tricalcium phosphate biomaterial (TCP) as a control for Ca+2 had a small non-significant effect, while BG significantly increased MG63 chemotaxis to titanium to levels comparable to sterile (STE). Similarly, cell viability at 5 days was increased in BG and TCP as compared to CTRL. SEM imaging confirmed the improved cytocompatibility of BG and TCP surfaces as compared to CTRL. Osteostimulative BG exhibited a strong chemotactic effect to osteoblasts, which was stronger than what was expected due to the chemotactic effect of Ca+2 alone (TCP). In addition, substantially increased cell attachment and viability was found on treated implant surfaces as compared to CTRL. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2645-2652, 2018.

Nd:YAG laser radiation (1.064 nm) accelerates differentiation of osteoblasts to osteocytes on smooth and rough titanium surfaces in vitro.

BACKGROUND: A number of studies revealed beneficial effects of low-level laser therapy (LLLT) regarding cell proliferation and differentiation. AIM: To investigate the effect of Nd:YAG (1.064 nm) laser radiation in the proliferation and differentiation potential of MG-63 osteoblast-like cells. Additionally, the effects of the surface configurations were to be evaluated. MATERIAL AND METHODS: MG-63 osteoblast cells were cultured on different surfaces: plastic tissue culture, smooth (polished) titanium-PT and rough titanium-SLA. The effects of both titanium surfaces and low-level laser therapy (LLLT) on cell adhesion were evaluated by the gene expression of molecules involved in cell proliferation and differentiation. In addition, scanning electron microscopy (SEM) and MTT proliferation assays were used to examine cell morphology and proliferation, respectively. RESULTS: Compared to smooth (PT) surfaces, SLA surfaces favoured MG-63 cell differentiation. Following the application of Nd:YAG laser irradiation, cells yielded statistically significantly improved differentiation on both smooth and SLA surfaces compared with non-irradiated surfaces. CONCLUSIONS: The findings of this present study suggest that both surface morphology and Nd:YAG laser irradiation influence the proliferation and differentiation potential of MG-63 cells.

Effect of Nd:YAG Low Level Laser Therapy on Human Gingival Fibroblasts.

Aim. To evaluate the effect of Low Level Laser Therapy (LLLT) on human gingival fibroblasts in terms of proliferation and growth factors' secretion (EGF, bFGF, and VEGF). Materials and Methods. Primary cultures of keratinized mucosa fibroblasts were irradiated by a Nd:YAG laser 1064 nm with the following energy densities: 2.6 J/cm(2), 5.3 J/cm(2), 7.9 J/cm(2), and 15.8 J/cm(2). Controls were not irradiated. Cultures were examined for cell proliferation and growth factors' secretion after 24, 48, and 72 hours. All experimental procedures were performed in duplicate. Data were analyzed by Student's t-test (p < 0.05). Results. All laser-irradiation doses applied promoted a higher cell proliferation at 48 hours in a dose-response relationship compared to controls. This difference reached statistical significance for the cultures receiving 15.8 J/cm(2) (p = 0.03). Regarding EGF, all laser irradiation doses applied promoted a higher secretion at 48 hours in a reverse dose-response pattern compared to controls. This difference reached statistical significance for the cultures receiving 2.6 J/cm(2) (p = 0.04). EGF levels at the other time points, bFGF, and VEGF showed a random variation between the groups. Conclusion. Within the limits of this study, LLLT (Nd:YAG) may induce gingival fibroblasts' proliferation and upregulate the secretion of EGF. Further studies are needed to confirm these results.

Oxytalan-positive peripheral ossifying fibromas express runt-related transcription factor 2, bone morphogenetic protein-2, and cementum attachment protein. An immunohistochemical study.

BACKGROUND: The peripheral ossifying fibroma (POF) represents one of the most common lesions of the periodontal tissues that may originate from the gingival soft tissues, the periosteum, or the periodontal ligament. AIM: To investigate the immunohistochemical expression of runt-related transcription factor 2 (Runx-2), bone morphogenetic protein-2 (BMP-2), and cementum attachment protein (CAP) in oxytalan-positive POF, to establish the use of POF as an in vivo model for the study of the periodontal ligament. MATERIALS AND METHODS: Thirty tumors that presented clinical and histologic features of POF, as well as oxytalan fibers, were included in the study. Immunohistochemical expression of Runx-2, BMP-2, and CAP was evaluated by light microscopy. RESULTS: Runx-2, BMP-2, and CAP were abundantly expressed by POFs; 22 of 30 tumors expressed positive staining for Runx-2, twenty-six tumors for BMP-2, and twenty-five tumors for CAP. The expression of Runx-2 was abundant in POFs where bone was histologically present (P = 0.04) and of BMP-2 in POFs where dystrophic calcifications were present (P = 0.03). CONCLUSION: It is suggested that oxytalan-positive POFs, purportedly originating from the periodontal ligament, express molecules that are specific to bone and cementum (Runx-2, BMP-2), or cementum only (CAP). Thus, the cell populations present in the lesion belong to the mineralized-tissue-forming cell lineages, the cementoblastic or osteoblastic lineage.

Effect of non-surgical periodontal therapy on C-reactive protein, oxidative stress, and matrix metalloproteinase (MMP)-9 and MMP-2 levels in patients with type 2 diabetes: a randomized controlled study.

BACKGROUND: It is well accepted that glycemic control in patients with diabetes mellitus (DM) is affected by systemic inflammation and oxidative stress. The effect of periodontal therapy on these systemic factors may be related to improvement on glycemic status. The aim of the present study is to assess over a period of 6 months the effect of non-surgical periodontal therapy on serum levels of high-sensitivity C-reactive protein (hsCRP), d-8-iso prostaglandin F2a (d-8-iso) as a marker of oxidative stress, and matrix metalloproteinase (MMP)-2 and MMP-9 on patients with type 2 DM. METHODS: Sixty participants with type 2 DM and moderate to severe periodontal disease were randomized into intervention (IG) and control (CG) groups. IG received scaling and root planing, whereas CG received supragingival cleaning at baseline and scaling and root planing at 6 months. Participants of both groups were evaluated at baseline and 1, 3, and 6 months. Periodontal data recorded at each visit included probing depth, clinical attachment loss, bleeding on probing, and gingival index. Blood was collected at each visit for the assay of serum glycated hemoglobin A1c (A1c), hsCRP, d-8-iso, MMP-2, and MMP-9. RESULTS: Although there was a trend to a reduction in hsCRP, d-8-iso and MMP-9 it did not reach statistical significance. MMP-2 levels remained unchanged after periodontal treatment. CONCLUSION: Effective non-surgical periodontal treatment of participants with type 2 DM and moderate to severe periodontal disease improved significantly A1c levels but did not result in a statistically significant improvement in hsCRP, d-8-iso, MMP-2, and MMP-9 levels.

Dental terms in Julius Pollux's the Onomasticon.

Julius Pollux's The Onomasticon, a lexicographical work, contains a large number of terms on dental and oral issues; through them, we can see people's perceptions about the dental arches and the oral cavity in the 2nd century CE. The dental arches are presented thoroughly, naming the groups of teeth and presenting their characteristics. Special mention is made of the wisdom teeth. Pollux also gives a brief description of the tooth in general, the alveolar process and the gingiva. He also refers to dental anomalies and diseases.

Attachment and proliferation of human osteoblast-like cells on guided bone regeneration (GBR) membranes in the absence or presence of nicotine: an in vitro study.

PURPOSE: To compare in vitro the attachment and proliferation of human osteoblast-like cells (MG63) on tissue culture plates and guided bone regeneration (GBR) membranes in the absence or presence of nicotine. MATERIALS AND METHODS: Membrane samples were fixed to wells and the cell number (CN) was counted after 24 hours (attachment assay) or 5 days (proliferation assay). The ratio of cell count (RCC) (CN at 5 days/CN at 24 hours) was calculated. The study had three parts: First, five different resorbable GBR membranes were compared (Resolut Adapt LT [RALT], Biocollagen [BC], Bio-Gide [BG], OsseoGuard [OG], and Demokritos Human Tissue Bank [DEM]). Next, cells were cultured on tissue culture plates with five different concentrations of nicotine. Finally, cells were cultured on the membrane that had demonstrated the highest RCC and CN in part 1 with four different concentrations of nicotine. RESULTS: At 24 hours, BG showed the highest CN and OG showed the lowest CN. At 5 days, BG showed the highest CN. The order of RCC was BG > OG > DEM > RALT ~ BC. At 24 hours, lower nicotine concentrations (0.3 and 3 µg/mL) showed higher CNs versus the control, whereas CNs for high nicotine concentrations (30 and 300 µg/mL) were lower than for the control. CN at 5 days and RCC were lowest with 300 µg/mL nicotine. At 24 hours and 5 days, all differences among wells with membrane were statistically insignificant. Nevertheless, CN at 5 days and RCC were highest with the lowest nicotine concentration (3 µg/mL) and lowest with high concentrations. CONCLUSIONS: Membrane materials influence attachment and proliferation of bone cells and, therefore, could affect the outcomes of GBR. On both tissue culture plates and membranes, there is a tendency toward a biphasic effect of nicotine, with stimulatory effects at low concentrations and inhibitory effects at high concentrations.

A randomized, controlled trial on the effect of non-surgical periodontal therapy in patients with type 2 diabetes. Part I: effect on periodontal status and glycaemic control.

AIM: the purpose of the present study was to assess the effect of non-surgical periodontal therapy on glycaemic control of type 2 diabetes patients with moderate-to-severe periodontitis. MATERIALS AND METHODS: this was a randomized, controlled clinical trial of patients with type 2 diabetes. A total of 60 patients with moderate-to-severe periodontal disease were assigned to either a periodontal treatment arm, consisting of scaling and root planing (intervention group [IG]), or a delayed treatment arm that received periodontal care after 6 months (control group [CG]). Periodontal parameters and glycosylated haemoglobin (A1C) were evaluated at 1, 3 and 6 months. RESULTS: all periodontal parameters improved significantly in the IG. A1C levels decreased statistically significantly more in the IG versus the CG (0.72%versus 0.13%; p<0.01) independently of other confounders. CONCLUSIONS: this study provides evidence that periodontal treatment contributes to improved glycaemic control in type 2 diabetes mellitus patients. Larger controlled trials are needed to confirm if this finding is generalizable to other populations of patients with type 2 diabetes.

RANKL and OPG mRNA level after non-surgical periodontal treatment.

Recent research evidence shows that the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) play an important role in osteoclastogenesis and the inflammatory bone loss during periodontitis. Bone remodeling process is dependent on the balance of these two proteins while a high ratio of RANKL/OPG characterizes the increased osteolytic process and it has been reported in inflammatory diseases including the periodontal disease. The purpose of this study was to determine the OPG and RANKL mRNA levels in periodontal tissues derived from patients with advanced chronic periodontitis after non-surgical periodontal therapy (SRP) and to compare the RANKL/OPG ration with that in healthy persons. Gingival biopsies were obtained from subjects with clinically healthy periodontium (H) (N = 11) and patients with advanced chronic periodontitis (CP) (N = 14). Total RNA was isolated from the gingival samples and 1 microg RNA was reverse transcribed to cDNA, followed by polymerase chain reaction (PCR) using specific primers for OPG and RANKL. The efficiency of reverse transcription was verified by the amplification of the GAPDH gene. The intensity of RT-PCR products was analyzed by a densitometer and was normalized to the intensity of the band for the housekeeping gene GAPDH. Immunohistochemical evaluation of the RANKL and OPG expression was also performed. The expression of RANKL as well as of OPG was reduced in CP specimens in comparison to that of healthy persons in a statistical significant way. However, the RANKL/OPG ratio showed to be slightly elevated in CP compared to H specimens but this finding was not of statistical significance. The immunohistochemical analysis revealed a non-uniform expression pattern for both proteins. Although further investigation is needed to identify the specific role of RANKL and OPG protein in periodontitis progression, our data after SRP might indicate the possible involvement of these proteins in the activation of pathways, which regulate the repair of the periodontal tissues.

Platelet-rich plasma effect on periodontally affected human gingival fibroblasts: an in vitro study.

OBJECTIVE: The purpose of this study was to evaluate the gingival fibroblast proliferative response derived from patients with chronic and aggressive periodontitis to homologous platelet-rich plasma (PRP). MATERIALS AND METHODS: Gingival fibroblasts derived from nine patients with chronic periodontitis, aggressive periodontitis and healthy periodontium were grown. Medium was replaced with DMEM containing 0.5% FBS in which cells remained for two days. Cells were incubated and cultured with medium containing 50 microl/ml homologous platelet-rich plasma (PRP) or not containing PRP (control) for 24 and 48 hours. PRP originated from three donors. Cell proliferation effect was evaluated at 24 and 48 hours. Cell viability was assessed with a hemocytometer. Viable cells were counted under a phase contrast microscope. RESULTS: The results revealed that incubation of human gingival fibroblasts, derived from healthy and intact periodontium, chronic periodontitis and aggressive periodontitis, in culture medium containing homologous PRP statistically significantly increased the cell proliferation at 24 and 48 hours of culture. CONCLUSION: The addition of PRP to human gingival fibroblast cultures significantly increased the proliferative response, irrespective of the presence of periodontitis, type of periodontitis and PRP donor.

Periodontitis associated with Hajdu-Cheney syndrome.

BACKGROUND: Hajdu-Cheney syndrome (HCS) is an inheritable, rare disorder of bone metabolism, associated with acro-osteolysis of the distal phalanges, short stature, distinctive craniofacial and skull changes, premature tooth loss, and periodontitis. This report focuses on the periodontal manifestations of HCS. METHODS: A 22-year-old female presented with the characteristic clinical features of HCS, including short stature, small face, prominent epicanthal folds, thin lips, small mouth, and short hands. There were no abnormal biochemical, hematological, or hormonal data. Tests for bone mineral density were indicative of osteoporosis. Cephalometric analysis revealed hypoplasia of the midface and increased cranial base angle; the maxilla and the mandible were set posteriorly. The sella turcica was enlarged, elongated, and wide open with slender clinoids. Hair samples were examined by scanning electron microscopy, and tooth cementum and dentin were evaluated histologically. RESULTS: According to the periodontal evaluation, gingival inflammation was 12.5%, bleeding on probing score was 24%, probing depths averaged 4 to 6 mm, and clinical attachment loss averaged 3 to 6 mm. Class II furcations were found on three teeth. Almost all teeth exhibited pathological mobility of varying degrees. There was a generalized, horizontal bone loss of approximately 50%. Three teeth had to be extracted because of severe localized periodontal destruction. Histologic examination of the dentin and the cementum was normal. CONCLUSIONS: HCS periodontitis is associated with an unpredictable and uneven, rapid rate of periodontal destruction of unknown etiology. Further research is required to identify the role of the possible pathogenic factors involved.

Time- and dose-dependent mitogenic effect of basic fibroblast growth factor combined with different bone graft materials: an in vitro study.

OBJECTIVES: In periodontal regeneration, the growth factor concentrations and the delivery system used are of great importance. In an attempt to assess the mitogenic effect of basic fibroblast growth factor (bFGF) on periodontal ligament (PDL) cells combined with different bone replacement materials, two allografts of cortical (DFDBA) and cancellous (DFBA) bone and an anorganic bovine material with a synthetic peptide (ABM P-15) were used. The purpose of this study was to evaluate the in vitro mitogenic effect of different doses of bFGF alone or in combination with DFDBA, DFBA and ABM P-15 on human PDL cells in a time-dependent mode. MATERIAL AND METHODS: PDL cell cultures were derived from the mid-root of four maxillary premolars. Cells were grown and reached confluence. On day 2 of quiescence, new medium was added along with (1) 1, 5, 10 and 25 ng/ml of bFGF alone, (2) 10 mg of DFDBA, DFBA and ABM P-15 alone and (3) their combination. The mitogenic effect was determined at 24 and 48 h of culture by using a hemocytometer chamber. The cells were counted under a phase contrast microscope. RESULTS: The results revealed that bFGF at the highest concentrations and after 48 h exerted a significant mitogenic effect on PDL cells, and also DFDBA and DFBA supported cell proliferation. Furthermore, DFDBA and DFBA enriched with bFGF had a significant mitogenic effect after 48 h of culture. ABM P-15 with 10 and 25 ng/ml of bFGF up-regulated PDL cell proliferation after 48 h of incubation. CONCLUSIONS: The findings of this study demonstrate the beneficial role of bFGF combined with DFDBA and DFBA as carriers in periodontal repair.