Protein adsorption/desorption dynamics on Ca-enriched titanium surfaces: biological implications.

Calcium ions are used in the development of biomaterials for the promotion of coagulation, bone regeneration, and implant osseointegration. Upon implantation, the time-dependent release of calcium ions from titanium implant surfaces modifies the physicochemical characteristics at the implant-tissue interface and thus, the biological responses. The aim of this study is to examine how the dynamics of protein adsorption on these surfaces change over time. Titanium discs with and without Ca were incubated with human serum for 2 min, 180 min, and 960 min. The layer of proteins attached to the surface was characterised using nLC-MS/MS. The adsorption kinetics was different between materials, revealing an increased adsorption of proteins associated with coagulation and immune responses prior to Ca release. Implant-blood contact experiments confirmed the strong coagulatory effect for Ca surfaces. We employed primary human alveolar osteoblasts and THP-1 monocytes to study the osteogenic and inflammatory responses. In agreement with the proteomic results, Ca-enriched surfaces showed a significant initial inflammation that disappeared once the calcium was released. The distinct protein adsorption/desorption dynamics found in this work demonstrated to be useful to explain the differential biological responses between the titanium and Ca-ion modified implant surfaces.

Characterization of magnesium doped sol-gel biomaterial for bone tissue regeneration: The effect of Mg ion in protein adsorption.

Magnesium is the fourth most abundant element in the human body with a wide battery of functions in the maintenance of normal cell homeostasis. In the bone, this element incorporates in the hydroxyapatite structure and it takes part in mineral metabolism and regulates osteoclast functions. In this study, sol-gel materials with increasing concentrations of MgCl2 (0.5, 1, and 1.5%) were synthesized and applied onto Ti surfaces as coatings. The materials were first physicochemically characterized. In vitro responses were examined using the MC3T3-E1 osteoblastic cells and RAW264.7 macrophages. Human serum protein adsorption was evaluated employing nLC-MS/MS. The incorporation of Mg did not affect the crosslinking of the sol-gel network, and a controlled release of Mg was observed; it was not cytotoxic at any of the tested concentrations. The cytoskeleton arrangement of MC3T3-E1 cells cultured on the Mg-doped materials changed in comparison with controls; the cells became more elongated, with protruded lamellipodia and increased cell surface. The expression of integrins (ITGA5 and ITGB1) was boosted by Mg-coatings. The ALP activity and expression of TGF-ß, OSX and RUNX2 genes were also increased. In RAW264.7 cells, TNF-α secretion was reduced, while TGF-ß and IL-4 expression rose. These changes correlated with the altered protein adsorption patterns. The Mg-doped coatings showed increased adsorption of anti-inflammatory (CLUS, IC1, CFAH, and VTNC), cell adhesion (DSG1, FILA2, and DESP) and tissue regeneration (VTNC and CYTA) proteins. This integrated approach to biomaterial characterization revealed the potential of Mg in bone tissue regeneration.

Influence of calcium ion-modified implant surfaces in protein adsorption and implant integration.

BACKGROUND: Calcium (Ca) is a well-known element in bone metabolism and blood coagulation. Here, we investigate the link between the protein adsorption pattern and the in vivo responses of surfaces modified with calcium ions (Ca-ion) as compared to standard titanium implant surfaces (control). We used LC-MS/MS to identify the proteins adhered to the surfaces after incubation with human serum and performed bilateral surgeries in the medial section of the femoral condyles of 18 New Zealand white rabbits to test osseointegration at 2 and 8 weeks post-implantation (n=9). RESULTS: Ca-ion surfaces adsorbed 181.42 times more FA10 and 3.85 times less FA12 (p<0.001), which are factors of the common and the intrinsic coagulation pathways respectively. We also detected differences in A1AT, PLMN, FA12, KNG1, HEP2, LYSC, PIP, SAMP, VTNC, SAA4, and CFAH (p<0.01). At 2 and 8 weeks post-implantation, the mean bone implant contact (BIC) with Ca-ion surfaces was respectively 1.52 and 1.25 times higher, and the mean bone volume density (BVD) was respectively 1.35 and 1.13 times higher. Differences were statistically significant for BIC at 2 and 8 weeks and for BVD at 2 weeks (p<0.05). CONCLUSIONS: The strong thrombogenic protein adsorption pattern at Ca-ion surfaces correlated with significantly higher levels of implant osseointegration. More effective implant surfaces combined with smaller implants enable less invasive surgeries, shorter healing times, and overall lower intervention costs, especially in cases of low quantity or quality of bone.

Evaluation of the inflammatory responses to sol-gel coatings with distinct biocompatibility levels.

The immune system plays a crucial role in determining the implantation outcome, and macrophages are in the frontline of the inflammatory processes. Further, cellular oxidative stress resulting from the material recognition can influence how cell responses develop. Considering this, the aim of this study was to study oxidative stress and macrophages phenotypes in response to sol-gel materials with distinct in vivo outcomes. Four materials were selected (70M30T and 35M35G30T, with high biocompatibility, and 50M50G and 50V50G, with low biocompatibility). Gene expression, immunocytochemistry and cytokine secretion profiles for M1 and M2 markers were determined. Moreover, oxidative stress markers were studied. Immunocytochemistry and ELISA showed that 50M50G and 50V50G lead to a higher differentiation to M1 phenotype, while 70M30T and 35M35G30T promoted M2 differentiation. In oxidative stress, no differences were found. These results show that the balance between M1 and M2, more than individual quantification of each phenotype, determines a biomaterial outcome.

A possible use of melatonin in the dental field: Protein adsorption and in vitro cell response on coated titanium.

Melatonin (MLT) is widely known for regulating the circadian cycles and has been studied for its role in bone regeneration and inflammation. Its application as a coating for dental implants can condition the local microenvironment, affecting protein deposition on its surface and the cellular and tissue response. Using sol-gel coatings as a release vehicle for MLT, the aim of this work was to assess the potential of this molecule in improving the osseointegration and inflammatory responses of a titanium substrate. The materials obtained were physicochemically characterized (scanning electron microscopy, contact angle, roughness, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, Si release, MLT liberation, and degradation) and studied in vitro with MC3T3-E1 osteoblastic cells and RAW264.7 macrophage cells. Although MLT application led to an increased gene expression of RUNX2 and BMP2 in 10MTL, it did not improve ALP activity. On the other hand, MLT-enriched sol-gel materials presented potential effects in the adsorption of proteins related to inflammation, coagulation and angiogenesis pathways depending on the dosage used. Using LC-MS/MS, protein adsorption patterns were studied after incubation with human serum. Proteins related to the complement systems (CO7, IC1, CO5, CO8A, and CO9) were less adsorbed in materials with MLT; on the other hand, proteins with functions in the coagulation and angiogenesis pathways, such as A2GL and PLMN, showed a significant adsorption pattern.

Effects of Nd:YAG laser irradiation for minimizing edema and pain after sinus lift surgery: randomized controlled clinical trial.

OBJECTIVE: The aim of the present study was to evaluate the effectiveness of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser used for low-level laser therapy (LLLT) on pain, oral health-related quality of life (OHRQoL), and swelling after sinus lift procedure. MATERIALS AND METHODS: Ten healthy patients, requiring bilateral direct sinus lift surgery, were included in this prospective, randomized study. The treatment sides were randomly assigned to LLLT or control groups. The experimental side received 8 J/cm(2) of energy density, a wavelength of 1064 nm, for 60 sec, and 0.5 W laser immediately after surgery. Swelling, pain perception, and OHRQoL were evaluated at different time intervals. The data were analyzed by the one way ANOVA. RESULTS: Evaluations of postoperative pain, OHRQoL, and swelling were made. We observed that the swelling and the OHRQoL in the Nd:YAG group were significantly improved when compared with the control group on the 3rd day after surgery (p<0.05). The pain levels after surgery was almost the same for both groups, without statistically significant differences (p>0.05). There were no statistically significant differences between groups with regard to any of the parameters evaluated on the 7th day. CONCLUSIONS: The results demonstrate that the 1064 nm Nd:YAG laser was effective in improving OHRQoL and reducing swelling after sinus lift surgery. Within the limitations of this study, we concluded that the 1064 nm Nd:YAG laser has beneficial effects on swelling and OHRQoL, making it suitable for LLLT.

Intrapulpal temperature changes during root surface irradiation with dual-wavelength laser (2780 and 940 nm): in vitro study.

This work reports that the ablation volume and rate of porcine skin changed significantly with the change of skin water content. Under the same laser irradiation conditions (532 nm Nd:YAG laser, pulse width = 11.5 ns, pulse energy = 1.54 J, beam radius = 0.54 mm), the ablation volume dropped by a factor of 4 as the skin water content decreased from 40 wt. % (native) to 19 wt. % with a change in the ablation rate below and above around 25 wt. %. Based on the ablation characteristics observed by in situ shadowgraph images and the calculated tissue temperatures, it is considered that an explosive rupture by rapid volumetric vaporization of water is responsible for the ablation of the high water content of skin, whereas thermal disintegration of directly irradiated surface layer is responsible for the low water content of skin.

Assessment of the soft tissue volumetric changes following acellular dermal matrix grafts with cone beam computerized tomography.

OBJECTIVE: The aim of this study was to use cone beam computerized tomography (CBCT), which consistently allowed the determination of the dimensions of the soft tissue, to evaluate acellular dermal matrix grafts (ADMG) used to increase gingival soft tissue thickness (GSTT). METHOD AND MATERIALS: In total, 90 gingival defects were included in the study. Surgical procedures were performed to augment the gingival tissue with ADMG. While GSTT measurements were assessed at baseline and 6, 12, and 18 months post-surgery, ADMG measurements were performed with CBCT at 6, 12, and 18 months post-surgery. RESULTS: All parameters showed statistically significant differences between time intervals. In the ADMG-treated sites, the baseline GSTT was 1.00 ± 0.37 mm and the final thickness was 1.66 ± 0.34 mm. The 6-month measurement of ADMG was 0.79 ± 0.08 mm, and the final measurement was 0.11 ± 0.09 mm. CONCLUSION: High-quality images of the GSTT and ADMG can be consistently obtained with CBCT. The present findings indicate that soft tissue augmentation can be achieved in gingival defects with the use of ADMG.

Case series of laser-assisted treatment of excessive gingival display: an alternative treatment.

OBJECTIVE: The objective of this study was to investigate the stable and significant outcomes of laser-assisted lip repositioning technique for the treatment of excessive gingival display. BACKGROUND DATA: "Gummy smile" is a major concern for a large number of patients visiting the dentist. The hyperactivity of the upper lip is one of the main causes of a gummy smile, and several techniques have been proposed for its treatment. METHODS: Ten patients with excessive gingival display were treated with laser-assisted lip repositioning technique. The technique is composed of removing a strip of mucosa by laser incisions from the maxillary buccal vestibule, and coronal repositioning of the new mucosal margin. The clinical dimensions of gingival display were measured from the left, right posterior, and anterior sides at baseline, 6 and 12 months postoperatively. Subjects completed surveys to evaluate satisfaction with outcomes. Clinical and patient-centered parameters [visual analog scale for pain and aesthetics (VAS)] were measured at 7 days and again at 12 months after the surgery. RESULTS: The baseline anterior gingival display of 4.3±1.8 mm significantly decreased to 1.1±1.0 mm at 6 months (p<0.0001) and was maintained at 12 months (1.2±1.5 mm). The baseline left, right gingival display (4.9±2.2 mm; 5.0±1.4 mm) significantly decreased (1.2±1.4 mm; 1.3±1.1 mm) at 12 months (p<0.0001). Patients were satisfied with their smile after surgery and would likely choose to undergo the procedure again. CONCLUSIONS: The treatment of gummy smile with laser-assisted lip repositioning successfully reduced the preoperative gingival display without postoperative complications, in all cases.

Laser-assisted laterally positioned flap operation: a randomized controlled clinical trial.

OBJECTIVE: The purpose of this randomized, controlled clinical trial was to compare the effectiveness of a new treatment approach, which consisted of laterally positioned flap (LPF) procedure combined with an external vestibular releasing incision made by a diode laser (LALPF) to LPF alone for the treatment of isolated gingival recession defects. METHODS: Thirty-two healthy patients presenting single Miller class II isolated gingival recessions with minimal loss of interdental papilla were treated with an LPF technique. Sixteen patients were randomly assigned to the test group (laser-assisted laterally positioned flap [LALPF]), and the other 16 patients were assigned to the control group (LPF). In the test group, diode laser was used for vestibular deepening in order to obtain maximum maneuverability of the advanced flap. Clinical and patient-centered parameters (visual analog scale for pain and aesthetics [VAS]) were measured at baseline, 7 days, and 6 months after the surgery. RESULTS: Complete root coverage from baseline to 6 months post-surgery was achieved for 46.7% of the control group and 81.2% of the test group (p=0.044). There were no differences in VAS pain measurements between the groups. Patient satisfaction with aesthetics was higher in LALPF group than in the LPF group. CONCLUSIONS: Six month results showed that the LALPF approach was effective for the treatment of single Miller class II gingival recessions.

Coronally advanced flap adjunct with low intensity laser therapy: a randomized controlled clinical pilot study.

AIM: Coronally advanced flap (CAF) technique and its modifications have been proposed in the literature. Low intensity laser therapy (LILT) is shown to increase wound healing. The aim of this split-mouth randomized controlled pilot study was to assess the effects of LILT with respect to root coverage after CAF procedure for the treatment of multiple-recession type defects (MRTD). MATERIAL AND METHODS: Ten patients with symmetrical 74 Miller I and II gingival recessions were included in this study (37 in test, 37 in control group). A diode laser (588 nm) was applied to test sites before and immediately after surgery, and for 5 min. daily 7 days post-operatively. Comparisons of the surgical sites were made with clinical measurements. RESULTS: Statistically significant differences were observed between test and control sites in the gingival recession depth (GRD), gingival recession width (GRW) and width of the keratinized tissue (WKT) and clinical attachment level (CAL) measurements after 1 year (p = 0.014, p = 0.015, p = 0.009 and p = 0.018 respectively). The test group presented greater complete root coverage (n = 7, 70%) compared with the control group (n = 3, 30%) after treatment. CONCLUSION: Within the limitations of this study, the results indicated that LILT may improve the predictability of CAF in multiple recessions.