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Poor bonding between bone tissue and noble titanium (Ti) surfaces is one of the major problems that should be resolved. Given that SiO2 is a documented differentiation promoter and polydopamine (PDA) is an adhesive molecule, it is worthwhile to investigate the synergetic performance of novel silica/polydopamine (SiO2/PDA) hybrid coatings on Ti substrates. The physicochemical properties of PDA, 2SiPDA, 10SiPDA, and 20SiPDA coatings including the microstructure, bond strength and corrosion resistance, and in vitro antibacterial activity against P. aeruginosa and S. aureus were examined. In addition, the osteogenesis level of MG63 human osteoblast-like cells on the coatings was detected. The experimental results indicated that the precipitated SiO2 particles were within the PDA layer with sub-micro-scale thickness. The hybrid coating (20SiPDA) containing an appropriate amount of SiO2 did not adversely affect shear bond strength compared with the Ti control and pure PDA coating. The SiO2/PDA coatings could effectively enhance the corrosion resistant ability of Ti implants. The 20SiPDA coatings elicited higher mortality rates of bacterial strains compared with the Ti control and pure PDA coating. More importantly, the incorporation of SiO2 in the PDA coating layer could improve adhesion, proliferation, differentiation, and mineralization of MG63 osteoblasts. The new SiO2/PDA coating may be suitable for serving as a decorated layer to improve osteogenesis of Ti implants. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the responses of the human osteosarcoma cell line MG63 to calcium silicate cements with different Si/Ca molar ratios and different surface roughness. In particular, the study evaluated integrin subunit levels, phosphor-focal adhesion kinase ( pFAK) levels and protein production at the cell attachment stage. The results indicated that the surface roughness (variations within a factor of 10) of the cements did not play a prominent role in cell attachment and proliferation, but the effect of composition was highlighted. Increased pFAK and total integrin levels and promoted cell attachment and cell cycle progression were observed upon an increase in cement Si content. Cement with a higher Si content was beneficial for collagen Type I ( COL I) adsorption, COL I secretion, and αlibβ3 subintegrin expression, whereas cement with a higher Ca content increased fibronectin ( FN) adsorption, FN secretion, and enhanced αvβ1 subintegrin levels. These results establish composition-dependent differences in integrin binding as a mechanism regulating cellular responses to biomaterial surfaces. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 769-780, 2014. [ABSTRACT FROM AUTHOR]

Calcium silicate cement (CSC) has favorable biocompatible properties that may support its clinical use as bone defect repair. A hybrid cement was developed consisting of a chitosan oligosaccharide (COS) solution in a liquid phase and gelatin (GLT)‐containing calcium silicate powder in a solid phase. The combination of GLT and COS was chosen due to the benefits achieved from several synergistic effects and for their clinical applications. In this study, the in vitro physicochemical properties of CSC‐GLT‐COS hybrid cement were investigated. The results indicated that all cement specimens formed apatite spherulites in simulated body fluid (SBF) for as little as 1 h. After immersion in a Tris‐HCl solution, a pore structure appeared on all specimen surfaces without any precipitation. The presence of GLT did not adversely affect the physiochemical properties of CSC, even after 30 days of immersion. In contrast, COS could promote the degradation of CSC, as evidenced in the results of mechanical strength, weight loss, and ion concentration. The in vitro physiochemical properties of the hybrid cement makes it an attractive choice for dental and orthopedic applications. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010. [ABSTRACT FROM AUTHOR]

A series of biodegradable poly (butylene succinate-co-terephthalate) (PBST) with different aromatic units content was synthesized and then melt blended by adding cellulose nanocrystals (CNCs) to manufacture the full organic composites. A network-like structure of CNCs in PBST matrix was evaluated by rheometer. The storage modulus and complex viscosity at low frequency region were significantly enhanced with increasing CNC content. Meanwhile, the decreasing tan δ and flow index were attributed to the excellent interaction between PBST and CNCs. When PBST has a content of the aromatic unit exceeds 30 mol%, the crystallization temperatures increased with increasing CNC contents. On the other hand, when PBST has 30 mol% content of the aromatic unit, the cold crystallization temperatures decreased with increasing CNC contents. These above observation in crystallization properties suggested that the CNC make a role of heterogeneous nucleation in PBST matrix. The result of mechanical properties evaluated by dynamic mechanical analysis showed a good reinforcement effect of the addition of stiff CNC. The PBST/CNC composites were suitable for cell growth and might have a potential as biomedical materials, which is confirmed by MTT assay. Image 1 • A natural organic reinforcing material was used to enhance the physical properties of PBST. • The storage modulus and complex viscosity were significantly enhanced with increasing CNC content. • The PBST/CNC composites might have a potential use in biomedical applications. [ABSTRACT FROM AUTHOR]

Poor osseointegration and implant-associated infection of titanium implants have prompted their urgent development. Strontium (Sr) is widely recognized to promote osteoblast differentiation and inhibit osteoclast growth. To this end, this study aimed to develop a Sr-containing polydopamine (PDA)-coated implant with practical antibacterial ability and excellent osseointegration ability to meet clinical applications. This hybrid coating used PDA as an adhesion layer and a carrier for Sr ions. The effects of Sr contents on shear bond strength, in vitro stability, antibacterial ability, and in vitro osteogenic activity of the implant were evaluated. The Sr-doped PDA surface was soaked in simulated body fluid (SBF) at pH 7.4 or 5.0 for a long time (up to 90 days) to evaluate the in vitro stability. The antimicrobial ability of the hybrid coating against E. coli and S. aureus was examined, while its cellular function was assessed using RAW 264.7 and MG63 cells. The current phase and chemical composition results indicated the presence of Sr ions on the surface of PDA. When Sr was added to PDA, the initial shear strength values were comparable to those of the PDA coating. Soaking time reduced the strength values of Sr-containing coatings, especially for 90 days. However, Sr coating significantly reduced the growth of the two bacteria in a dose-dependent manner. Likewise, Sr coating had a significant dose-dependent inhibitory effect on the development of RAW 264.7 cells but improved MG63 osteogenesis. In conclusion, 40 % Sr-containing PDA hybrid coating on titanium implants may be a potential implant in terms of in vitro stability, antibacterial ability, and osteogenic activity. • Sr was incorporated into PDA coating on Ti surfaces. • Sr hybrid coatings reduced significantly bacterial growth. • Sr hybrid coatings reduced macrophage growth but enhanced MG63 osteogenesis. • The hybrid coating containing 40 % Sr on Ti may be a potential implant. [ABSTRACT FROM AUTHOR]

Abstract Titanium and its alloys have been used as implant materials. Non-ideal osseointegration of the implant materials has facilitated the development of the bioactive coatings on the implant surfaces. In this work, the bioactive calcium silicate (CaSi) powder prepared in a green synthesis route was used to cover the surface of Ti implants by a facile electrospray deposition method. Post annealing in air was also applied to form the oxidation layer on the Ti surface with the aim of increasing the bond strength between the CaSi coating layer and Ti substrate. For the characterization of the coatings several analytical methods such as X-ray diffraction, scanning electron microscopy, secondary neutral mass spectrometry, and Raman-spectroscopy were used, in addition to the measurement of bond strength and corrosion resistance. The results indicated a uniform CaSi layer with a thickness of about 1 μm deposited on the Ti substrate. Annealing in the range of 700–900 °C in air resulted in the formation of rutile phase of TiO 2 ; more importantly, annealing at 800 °C did not significantly affect the composition of the CaSi layer consisting of β-Ca 2 SiO 4. The bond strength between the coating layer and Ti substrate can be remarkably enhanced at an annealing temperature of 700 or 800 °C compared with the as-prepared coating without annealing. The annealed coatings had a better corrosion resistance than the as-prepared coating. It is concluded that the electrospray method associated with the post-annealing can be successfully used for the deposition of a CaSi layer with a defined structure and composition on titanium implants. Highlights • It is the first time to coat a homogeneous calcium silicate layer on the Ti substrate by a facile electrospray deposition. • Annealing in the range of 700−800 °C maintained the composition of the CaSi material. • The annealing at 800 °C achieved the significantly higher bond strength compared to the as-prepared coating. • The 800 °C-annealed coating had the enhanced corrosion-resistant ability. [ABSTRACT FROM AUTHOR]

Abstract Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si 3 N 4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P < 0.05) increased with the increasing soaking time. When zirconia was treated for 10 days, the shear bond strength value of 27.4 MPa was significantly (P < 0.05) higher than the control (18.6 MPa), associated with greater remaining amounts of veneering ceramics on the zirconia surface. The failure mode of the treated zirconia was almost the mixed failure. On the basis of the data, surface modification using Si 3 N 4 in NaOH solution for zirconia core could be a simple and effective method for enhancing the veneering ceramic–zirconia bonding. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the physicochemical properties and the in vitro and in vivo osteogenesis of the newly developed calcium silicate containing 5 wt% gelatin (CSG) cement compared with calcium silicate (CS) and calcium sulfate hemihydrate (CSH) cements. In addition to the phase composition and microstructure, washout resistance, setting time, and diametral tensile strength of the bone cements were also performed. In vitro examination of cell growth, differentiation, and mineralization were performed with macrophage cell line (RAW 264.7), MG63 human osteoblast-like cells, and human mesenchymal stem cells (hMSCs). The mini-pig model with mandibular alveolar bone defect was used to assess the in vivo function of cement. Histological and histomorphometric assessments were performed at 6 and 12 weeks after implantation. The results indicated that the CS and CSG powders were mainly composed of poorly crystalline β-dicalcium silicate, and the irregular CSH powders had a highly crystalline phase. After setting, the product of CS and CSG was calcium-silicate-hydrate gel and CSH exhibited a plate-like gypsum crystal structure. The setting time of CS, CSG, and CSH was 19, 35, and 10 min, respectively. Gelatin effectively improved the washout resistance and diametral tensile strength of CS from 2.4 MPa to 3.4 MPa, while CSH had no washout resistance and its strength was 7.6 MPa. The osteogenic activity of MG63 and hMSC cells on the CSG cement surface was consistently shown to be significantly higher than that on the CSH cement surface. Interestingly, CS and CSG cements exhibited lower macrophage expression compared to CSH cements. Twelve week after implantation, the amount of new bone in the defect area of the CS group was slightly higher than that of the CSG and CSH groups. It is concluded that CSG cement had improved anti-washout performance, favorable osteogenesis in vitro and in vivo, which was beneficial for clinical application. Unlabelled Image • It is the first work on in vitro and in vivo osteogenesis of gelatin/CaSi cement. • Gelatin/CaSi cement supported osteoblast differentiation and inhibited the osteoclast growth. • Gelatin/CaSi cement was degradable and osteogenic in a mini-pig model. • Gelatin/CaSi cement is a promising bone graft material for bone repair and regeneration. [ABSTRACT FROM AUTHOR]

Calcium silicate cement has attracted much attention for bone defect repair and regeneration due to its osteogenic properties. Biomaterial-associated infections and washout have become a common clinical problem. In order to enhance the antibacterial and washout performance of calcium silicate cement to meet clinical needs, different types of chitosan, including chitosan polysaccharide (CTS), quaternary ammonium chitosan (QTS), and chitosan oligosaccharide (COS), as a liquid phase were added to the calcium silicate powder. The physicochemical properties, in vitro bioactivity, antibacterial efficacy, and osteogenic effects (MG63 cells) of the cement were evaluated. Antibacterial activity was conducted with Gram-negative Escherichia coli (E. coli) and a Gram-positive Staphylococcus aureus (S. aureus) bacteria. The amount of intracellular reactive oxygen species (ROS) produced in the bacteria cultured with the chitosan solution was also detected. The experimental results showed that the chitosan additive did not affect the crystalline phase of calcium silicate cement, but increased the setting time and strength of the cement in a concentration-dependent manner. Within the scope of this study, CTS and QTS solutions with a concentration of not <1 wt% improved the washout resistance of the control cement, while the COS solutions failed to strengthen the cement. When soaked in simulated body fluid (SBF) for 1 day, all cement samples formed apatite spherules. As the soaking time increased, the diametral tensile strength of all cements decreased and the porosity increased. The assays of MG63 cell function showed lower osteogenic activity of osteoblastic cells grown on the surfaces of the chitosan-incorporated cements in comparison with the control cement without chitosan. At the same 1% concentration, compared with QTS and COS cement, CTS cement had lower cell attachment, proliferation, differentiation, and mineralization. Conversely, the CTS cement resulted in the highest bacteriostasis ratio among the three hybrid cements against two bacteria. The ROS production followed the order of CTS > QTS > COS at the same 1% concentration. In conclusion, calcium silicate cement with 1% QTS may be a viable candidate for bone defect repair in view of anti-washout performance, setting time, antibacterial activity, and osteogenic activity shown in this study. • It is the first work to systematically explore chitosan/calcium silicate hybrid cements. • CTS and QTS solutions with a concentration of ≥1 wt% improved washout resistance of the CaSi cement. • Chitosan efficiently inhibited the bacterial growth in a dose-dependent fashion. • CaSi cement with 1% QTS may be a good candidate for repairing bone defects. [ABSTRACT FROM AUTHOR]

There is a great need to develop new approaches for preventing bacterial adhesion and promoting cell growth on the surface of Ti implants. To this end, various metal ions (Ag+, Cu2+, Sr2+ or Zn2+) were sprayed onto the surface of the PDA (polydopamine)-immobilized Ti. The antibacterial activity of metal ion coatings against Gram-negative E. coli and Gram-positive S. aureus were examined. The content of reactive oxygen species (ROS) production from the metal ions in bacteria was also determined. L929, RAW 264.7 and human mesenchymal stem cells (hMSCs) were used to analyze biological function of the coatings. The results of phase composition and microstructure showed that metal ions were successfully coated on PDA-immobilized Ti surface. Three divalent metal ion coatings effectively inhibited bacterial growth in a concentration-dependent manner. Samples of Cu, Sr and Zn ions in E. coli and S. aureus produced 3–8 times more ROS than the negative control. The presence of Cu and Ag remarkably reduced the cell function, as evidenced by poor cell viability and differentiation. In contrast, high content of Sr promoted hMSC proliferation and differentiation. It is eventually concluded that, taking antibacterial ability and osteogenic activity into account, 10% Sr-coated Ti had potential for implant applications. • Cu, Zn or Sr was incorporated into PDA-coated Ti surfaces. • Cu-, Sr- or Zn-incorporated PDA coatings were highly effective in inhibiting bacterial adhesion. • 10% Sr-coated Ti implants exhibited excellent antibacterial ability and osteogenic activity. [ABSTRACT FROM AUTHOR]

Calcium silicate (CaSi) bone cement with antibacterial and osteogenic properties has attracted significant interest. However, there is a need to develop a variety of new premixed bone cement to meet the clinical requirements of fast setting time, ease of handling, and efficient antibacterial properties. In this study, different volume ratios of polyethylene glycol (PEG) and lactic acid liquids were added to calcium silicate, and the effects of varying liquid-to-powder ratios (L/P) were examined. This study assessed the physicochemical properties, cytotoxicity, and antibacterial activity against S. aureus and E. coli of this premixed cement. The results from the experiments indicated that lactic acid significantly reduced the setting time of the CaSi-based cement and enhanced its mechanical strength. Furthermore, the appropriate concentration of lactic acid and matching L/P ratio improved its washout resistance. The cell viability of all premixed cement was found to be over 80%. The premixed cement containing PEG and lactic acid exhibited superior antibacterial properties compared to the CaSi control. Based on its setting time, washout resistance, and antibacterial activity, a premixed cement with a liquid phase of 80% PEG and 20% lactic acid at an L/P ratio of 0.4 appeared promising for use in dental and orthopedic practice.

Background/purpose: Bacteria-associated oral diseases such as dental caries and periodontitis are widespread epidemics that cause oral pain and loss of function. The purpose of this study was to evaluate the in vitro cytotoxicity and antibacterial activity of different concentrations of hypochlorous acid (HOCl)., Materials and Methods: Five different concentrations (100, 200, 300, 400, and 500 ppm) of HOCl were evaluated for their antimicrobial efficacy against Gram-negative ( A. actinomycetcmcomitans and P. gingivalis ) and Gram-positive bacteria ( S. mutans and S. sanguinis ) after treatment for 1 and 10 min. Sodium hypochlorite (NaOCl) and chlorhexidine (CHX) were used as positive controls. In addition, HOCl was examined for L929 cytotoxicity and RAW 264.7 growth., Results: The bacteriostatic ratio of NaOCl was comparable to that of CHX and significantly ( P  < 0.05) higher than that of all HOCl solutions. Higher HOCl concentration had significantly ( P  < 0.05) higher antibacterial effect, and the bacteriostatic ratio of 10 min treatment was slightly higher than that of 1 min treatment. CHX and NaOCl seeded into L929 cells resulted in low cell viability with only 30-39%, much significantly ( P  < 0.05) lower than all HOCl groups (greater than 80%). All HOCl solutions met the recommendations of ISO 10993-5 and showed no cytotoxicity, although there was a concentration-dependent decrease in cell viability. All antimicrobial agents showed the same trend of response to RAW 264.7 as L929., Conclusion: Within the limit of this study, 400 ppm HOCl disinfectant may be a potential antimicrobial candidate for mouthwash, endodontic irrigants, and periodontitis treatment., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2023 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Oral infection is a common clinical symptom. While antibiotics are widely employed as the primary treatment for oral diseases, the emergence of drug-resistant bacteria has necessitated the exploration of alternative therapeutic approaches. One such modality is antimicrobial photodynamic therapy (aPDT), which utilizes light and photosensitizers. Indeed, aPDT has been used alone or in combination with other treatment options dealing with periodontal disease for the elimination of biofilms from bacterial community to achieve bone formation and/or tissue regeneration. In this review article, in addition to factors affecting the efficacy of aPDT, various photosensitizers, the latest technology and perspectives on aPDT are discussed in detail. More importantly, the article emphasizes the novel design and clinical applications of photosensitizers, as well as the synergistic effects of chemical and biomolecules with aPDT to achieve the complete eradication of biofilms and even enhance the biological performance of tissues surrounding the treated oral area., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2023 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

A variety of implant placement and loading protocols are identified, ranging from immediate implant placement on the day of extraction to delayed placement for at least 6 months after complete healing. The method of assessment of implant placement and loading plays an important role in the implantation. The expected clinical outcomes depend largely on multiple factors, such as the macroscopic design of the implant, surgical technique, and the quality and quantity of local bone in contact with the implant, which would be described in detail. The purpose of this literature review was to explore the relationship between the factors influencing the implant placement stability and implant design. By understanding the original appearance of implant design and the stability requirements of implant placement, it is hoped that more research in the future can meet the needs of dentists and patients., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2023 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Background/purpose: Bridge stability under loading was influenced by bridge span with the connector and implant abutment design. Thus, the purpose of this study was to evaluate the effects of rigid and non-rigid connector designs and pontic connections of different abutment systems in the tooth-implant supported prosthesis (TISP) at different span distances on the biomechanical stress distribution of the overall system components., Materials and Methods: For comparative analysis, rigid and non-rigid bridge connections were fitted with three implant abutment systems (one-piece, two-piece and three-piece), and five implant-to-natural tooth distance configurations (12 mm, 14 mm, 16 mm, 18 mm, and 20 mm) were provided., Results: The maximum stress between TISP components occurred at the distal side of crown margin of cement1 in rigid connector with one-piece group and the bottom of the crown3 in non-rigid connector with one-piece group, while the other groups were more concentrated at the junction between the mesial side of the implant collar and the abutment. In addition, neither the rigid nor non-rigid connector model showed that stress distribution increased proportionally with the bridge span distance., Conclusion: It was clinically recommended that if the implant with a shorter bridge distance of 12 mm from the natural tooth, the rigid connection of the three-piece abutment can be used as the TISP design. If the bridge distance was 18 mm longer, the non-rigid connection of the three-piece abutment could maintain the physiological movement of the natural tooth and avoid the excessive stress on the bone crest around the implant., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2022 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Background/purpose: The bond strength and durability of highly translucent zirconia ceramics to dentin is still unclear. The purpose of this study was to investigate the effect of various surface treatments on the bond strength of self-adhesive resin cements to high-translucent zirconia crowns and dentin., Materials and Methods: A high-transparent zirconia and three self-adhesive resin cements (G-CEM LinkAce (GCL), RelyX U200 (RXU) and TotalCem (TTC)) were used. The zirconia surface was sandblasted with 50 μm alumina particles or coated with an SR Link primer, while a dentin primer (Tetric N-Bond Universal, TBU) was applied to the surface of the dentin. By using three self-adhesive resin cements, zirconia samples were bonded to the dentin surfaces of human teeth. The shear strength of the specimens was measured before and after 10,000-cycle thermocycling or 90-day aging., Results: When using GCL to bond with the untreated dentin and various zirconia surfaces, the shear bond strength of the sandblasted (Z SB ) and RS Link primer-coated (Z LK ) groups was significantly higher than that of the untreated control group (Zc). However, in the case of TBU-treated dentin, the shear strength of the Z SB + LK  + D TBU group was significantly higher than that of the other groups. After thermocycling and aging, the shear strength of the Z SB + LK  + D TBU group using GCL and RXU cements decreased slightly, while the TTC showed no impact., Conclusion: The zirconia surface pretreated by sandblasting and bonding agent, which was sequentially bonded with a primer-treated dentin by using resin cements, can provide excellent shear bond strength and anti-aging performance., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Background/purpose: The design of the connectors and implant abutments could affect the stress distribution of the tooth-implant supported prosthesis (TISP) entire system after loading. Therefore, the purpose of this study was to investigate the stress distribution of the TISP in different connectors and different implant abutments after loading., Materials and Methods: The TISP design used in this study was divided into six models. R1, R2 and R3 represented the tooth and the one-piece, two-piece and three-piece abutment implant system connected by a rigid connector, respectively, while NR1, NR2 and NR3 were the corresponding tooth-abutment implant systems connected by a non-rigid connector. A vertical occlusal load of 50 N was applied at a right angle on the 6 occlusal points of the occlusal surface., Results: As a result, regarding the maximum average stress distribution, R1 and NR1 appeared on the implant fixture, and the other four models were on the implant abutment. On the other hand, regardless of the abutment implant system, the maximum von Mises stress generated by the rigid connector was greater than the corresponding non-rigid connector in the cortical bone around implant. In addition, the three-piece abutment implant system had lower von Mises stress than the one-piece and two-piece implant systems in the cortical bone., Conclusion: It is concluded that by adding a flexible non-rigid connector and three-piece abutment device design to TISP, the occlusal load of the implant was dispersed, and the stress could be gradually introduced into the relatively strong implant abutment., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Background/purpose: The three-unit bridge that combines a natural tooth and an implant provides extended treatment possibilities for partially edentulous patients. We conducted a systematic review and meta-analysis of clinical trials to evaluate three-unit porcelain-fused-to-metal (PFM) tooth-implant-supported prosthesis (TISP) compared with implant-supported-prosthesis (ISP) reconstruction outcomes and complications., Materials and Methods: The PubMed, Embase, and Cochrane library databases were searched for articles published before February 2021. The meta-analysis used a random-effects model to calculate overall effect size. The study was registered with PROSPERO (number: CRD 42021232606)., Results: Seven articles published between 2004 and 2015, with sample sizes ranging from 10 to 250 patients were included. No significant difference in the prosthesis failure rate, implant failure rate, prosthesis technical complication rate, implant technical complication rate, and marginal bone level change was observed between the TISP group and the ISP group. In TISP group, natural tooth failure rate was reported to range from 0% to 4.3%, biological complication related to the natural tooth was reported to range from 0% to 26.9%, and no trial reported natural tooth intrusion., Conclusion: The three-unit short-span TISP is a potentially reliable treatment option for patients with missing posterior teeth., (© 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

Poor bonding between bone tissue and noble titanium (Ti) surfaces is one of the major problems that should be resolved. Given that SiO 2 is a documented differentiation promoter and polydopamine (PDA) is an adhesive molecule, it is worthwhile to investigate the synergetic performance of novel silica/polydopamine (SiO 2 /PDA) hybrid coatings on Ti substrates. The physicochemical properties of PDA, 2SiPDA, 10SiPDA, and 20SiPDA coatings including the microstructure, bond strength and corrosion resistance, and in vitro antibacterial activity against P. aeruginosa and S. aureus were examined. In addition, the osteogenesis level of MG63 human osteoblast-like cells on the coatings was detected. The experimental results indicated that the precipitated SiO 2 particles were within the PDA layer with sub-micro-scale thickness. The hybrid coating (20SiPDA) containing an appropriate amount of SiO 2 did not adversely affect shear bond strength compared with the Ti control and pure PDA coating. The SiO 2 /PDA coatings could effectively enhance the corrosion resistant ability of Ti implants. The 20SiPDA coatings elicited higher mortality rates of bacterial strains compared with the Ti control and pure PDA coating. More importantly, the incorporation of SiO 2 in the PDA coating layer could improve adhesion, proliferation, differentiation, and mineralization of MG63 osteoblasts. The new SiO 2 /PDA coating may be suitable for serving as a decorated layer to improve osteogenesis of Ti implants.

D-galactose is known to cause oxidative stress and induce aging-related diseases. Our previous study demonstrated that diosgenin can prevent osteoporosis in menopausal rats. The aim of the present study was to determine the effects of oral administration of diosgenin on bone loss in a D-galactose-induced aging rat model. Three groups of twelve-week-old male Wistar rats received a daily injection of D-galactose (150 mg/kg/day, i.p.) and orally administered diosgenin (0, 10, or 50 mg/kg/day) for eight weeks, while a control group received saline injection (1 ml/kg/day, i.p.), then the femurs were taken to measure mechanical and morphological properties. The results showed that frame volume and femur volume decreased and porosity and frame density increased in the D-galactose-induced aging rats compared to controls and that these effects were prevented by co-administration of diosgenin. This suggests that diosgenin might prevent bone loss during aging and provide beneficial effects in osteoporosis in the elderly.

Objective: Commercial quick-heating phosphate-bonded investments are frequently used to reduce the operating time during the dental casting process. The aim of this study was to evaluate the characteristics of commercial quick-heating phosphate-bonded investments., Method and Materials: Characterization of the 2 investments (Maruvest-Speed [Megadental] and Z4 C&B [Neirynck and Vogt]) focused on the setting expansion, compressive strength, thermal expansion, and surface roughness. Two different heating methods-the quick-heating method (QHM) and conventional heating method (CHM)-were used with the investments. The dimensional accuracy and surface roughness of the nickel-chromium alloy castings obtained from the investments were also examined., Results: The Maruvest-Speed investment had a significantly greater setting expansion (2.2%) than the Z4 investment (1.1%) after a 30-minute setting time. The fired strength of both investments was greater with QHM (21.2 to 27.7 MPa) than with CHM (13.8 to 17.9 MPa). The thermal expansion of the Maruvest-Speed investment and Z4 with QHM was 1.7% and 1.4%, respectively. There was no significant difference in surface roughness of the castings between samples treated with QHM and CHM. The dimensional accuracy of the castings was larger in length and slightly deformed in bend., Conclusion: The characteristics of the 2 commercial quick-heating phosphate-bonded investments for the accelerated casting technique may be acceptable.

Bioceramic coatings like hydroxyapatite (HA) have shown promising bioactive properties in load-bearing implant applications. The aim of this work is to deposit functionally graded HA/Ti layers consisting of an underlying Ti bond coat, the alternating layer, and an HA top-layer on Ti6Al4V substrates using plasma spray to improve the coating-substrate interface properties. The alternating layers were created by means of changing the feeding rate and input power of Ti and HA powders, which gradually decrease Ti content with increasing depth from the Ti bond-coat. The major consideration is to examine the stability of the graded coatings. Experimental results indicated that surface chemistry and morphology of the graded coatings were similar to those of monolithic HA coatings. The bond strength values of the as-sprayed graded coatings were much superior to those of monolithic HA coatings. The cyclic fatigue did have a statistically significant effect on bond strength of monolithic HA coatings, with a decrease of 23%. However, the graded coatings were able to survive 1 million cycles of loading in air without significantly reduced bond strength. The in vitro electrochemical measurement results also indicated that the graded coatings had a more beneficial and desired behavior than monolithic HA coatings after fatigue.