Purpose: The aim of this study was to provide an overview on the biology and soft tissue sealing around dental implants and teeth. Study selection: This is a narrative review performed through scientific articles published between 1977 and 2014, indexed in MEDLINE and PubMed databases. The study selected articles that focused on epithelial sealing around dental implant or teeth with cell biology and histology of soft tissue. Results: Implant therapy has been widely applied in dental rehabilitation for many years, with predictable long-term results. The longevity and functionality of dental implants is dependent on both osseointegration around the implant body and the establishment of a soft tissue barrier that protects the underlying hard tissue structures and the implant itself. The health and stability of the peri-implant mucosa also affects the esthetics of the implant. The healing and maintenance of the epithelial and connective tissues around implants are increasingly recognized as being fundamental to implant success. However, there has been little research into the function or formation of the soft tissue seal around dental implants, and the roles of this unique mucosal interface remain unclear. Conclusions: This narrative review explores the extent of the current knowledge of soft tissue barriers around implants from both a basic and clinical perspective, and aims to consolidate this knowledge and highlight the most pertinent questions relating to this area

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Purpose: Polyetheretherketone (PEEK) is a polymer that has many potential uses in dentistry. The aim of this review was to summarize the outcome of research conducted on the material for dental applications. In addition, future prospects of PEEK in the field of clinical dentistry have been highlighted. Study selection: An electronic search was carried out via the PubMed (Medline) database using keywords ‘polyetheretherketone', ‘dental' and ‘dentistry' in combination. Original research papers published in English language in last fifteen year were considered. The studies relevant to our review were critically analyzed and summarized. Results: PEEK has been explored for a number of applications for clinical dentistry. For example, PEEK dental implants have exhibited lesser stress shielding compared to titanium dental implants due to closer match of mechanical properties of PEEK and bone. PEEK is a promising material for a number of removable and fixed prosthesis. Furthermore, recent studies have focused improving the bioactivity of PEEK implants at the nanoscale. Conclusion: Considering mechanical and physical properties similar to bone, PEEK can be used in many areas of dentistry. Improving the bioactivity of PEEK dental implants without compromising their mechanical properties is a major challenge. Further modifications and improving the material properties may increase its applications in clinical dentistry.

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Purpose: To recapitulate a 2003 study inquiring of US dental schools whether they teach the face bow transfer by means of a survey in order to determine if compliance with clinical evidence has improved. Methods: The same 54 dental schools surveyed in 2003 were asked the same question regarding whether they teach the use of the face bow transfer in the complete denture curriculum. Results: Teaching of the face bow transfer has increased in prevalence from 84% of surveyed schools in 2003 to 93.75% of surveyed schools in 2015. Conclusions: This finding is especially interesting in light of the fact that there is no compelling evidence supporting the use of the face bow transfer with regard to improving patient outcomes. With respect to the continued unjustified teaching of the face bow transfer, some possible reasons for non-compliance with best available evidence are presented using the medical literature for reference.

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Purpose: The purpose of this study was to compare the fracture resistance of Co-Cr post- cores fabricated with 3 different techniques: traditional casting (TC), computer-aided design and manufacturing (CAD/CAM) milling (CCM) and direct metal laser sintering (DMLS). Methods: Forty intact human mandibular premolar were endodontically treated. The roots were then randomly divided into four groups according to the post systems: the control group was only filled with gutta percha. Co-Cr metal posts were fabricated with TC, CCM and DMLS in the other three groups. The posts were luted with a resin cement and subjected to compression test at a crosshead speed of 1 mm/min. The statistical analysis of the data was performed using one-way analysis of variance (ANOVA) and multiple comparison post hoc Tukey tests (a = .05). The samples were examined under a stereomicroscope with ?20 magnification for the evaluation of the fracture types. Results: The mean fracture loads were 432.69 N for control, 608.89 N for TC, 689.40 N for DMLS and 959.26 N for CCM. One-way ANOVA revealed significant difference between the groups ( p < 0.01). In the post hoc Tukey test, there were significant differences between groups except DMLS and TC. Conclusion: While Co-Cr posts fabricated by TC and DMLS systems performed similarly in terms of fracture resistance, posts fabricated by CCM techniques showed higher fracture resistance values. Significance: Co-Cr metal posts fabricated by CCM and DMLS could be an alternative to TC processing in daily clinical application.

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Purpose: The purpose of the study was to verify the finite element analysis model of three- unite fixed partial denture with in vitro electronic strain analysis and analyze clinical situation with the verified model. Methods: First, strain gauges were attached to the critical areas of a three-unit fixed partial denture. Strain values were measured under 300 N load perpendicular to the occlusal plane. Secondly, a three-dimensional finite element model in accordance with the electronic strain analysis experiment was constructed from the scanning data. And the strain values obtained by finite element analysis and in vitro measurements were compared. Finally, the clinical destruction of the fixed partial denture was evaluated with the verified finite element analysis model. Results: There was a mutual agreement and consistency between the finite element analysis results and experimental data. The finite element analysis revealed that failure will occur in the veneer layer on buccal surface of the connector under occlusal force of 570 N. Conclusions: The results indicate that the electronic strain analysis is an appropriate and cost saving method to verify the finite element model. The veneer layer on buccal surface of

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Purpose: This study investigated the effects of surface treatments on bond strength between resin cement and differently sintered zirconium-oxide ceramics. Methods: 220 zirconium-oxide ceramic (Ceramill ZI) specimens were prepared, sintered in two different period (Short = Ss, Long = Ls) and divided into ten treatment groups as: GC, no treatment; GSil, silanized (ESPE-Sil); GSilPen, silane flame treatment (Silano-Pen); GSb, sandblasted; GSbSil, sandblasted + silanized; GSbCoSil, sandblasted + silica coated (CoJet) + silanized; GSbRoSil, sandblasted + silica coated (Rocatech-Plus) + silanized; GSbDSil, sandblasted + diamond particle abraded (Micron MDA) + silanized; GSbSilPen, sandblasted + silane flame treatment + silanized; GSbLSil, sandblasted + Er:Yag (Ascle- pion-MCL30) laser treated + silanized. The composite resin (Filtek Z-250) cylinders were cemented to the treated ceramic surfaces with a resin cement (Panavia F2.0). Shear bond strength test was performed after specimens were stored in water for 24 h and thermo- cycled for 6000 cycles (5-55 8C). Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tamhane's multiple comparison test (a = 0.05). Results: According to the ANOVA, sintering time, surface treatments and their interaction were statistically significant ( p < 0.05). The highest bond strengths were obtained in GSbCoSil (Ss = 13.36/Ls = 11.19 MPa) and lowest values were obtained in GC (Ss = 4.70/ Ls = 4.62 MPa) for both sinter groups. Conclusions: Sintering time may be effective on the bond strength and 30 mm silica coating (Cojet) with silane coupling application technique increased the bond strength between resin cement and differently sintered zirconium-oxide ceramics.

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Purpose: To evaluate the effect of glass fiber/filler particles proportion on flexural strength and diametral tensile strength of an experimental fiber-reinforced composite. Methods: Four experimental groups (N = 10) were created using an experimental short fiberreinforced composite, having as a factor under study the glass fiber (F) and filler particle (P) proportion: F22.5/P55 with 22.5 wt% of fiber and 55 wt% of filler particles; F25/P52.5 with 25 wt% of fiber and 52.5 wt% of filler particles; F27.5/P50 with 27.5 wt% of fiber and 50 wt% of filler particles; F30/P47.5 with 30 wt% of fiber and 47.5 wt% of filler particles. The experimental composite was made up by a methacrylate-based resin (50% Bis-GMA and 50% TEGDMA). Specimens were prepared for Flexural Strength (FS) (25 mm ? 2 mm ? 2 mm) and for Diametral Tensile Strength (DTS) (3 ? 6 Ø mm) and tested at 0.5 mm/min in a universal testing machine. Results: The results (in MPa) showed significance (different superscript letters mean statistical significant difference) for FS (p < 0.009) and DTS ( p < 0.001) - FS results: F22.5/P55:217.24 ? 20.64^B; F25/P52.5: 245.77 ? 26.80^AB; F27.5/P50: 246.88 ? 32.28^AB; F30/P47.5:259.91 ? 26.01^A. DTS results: F22.5/P55: 21.82 ? 4.42^B; F25/P52.5: 22.00 ? 7.40^B; F27.5/P50:18.63 ? 4.41^B; F30/P47.5: 31.05 ? 2.97^A. In SEM analysis, areas without fiber reinforcement demonstrated to be more prone to the presence of bubbles and crack development. The group F30/P47.5 showed areas with a great quantity of fibers without empty spaces for crack propagation. Conclusion: Increasing fiber content results in higher flexural and diametral tensile strength of an experimental composite reinforced with glass fibers.

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Purpose: The present article describes a novel clinical procedure for mandibular overdentures supported by two freestanding implants loaded immediately after placement via computer-guided flapless surgery. Methods: A conventional acrylic complete denture was fabricated, and CT scans obtained using the denture as a radiographic guide. Preoperative computer-assisted planning was performed using commercially available software, permitting simulation of implant placement at optimal positions. Using simulation data, a surgical guide was manufactured and used during surgery. The surgical guide was placed and local anesthesia injected for drilling of anchor pins to stabilize the surgical guide. The drilling protocol for each osteotomy site achieved an insertion torque greater than 35 Ncm. Immediately after implant placement, a keeper of the magnetic attachment was connected to each implant,and the magnetic assembly incorporated into the denture. The mucosal surface of the denture around the magnet was relieved to avoid excessive tissue pressure. The patients were instructed to wear the denture in place continually for the following 7 days. After six months of healing and follow-up, a final denture with a metal framework may be fabricated if necessary.Conclusion: A novel treatment protocol for immediately loaded implant-supported mandibular overdentures is described in detail. The protocol ensures secure precise and safe implant placement, successful osseointegration, and immediate improvement of oral health-related quality of life for patients with unstable complete dentures.

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Patients: This report describes the case of a 48-year-old female patient who initially received a 4-unit fixed-fixed (FF) resin-bonded fixed dental prosthesis (RBFDP) for replacement of mandibular left second premolar and first molar. Twenty-one months later, debond of the RBFDP was found at one of retainers. A new fixed-movable RBFDPs with a modified non-rigid connector as well as increased resistance form features was placed and successfully retained at the 16-year clinical review. Discussion: RBFDPs are a conservative tooth replacement option that requires minimum tooth preparation and retention by a resin cement to etched enamel. However debonding is the most frequently seen complication and has been attributed to the relative movement between abutment teeth during function that stress the bonding interface. This case report highlights the use of modified non-rigid connector which allows relative movement be- tween abutment teeth and therefore a reduced stress on the bonding interface. Conclusion: It is proposed that the use of modified non-rigid connectors that allow indepen- dent movement between the abutment teeth during function was responsible for the long term clinical success of fixed-movable RBFDPs.

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