Marginal Bone Loss Around Early-Loaded SLA and SLActive Implants: Radiological Follow-Up Evaluation Up to 6.5 Years

Bio-Inspired Micro- and Nano-Scale Surface Features Produced by Femtosecond Laser-Texturing Enhance TiZr-Implant Osseointegration

Surface design plays a critical role in determining the integration of dental implants with bone tissue. Femtosecond laser-texturing has emerged as a breakthrough technology offering excellent uniformity and reproducibility in implant surface features. However, when compared to state-of-the-art sandblasted and acid-etched surfaces, laser-textured surface designs typically underperform in terms of osseointegration. This study investigates the capacity of a bio-inspired femtosecond laser-textured surface design to enhance osseointegration compared to state-of-the-art sandblasted & acid-etched surfaces. Laser-texturing facilitates the production of an organized trabeculae-like microarchitecture with superimposed nano-scale laser-induced periodic surface structures on both 2D and 3D samples of titanium-zirconium-alloy. Following a boiling treatment to modify the surface chemistry, improving wettability to a contact angle of 10°, laser-textured surfaces enhance fibrin network formation when in contact with human whole blood, comparable to state-of-the-art surfaces. In vitro experiments demonstrate that laser-textured surfaces significantly outperform state-of-the-art surfaces with a 2.5-fold higher level of mineralization by bone progenitor cells after 28 days of culture. Furthermore, in vivo evaluations reveal superior biomechanical integration of laser-textured surfaces after 28 days of implantation. Notably, during abiological pull-out tests, laser-textured surfaces exhibit comparable performance, suggesting that the observed enhanced osseointegration is primarily driven by the biological response to the surface.

The Mineral Apposition Rate on Implants with Either a Sandblasted Acid-Etched Implant Surface (SLA) or a Nanostructured Calcium-Incorporated Surface (XPEED®): A Histological Split-Mouth, Randomized Case/Control Human Study

This study aimed to histologically evaluate the effects of XPEED® and SLA surface on the mineral apposition rate (MAR) at 3 and 5 weeks in titanium dental implants placed in human bone. In total, 17 titanium dental implants with XPEED® surface (n = 9) used as test and SLA surface (n = 8) used as control were included in this study. Each patient received four doses of tetracycline 500 mg at 12 h intervals 2 weeks prior to biopsy retrieval. Implant retrieval was performed, and retrieved biopsies were carefully treated for histomorphometric evaluation under epifluorescence microscopy. At 3 and 5 weeks, newly formed bone appeared in direct contact with both types of tested surfaces. At 3 weeks, the MAR value was, respectively, 2.0 (±0.18) μm/day for XPEED® implants and 1.5 (±0.10) μm/day for SLA implants (p = 0.017). At 5 weeks, lower MAR values for both XPEED® and SLA implants were noted, with 1.2 (±0.10) μm/day and 1.1 (±0.10) μm/day, respectively (p = 0.046). The overall evaluation by linear regression analysis for both time and implant surfaces showed a decreased osteoblast activity at 5 weeks compared to 3 weeks (p < 0.005). The results of the present study show that the bone apposition rate occurs faster around implants with XPEED® surface at 3 weeks and 5 weeks of healing. MAR values may support the use of implants with XPEED® surfaces in early loading protocols.

Eleven- to fifteen-year outcome for two-piece implants with an internal tube-in-tube connection: a cross-sectional analysis of 245 implants

PURPOSE

The aim of this retrospective study was to evaluate the outcomes of a two-piece implant system with a tube-in-tube internal connection after up to 15 years of clinical use.

MATERIAL AND METHODS

A retrospective follow-up examination of patients treated with internal tube-in-tube implants between 2003 and 2006 was conducted. The implant survival rates, peri-implant conditions (marginal bone loss, bleeding on probing, plaque index, probing depth), and technical complications were determined.

RESULTS

In total, 312 dental implants were placed in 152 patients. Of the original 152 patients enrolled, 245 implants in 112 patients were available for a follow-up evaluation after 11 to 15 years (mean observation time, 12.9 ± 1.1 years). The overall implant survival rate was 93.9%. Outcomes for MBL (1.49 ± 1.23 mm), PI (24.3 ± 22.2%), BOP (18.3 ± 28.7%), and PD (2.74 ± 1.21 mm) were observed. Selected parameters (time after implant surgery, smoking habits, bone augmentation (GBR)) showed an influence on MBL and PD.

CONCLUSIONS

The internal tube-in-tube implant system showed favorable long-term results. The correlation of MBL and PD with the patient-specific factor smoking habit is in accordance with other studies.

CLINICAL RELEVANCE

Camlog Root-Line implants with a tube-in-tube implant-abutment connection and a 1.6-mm polished neck configuration have demonstrated favorable long-term outcomes in daily clinical practice. However, it is important to note that these implants are no longer available on the market.

Clinical and radiographic outcomes of lateral sinus floor elevation with simultaneous hydrophilic implants placement: A retrospective study of 2-5 years

AIMS

To investigate the clinical and radiographic outcomes of a chemically modified sandblasted large-grit acid-etched implant (hydrophilic) in lateral sinus floor elevation (LSFE), compared with a conventional one (hydrophobic).

MATERIALS AND METHODS

A retrospective study design was adopted. Patients who received LSFE with simultaneous implant placement were recruited. According to different types of implant surfaces, patients were divided into two groups (the hydrophilic group and the hydrophobic group). Implant survival rate (SR), endo-sinus bone stability on the radiographs, mean probing depths, percentage of bleeding on probing, marginal bone loss, and patient satisfaction were evaluated.

RESULTS

A total of 106 patients with 180 implants (hydrophilic:101, hydrophobic:79) in 119 maxillary sinuses were included. The follow-up period ranged from 2 to 5 years. Three hydrophobic implants and one hydrophilic implant in four different patients failed. The SR of the hydrophilic group was higher than that of the hydrophobic group but without a significant difference (p > .05). The change and change rate of endo-sinus bone height (ΔESBH and RΔESBH) and bone volume (ΔESBV and RΔESBV) in the hydrophilic group were less than those in the hydrophobic group, with a significant difference at 6 months after implantation. No other significant difference was found between the two groups.

CONCLUSION

Within the limitations of this study, both hydrophilic and hydrophobic implants were suitable for LSFE with predictable clinical outcomes. Meanwhile, hydrophilic implants could contribute to the grafted endo-sinus bone stability during healing time.

Soft and Hard Tissue Integration around Percutaneous Bone-Anchored Titanium Prostheses: Toward Achieving Holistic Biointegration

A holistic biointegration of percutaneous bone-anchored metallic prostheses with both hard and soft tissues dictates their longevity in the human body. While titanium (Ti) has nearly solved osseointegration, soft tissue integration of percutaneous metallic prostheses is a perennial problem. Unlike the firm soft tissue sealing in biological percutaneous structures (fingernails and teeth), foreign body response of the skin to titanium (Ti) leads to inflammation, epidermal downgrowth and inferior peri-implant soft tissue sealing. This review discusses various implant surface treatments/texturing and coatings for osseointegration, soft tissue integration, and against bacterial attachment. While surface microroughness by SLA (sandblasting with large grit and acid etched) and porous calcium phosphate (CaP) coatings improve Ti osseointegration, smooth and textured titania nanopores, nanotubes, microgrooves, and biomolecular coatings encourage soft tissue attachment. However, the inferior peri-implant soft tissue sealing compared to natural teeth can lead to peri-implantitis. Toward this end, the application of smart multifunctional bioadhesives with strong adhesion to soft tissues, mechanical resilience, durability, antibacterial, and immunomodulatory properties for soft tissue attachment to metallic prostheses is proposed.

Outcomes of treatment with short dental implants compared with standard-length implants: a retrospective clinical study

BACKGROUND

The size of dental implants is a key success factor for appropriate osseointegration. Using shorter implants allows the possibility of avoiding complex surgical procedures and reduces the morbidity of treatment. Shorter implants also enable implant-prosthetic rehabilitation after maxillofacial reconstructions where only limited bone is available. In this study, the success rates of short implants were examined and compared to those of standard-sized implants.

METHODS

Patients who received dental implants between 2007 and 2016 at the Department of Oro-Maxillofacial Surgery and Stomatology Semmelweis University were enrolled in the study. Several clinical parameters were recorded and supplemented with radiological examinations. The data were statistically analysed.

RESULTS

Thirty-four patients with a total of 60 implants were included. The average time after prosthetic loading was 39.33 ± 21.96 months in the group with 8-mm implants and 41.6 ± 27.5 months in the group with > 8-mm implants. No significant differences were observed between the two groups in terms of probing depth (short implants, 2.84 ± 0.09 mm; standard implants, 2.91 ± 0.35 mm) or mean marginal bone loss (short implants, 1.2 ± 1.21-mm mesially and 1.36 ± 1.47-mm distally; standard implants: 0.63 ± 0.80-mm mesially and 0.78 ± 0.70-mm distally).

CONCLUSIONS

In this study, the success rate of short dental implants was comparable to that of standard-sized implants. Consequently, it can be claimed that the long-term success of short dental implants does not differ significantly from the long-term success of standard implants.

Influence of obesity on osseointegration of implants with different surface treatments: A preclinical study

OBJECTIVE

The aim of the present study was to evaluate the effect of obesity on the osseointegration of implants with hydrophobic and hydrophilic surfaces.

MATERIALS AND METHODS

Sixty-four male rats were distributed among four experimental groups: H-HB (Healthy/Hydrophobic): healthy animals with hydrophobic implants; H-HL (Healthy/Hydrophilic): healthy animals with hydrophilic implants; O-HB (Obese/Hydrophobic): animals with induced obesity and hydrophobic implants; O-HL (Obese/Hydrophilic): animals with induced obesity and hydrophilic implants. One hundred and twenty-eight implants were installed in the tibiae of the animals bilaterally (64 on the left tibiae and 64 on the right one) after 75 days of a specific diet (standard or high-fat diet) and euthanasia was performed in the experimental periods of 15 and 45 days after implant placement. Bone formation was assessed by biomechanical analysis (on the left tibiae of each animal), and microtomographic and histomorphometric analyses (on the right tibiae of each animal). Statistical analysis was performed using the Shapiro-Wilk test for normality and ANOVA followed by Tukey test to observe whether there was a significant difference between groups (p < 0.05); the t-test was used to compare the animals' body weight.

RESULTS

The biomechanical analysis showed an increase in the removal torque value of animals after 45 days in comparison to after 15 days, with the exception of O-HB groups. The microtomographic analysis demonstrated no significant differences in the mineralized bone tissue volume between the groups. In the histomorphometric analysis, the H-HL/45 day group/period demonstrated higher bone-implant contact, in comparison to H-HL/15 days and the O-HL/45 day group/period showed an increase in bone area between the implant threads, in comparison to O-HL/15 days.

CONCLUSION

In conclusion, obesity does not interfere with the osseointegration of hydrophobic and hydrophilic implants.

Nanostructured Calcium-Incorporated Surface Compared to Machined and SLA Dental Implants-A Split-Mouth Randomized Case/Double-Control Histological Human Study

Background: Implant surface topography is a key element in achieving osseointegration. Nanostructured surfaces have shown promising results in accelerating and improving bone healing around dental implants. The main objective of the present clinical and histological study is to compare, at 4 and 6 weeks, (w) bone-to-implant contact in implants having either machined surface (MAC), sandblasted, large grit, acid-etched implant surface (SLA) medium roughness surface or a nanostructured calcium-incorporated surface (XPEED®). Methods: 35 mini-implants of 3.5 × 8.5 mm with three different surface treatments (XPEED® (n = 16)—SLA (n = 13)—MAC (n = 6), were placed in the posterior maxilla of 11 patients (6 females and 5 males) then, retrieved at either 4 or 6w in a randomized split-mouth study design. Results: The BIC rates measured at 4w and 6w respectively, were: 16.8% (±5.0) and 29.0% (±3.1) for MAC surface; 18.5% (±2.3) and 33.7% (±3.3) for SLA surface; 22.4% (±1.3) and 38.6% (±3.2) for XPEED® surface. In all types of investigated surfaces, the time factor appeared to significantly increase the bone to implant contact (BIC) rate (p < 0.05). XPEED® surface showed significantly higher BIC values when compared to both SLA and MAC values at 4w (p < 0.05). Also, at 6w, both roughened surfaces (SLA and XPEED®) showed significantly higher values (p < 0.05) than turned surface (MAC). Conclusions: Nanostructured Calcium titanate coating is able to enhance bone deposition around implants at early healing stages.

Model-free digital workflow and immediate functional loading of implant-supported monolithic glass-ceramic crowns: A case series

OBJECTIVES

The aim of this study is to evaluate surgical and prosthetic outcomes of immediate functional loading of implants with glass-ceramic screw-retained single crowns.

METHODS

A total of 22 implants were placed. Within 24 hours, functional full-contour glass ceramic crowns were delivered to patients. The amount of attached gingiva, Simplified Oral Hygiene Index Score, bleeding on probing, time after extraction, bone type, implant size, soft tissue thickness, primary stability, a general fit of the restoration, occlusal and proximal contacts were recorded. Restorations were followed-up at 1, 3, and 6 months tracking marginal bone loss (MBL), noting changes in occlusal and interproximal contacts, checking other possible complications.

RESULTS

One implant failed and was removed after 4 weeks (95.5 % survival rate). The rest of the implants and crowns functioned with no complications during the follow-up period of 6 months. Factors such as time after extraction, bone type, implant size, soft tissue thickness, and primary stability recorded in Ncm and implant stability quotient (ISQ) values, were not associated with MBL (p<0.05). Mean MBL was found to be 0.3 mm (standard deviation = 0.42) mesially and 0.4 mm (standard deviation = 0.66) distally. One distal and one mesial proximal contact were found to be missing at the 6-month check-up appointment.

CONCLUSIONS

Within the limits of this study, fully digital workflow without a 3D printed model could be successfully employed for immediate functional loading with single-unit implant-supported crowns. Further studies are needed to obtain long-term results with a larger sample of patients.

CLINICAL SIGNIFICANCE

Model-free digital workflow and immediate functional loading of implant-supported monolithic glass-ceramic crown might be viable option to restore a single tooth defect.

The response of soft tissue cells to Ti implants is modulated by blood-implant interactions

Titanium-based dental implants have been highly optimized to enhance osseointegration, but little attention has been given to the soft tissue-implant interface, despite being a major contributor to long term implant stability. This is strongly linked to a lack of model systems that enable the reliable evaluation of soft tissue-implant interactions. Current in vitro platforms to assess these interactions are very simplistic, thus suffering from limited biological relevance and sensitivity to varying implant surface properties. The aim of this study was to investigate how blood-implant interactions affect downstream responses of different soft tissue cells to implants in vitro, thus taking into account not only the early events of blood coagulation upon implantation, but also the multicellular nature of soft tissue. For this, three surfaces (smooth and hydrophobic; rough and hydrophobic; rough and hydrophilic with nanostructures), which reflect a wide range of implant surface properties, were used to study blood-material interactions as well as cell-material interactions in the presence and absence of blood. Rough surfaces stimulated denser fibrin network formation compared to smooth surfaces and hydrophilicity accelerated the rate of blood coagulation compared to hydrophobic surfaces. In the absence of blood, smooth surfaces supported enhanced attachment of human gingival fibroblasts and keratinocytes, but limited changes in gene expression and cytokine production were observed between surfaces. In the presence of blood, rough surfaces supported enhanced fibroblast attachment and stimulated a stronger anti-inflammatory response from macrophage-like cells than smooth surfaces, but only smooth surfaces were capable of supporting long-term keratinocyte attachment and formation of a layer of epithelial cells. These findings indicate that surface properties not only govern blood-implant interactions, but that this can in turn also significantly modulate subsequent soft tissue cell-implant interactions.

Stability of dental implants with sandblasted and acid-etched (SLA) and modified (SLActive) surfaces during the osseointegration period

Background. The surface properties of implants are effective factors for increasing the osseointegration and activity of osteoprogenitor cells. This study compared the stability of dental implants with sandblasted and acid-etched (SLA) and modified surfaces (SLActive) using the resonance frequency analysis (RFA). Methods. In a split-mouth design, 50 dental implants with either SLA surface properties (n=25) or modified (SLActive) surface properties (n=25) were placed in the mandibles of 12 patients with a bilateral posterior edentulous area. Implant stability was measured using RFA (Osstell) at implant placement time and every week for 1, 2, and 3 months before the conventional loading time. Results. One week following the implantation, implant stability increased from 70 to 77.67 for SLA and from 71.67 to 79 for SLActive (P < 0.05). Stability improved each week except in the 4th week in SLActive surface measurements. No significant differences were observed between the groups at 2 and 3 months (P > 0.05). Conclusions. For both implant surfaces, increased stability was observed over time, with no significant differences between the groups.

Effect of Implant Surface Modification on Bone Mineral Density and Survival Rate in the Maxilla After a Short Period Using Cone Beam Computed Tomography

ABSTRACT

This study was aimed to objectively measure the changes in bone density amount obtained through cone-beam computed tomography around dental implants after a short period of time in the maxilla. Thirty-two SLActive Straumann implants were inserted into 12 healthy patients. Changes in bone density were measured at the surgery time (Bone mineral density (BMD)0) and 60 days after investment (Bone mineral density (BMD)60). Statistically, significant differences were observed between traumatic and sinus zones at the time of surgery and after 60 days respectively (P ≤ 0.05). For each group, a significant decrease in density was observed with the following variables (male, age of 18-40 years, sinus zone, and implant diameter of 4.1 mm). The survival rate was 83.8% after 60 days. Implant surface modification has no significant effect on bone mineral density after a short period of time in the sinus zone. Early loading of the prosthesis can be performed in the traumatic zone only.

Greater Osseointegration Potential with Nanostructured Surfaces on TiZr: Accelerated vs. Real-Time Ageing

Surface chemistry and nanotopography of dental implants can have a substantial impact on osseointegration. The aim of this investigation was to evaluate the effects of surface chemistry and nanotopography on the osseointegration of titanium-zirconium (TiZr; Roxolid^®) discs, using a biomechanical pull-out model in rabbits. Two discs each were placed in both the right and left tibiae of 16 rabbits. Five groups of sandblasted acid etched (SLA) discs were tested: (1) hydrophobic without nanostructures (dry/micro) (n = 13); (2) hydrophobic with nanostructures, accelerated aged (dry/nano/AA) (n = 12); (3) hydrophilic without nanostructures (wet/micro) (n = 13); (4) hydrophilic with nanostructures, accelerated aged (wet/nano/AA; SLActive^®) (n = 13); (5) hydrophilic with nanostructures, real-time aged (wet/nano/RTA). The animals were sacrificed after four weeks and the biomechanical pull-out force required to remove the discs was evaluated. Adjusted mean pull-out force was greatest for group wet/nano/RTA (64.5 ± 17.7 N) and lowest for group dry/micro (33.8 ± 10.7 N). Multivariate mixed model analysis showed that the pull-out force was significantly greater for all other disc types compared to the dry/micro group. Surface chemistry and topography both had a significant effect on pull-out force (p < 0.0001 for both), but the effect of the interaction between chemistry and topography was not significant (p = 0.1056). The introduction of nanostructures on the TiZr surface significantly increases osseointegration. The introduction of hydrophilicity to the TiZr implant surface significantly increases the capacity for osseointegration, irrespective of the presence or absence of nanotopography.

Trabeculae microstructure parameters serve as effective predictors for marginal bone loss of dental implant in the mandible

Marginal bone loss (MBL) is one of the leading causes of dental implant failure. This study aimed to investigate the feasibility of machine learning (ML) algorithms based on trabeculae microstructure parameters to predict the occurrence of severe MBL. Eighty-one patients (41 severe MBL cases and 40 normal controls) were involved in the current study. Four ML models, including support vector machine (SVM), artificial neural network (ANN), logistic regression (LR), and random forest (RF), were employed to predict severe MBL. The area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, and specificity were used to evaluate the performance of these models. At the early stage of functional loading, severe MBL cases showed a significant increase of structure model index and trabecular pattern factor in peri-implant alveolar bone. The SVM model exhibited the best outcome in predicting MBL (AUC = 0.967, sensitivity = 91.67%, specificity = 100.00%), followed by ANN (AUC = 0.928, sensitivity = 91.67%, specificity = 93.33%), LR (AUC = 0.906, sensitivity = 91.67%, specificity = 93.33%), RF (AUC = 0.842, sensitivity = 75.00%, specificity = 86.67%). Together, ML algorithms based on the morphological variation of trabecular bone can be used to predict severe MBL.

Early Loading of Mandibular Molar Single Implants: 1 Year Results of a Randomized Controlled Clinical Trial

The purpose of this study was to compare the implant survival, peri-implant marginal bone level, and peri-implant soft tissue of three different types of implants. This was performed with an early loading protocol, using a complete digital workflow, for one year of follow-up. Twenty-four patients with a single missing tooth in the mandibular posterior region were randomly assigned to the control group (SLActive Bone level implant; Institut Straumann AG, Basel, Switzerland), experiment group 1 (CMI IS-III Active implant; Neobiotech Co., Seoul, Korea), and experiment group 2 (CMI IS-III HActive implant; Neobiotech Co., Seoul, Korea). For each patient, a single implant was installed using the surgical template, and all prostheses were fabricated using a computer-aided design/computer-aided manufacturing system on a 3-dimensional model. A provisional prosthesis was implanted at 4 weeks, and a definitive monolithic zirconia prosthesis was substituted 12 weeks following the implant placement. The implant stability quotient (ISQ) and peri-implant soft tissue parameters were measured, and periapical radiographs were taken at 1, 3, 4, 8, 12, 24, 36, and 48 weeks after implant placements. Seven implants in the control group, nine implants in the experiment 1 group, and eight implants in the experiment 2 group were analyzed. There were no significant differences among the three groups in terms of insertion torque, ISQ values between surgery and 8 weeks of follow-up, marginal bone loss at 48 weeks of follow-up, and peri-implant soft tissue parameters (P > 0.05). Statistically significant differences in ISQ values were observed between the control and experiment 1 groups, and the control and experiment 2 groups at the 12 to 48 weeks' follow-ups. Within the limits of this prospective study, an early loading protocol can be applied as a predictable treatment modality in posterior mandibular single missing restorations, achieving proper primary stability.

Implant stability and survival rates of a hydrophilic versus a conventional sandblasted, acid-etched implant surface: Systematic review and meta-analysis

BACKGROUND

Modifying the implant surface via enhancing the wettability (hydrophilicity) improves osseointegration, reducing the healing period. In this study, the authors aimed to evaluate the stability and survival rates of implants with a hydrophilic surface compared with those with a sandblasted, acid-etched surface.

TYPES OF STUDIES REVIEWED

The included studies (randomized controlled trials) were identified through searches of PubMed, ScienceDirect, and Cochrane Library databases without date of publication restrictions. Quality assessment was performed using the Cochrane Collaboration tool. For primary outcome, confidence intervals were set at 95%; weighted means across the studies were calculated using a fixed-effects model or risk ratios and their 95% confidence intervals for secondary outcome.

RESULTS

The authors included 5 randomized controlled trials (246 dental implants) in the systematic review, which compared a hydrophilic with conventional sandblasted, acid-etched implant surface. The implant stability (primary outcome) was measured at baseline and 3, 6, and 8 weeks, and implant survival rates were measured as a secondary outcome. Overall, compared with the control groups, no clinically significant differences in implant stability or survival rates were identified for the hydrophilic surface groups.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The results did not show any clinically significant effect of a hydrophilic surface on improving implant stability or survival rates. However, these findings must be analyzed carefully owing to the limitations of this review, such as the small samples size and some differences among the included studies.

Evaluation of osseintegration between traditional and modified hydrophilic titanium dental implants - Systematic analysis

The aim of the study was to conduct a systematic review to access the osseointegration between traditional and modified Hydrophilic Titanium Dental Implants for period of 10 years. PUBMed articles were searched from last ten years up to 15/12/2019 from which 24 studies included in this review. This systematic review compiles the data about osseintegration in hydrophilic titanium implants in human trials. It sheds light on the mechanism of integration of hydrophilic surfaces and numeric data to support the purpose of the review.

The osteoinduction of RGD and Mg ion functionalized bioactive zirconia coating

The objective of this study was to investigate the adhesion, proliferation and mineralization of osteoblasts on arginine-glycine-aspartic acid (RGD)- and magnesium ion (Mg⁺)-decorated zirconia coatings. The zirconia coatings were prepared via a plasma spray; RGD and Mg⁺ were immobilized via a silane-coupling agent and ion implantation, respectively. This study employed scanning electron microscopy (SEM) to observe the surface morphology of RGD- and Mg⁺-decorated zirconia coatings; surface roughness and wettability were also measured. The initial adhesion of osteoblasts was measured, and cell morphology and focal adhesion were observed. In addition, the expressions of the integrins a1, a2, a5, av, and ß1 were measured using RT-PCR. A cell count was conducted to measure proliferation. The expressions of ALP and OCN were detected based on a western blot analysis, and mineralized nodules were observed to visualize the mineralization of osteoblasts. A nanoscale surface structure could be found on the Mg⁺-decorated zirconia coating, and the RGD-decorated zirconia coating showed better wettability (p < 0.05). Cells on the RGD- and Mg⁺-decorated zirconia coating possessed better spreading properties than did cells on nondecorated surfaces, and more focal adhesion was observed. The higher expressions of the integrins a5, av and ß1 were found on the RGD-decorated zirconia coating (p < 0.05). The western blot results demonstrated that the introduction of Mg⁺ heightened the expressions of ALP and OCN. More and bigger mineralized nodules were observed on the Mg⁺- and RGD-decorated zirconia coating, which consisted of small mineralized nodules. RGD- and Mg⁺-functionalized zirconia coating facilitates the osteogenic reaction of osteoblasts. RGD improves the adhesion of osteoblasts, and Mg⁺ benefits the mineralization of osteoblasts. In addition, a synergistic effect was found between RGD and Mg⁺, allowing better performances with regard to adhesion, proliferation and mineralization when the two were used together rather than as separate decorations.

Nano-scale modification of titanium implant surfaces to enhance osseointegration

The main aim of this review study was to report the state of art on the nano-scale technological advancements of titanium implant surfaces to enhance the osseointegration process. Several methods of surface modification are chronologically described bridging ordinary methods (e.g. grit blasting and etching) and advanced physicochemical approaches such as 3D-laser texturing and biomimetic modification. Functionalization procedures by using proteins, peptides, and bioactive ceramics have provided an enhancement in wettability and bioactivity of implant surfaces. Furthermore, recent findings have revealed a combined beneficial effect of micro- and nano-scale modification and biomimetic functionalization of titanium surfaces. However, some technological developments of implant surfaces are not commercially available yet due to costs and a lack of clinical validation for such recent surfaces. Further in vitro and in vivo studies are required to endorse the use of enhanced biomimetic implant surfaces. STATEMENT OF SIGNIFICANCE: Grit-blasting followed by acid-etching is currently used for titanium implant modifications, although recent technological biomimetic physicochemical methods have revealed enhanced osteoconductive and anti-microbial outcomes. An improvement in wettability and bioactivity of titanium implant surfaces has been accomplished by combining micro and nano-scale modification and functionalization with protein, peptides, and bioactive compounds. Such morphological and chemical modification of the titanium surfaces induce the migration and differentiation of osteogenic cells followed by an enhancement of the mineral matrix formation that accelerate the osseointegration process. Additionally, the incorporation of bioactive molecules into the nanostructured surfaces is a promising strategy to avoid early and late implant failures induced by the biofilm accumulation.

Randomized controlled clinical trial on calcium phosphate coated and conventional SLA surface implants: 1-year study on survival rate and marginal bone level

BACKGROUND

Calcium phosphate (CaP)-coated surface showed enhanced contact osteogenesis around dental implant and finally accelerate osseointegration in early healing phase.

PURPOSE

The aim of this randomized controlled trial was to compare the peri-implant marginal bone level around uncoated and CaP-coated sandblasted, large-grit, acid-etched (SLA) surface implants during the first year after placement.

MATERIALS AND METHODS

This study was performed upon 34 patients with randomized and double-blinded design. Clinical and radiographic examinations were performed immediately after implant placement, at re-entry after 3 months, and after 12 months to evaluate the initial stability and change in the marginal bone level. The distance from the implant shoulder to the top of the bone-to-implant contact was defined as the marginal bone level, and its alteration was measured at 1 year after implant installation.

RESULTS

None of the implants failed, and most of them showed a marginal bone loss of less than 1 mm. Small changes in the bone level were noted at all sites in the control and test groups, and there were no clinically significant differences in the changes in the marginal bone.

CONCLUSION

Both CaP-coated and uncoated SLA surface implants showed comparably successful marginal bone stability without any complications during the first year after placement.

Peri-implant marginal bone loss rate pre- and post-loading: An exploratory analysis of associated factors

OBJECTIVES

To perform an exploratory analysis of factors influencing annual rates of peri-implant marginal bone loss (RBL) calculated over different time frames, at implants unaffected by peri-implantitis.

MATERIAL AND METHODS

A total of 154 implants from 86 patients were reviewed at 1.6-6.8 years after placement. Marginal bone levels (MBL) were assessed on intraoral radiographs at three time-points: immediately post-placement, time of loading, and least 1-year post-loading. RBLs (mm/year) were computed using these three time frames and corresponding MBL changes as: RBL placement-loading, RBL loading-review, RBL placement-review. Exploratory ordination of three RBLs, corresponding time durations, and 17 background factors were used for visualization. Hierarchical linear mixed-effects models (MEM) with predictor selection were applied to RBL outcomes. The correlation of actual MBL with MBLs predicted by RBL placement-loading and RBL loading-review was tested.

RESULTS

Median RBL placement-loading was 0.9 mm/year (IQR = 2.02), loading-review was 0.06 mm/year (IQR = 0.16), and overall RBL placement-review was 0.21 mm/year (IQR = 0.33). Among-patient variance was highest for RBL placement-loading (SD = 0.66). Longer time predicted lower RBL in all time frames. Shorter time of loading significantly predicted lower RBL placement-review. Augmentation predicted lower RBL placement-loading, while anterior location and older age predicted lower RBLs placement-loading placement-review. Only MBL projected using RBL placement-loading significantly correlated with actual MBL.

CONCLUSIONS

Exploratory analysis indicated RBL varied with the time duration used for calculation in pre- and post-loading, and overall periods. In each period, RBL declined with increasing time. Earlier loading predicted lower overall RBL. Higher pre-loading RBL predicted worse actual bone level.

How do peri-implant biologic parameters correspond with implant survival and peri-implantitis? A critical review

Objectives

The aim of this critical review was to evaluate whether commonly used biologic diagnostic parameters correspond to implant survival and peri‐implantitis prevalence.

Materials and methods

Publications from 2011 to 2017 were selected by an electronic search using the Pubmed database of the US National Library of Medicine. Prospective and retrospective studies with a mean follow‐up time of at least 5 years and reporting prevalence of peri‐implantitis as well as mean bone loss and standard deviation were selected. The correlation between reported prevalence of peri‐implantitis and reported implant survival, mean follow‐up time, mean bone loss, mean probing depth, and mean bleeding on probing was calculated. Mean bone loss and standard deviation were used for estimation of proportion of implants with bone loss exceeding 1, 2, and 3 mm.

Results

Full‐text analysis was performed for 255 papers from 4,173 available ones, and 41 met all the inclusion criteria. The overall mean weighted survival rate was 96.9% (89.9%–100%) and the reported prevalence of peri‐implantitis ranged between 0% and 39.7%, based on 15 different case definitions. The overall weighted bone loss was 1.1 mm based on 8,182 implants and an average mean loading time ranging from 5 to 20 years. No correlation was found between mean bone loss and the reported prevalence of peri‐implantitis. The estimated prevalence of implants with bone loss above 2 mm was 23%. The overall weighted mean probing depth was 3.3 mm, and mean weighted bleeding was 52.2%. Only a weak correlation was found between survival and function time (r = −0.49). There was no relation between the probing depth or bleeding and the mean bone loss, mean follow‐up time, and reported prevalence of peri‐implantitis.

Conclusion

Biologic parameters mean probing depth and mean bleeding on probing do not correlate with mean bone loss and this irrespective of follow‐up. Case definition for peri‐implantitis varied significantly between studies indicating that an unambiguous definition based on a specified threshold for bone loss is not agreed upon in the literature.

Permanent wettability of a novel, nanoengineered, clinically available, hyaluronan-coated dental implant

The objectives of this study are to evaluate long-term wettability of novel surface-engineered, clinically available dental implants, featuring a surface nanolayer of covalently linked hyaluronan, and to confirm the relationships between wetting properties and surface nanostructure and microstructure. Wettability measurements were performed on clinically available hyaluronan-coated Grade 4 titanium implants, packaged and sterile, that is, in the "on the shelf" condition, after 1 year from production. Wetting properties were measured by the Wilhelmy plate method. Analysis of the surface structure and chemistry was perfomed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis, atomic force microscopy (AFM), and ζ-potential measurement, either on implants or disks or plates subjected to the same surface-engineering process. Results show that hydrophilicity and ensuing capillary rise of the hyaluronan-coated implant surface is unaffected by aging and dry storage. Chemical analysis of the implant surface by XPS and evaluation of the ζ potential indicate that hyaluronan chemistry and not that of titanium dictates interfacial properties. Comparison between XPS versus EDX and SEM versus AFM data confirm that the thickness of the hyaluronan surface layer is within the nanometer range. Data show that nanoengineering of the implant surface by linking of the hydrophilic hyaluronan molecule endows tested titanium implants by permanent wettability, without need of wet storage as presently performed to keep long-term hydrophilic implant surfaces. From an analytical point of view, the introduction in routine clinical practice of nanoengineered implant surfaces requires upgrading of analytical methods to the nanoscale.

Implant placement and loading protocols in partially edentulous patients: A systematic review

OBJECTIVES

To systematically review the evidence for the clinical outcome of fixed implant prostheses treated with different combinations of implant placement and loading protocols in partially edentulous patients.

MATERIALS AND METHODS

An electronic search was performed in Medline, Embase, and Central to identify studies investigating the outcome of implants subjected to immediate placement + immediate restoration/loading (Type 1A), immediate placement + early loading (Type 1B), immediate placement + conventional loading (Type 1C), early placement + immediate restoration/loading (Type 2-3A), early placement + early loading (Type 2-3B), early placement + conventional loading (Type 2-3C), late placement + immediate restoration/loading (Type 4A), late placement + early loading (Type 4B), late placement + conventional loading (Type 4C) with implant-supported fixed dental prostheses (IFDPs) in partially edentulous patients. Only human studies with at least 10 cases and a minimum follow-up time of 12 months, reporting on solid-screw-type implants with rough surfaces and an intra-osseous diameter between 3 and 6 mm, were included. A cumulative survival rate for each type of the implant placement and loading protocols was weighted by the duration of follow-up and number of implants.

RESULTS

The search provided 5,248 titles from which 2,362 abstracts and 449 full-text articles were screened. A total of 69 publications that comprised 23 comparative studies (15 randomized controlled trials, 7 controlled clinical trials) and 47 noncomparative studies (34 prospective cohort studies, 13 retrospective cohort studies) were included for analysis. Considerable heterogeneity in study design was found, and therefore, a meta-analysis of controlled studies was not possible. The weighted cumulative survival rate of each type of placement and loading protocol was 98.4% (Type 1A), 98.2% (Type 1B), 96.0% (Type 1C), 100% (Type 2-3B), 96.3% (Type 2-3C), 97.9% (Type 4A), 98.3% (Type 4B), and 97.7% (Type 4C). Type 1C, Type 2-3C, Type 4B, and Type 4C were scientifically and clinically validated (SCV). Type 1A, Type 1B, and Type 4A were clinically documented (CD), and Type 2-3A and Type 2-3B were clinically insufficiently documented (CID).

CONCLUSIONS

Evaluating outcomes in oral implantology by combining the placement and loading protocols are paramount. The selected loading protocol appears to influence the outcome of immediate implant placement.