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Objective: Bone platform switching results in an inward bone ring in the coronal part of an implant that is in continuity with the alveolar bone crest. Bone platform switching is achieved by using a dental implant with a reverse conical neck (RCN). A retrospective study was performed to determine the impact of RCN on crestal bone remodeling (CBR). Method and Materials: A series of 191 implants with the same morphology, but three slopes of RCN, were evaluated. Lost implants and CBR around implants still in place at the end of the follow-up were considered to investigate those variables potentially associated with the clinical outcome. Radiographic examinations were performed for each implant before surgery and at the end of the follow-up to detect the degree of CBR. Time-dependent cutoff values were used to select implants with higher CBR. These implants were considered unsuccessful. The Kaplan-Meier algorithm was applied to detect those variables potentially associated with the clinical outcome (ie, lost implants or implants with higher CBR). Results: Only 5 of 191 implants were lost (survival rate 97.4%). No statistical differences were detected among the studied variables by using lost implants. Conclusions: Although no statistical differences were detected among the three types of implants, the data seem to indicate a correlation between CBR and the slope of the RCN, with a better outcome for implants with a more angulated RCN. [ABSTRACT FROM AUTHOR]

Background: Osseointegration is essential for a long‑term successful and inflammation‑free dental implant. Such a result depends on osteoblastic cells growth and differentiation at the tissue‑implant interface. The aim of this study was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human osteoblasts (HOb) culture at two different time‑points. Materials and Methods: The expression levels of some bone‑related (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analyzed using real time reverse transcription‑polymerase chain reaction (real time RT‑PCR). Results: Real‑time RT‑PCR data showed that after 3 days of treatment with TiA4GR, the genes up‑regulated were COL3A1, ALPL, SPP1, and RUNX2. Moreover, no difference in gene expression was noticed 4 days later. On the other hand, the genes that overexpressed after 3 days of treatment with AoN5GR were ALPL, SPP1, and RUNX2. In both cases, the expression of COL1A1 and SPARC was negatively regulated. Conclusion: Our data showed that both titanium surfaces led to osteoblasts recruitment, maturation, and differentiation, thus promoting osseointegration at the tissue‑implant interface. [ABSTRACT FROM AUTHOR]

Background: The main requirements for a good material are its ability to promote attraction and adhesion of bone precursor cells and their proliferation and differentiation. Different biocompatible materials are currently employed as scaffold. Among these, titanium is considered a “gold standard” because of its biocompatibility and good corrosion resistance. Materials and Methods: The aim of this work was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human fibroblasts (HFb) culture at two different time‑points. The expression levels of some adhesion and traction‑resistance related genes (COL11A1, COL2A1, COL9A1, DSP, ELN, HAS1, and TFRC) were analyzed using real time reverse transcription‑polymerase chain reaction. Results: After 7 days of treatment with TiA 4GR, the only two up‑regulated genes were COL2A1 and DSP. After 15 days of treatment, none of genes over expressed. Conclusion: Our preliminary results suggest that neither AoN 4GR nor AoN 5GR are able to promote the production of protein involved in cell–cell and cell–matrix adhesion and in stress‑resistance, required for a good outcome in dental implantology. [ABSTRACT FROM AUTHOR]

Purpose: Titanium is the gold standard among materials used for prosthetic devices because of its good mechanical and chemical properties. When exposed to oxygen, titanium becomes an oxide that is biocompatible and able to induce osseointegration. There are three allotropic forms of titanium dioxide: brookite, rutile and anatase. Anatase can be prepared as a colloidal suspension and then used to coat surfaces. Anatase coating (AC) can potentially have specific biologic effects. Materials and Methods: We tested the effect of AC on bone in an in vivo study by using spiral dental implants covered with AC and then inserted in rabbit tibia. Results: The histologic analysis has demonstrated that (1) bone growth is equal around AC and standard fixtures but (2) AC fixtures have an antibacterical propriety that protect implants from subsequent peri-implantitis. Conclusions: This study demonstrates that the AC implant inserted in rabbit tibia guarantees good osseointegration of normal titanium implants providing an addition antibacterical propriety. [ABSTRACT FROM AUTHOR]

Purpose: Piezo-electric surgery (PES) uses a modulated ultrasonic frequency that allows highly precise and safe curing of hard tissue. Since PES split crest and immediate insertion of implants is a new surgical technique, we performed a retrospective pilot study. Material and methods: In the period between January 2003 and December 2007, 15 patients (10 females and 5 males, median age 44.7 years) were operated and 52 fixtures were inserted. The mean follow-up was 22 months. Kaplan Meier and Cox statistic test were used. Results: Only one out of 52 implants was lost (i.e. survival rate - 98.1%) and no differences were detected by using lost implants. To detect if the studied variables have any impact on PES split crest, bone loss around implant' neck was analyzed (i.e. success rate). Although univariate test showed a lower crestal bone resorption for immediately loading, wide diameter, standard length, implant' specific type and number of prosthetic units = 0.8, multivariate analysis did not demonstrated any statistical difference. Conclusion: Implants inserted in PES split crest have high survival rate. The success rate is lower if compared with that of fixtures inserted in unsplitted alveolar ridge. [ABSTRACT FROM AUTHOR]

Objectives: Computer planned flapless surgery and immediate loading are the most recent topics in implantology. One new computer-planned implant system uses a three-dimensional parallelometer able to transfer the implant position from the virtual project to the master model. The aim of this study was to verify if the new medical device gives an advantage in term of implant failures and/or crestal bone remodeling., Material and Methods: A retrospective study was planned to analyze a series of 193 immediately loaded fixtures inserted by means of flapless surgery. From those sixty six implants were inserted with computer planning whereas 127 were inserted "free-hand". Several variables related to patient, anatomy, implant, surgery and prosthesis were investigated. To detect the clinical outcome implant' failure and peri-implant bone resorption were considered. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome., Results: Implant length and diameter ranged from 10 to 16 mm and from 3.75 to 6.0 mm, respectively. Implants were inserted to replace 46 incisors, 30 cuspids, 75 premolars and 42 molars. The mean follow-up period was 15 months. Seven implants were lost (survival rate 96.4%) but no studied variable has a statistical impact on failures. On the contrary, implants inserted in sites with completed bone healing, wide diameter fixtures and implants inserted in totally edentulous jaw had a significantly lower crestal bone resorption. The other variables (age, gender, upper/lower jaws, tooth site, implant' type and length, number of prosthetic units antagonist condition) did not have impact on crestal remodeling., Conclusion: Computer-planned and cast model transferred implantology is a reliable technology that provides a slightly higher clinical outcome than "free hand" technique at least in healed sites, wider implants and totally edentulous jaws.

Background: The aim of research was to study spiral family implant by finite element analysis (FEA) inserted in different bone qualities connected with abutments of different angulations., Methods: The biomechanical behaviour of 4.2 × 13 mm dental implants, connecting screw, straight and 15° and 25° angulated abutments subjected to static loads, in contact with high and poor bone qualities was evaluated by FEA., Results: The lowest stress value was found in the system composed by implants and straight abut-ments loaded with a vertical force, while the highest stress value was found in implants with 15° angulated abutment loaded with an angulated force. In addition, we found the lower the bone quality, the higher the distribution of the stress within the bone., Conclusion: Spiral family implants can be used successfully in low bone quality but applying a straight force is recommended.