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To compare the accuracy of 6 desktop 3D printers in dentistry.A parallelepiped (PP) with known geometry and holes of different diameters was designed and printed with 6 desktop 3D printers (Sheraprint 40®; Solflex 350®; Form 2®; MoonRay D75®; Vida HD®; XFAB 2000®). For each printer, 9 PPs were printed with proprietary materials; these PPs were not cured and underwent dimensional analysis by optical microscopy and precision probing. A file representative of a dentate model (DM) was also printed with the aforementioned printers. For each printer, 3 DMs were printed with the proprietary materials. These DMs were cured and after 1 month, scanned with a desktop scanner and superimposed on the virtual reference model, to investigate trueness.Dimensional analysis by optical microscopy and precision probing highlighted the reliability of the 3D printed models; errors were compatible with clinical use. However, both linear and diameter measurements revealed statistically significant differences between the machines. The trueness of the DMs 1 month after printing was low, suggesting that they underwent dimensional contraction over time, albeit with differences between the printers.The 3D printed models showed acceptable accuracy, although statistically significant differences were found among them.

The aim of this 10-year follow-up study was to evaluate the implant survival and complication rates of fixed restorations supported by locking-taper implants.Over a 10-year period (January 2002 to December 2011) all patients referred to a single private practice for treatment with fixed restorations (single crowns, SCs; fixed partial prostheses, FPPs; fixed full arches, FFAs) supported by dental implants were considered for inclusion in the study. At each annual follow-up session, clinical, radiographic, and prosthetic parameters were assessed. The surviving implant-supported restorations were defined as "complication free" in the absence of any biological or prosthetic (mechanical or technical) complication. The cumulative implant survival and the "complication-free" survival of fixed implant-supported restorations were identified using the Kaplan-Meier method. The Log-rank test was used to identify correlations between the study variables.In total, 1494 locking-taper implants (727 maxilla, 767 mandible) were placed in 642 patients (356 males, 286 females). Nineteen implants (12 maxilla, 7 mandible) failed. Implant failures were attributed to lack of osseointegration (14 implants), peri-implantitis (4 implants), and mechanical overloading (1 implant). An overall 10-year cumulative implant survival rate of 98.7% (98.3% maxilla, 99.1% mandible) was found. The implant survival rates did not significantly differ with respect to implant location, position, bone type, implant length and diameter, and type of restorations. Among the surviving implant-supported restorations (478 SC, 242 FPP, 19 FFA), a few biological (11/739: 1.4%) and prosthetic (27/739: 3.6%) complications were reported. The incidence of mechanical complications was low (3/739: 0.4%), with three loosened abutments in three SCs (3/478: 0.6%), and no abutment fractures; technical complications were more frequent (24/739: 3.2%), with an incidence of decementation of 2.0% (SC 2.0%, FPP 1.6%, FFA 5.2%) and ceramic/veneer chipping/fracture of 1.2% (SC 0.0%, FPP 2.8%, FFA 10.5%). A 10-year cumulative "complication-free" survival of restorations of 88.6% (SC 91.7%, FPP 83.1%, FFA 73.8%) was reported. The complication rates differ significantly with respect to the type of restoration (p0.05).Fixed restorations on locking-taper implants seem to be a successful procedure for the rehabilitation of partially and completely edentulous arches.

Purpose The maxillary sinus lift is recognized and stable, and there have been different innovations to optimize the technique. The aim of this study was to investigate the maxillary sinus lift technique with the use of a blood clot and without the use of a bone graft. Materials and Methods Ten patients were recruited for a unilateral sinus lift; patients without sinus pathology or other contraindication were selected. The maxillary sinus was accessed conventionally under local anesthesia followed by an osteotomy and a 1-cm 2 bony window access. The sinus membrane was detached and the window was repositioned above and stabilized with a 12- or 14-mm osteosynthesis screw introduced through the alveolar ridge. Dental implants were installed in the second surgical stage. Standardized panoramic radiographic checks were performed at every stage. Results Seven completely edentulous patients and 3 partially dentate patients were treated surgically. From the first to the second surgery, a bone gain of 2.37 mm was obtained, although loss of bone height was observed in 1 completely edentulous patient. In 7 patients, it was not possible to install the implants owing to insufficient bone height or inadequate bone quality. Conclusion The protocol used in this investigation failed in the bone increase required for implant installation.

In contrast to the excellent long-term outcomes described for implant-supported mandibular overdentures, less favorable long-term survival and success rates have been reported for maxillary implants supporting overdentures. The aim of this study was to evaluate the treatment outcome of "planned" bar-retained maxillary and mandibular overdentures supported by Morse taper connection implants, investigating implant survival, peri-implant tissue health, marginal bone resorption and prosthetic complications.Over a 2-year period, 60 patients were enrolled in this study, in four different clinical centers. The overdentures (maxilla 38, mandible 34) were planned with support from four implants anchored on a bar. A total of 288 Morse taper connection implants (Leone Implant System(®)) were inserted (152 maxilla, 136 mandible). Implants were evaluated 5 years after insertion. Success criteria included the absence of pain, suppuration or clinical mobility, the distance between implant shoulder and first crestal bone-implant contact (DIB)2 mm and no exudate history.The overall 5-year implant survival rate was 98% (maxilla 97.4%, mandible 98.6%), with 282 implants still in function. Among these surviving implants, 278 (98.6%) were classified in the success group. At the 5-year examination, the mean DIB was 0.7 mm (±0.53). Few prosthetic complications were reported.With "planned" bar-retained maxillary and mandibular overdentures supported by Morse taper connection implants, satisfactory survival and success rate can be achieved.

This prospective clinical study evaluated the survival rate and the implant-crown success of 314 Morse taper connection implants, used for single-tooth replacement, after 1 year of functional loading.Over a 4-year period (January 2003 to January 2007), 314 implants (168 maxilla, 146 mandible) were inserted in 302 patients (128 males, 174 females, aged between 23 to 79 years) in six different clinical centres. The sites included anterior (n = 118) and posterior (n = 196) teeth. To evaluate implant-crown success, the following clinical, prosthetic and radiographic parameters were assessed: modified plaque index (mPI), modified sulcus bleeding index (mBI), probing depth (PD), distance from the implant crown margin to the coronal border of the peri-implant mucosa (DIM), width of keratinised mucosa (KM), prosthesis function, and the distance between the implant shoulder and first crestal bone-implant contact (DIB). Success criteria included: absence of suppuration and mobility, PD5.0 mm, absence of prosthetic complications, absence of continuous peri-implant radiolucency, and DIB1.5mm after 1-year of functional loading. Prosthetic restorations were all-ceramic (n=116) and metal-ceramic (n=198) crowns.The implant survival rate was 98.4% (5 implant losses, 1 drop-out). A few prosthetic complications (0.6% implant-abutment loosening) were reported. The mean DIB was 0.887 + or - 0.308mm. Among the survived implants (308), four did not fulfill the success criteria, giving an implant-crown success of 98.7%.The use of Morse taper connection implants represents a successful procedure for single-tooth replacement, in the anterior and posterior areas of both arches. The high mechanical stability amy reduce prosthetic complications.

The objective of this study was to evaluate the airway volume of growing patients combining a morphological approach using cone beam computed tomography associated with functional data obtained by polysomnography examination after rapid maxillary expansion treatment.22 Caucasian patients (mean age 8.3±0.9 years) undergoing rapid maxillary expansion with Haas type expander banded on second deciduous upper molars were enrolled for this prospective study. Cone beam computed tomography scans and polysomnography exams were collected before placing the appliance (T0) and after 12 months (T1).Image processing with airway volume computing and analyses of oxygen saturation and apnoea/hypopnoea index were performed.Airway volume, oxygen saturation and apnea/hypopnea index underwent significant increase over time. However, no significant correlation was seen between their increases.The rapid maxillary expansion treatment induced significant increases in the total airway volume and respiratory performance. Functional respiratory parameters should be included in studies evaluating the RME treatment effects on the respiratory performance.

This prospective clinical study evaluated the incidence of abutment loosening of Morse taper-connection implants used for single-tooth replacement. In addition, the cumulative survival rate and the implant/crown success were evaluated.Implants were evaluated 12, 24, 36, and 48 months after insertion. The incidence of abutment loosening, modified Plaque Index, modified Sulcus Bleeding Index, probing depth, distance from the implant-crown margin to the coronal border of the peri-implant mucosa, width of keratinized mucosa, and the distance between implant shoulder and first bone-implant contact (DIB) were assessed. The cumulative survival rates were calculated with Kaplan-Meier estimates. Implant/crown success criteria included absence of abutment loosening, absence of suppuration and mobility, probing depth5.0 mm, and DIB1.5 mm after 12 months and not exceeding 0.2 mm for each following year.Over a 4-year period (2003-2007; mean follow-up per implant: 30.79 months), 307 implants (162 maxillary, 145 mandibular) were inserted in 295 patients (125 men and 170 women aged between 24 and 79 years) at six different clinical centers. The sites included anterior (n = 115) and posterior (n = 192) teeth. At the end of the study, a very low percentage of implant-abutment loosening (0.66%) was found, with only two loosened abutments. The cumulative implant survival rate was 98.4%. Mean DIB was 1.14 mm (48 months). Only four surviving implants did not meet the criteria for success, and the implant/crown success rate was 97.07%.Based upon this study of 307 implants observed during a 4-year period, Morse taper-connection implants represent a good solution for single-tooth restorations, with a very low incidence of abutment loosening (0.66%).

Aim: Wide-diameter implants (WDIs, diameter ≥4.5 mm) are increasingly being used in patients with poor bone quality and reduced bone height. The aim of this study was to evaluate the survival rate, peri-implant bone loss, biological and prosthetic complications of wide-diameter (4.8 mm) locking-taper implants used in the restoration of partially and fully edentulous patients. Materials and methods: Between January 2002 and December 2011, all patients referred to a private clinic for treatment with WDIs were considered for inclusion in the study. At each annual follow-up session, clinical and radiographic parameters were assessed: the outcome measurements were implant failure, peri-implant bone loss (distance between the implant shoulder and the first visible bone-to-implant contact: DIB), biological and prosthetic complications. The cumulative survival rate (CSR) was assessed using the Kaplan-Meier estimator; Log-rank was applied to evaluate correlations between the study variables. The statistical analysis was performed at the patient and at the implant level. Results: A total of 438 WDIs were placed in 411 patients. Four implants failed, for a CSR of 99% (patient-based) and 99.1% (implant-based) at 10-year follow-up. The CSR did not differ significantly with respect to patients’ gender, age, smoking or parafunctional habit, implant location, position, length, bone type or prosthetic restoration. A mean DIB of 0.34 mm (± 0.23), 0.45 mm (± 0.27) and 0.75 mm (± 0.33) was shown at the 1-, 5- and 10-year follow-up examination. Conclusions: Wide-diameter, locking-taper implants can be a good treatment option for the rehabilitation of partially and fully edentulous patients over the long term.

Purpose To compare the trueness and precision of 3D-printed versus milled monolithic zirconia crowns (MZCs). Methods A model of a maxilla with a prepared premolar was scanned with an industrial scanner (ATOSQ®, Gom) and an MZC was designed in computer-assisted-design (CAD) software (DentalCad®, Exocad). From that standard tessellation language (STL) file, 10 MZCs (test) were 3D-printed with a Lithography-based Ceramic Manufacturing (LCM) printer (CerafabS65®, Lithoz) and 10 MZCs (control) were milled using a 5-axis machine (DWX-52D®, DGShape). All MZCs were sintered and scanned with the aforementioned scanner. The surface data of each sample (overall crown, marginal area, occlusal surface) were superimposed to the original CAD file (ControlX®, Geomagic) to evaluate trueness: (90-10)/2, absolute average (ABS AVG) and root mean square (RMS) values were obtained for test and control groups (MathLab®, Mathworks) and used for analysis. Finally, the clinical precision (marginal adaptation, interproximal contacts) of test and control MZCs was investigated on a split-cast model printed (Solflex350®, Voco) from the CAD project, and compared. Results The milled MZCs had a significantly higher trueness than the 3D-printed ones, overall [(90-10)/2 printed 37.8 µm vs milled 21.2 µm; ABS AVG printed 27.2 µm vs milled 15.1 µm; RMS printed 33.2 µm vs milled 20.5 µm; p = 0.000005], at the margins [(90-10)/2 printed 25.6 µm vs milled 12.4 µm; ABS AVG printed 17.8 µm vs milled 9.4 µm; RMS printed 22.8 µm vs milled 15.6 µm; p= 0.000011] and at the occlusal level [(90-10)/2 printed 50.4 µm vs milled 21.9 µm; ABS AVG printed 29.6 µm vs milled 14.7 µm; RMS printed 38.9 µm vs milled 22.5 µm; p = 0.000005]. However, with regard to precision, both test and control groups scored highly, with no significant difference either in the quality of interproximal contact points (p = 0.355) or marginal closure (p = 0.355). Conclusions Milled MZCs had a statistically higher trueness than 3D-printed ones; all crowns, however, showed high precision, compatible with the clinical use. Clinical significance Although milled MZCs remain more accurate than 3D-printed ones, the LCM technique seems able to guarantee the production of clinically precise zirconia crowns.