Accuracy of complete-arch digital implant impression with intraoral optical scanning and stereophotogrammetry: An in vivo prospective comparative study.

OBJECTIVES: To assess accuracy of intraoral optical scanning (IOS) and stereophotogrammetry (SPG), complete-arch digital implant impressions in vivo. MATERIALS AND METHODS: Consecutive patients needing implant-supported screw-retained zirconia complete-arch fixed-dental prostheses (ISZ-FDP) were recruited. For each patient, three impressions were taken: IOS, SPG (tests), and open-tray plaster (reference). Linear (ΔX, ΔY, and ΔZ), three-dimensional (ΔEUC), and angular deviations (ΔANGLE) were evaluated and stratified according to scanning technology for each implant. Potential effects of impression device (IOS and SPG), arch (maxilla and mandible), and implant number (4 and 6) were evaluated through multivariable analysis. Significance level was set at .05. RESULTS: A total of 11 complete arches (5 maxillae, 6 mandibles) in 11 patients were rehabilitated with ISZ-FDPs supported by 4 (n = 8) and 6 implants (n = 3). A total of 50 implants and 100 implant positions were captured by two investigated devices and compared to respective reference (mean ΔEUC IOS 137.2, SPG 87.6 µm; mean ΔANGLE 0.79, 0.38°). Differences between measurements (SPG-IOS) were computed for each implant, with negative values indicating better SPG accuracy. Significant mean ΔEUC difference of -49.60 µm (p = .0143; SD 138.15) and mean ΔANGLE difference of -0.40° (p < .0001; SD 0.65) were observed in favor of SPG. Multivariable analysis showed significant effect on ΔEUC (p = .0162) and ΔANGLE (p = .0001) only for impression devices, with SPG performing better. CONCLUSIONS: SPG experienced significantly higher linear and angular accuracy. No effect of type of arch or implant number was detected. Higher extreme deviations were experienced for IOS. SPG can be feasible for complete-arch digital impressions with caution, and rigid prototype try-in is recommended before screw-retained prosthesis manufacturing.

Clinical and radiological outcomes of novel digital workflow and dynamic navigation for single-implant immediate loading in aesthetic zone: 1-year prospective case series.

OBJECTIVES: To evaluate clinical, radiological performance of novel digital workflow integrating dynamic navigation to streamline in one-visit single-implant immediate loading in aesthetic zone. MATERIAL AND METHODS: Consecutive patients requiring one single-implant in aesthetic zone of both jaws were treated between May and September 2017. Primary outcomes were implant and prosthetic success rates, surgical and prosthetic complications, marginal bone loss (MBL), final pink aesthetic score (PES-f), and implant stability quotient (ISQ-f). Secondary outcomes were ISQ-0 and PES-0 at implant positioning and PES-p at definitive prosthesis placement. Potential effect of jaw (maxilla vs mandible), biotype (thin vs thick), type of incision (flap vs flapless), and implant site (healed vs. post-extractive) on the primary outcomes (MBL, PES-f, and ISQ-f) was evaluated through a multivariable analysis. RESULTS: Fifty-two implants were placed (follow-up 18.6, 15-20 months). One post-extractive implant failed. No other surgical, biological complications occurred, accounting for 98.10% cumulative success rate (CSR). No definitive prostheses failed. Mean MBL was -0.63 ± 0.25 mm (-1.69 to -0.06). PES-f was 12.34 ± 1.41 (9-14). ISQ-f was 78.1 ± 3.2 (70-84). Age had significantly negative effect on MBL and PES-f (p = .0058 and p = .0052). No other variables significantly affected primary outcomes. CONCLUSIONS: Within study limitations, investigated digital workflow integrating dynamic navigation was reliable for single-implant immediate loading in aesthetic zone in one visit. No statistically significant difference was found for MBL, PES-f, and ISQ-f, considering type of incision (flap vs. flapless), implant site (healed vs post-extractive), jaw (maxilla vs. mandible), and biotype (thick vs. thin). Live-tracked dynamic navigation may have contributed to improve operator clinical performance regardless of implant site characteristics. Further investigations are needed to confirm positive outcomes.

Accuracy of intraoral optical scan versus stereophotogrammetry for complete-arch digital implant impression: An in vitro study.

PURPOSE: To assess and compare the accuracies of intraoral scanners (IOS) and stereophotogrammetry (SPG) devices for complete-arch digital implant impressions. METHODS: A 4-analog model was digitized using a desk scanner to obtain a reference file. Thirty test scans were conducted using the investigated IOS device, while an additional 30 scans were performed using the SPG device. Using the best-fit algorithm, the resulting 60 test files were aligned with the reference file. Linear (ΔX, ΔY, and ΔZ-axis) and angular deviations (ΔANGLE) were evaluated. Three-dimensional (3D) deviation was calculated based on the Euclidean distance (ΔEUC). The analysis was stratified according to the scanning device and implant position. Fisher's F and t-tests were used to compare the variances and expected values of the two scanning systems. RESULTS: IOS expressed a higher 3D (ΔEUC) mean deviation than SPG (52.8 µm vs. 33.4 µm, P < 0.0001), with extreme measurements up to 181.9 µm. A significantly higher standard deviation (SD) was associated with IOS (37.1 µm vs. 17.7 µm, P < 0.0001). Considering angular deviations, the IOS showed slightly higher angular mean deviations (ΔANGLE) than the SPG (0.28° vs. 0.24°, P = 0.0022), with extreme measurements of up to 0.73°. The SPG SD values were significantly lower than the IOS SD values (0.14° vs. 0.04°, P < 0.0001). CONCLUSIONS: The SPG showed significantly higher 3D and angular accuracies for complete arch implant impressions, with consistent repeatability. IOS scanning revealed significantly higher extreme deviations exceeding the acceptable threshold value. Despite study limitations, SPG appears more feasible than IOS for complete-arch digital implant impressions.

Influence of Implant Scanbody Wear on the Accuracy of Digital Impression for Complete-Arch: A Randomized In Vitro Trial.

The aim of this study was to evaluate the influence of implant scanbody (ISB) wear on the accuracy of digital impression for complete-arch. A polymethylmethacrylate (PMMA) edentulous mandibular model with four internal hexagonal interlocking conical connections was scanned with an extraoral optical scanner to achieve a reference file. Four cylindrical polyetheretherketone (PEEK) ISBs were scanned 30 times with IOS, and the test files were aligned to the reference file with a best-fit algorithm. For each analog linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Euclidean distance (ΔEUC) was calculated from the linear deviation, reporting a mean of 82 µm (SD 61) ranging from 8 to 347 µm. ΔANGLE error mean was 0.33° (SD 0.20), ranging from 0.02 to 0.92°. From a multivariate analysis, when ΔEUC was considered as a response variable, a significant influence of ISB wear by scan number in interaction to position for implant 3.6 was identified (p < 0.0001); when ΔANGLE was considered as a response variable, a significant effect of position 3.6 was recorded ((p < 0.0001). The obtained results showed that the ISB wear negatively influenced the accuracy of IOS, suggesting that ISB base wear could be detrimental for the seating of ISBs on angulated implants.

Accuracy of complete-arch digital implant impression with or without scanbody splinting: An in vitro study.

OBJECTIVES: To assess accuracy of implant complete-arch digital impression with intraoral scanner (IOS) and implant scanbody splinting (ISS). METHODS: An edentulous mandibular model with 4 analogues was fabricated. Four polyetheretherketone (PEEK) implant scanbodies (ISBs) were scanned, according to a randomized sequence, by investigated IOS with (ISS+) and without implant scanbody splinting (ISS-), resulting in 30 test and 30 control files. The model was digitized by industrial optical scanner and the related file superimposed to the test and control files by a best fit algorithm. Linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were evaluated for each analogue. A global measure of linear absolute error (ΔASS) was calculated considering the sum of absolute linear discrepancies. Influence of ISS and implant position on IOS accuracy was assessed using General Linear Model and possible interaction between ISS and implant position evaluated. RESULTS: Implant position showed a significant main effect (p<0.0001) and interaction with ISS (p=0.0454) when ΔASS was considered as response variable. Posterior implants resulted as less accurate. ISS was able to reduce ΔASS for both distal analogues (4.7, p=0.0188). When ΔANGLE was considered as a response variable, implant position and ISS showed significant main and interactive effects (p=0.0039, p<0.0001, p<0.0001). Analogue 3.6 was associated with highest angular discrepancy. This error was significantly reduced by ISS (p<0.0001). CONCLUSIONS: Complete-arch implant digital impression with scanbody splinting showed a significant improvement of the overall accuracy, particularly reducing linear and angular deviations at the most critical posterior implant positions. CLINICAL SIGNIFICANCE: Intraoral scanner accuracy for implant complete-arch digital impression could be improved by a low cost, easy to assemble and use implant scanbodies splinting 3D printed modular chain.

Influence of implant scanbody material, position and operator on the accuracy of digital impression for complete-arch: A randomized in vitro trial.

PURPOSE: To evaluate the influence of implant scanbody (ISB) material, position and operator on the accuracy of a confocal microscopy intraoral scanning (IOS) for complete-arch implant impression. METHODS: An edentulous maxillary model with 6 internal hexagonal connection analogues was scanned with an extraoral optical scanner to achieve a reference file. Three ISBs made of different materials (polyetheretherketone (Pk), titanium (T) and Pk with a titanium base (Pkt)) were scanned with IOS by 3 operators. The resulting 45 test files were aligned to the reference file with a best fit algorithm. Linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Absolute values of the linear discrepancies were summed up to obtain a global measure of linear absolute error (ΔASS). Influence of ISB material, position and operator was statistically assessed using the mixed general linear model. RESULTS: At multivariate analysis, whenΔASS was considered as response variable, it was identified a significant influence of material (p<0.0001) and position (p=0.0009) while no significant operator effect was detected. When ΔANGLE was considered as response variable, material and position significantly influenced the expected ΔANGLE (p=0.0232 and p<0.0001) and no operator effect was identified. CONCLUSIONS: The investigated IOS for complete-arch digital impression was influenced by the ISB material with peek reporting the best results on both linear and angular measurements followed by titanium, peek-titanium resulting as the less accurate. Implant angulation affected significantly the linear deviations while implant position the angular deviations. Operator did not show any significant effect on the IOS accuracy.

A multidisciplinary approach for investigating dietary and medicinal habits of the Medieval population of Santa Severa (7th-15th centuries, Rome, Italy).

A multidisciplinary approach, combining stable isotope analysis from bone proteins and investigations on dental calculus using DNA analysis, light microscopy, and gas chromatography coupled with mass spectrometry, was applied to reconstruct dietary and medicinal habits of the individuals recovered in the cemetery of the Castle of Santa Severa (7th-15th centuries CE; Rome, Italy). Stable isotope analysis was performed on 120 humans, 41 faunal specimens and 8 charred seeds. Dental calculus analyses were carried out on 94 samples. Overall, isotope data indicated an omnivorous diet based on C3-terrestrial protein, although some individuals possessed carbon values indicative of C4 plant consumption. In terms of animal protein, the diet was probably based on cattle, sheep, pig and chicken products, as witnessed by the archaeozoological findings. Evidence from calculus suggested the consumption of C3 cereals, Fabaceae, Fagaceae, milk and dairy products. Secondary metabolites of herbs and wine were also detected. The detection of marine fish ancient DNA, as well as of ω3 fatty acids in calculus, hypothesized the consumption of marine foodstuffs for this coastal population, despite the lack of a clear marine isotopic signal and the presence of polyunsaturated fatty acids in plant tissues. Moreover, the knowledge of ethnopharmacological tradition and the application of medicinal plants (e.g. Punica granatum L., Ephedra sp. L.) were also identified. The detection of artemisinin, known to have antimalarial properties, led to hypothesize the presence of malaria in the area. Altogether, the combined application of microscopy and biomolecular techniques provided an innovative reconstruction of Medieval lifeways in Central Italy.

An a priori prediction model of response to peginterferon plus ribavirin dual therapy in naïve patients with genotype 1 chronic hepatitis C.

BACKGROUND: Aim was to select naïve patients with genotype 1 chronic hepatitis C having a high probability of response to Peg-interferon+ribavirin therapy. METHODS: In 1073 patients (derivation cohort), predictors of rapid and sustained virological response were identified by logistic analysis; regression coefficients were used to generate prediction models for sustained virological response. Probabilities at baseline and treatment week 4 were utilized to develop a decision rule to select patients with high likelihood of response. The model was then validated in 423 patients (validation cohort). RESULTS: In the derivation cohort, 257 achieved rapid virological response and 818 did not, with sustained virological response rates of 80.2% and 25.4%, respectively; interleukin-28B polymorphisms, fibrosis staging, gamma-glutamyl transferase, and viral load predicted sustained virological response. Assuming a <30% sustained virological response probability for not recommending Peg-interferon+ribavirin, 100 patients (25.6%) in the validation cohort were predicted a priori to fail this regimen. Assuming a ≥80% sustained virological response probability as a threshold to continue with Peg-interferon+ribavirin, 61 patients were predicted to obtain sustained virological response, and 55 of them (90.2%) eventually did. CONCLUSIONS: This model uses easily determined variables for a personalized estimate of the probability of sustained virological response with Peg-interferon+ribavirin, allowing to identify patients who may benefit from conventional therapy.