Aim: To evaluate the potential synergistic activity of metronidazole (MTZ) and chlorhexidine (CHX) against Porphyromonas. gingivalis (P. gingivalis) growth. Methods: Antimicrobial susceptibility tests of P. gingivalis to MTZ and CHX were performed on in vitro serial 2-fold dilutions of MTZ (from 1 mg/mL to 0.015 mg/mL) and CHX (from 1 mg/mL to 0.03 mg/mL) in thioglycollate medium broth in a 96-well plate. The turbidity of each sample was analyzed by absorbance spectrophotometry at 450 nm wavelengths by using an enzyme-linked immunosorbent assay (ELISA) reader. The MIC50 (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) were assessed. To investigate the potential synergism between MTZ and CHX, bacterial cells were treated with MTZ or CHX, as described above, either alone or in combination. Results: The MIC50 of MTZ was 0.03 mg/mL while that of CHX ranged from 0.12 to 0.06 mg/mL. MTZ and CHX exerted a significant inhibitory effect on P. gingivalis growth in a dose-dependent manner. MTZ at a low and ineffective concentration of 0.015 mg/mL, associated with a suboptimal concentration of CHX (0.03 mg/mL), exhibited a significant synergistic inhibitory effect on bacterial growth (50% inhibition vs. control) (p < 0.001), and the effect was more remarkable with 0.06 mg/mL CHX (75% inhibition vs. control). Conclusions: CHX and MTZ showed a significant synergistic effect against P. gingivalis growth. A non-effective concentration of MTZ (0.015 mg/mL) combined with suboptimal concentrations of CHX (0.03 mg/mL and 0.06 mg/mL) were related to a 50% growth in the inhibition and 99.99% death of P. gingivalis, respectively. The applicability of the clinical use of these concentrations should be tested in randomized controlled trials.

The aim of this study was to evaluate the clinical application of fixed screw-retained complete-arch rehabilitations supported by four narrow-diameter implants (NDIs). The records of patients treated with complete-arch prostheses screwed onto four NDIs treated with an immediate loading protocol between 2010 and 2020 with at least 1 year of follow-up after the positioning of the definitive restoration were reviewed. The implants were placed according to the final prosthetic design and were immediately loaded. The interim prostheses were replaced after the healing period by definitive acrylic resin titanium-supported prostheses. Patients were followed to evaluate treatment success, the implant survival rate (ISR), and the prosthetic survival rate (PSR). A total of 121 NDIs were positioned in 30 patients to restore 30 complete arches (18 maxilla and 12 mandible). One implant did not achieve osseointegration, resulting in an overall ISR of 99.2%. No prosthetic or implant failures occurred during the 1 to 11 years of follow-up. Three biological and four prosthetic complications occurred, resulting in a treatment rehabilitation survival of 94.1% and a PSR of 86.7%. Despite the limitations of the present retrospective study, such as the use of one single type of dental implant and patients treated in a single rehabilitation center, complete-arch rehabilitation with fixed prostheses supported by four NDIs seems to be a reliable treatment in the medium to long term.

The aim of this study was to systematically review the current scientific literature regarding the accuracy of fully guided flapless implant positioning for complete-arch rehabilitations in edentulous patients and to assess if there was any statistically significant correlation between linear deviation at shoulder point, at apex point and angular deviation. The electronic and manual literature search of clinical studies was carried out using specified indexing terms. A total of 13 studies were eligible for qualitative analysis and 277 edentulous patients were rehabilitated with 1556 implants patients by means of fully guided mucosa-supported template-assisted flapless surgery. Angular deviation was 3.42° (95% CI 2.82–4.03), linear deviation at shoulder point 1.23 mm (95% CI 0.97–1.49) and linear deviation at apex point 1.46 mm (95% CI 1.17–1.74). No statistically significant correlations were found between the linear and angular deviations. A statistically significant correlation was found between the two linear deviations (correlation coefficient 0.91) that can be summarized by the regression equation y = 0.03080 + 0.8254x. Computer-assisted flapless implant placement by means of mucosa-supported templates in complete arch restorations can be considered a reliable and predictable treatment choice despite the potential effects that flapless approach could bring to the overall treatment.

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 (Delta X, Delta Y and Delta Z-axis) and angular deviations (Delta ANGLE) were evaluated for each analogue. A global measure of linear absolute error (Delta ASS) 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 Delta ASS was considered as response variable. Posterior implants resulted as less accurate. ISS was able to reduce Delta ASS for both distal analogues (4.7, p=0.0188). When Delta ANGLE 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 improve-ment 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.

OBJECTIVE: To evaluate the learning curve by unskilled operator for a complete arch digital impression in terms of scanning time and accuracy. MATERIALS AND METHODS: Three unskilled operators (OP1, OP2, and OP3) were enrolled to scan for 15 times each one an edentulous maxillary polymethylmethacrylate (PMMA) milled model with six implant analogs in different angulation and depth. The scanning times were recorded for each scan of the randomized sequence. The resulting 45 test files were aligned by the reference one, obtained by a high-precision industrial scanner. Each test file was processed with dedicated software to assess the linear (DX, DY, and DZ axis) deviations, that were summed up to obtain an average value of three-dimensional deviation. RESULTS: The three operators showed a mean scan time of 169.6 seconds (s), 217,9 s, 193,7 s respectively. Each operators show a statistically significant scan time reduction from the first to last scan: OP1 p=0,001; OP2 p=0,008; OP3 p=0,003. The average three-dimensional (3D) errors reported were OP1 133 microns (mm), OP2 111 mm and OP3 107 mm. Regarding the accuracy, a statistically significant reduction in the average 3D error was reported: OP1 p = 0.02; OP2 p = 0.04; OP3 p = 0.04. CONCLUSION: Within the limitation of this in vitro study, it seems to be that the repetitive use of IOS significatively affects the investigated variables in an overall scanning time reduction and scan accuracy enhancement.

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.

The aim of this study was to assess the soft tissues health around the implant/abutment interfaces of fixed screw-retained prosthesis supported by four dental implants after at least 1-year in function. All the implants were placed between December 1, 2015 and April 30, 2019. Digital implant surgical planning was performed for all the complete-arch rehabilitations and then full-guided surgery was performed. The fixed-interim prostheses were delivered the day of the surgery and replaced by definitive prostheses after the healing period. Patients were followed-up to determinate peri-implant scores, such as Plaque Score (PS) and Bleeding on Probing (BoP). A total of 160 implants were placed in 37 patients, whereas 3 patients received both arches rehabilitated. A total of 40 complete-arch rehabilitations were performed, 26 in the maxilla and 14 in the mandible. Only 5 implants failed resulting in an overall implant survival rate of 96.9%. BoP was detected around 6 implants (3.7%) and 16 implants showed a superficial amount of plaque resulting a Plaque Score of 10%. Within the limitation of this study, it seems that the use of a fixed screw-retained prostheses supported by four dental implants to rehabilitate edentulous jaws could be a valid treatment option in the short and medium term without critical peri-implant issues. However, several perspective studies with longer follow-up are needed to achieve more predictable results.

The purpose of this review was twofold. The first aim was to show predictable protocols of guided endodontic microsurgery (EMS) and to describe its clinical outcomes. The second aim was to verify the accuracy of this technique compared to the traditional pathway. An electronic search of publications was established from two electronic databases, Cochrane and PubMed, by two independent researchers. The search strategy used a combination of controlled vocabulary and free-text words. Inclusion and exclusion criteria were defined by the authors before the start of the study. Inclusion criteria were: all studies published in English language; studies in vivo on humans; human cadaver studies; studies analyzing guided surgery in apicoectomy. The initial search yielded 67 citations, of which 10 were included. The studies included in this review analysis have shown two different technique both for digitization of dental arch and for surgical procedures too. Guided endodontic micro-surgery is a more predictable technique with less intra-operative and post-operative complications compared to the "freehand" technique and this procedure has shown a greater accuracy.

The aim of this systematic review was to evaluate survival rate of short dental implants placed in the posterior area of the maxilla. The electronic literature search of studies published between January 1, 2010 and February 29, 2020 was performed using specific word combinations. The outcome was to meta-analyse the implant survival rate (ISR). The search generated 238 potential studies. After screening procedures, only nine randomized controlled trials fulfilled the inclusion criteria and were selected for qualitative and quantitative analysis. ISR of short implants ranged from 91.9% to 100%, while standard-length implants ISR ranged from 82.9% to 100% with a follow-up from 1 to 5 years in function. The risk ratio difference was 1.24 (95% confidence interval: 0.63–2.45, P = 0.52) for short dental implants failure when compared with standard dental implants, and was not statistically significant. Based on the evidence of the included studies, short implants (≤6 mm) reported high survival rates over short to medium follow-up in posterior maxilla, but the long-term success is as yet not demonstrated.

Background: Due to its high biocompatibility, low bacterial surface adhesion, high flexural strength, absence of mucosal discoloration, toughness, and esthetic properties, zirconium oxide has gained popularity and its properties have led to the introduction of zirconia-based restorations in the fabrication of fixed implant-supported prostheses. Despite the broad clinical application of zirconia implant bridges scientific evidence is limited due to the lack of long-term data. Aim/Hypothesis: To retrospectively evaluate clinical and radiological outcomes of screw-retained zirconia implant bridges (ZrPIB) up to 12 years. To investigate for any difference of screw-retention at implant and abutment level. To assess long-term reliability of moderately rough oxidized surface implant. Materials and Methods: A retrospective chart review of partially and fully edentulous consecutive implant patients, male and female, aged ≥ 18 years, treated with implant supported screw retained fixed dental prostheses in three private dental clinics (AP, GF, GS) between December 2004 and June 2017 was conducted according to strict inclusion and exclusion criteria. One clinician for each center performed all the surgical and prosthetic procedures, and three dental laboratories, qualified in CAD/CAM technology designed and manufactured the screw retained porcelain fused to zirconia implant prosthesis. Outcomes were implant and prosthetic survival rates, prosthetic success rate, mechanical and biologic complications, marginal bone level (MBL) change, soft tissue condition. Effects of bridge type and level, implant type and connection, and follow up on MBL were tested (P < 0.05) through a Generalized Linear Effects Model (GLMM). Results: Ninety-eight patients, 59 (60.2%) female and 39 (39.8%) male, in most cases (86.4%) between 50 and 80 years old (mean 60.7 ± 11.7, median 62 ± 1.1, minimum 21 maximum 84), accounting for a total of 337 implants and 111 bridges were eligible to be included and investigated. No zirconia fractures were reported. Two implants and 2 ZrPIBs failed, yielding to a cumulative implant and prosthetic survival rate of 99.4% and 98.2%. Chipping was the most common complications (13.5%), accounting for a cumulative prosthetic success of 91.9% over an observation time of ≥ 10y (40 ZrPIBs, 36%), 5 to 9y (38, 34.2%), 2 to 4y (33, 22.8%). MBL change was -0.18 ± 0.59 mm. Thirteen implants experienced peri-implantitis (3.8%), 9 mucositis (2.7%). Low significance of implant level vs abutment level bridges (P = 0.013) was found, with higher MBL observed in ZrPIBs delivered at implant level (P = 0.013). Successful soft tissue parameters and patient satisfaction were reported. Conclusions and Clinical Implications: Within the limitations of this retrospective study, ZrPIBs are a reliable treatment option for partial and complete edentulism long-term. Stable bone levels and low peri-implantitis rate confirm positive performance of moderately-rough oxidized-surface implants supporting screw retained ZrPIBs. Screw-retention at implant level is not detrimental to bone and soft tissue integration. Zirconia fracture and porcelain chipping might be limited with well-managed laboratory and clinical protocols. Keywords: CAD/CAM, zirconia, complete-arch, screw-retained, dental implants

The aim of this review was to establish the efficacy of Ozone therapy (OT) in Periodontal disease's (PD) tratment. An electronic search of publications was established from two electronic databases: PubMed and Web of Science. The search strategy used a combination of controlled vocabulary and freetext words. Inclusion and exclusion criteria were defined by the authors before the start of the study. The inclusion criteria were: all studies published in English language; studies in vivo on humans; studies analyzing the correlation between PD and OT. The search resulted in 102 titles. Only 9 articles were included in the quantitative analysis. By the analyzed studies a strictly connection is still not evincible. More clinical trials are recommended to investigate the role of ozone, in its various types of topical administration, as a valid subgingival irrigant to achieve the goal of periodontal tissue health.

The use of digital tools offers a new perspective to daily clinical activities even though sometimes different clinical approaches are necessary. This case report of a maxillary anterior rehabilitation demonstrates the application of a gingival displacement technique to enhance the recording of subgingival finish line by means of an intraoral optical scanner (IOS). The temporary restoration was used as a guide for the radiosurgery tip in order to displace the gingiva in a guided and mini-invasive approach. It was then possible to create the space between the tooth structure and the soft tissues for the light beam of the IOS to properly detect the finish lines of the dental preparation. Six single porcelain fused to zirconia crowns were delivered. This technique could be considered as a solution of complex cases with subgingival dental preparation to be detected by means of an IOS.

The aim of the present study was to analyse the clinical potential of radiosurgery applied to modern dentistry through a revision of the indexed literature. Radiosurgery represents a recent form of electrosurgery working at a frequency of 3.0-4.0 MHz. The depth of penetration of the waves is inversely proportional to the frequency. Radiowaves working at high frequency express a lower penetration with a consequent lower tissue alteration. The authors analyzed the literature in order to give to the scientific community an overview of the possible applications of radiosurgery in the clinical dental practice and their effectiveness. Radiosurgery can be used in prosthodontics, in periodontal and implant surgery, in the treatment of trigeminal neuralgia, in the treatment of obstructive sleep apnea syndromes (OSAS) and in endodontics. Our analysis shows that although there are few articles in indixed literature on the applications of radiosurgery in dentistry, thanks to the benefits that derive from it, radiosurgery will spread more in the daily clinical practice of the dentists.

The purpose of this study is to evaluate the influence of implant scanbody (ISB) material and operator on scanning fluency and polygonal mesh numbers of a confocal microscopy intraoral scanning (IOS). An edentulous maxillary master model with 6 implant analogues was assembled. Thereafter 3 ISBs featured with same geometry but different materials (polyetheretherketone (PK), titanium (T) and PK with a titanium base (PKT)) were produce and scanned according to a randomized sequence by three different operators. The confocal microscopy IOS resulted in 45 STL test files that were processed to a dedicate software to obtain the request data. The overall analysis of fluency (imm/sec) showed the following results: mean 11.997 imm/sec, SD 2.355. The multivariate analysis showed statistical significance of material (p<.0001) and operator (p<.0001) influence. The univariate analysis referred to polygonal mesh numbers expressed the following results: mean 30327.8, SD 2432.5. The multivariate analysis stressed how there is a related effect to materials (p<.0001) and operator (p=0.0205). PKT represented the material with the best results for both. Analyzing the overall distribution histogram for scanning fluency, the IOS device seems to work with higher frequency at level of 13 imm/sec. The distribution of the measurements in the reference histograms showed an effect related to both variables referring to scanning fluency as well as to polygonal mesh numbers. Operator can be considered as a random effect; regarding the materials, the difference between PKT and PK can be related to the different base material. The dissimilar optical properties of T justify the different behavior.

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 (Delta X, Delta Y and Delta Z-axis) and angular deviations (Delta ANGLE) were assessed. Absolute values of the linear discrepancies were summed up to obtain a global measure of linear absolute error (Delta ASS). Influence of ISB material, position and operator was statistically assessed using the mixed general linear model. Results: At multivariate analysis, when Delta ASS 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 Delta ANGLE was considered as response variable, material and position significantly influenced the expected Delta ANGLE (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. (C) 2019 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.