Stability of class II correction with the Austro Repositioner associated with multi-brackets fixed appliances in dolichofacial patients.

BACKGROUND: The purposes of the present study were to evaluate the changes produced by the Austro Repositioner, and to assess the stability of Class II malocclusion treatment with the Austro Repositioner associated with fixed appliances and its capacity to control the vertical dimension in dolichofacial patients. METHODS: A group of patients with Class II malocclusion due to mandibular retrognathism and a dolichofacial growth pattern treated with the Austro Repositioner combined with fixed appliances were compared to a matched untreated control group of subjects with Class II malocclusion. Evaluations were made on the basis of lateral cephalograms taken at T1 (initial records), T2 (end of treatment), and T3 (1 year after treatment). Statistical comparisons were performed with paired- and two-sample t tests. RESULTS: The experimental (treated) group comprised 30 patients, 14 boys and 16 girls, and the control group comprised 30 subjects (15 boys and 15 girls) with similar ages at T1, T2 and T3. In the treated group, a significant decrease in the ANB angle was found (- 3.79 ± 1.46; p < 0.001). No significant differences were found in the maxillary skeletal measurements. In contrast, the SNB angle showed a significant increase of 3.77 ± 1.49 in the treated group compared with a nonsignificant increase of 0.77 ± 1.55 in the control group (p = 0.002). Vertical changes showed a significant decrease in the FMA angle (- 3.36 ± 1.62), while the lower anterior facial height distance and the overbite increased significantly in the treated group, reflecting a change in vertical dimensions after treatment. No significant changes were observed in either the treated or control group during the one-year posttreatment period; thus, the treatment results remained stable. CONCLUSIONS: The Austro Repositioner combined with fixed appliances could be considered an optimal treatment modality in Class II dolichofacial patients.

Primary stability and PES/WES evaluation for immediate implants in the aesthetic zone: a pilot clinical double-blind randomized study.

The use of immediate implants in the aesthetic area is a technique widely used in modern implantology. The characteristics of the patient, the implant, and the surgical procedure used may influence the final results. The aim was to assess whether the implant design affects primary (P.S.) and secondary stability (S.S.), bone level (B.L.), and PES/WES evaluation. Twenty implants with two different designs (n = 10) were immediately placed and randomly located in the upper anterior maxilla with no grafting material. Implant-Stability-Quotient (ISQ), B.L., and Pink-Esthetic-Score/White-Esthetic-Score (PES/WES) were evaluated. Shapiro-Wilk normality test was performed to determine the sample normality, as the data did not follow a normal distribution, the Wilcoxon-Mann-Whitney test was applied (p < 0.05). ISQ was determined at placement (PS): control 59.1 (C.I.54.8-63.3); experimental 62.2(C.I.60.1-64.2) and three months after placement (SS): control 62.2.1 (C.I.53.3-71.0); experimental 67.2(C.I.65.8-68.5). The BL was measured at three months after placement: control 0.38 mm (C.I.- 0.06 to + 0.83); experimental 0.76 mm (C.I.0.33-1.19) and at 12 months post-loading: control 0.07 mm (C.I.- 0.50-0.65); experimental 0.90 mm (C.I.0.38-1.42). PES/WES values were evaluated for the control group: 15 (C.I.12.68-17.32), and for the experimental group 15.20 (C.I.11.99-18.41). No significant differences were shown between both implant designs. A good grade of osseointegration and primary/secondary stability was achieved, as well as proper maintenance of crestal bone and adequate PES/WES scores. The criteria for selection for the ideal patient for immediate implant placement is essential.ClinicalTrials Protocol ID: NCT04343833.

Stability of Class II Malocclusion Treatment with the Austro Repositioner Followed by Fixed Appliances in Brachyfacial Patients.

One of the goals of functional-appliance devices is to modify the vertical growth pattern, solving several kinds of malocclusion. This study aimed to evaluate Class II malocclusion treatment's stability with Austro Repositioner, followed by fixed appliances, and assess its capacity to modify vertical dimensions in brachyfacial patients. A test group of 30 patients (16 boys and 14 girls, mean 11.9 years old) with Class II malocclusion due to mandibular retrognathism and brachyfacial pattern treated with Austro Repositioner and fixed appliance were compared to a matched untreated Class II control group of 30 patients (17 boys and 13 girls, mean age 11.7 years old). Lateral cephalograms were taken at T1 (initial records), T2 (end of treatment), and T3 (one year after treatment). Statistical comparisons were performed with a paired-sample t-test and two-sample t-tests. Significant improvements in the skeletal Class II relationship were observed in the treated group. The ANB angle decreased (4.75°), the SNB angle increased (3.92°), and the total mandibular length (Co-Pg) increased (8.18 mm) (p < 0.001). Vertical dimensions were also significantly modified, the FMA angle increased (3.94°), LAFH-distance increased (3.15 mm), and overbite decreased (3.35 mm). These changes remained stable one year after treatment. The Austro Repositioner was adequate for treating the skeletal Class II malocclusion resulting from the mandible retrusion in brachyfacial patients.

Influence of Connection Type and Platform Diameter on Titanium Dental Implants Fatigue: Non-Axial Loading Cyclic Test Analysis.

Two-pieces dental implants must provide stability of the implant-abutment-interface. The connection type and platform diameter could influence the biomechanical resistance and stress distribution. This study aims to evaluate the fatigue for different types of connections, external and internal, and different platform diameters. Three implant designs with the same length were used: (a) external hexagon/narrow platform; (b) internal double hexagon/narrow platform; (c) internal octagon/regular platform. A fatigue test was developed to establish the number of cycles needed before fracture. A 30º oblique load with a sinusoidal function of fatigue at a frequency of 15 Hz and 10% stress variation was applied to each system. The fatigue load limit (FLL) for design (a) was 190N, being the nominal-curvature-moment (NCM) = 1.045; FLL = 150 N, with a NCM = 0.825 for (b), and FLL = 325 N, with a NCM = 1.788 for (c). The platform diameter affects the FLL, obtaining lower FLL on a narrow platform. The connection type interferes with the implant walls' width, especially in narrow implants, making internal connections more unstable at this level. Long-term clinical studies to assess the restoration's success rate and survival are mandatory.

Volumetric Changes in Morse Taper Connections After Implant Placement in Dense Bone. In-Vitro Study.

The stability of the implant-abutment interface is crucial for the maintenance of the implant index integrity. Several factors are capable of inducing deformation in implant-abutment connection, such as the actual insertion of the implant into the bone. This study aimed to evaluate the deformations produced in the connection after the insertion of the implant. Ten implants with two different implant carriers (Type A: carrier attached to platform and Type B: carrier attached inside the index-connection) were placed in artificial Type II bone, and volumetric changes were evaluated for different connection features with a 3D digital microscope. ANOVA (analysis of variance), Wilcoxon, and Tukey HSD post-test were used for statistical comparisons. Type A implants presented deformation at the platform level (inner slot angles and slot width), but no volumetric changes were observed inside the connection. Type B implants presented deformation in three parameters inside the connection (outer channel length, coronal step width, and coronal step length). Within the limitations of this study, we can conclude that more deformation is expected at the internal connection when the implant carrier engages this area. The engagement area should be as far away as possible from the index connection.

Long-Term Clinical Outcomes of Treatment with Dental Implants with Acid Etched Surface.

Implant dentistry constitutes a therapeutic modality in the prosthodontic treatment of partially and totally edentulous patients. This study reports a long-term evaluation of treatment by the early loading of acid-etched surface implants. Forty-eight partially and totally edentulous patients were treated with 169 TSA Defcon® acid-etched surface implants for prosthodontic rehabilitation. Implants were loaded after a healing free-loading period of 6-8 weeks in mandible and maxilla, respectively. Implant and prosthodontic clinical findings were followed during at least 17 years. Clinical results indicate a survival and success rate of implants of 92.9%, demonstrating that acid-etched surface achieves and maintains successful osseointegration. Five implants in three patients were lost during the healing period. Sixty-five prostheses were placed in 45 patients over the remaining 164 implants, 30 single crowns, 21 partially fixed bridges, 9 overdentures, and 5 full-arch fixed rehabilitations. A total of 12 implants were lost during the follow-up period. Mean marginal bone loss was 1.91 ± 1.24 mm, ranging from 1.1 to 3.6 mm. The most frequent complication was prosthetic technical complications (14.2%), followed by peri-implantitis (10.6%). The mean follow-up was of 214.4 months (208-228 months). Prosthodontic rehabilitation with an early-loading protocol over acid-etched surface implants is a successful implant treatment.

Control of Peri-Implant Mucous Inflammation by Using Chlorhexidine or Ultraviolet C Radiation for Cleaning Healing Abutments. Double-Blind Randomized Clinical Trial.

Two-phase implants must be exposed to the external environment after the period of osteointegration has elapsed. For this purpose, a healing abutment is placed passing through the mucosa while forming the emergence profile. The continuous connection and disconnection can lead to an alteration in the tissue maturation, both because of the contact of bacterial plaque and because of the mechanical trauma that involves its manipulation, manifesting with different degrees of erythema or bleeding. To assess whether this epithelium disruption can be counteracted, a blinded study design was developed on 150 unitary implant patients divided into three groups (n = 50), applying chlorhexidine (group 1), ultraviolet C (UV-C) at a wavelength of 254 nm (group 2)and no treatment as a control group (group 3), during each of the disconnections and connections during the prosthodontic treatment (1 time per week for four weeks). All groups showed a better epithelium aspect at the end of the evaluation. Although there were no statistically significant differences in the degree of inflammation, the UV-C treated group had the lowest plaque accumulation, and the highest was for the chlorhexidine-treated group.

Effect of Rough Surface Platforms on the Mucosal Attachment and the Marginal Bone Loss of Implants: A Dog Study.

: The preservation of peri-implant tissues is an important factor for implant success. This study aimed to assess the influence of the surface features of a butt-joint platform on soft-tissue attachment and bone resorption after immediate or delayed implant placement. All premolars and first molars of eight Beagle dogs were extracted on one mandible side. Twelve-weeks later, the same surgery was developed on the other side. Five implants with different platform surface configurations were randomly inserted into the post-extracted-sockets. On the healed side, the same five different implants were randomly placed. Implants were inserted 1 mm subcrestal to the buccal bony plate and were connected to abutments. The primary outcome variables were the supracrestal soft tissue (SST) adaptation and the bone resorption related to the implant shoulder. The SST height was significantly larger in immediate implants (IC95% 3.9-4.9 mm) compared to delayed implants (IC95% 3.1-3.5 mm). Marginal bone loss tended to be higher in immediate implants (IC95% 0.4-0.9 mm) than in delayed implants (IC95% 0.3-0.8 mm). Linear-regression analysis suggested that the SST height was significantly affected by the configuration of the platform (0.3-1.9 mm). Roughened surface platforms resulted in higher SST height when compared to machined surface platforms. Marginal bone loss was less pronounced in roughened designs.