Heating of metallic orthodontic devices during anti-aging treatment with vacuum and electromagnetic fields: In vitro study.

BACKGROUND: The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non-invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances. The aim of this study was to evaluate in vitro heating of the orthodontic bracket following electromagnetic fields and negative pressure (V-EMF) used as an anti-aging treatment. METHODS: Two different types of titanium alloy wires, one made of "beta-Titanium" alloy and the other "Ni-Ti" (DW Lingual Systems GmbH-Bad Essen-Germany) were used. The orthodontic wires and brackets mounted on a resin mouth were covered with porcine muscle tissue, then subjected to anti-aging therapy with a Bi-one LifeTouchTherapy medical device (Expo Italia Srl-Florence-Italy) which generates a combination of vacuum and electromagnetic fields (V-EMF) already adopted for antiaging therapy. During administration of the therapy, the orthodontic brackets and porcine tissue were thermally monitored using a Wavetek Materman TMD90 thermal probe (Willtek Communications GmbH-Germany). In total 20 orthodontic mouths were used, 10 with Beta Titanium wires and 10 with Nickel Titanium wires. RESULTS: A temperature increase of about 1°C was recorded in each group. The outcome of the present research shows that the absolute temperatures measured on orthodontic appliances, which, despite having a slightly different curve, both show an increase in temperature of 1.1°C at the end of the session, thus falling well within the safety range of 2°C as specified by the standard CENELEC EN 45502-1. Therefore, V-EMF therapy can be considered safe for the entire dental system and for metal prostheses, which tend to heat up at most as much as biological tissue (+0.9°C/1.1°C vs. 1.1°C/1.1°C). CONCLUSION: In conclusion, anti-aging therapy with V-EMF causes a thermal increase on orthodontic brackets that is not harmful to pulp health.

Implant Stability and Histomorphometric Analysis Comparing Two Different Implant Macrogeometries Placed in Fresh Sockets: An Experimental Study in Sheep.

PURPOSE: The aim of the present animal study was to examine the impact of two implant designs that promote different insertion torque values on implant stability and evaluate, histomorphometrically, the bone healing for immediate implant placement in fresh sockets. MATERIALS AND METHODS: Twelve female sheep (35.0±5.0kg) and 48 conical Morse-taper dental implants divided into two groups (n = 24 per group): G1 group, where the implants present a design that can provide high insertion torque values; and G2 group, where the implants present a design that can provide low insertion torque values. Both had the same surface treatment, and dimensions (4.0 mm in diameter and 10 mm in length). The first two posterior teeth (both sides) were extracted carefully. Sequentially, there were osteotomies in the mesial socket of each molar tooth. The final implant position was 2 mm below the buccal bone crest level. On the right side, implants of the G1 were placed anteriorly, followed by implants of the G2; and, on the left side, it was the reverse. A digital torquemeter was used to measure the maximum final insertion torque value (f-IT). The initial implant stability quotient (ISQ) was measured immediately after the implant insertion (T0) and immediately after the euthanasia and removing the mandibles with the implants. The animals were euthanized (n=6 animals/ time) at 21 days (T1) and 35 days (T2). The t-test was used to compare statistical differences for each intragroup parameter analyzed. Pearson's correlation was used to analyze possible correlations: f-IT and BIC%, f-IT and ISQ, and ISQ and %BIC. RESULTS: Regarding the insertion torque, the G1 presented higher values than the G2, with a statistically significant difference (p<0.0001). The ISQ mean values were higher in the B-L direction than those obtained for M-D for both groups. %BIC measurements showed higher values in samples from G2 than G1 at both times and in both directions. New bone, medullary spaces, and collagen matrix had statistical differences between the groups at each evaluation time. CONCLUSION: Using implants with a modified macrogeometry plays a significant role in implant stability and the healing process of bone tissue around the implant. It is important for clinicians to carefully consider implant macrogeometry when planning dental implant surgery to achieve optimal implant stability and successful osseointegration, mainly in cases of immediate implant placement.

Does the index in Morse taper connection affect the abutment stability? An in vitro experimental study.

The present study compared three different implant and abutment sets of type Morse taper (MT) connection, with- and without-index, were analyzed regarding their mechanical behavior without and with cyclic load application simulating the masticatory function. Ninety implant and abutment (IA) sets were used in the present study, divided into three groups (n = 30 samples per group): Group A, Ideale solid straight abutment (one piece) without index; Group B, Ideale abutment with an angle of 30-degree (two pieces) without index; Group C, Ideale abutment with an angle of 30-degree (two pieces) with index. The abutment stability quotient (ASQ) values, detorque value and rotation angle were measured before and after the cycling load. Twenty IA sets of each group were submitted to mechanical load at 360,000 cycles. The ASQ without load were 64.7 ± 2.49 for the group A, 60.2 ± 2.64 for the group B, 54.4 ± 3.27 for the group C; With load were 66.1 ± 5.20 for the group A, 58.5 ± 6.14 for the group B, 58.9 ± 2.99 for the group C. Detorque values were lower in groups B and C compared to group A (p < 0.05). In conclusion, the presence of the index did not influence the stability values. However, solid straight abutments (group A) showed higher values of stability compared to groups of angled abutments (groups B and C).

Fibroblasts and osteoblasts behavior after contact with different titanium surfaces used as implant abutment: An in vitro experimental study.

Background: The goal of this in vitro study was to compare three different surfaces: two types of implant surfaces commercially available ([a] smooth/machined and [b] acid-treated surface) versus (c) anodized surface. Discs were manufactured with commercially pure titanium (CP) grade IV, which were subsequently analyzed by scanning microscopy and fibroblastic and osteoblastic cell cultures. Methods: Ninety-nine discs (5 × 2 mm) were manufactured in titanium grade IV and received different surface treatments: (i) Mach group: machined; (ii) AA group: double acid etch; and (iii) AN group: anodizing treatment. Three discs from each group were analyzed by Scanning Electron Microscopy (SEM) to obtain surface topography images and qualitatively analyzed by EDS. Balb/c 3T3 fibroblasts and pre-osteoblastic cells (MC3T3-E1 lineage) were used to investigate each group's biological response (n = 10/cellular type). The data were compared statistically using the ANOVA one-way test, considered as a statistically significant difference p < 0.05. Results: The AA group had numerous micropores with diameters between 5 and 10 µm, while nanopores between 1 and 5 nm were measured in the AN group. The EDX spectrum showed a high titanium concentration in all the analyzed samples. The contact angle and wetting tension were higher in the AA, whereas similar results were observed for the other groups. A lower result was observed for base width in the AA, which was higher in the other two groups. The AN showed the best values in the fibroblast cells, followed by Mach and AA; whereas, in the culture of the MC3T3 cells, the result was precisely the opposite (AA > Mach > AN). There was similar behavior for cell adhesion for the test groups (Mach and AN), with greater adhesion of Balb/c 3T3 fibroblasts compared to MC3T3 cells; in the AA group, there was greater adherence for MC3T3 cells compared to Balb/c 3T3 fibroblasts. Conclusions: The findings suggest that different surface characteristics can produce different biological responses, possibly cell-line dependent. These findings have important implications for the design of implantable medical devices, where the surface characteristics can significantly impact its biocompatibility.

Histologic Osseointegration Level Comparing Titanium and Zirconia Dental Implants: Meta-analysis of Preclinical Studies.

Purpose: To assess the literature comparing histologic levels of osseointegration for titanium vs zirconia dental implants. Materials and Methods: This systematic review was conducted following the PRISMA guidelines and was registered in PROSPERO (CRD42021236781). Electronic and manual searches were carried out through the PubMed/MEDLINE, PubMed Central, and Embase databases with a platform-specific search strategy combining controlled terms (MeSH and Emtree) and text words. The articles were selected by two independent investigators who evaluated the articles based on the criteria for eligibility. Results: A total of 17 articles were included. All were preclinical studies. The populations included dogs (27.55%), minipigs (14.28%), rats (14.28%), and rabbits (43.89%); and the implantation site varied among the mandible (36.82%), maxilla (9.04%), tibia (17.64%), skull (10.70%), and femur (25.80%). A total of 370 titanium (Ti) implants and 537 zirconia (Zr) implants were evaluated. The average osseointegration (% bone-to-implant contact) for Zr was 55.51% (17.6% to 89.09%), and for Ti was 58.50% (23.2% to 87.85%). There was no statistical difference between studies at the 2-month follow-up (P = .672), but this difference was significant at 1 and 3 months (P < .001). Conclusions: Within the limitations of this review, Zr implants had a similar level of osseointegration compared to Ti implants. Nonetheless, because these findings are based on preclinical research, all data must be carefully examined.

Influence of Restorative Material on the Distribution of Loads to the Bone in Hybrid Abutment Crowns-In Vitro Study.

Background: The objective of this study was to evaluate the load transmitted to the peri-implant bone by seven different restorative materials in single-unit rehabilitations with morse taper implants using a strain gauge. Materials: In a polyurethane block that simulated type III bone, a morse taper platform implant was installed (3.5 × 11 mm) in the center and 1 mm below the test base surface, and four strain gauges were installed around the implant, simulating the mesial, distal, buccal and lingual positions. Seven similar hybrid abutment crowns were crafted to simulate a lower premolar using different materials: 1-PMMA; 2-glass ceramic over resin matrix; 3-PEEK + lithium disilicate; 4-metal-ceramic; 5-lithium disilicate; 6-zirconia + feldspathic; 7-monolithic zirconia. All groups underwent axial and oblique loads (45 degrees) of 150 N from a universal testing machine. Five measurements (n = 5) were performed with each material and for each load type; the microdeformation data underwent statistical analysis. The data were obtained in microdeformation (µÎµ), and the significance level was set at p ≤ 0.05. Results: There was no statistically significant difference in the evaluation among the materials under either the axial load or the oblique load at 45 degrees. In turn, in the comparison between axial load and oblique load, there was a difference in load for all materials. Conclusion: The restorative material did not influence the load transmitted to the bone. Furthermore, the load transmitted to the bone was greater when it occurred obliquely at 45° regardless of the material used. In conclusion, it appeared that the different elastic modulus of each material did not influence the load transmission to the peri-implant bone.

Evaluation of Behavior of Castable versus Machined Solid Abutments for Morse Tapper Implant Connection: A Clinical Retrospective Study.

Objective: The primary objective of the present retrospective clinical study was to evaluate and compare the clinical performance presented by castable abutments developed for the MT system versus intermediate machined abutments, specifically regarding prosthetic or implant fractures/loss; the secondary objective was to verify the looseness of the abutments and the behavior of the peri-implant soft tissues. Methods: This clinical retrospective study was conducted on patients rehabilitated between 2019 and 2020. Inclusion criteria were patients in good general health, with an implants-supporting single crown; with solid machined abutments (control group) or castable UCLA abutments; with a connection portion (base) machined in cobalt-chrome (test group) over Morse taper DuoCone implants in the posterior mandible area; and at least two years in function. Clinical assessment was carried out by the same professional, considering the following parameters: (A) prosthetic: (i) loosening of the fixation screw, (ii) fracture of the screw and (iii) the number of times the patient had some type of complication after the installation of the prostheses were evaluated; (B) biological: (i) without keratinized mucosa (KM), (ii) 1 mm or less, (iii) between 1 and 2 mm and (iv) greater than 2 mm of KM width; and the presence or absence of mucositis. Furthermore, radiographic evaluation was performed in order to assess the marginal bone loss. These evaluations permitted to compare the groups analyzed and patients enrolled. Data were statistically analyzed, with the level of significance set at α = 0.05. Results: 79 patients with 120 MT implants were evaluated (80 castable UCLA abutments and 40 machined solid abutments). The follow-up was from 2 to 4 years. There was a 100% implant survival rate. Therefore, the control group showed two fractured abutments (5%) and no abutment loosening (95% for prosthetic survival rate), whereas the test group showed no abutment fracture but nine loosening screws (11.3%) (100% for prosthetic survival rate). Keratinized mucosa was considered thin or absent in 19 implants in the control group (47.5%) and 42 in the test group (52.5%). Mucositis was found in 11 implants in the control group (27.5%) and 27 in the test group (33.8%). A positive correlation was observed between the width of keratinized mucosa and mucositis (r = 0.521, p = 0.002). The mean marginal bone loss was 2.3 mm, ranging from 1.1 to 5.8 mm. No correlation was observed when considering marginal bone loss versus the three parameters (implant diameter, implant length and time of the prosthesis in function). Conclusions: The results suggest that UCLA-type abutments are a viable option for rehabilitating implants with Morse taper connections, suggesting lower fracture risk. Further research is necessary to confirm these findings and thoroughly evaluate the clinical performance and long-term outcomes.

New strategy for osseodensification during osteotomy in low-density bone: an in vitro experimental study.

The goal of this in vitro study was to evaluate and propose a new strategy for osseodensification technique using a drill counterclockwise to densification of bone of low density. Synthetic bone blocks of two different low densities (type III and IV) were used for the tests. The conventional drilling group (CD group) used Turbo-drill in a clockwise direction, and the osseodensification group (OD group) applied Turbo-drill in a counterclockwise direction. The applied tests were: (i) measurement of the temperature variation (ΔT) and (ii) measurement of the torque during the osteotomies, comparing the new strategy with the conventional drilling. Both groups were tested without (condition c1) and with (condition c2) irrigation, generating four subgroups: CDc1, CDc2, ODc1, and ODc2. Twenty osteotomies were made for each subgroup with a thermocouple positioned intra-bone (1 mm distant from the osteotomy) to measure the temperature produced. Other 20 samples/group were used to measure the torque value during each osteotomy in both synthetic bone density blocks. The mean of the ΔT during the osteotomies in type III bone was: 6.8 ± 1.26 °C for the CDc1 group, 9.5 ± 1.84 °C for the ODc1, 1.5 ± 1.35 °C for the CDc2, and 4.5 ± 1.43 °C for ODc2. Whereas, in the type IV bone, the ΔT was: 5.2 ± 1.30 °C for the CDc1 group, 7.0 ± 1.99 °C for the ODc1, 0.9 ± 1.05 °C for the CDc2, and 2.7 ± 1.30 °C for ODc2. The maximum torque during the osteotomies was: 8.8 ± 0.97 Ncm for CD samples and 11.6 ± 1.08 Ncm for OD samples in the type III bone; and 5.9 ± 0.99 Ncm for CD samples and 9.6 ± 1.29 Ncm for OD samples in the type IV bone. Statistical differences between the groups were detected in tests and conditions analyzed (p < 0.05). Using the drill counterclockwise for osseodensification in low-density bone generated a significantly greater torque of a drill than in CD and temperature variation during osteotomies. However, the temperature range displayed by the OD group was below critical levels that can cause damage to bone tissue.

Biomechanical evaluation of abutment stability in morse taper implant connections in different times: A retrospective clinical study compared with an in vitro analysis.

Objectives: Micromotion between a dental implant and abutment can adversely affect clinical performance and compromise successful osseointegration by creating a bacterial harbor, enabling screw loosening, and imparting disruptive lateral forces on the cortical bone. Thus, the aim of the present study was to measure the abutment stability evolution using resonance frequency analysis (RFA) in vivo at four different times (baseline, 3, 4, and 12 months), and compare these data obtained with the RFA measured after mechanical cycling (in vitro) corresponding to the proposed times in numbers of cycles. Methods: To evaluate the abutment stability, RFA was performed in 70 sets of implant/abutment (IA) with a total of 54 patients (31 women, 23 men). These IA sets were divided into three groups, according to the abutment angulation: straight abutment (Abt1 group), 17-degree angled abutment (Abt2 group), and 30-degree angled abutment (Abt3 group). Abutment stability was measured immediately at implant placement and the abutment installation (T1), 3 (T2), 4 (T3), and 12 months (T4) later. For the in vitro analysis, ten sets of each group were submitted to mechanical cycling: T1 = 0 cycles, T2 = 90,000 cycles, T3 = 120,000 cycles, and T4 = 360,000 cycles. All data collected were statistically evaluated using the GraphPad Prism 5.01 software, with the level of significance was α = 0.05. Results: In vivo, the overall data of implant stability quotient (ISQ) values obtained for all groups in each evaluation time were 61.5 ± 3.94 (95% CI: [60-63]) at T1, 62.8 ± 3.73 (95% CI, [61-64]) at T2, 63.4 ± 3.08 (95% CI: [61-64]) at T3, and 65.5 ± 4.33 (95% CI: [63-68]) at T4. Whereas in vitro, the ISQ were 61.5 ± 2.66 (95% CI: [59-63]) at T1, 63.2 ± 3.02 (95% CI, [61-65]) at T2, 63.9 ± 2.55 (95% CI: [62-66]) at T3, and 66.5 ± 2.97 (95% CI: [64-68]) at T4. In both evaluations (in vivo and in vitro), the data showed a significant difference (ANOVA test with p < 0.0001). Conclusions: The RFA to measure the abutment stability used in this study showed that there was a progressive increase in stability among the predetermined times for the measurements, in both analysis (in vivo and in vitro). Furthermore, the values at each time point were similar, with no statistical difference between them.

Marginal Bone Level and Clinical Parameter Analysis Comparing External Hexagon and Morse Taper Implants: A Systematic Review and Meta-Analysis.

The goal of this systematic review was to verify the marginal bone loss (MBL) and other clinical parameters comparing external hexagon (EH) and Morse taper (MT) implants when they were evaluated within the same study. The focused question was, "For patients (P) treated with external connection (I) or Morse taper (C) dental implants, were there differences in the marginal bone crest maintenance after at least three months in occlusal function (O)"? As for the inclusion criteria that were considered, they included clinical studies in English that compared the MBL in implants with EH and MT, with follow-up of at least three months, that were published between 2011 and 2022; as for the exclusion criteria, they included publications investigating only one type of connection that analyzed other variables and did not report results for the MBL, reports based on questionnaires, interviews, and case reports/series, systematic reviews, or studies involving patients with a significant health problem (ASA Physical Status 3 and above). The PubMed/MEDLINE, Embase, and Web of Science databases were screened, and all of the data obtained were registered in a spreadsheet (Excel®). The Jadad scale was used to assess the quality of the studies. A total of 110 articles were initially identified; 11 were considered for full-text reading. Then, six articles (four RCTs and two prospective studies) met the eligibility criteria and were included in this study. A total of 185 patients (mean age of 59.71) were observed, and the follow-up ranged from 3 months to 36 months. A total of 541 implants were registered (267 EH and 274 MT). The survival rate ranged between 96% and 100% (the average was 97.82%). The MBL was compared among all periods studied; therefore, the common assessment period was the 12-month follow-up, presenting greater MBL for EH than for MT (p < 0.001). A mean MBL of 0.60 mm (95% CI 0.43-0.78) was found after the same period. BoP was reported in 5 studies and plaque index was reported in 4 (2 with more than 30%). Deep PD was observed in three studies. High heterogeneity was observed (I2 = 85.06%). Thus, within the limitation of this review, it was possible to conclude that there is higher bone loss in EH than in MT implants when evaluating and comparing this variable within the same study. However, the results must be carefully interpreted because of this review's limited number of clinical studies, the short assessment period, and the high heterogeneity found.

Current Status of Peri-Implant Diseases: A Clinical Review for Evidence-Based Decision Making.

BACKGROUND: the prevalence of peri-implant diseases is constantly growing, particularly with the increasing use of dental implants. As such, achieving healthy peri-implant tissues has become a key challenge in implant dentistry since it considers the optimal success paradigm. This narrative review aims to highlight the current concepts regarding the disease and summarize the available evidence on treatment approaches clarifying their indications for usage following the World Workshop on the Classification of Periodontal and Peri-implant Diseases (2017). METHODS: we reviewed the recent literature and conducted a narrative synthesis of the available evidence on peri-implant diseases. RESULTS: scientific evidence on case definitions, epidemiology, risk factors, microbiological profile, prevention, and treatment approaches for peri-implant diseases were summarized and reported. CONCLUSIONS: although there are numerous protocols for managing peri-implant diseases, they are diverse and nonstandardized, with no consensus on the most effective, leading to treatment confusion.

Marginal Bone Level and Biomechanical Behavior of Titanium-Indexed Abutment Base of Conical Connection Used for Single Ceramic Crowns on Morse-Taper Implant: A Clinical Retrospective Study.

The goal of this retrospective clinical study was to evaluate the behavior of Morse-taper indexed abutments by analyzing the marginal bone level (MBL) after at least 12 months of function. Patients rehabilitated with single ceramic crowns between May 2015 and December 2020 received single Morse-taper connection implants (DuoCone implant) with two-piece straight abutment baseT used for at least 12 months, presenting periapical radiograph immediately after crown installation were enrolled. The position of the rehabilitated tooth and arch (maxilla or mandible), crown installation period, implant dimensions, abutment transmucosal height, installation site (immediate implant placement or healed area), associated with bone regeneration, immediate provisionalization, and complications after installation of the final crown were analyzed. The initial and final MBL was evaluated by comparing the initial and final X-rays. The level of significance was α = 0.05. Seventy-five patients (49 women and 26 men) enrolled had a mean period of evaluation of 22.7 ± 6.2 months. Thirty-one implant-abutment (IA) sets had between 12-18 months, 34 between 19-24 months, and 44 between 25-33 months. Only one patient failed due to an abutment fracture after 25 months of function. Fifty-eight implants were placed in the maxilla (53.2%) and 51 in the mandible (46.8%). Seventy-four implants were installed in healed sites (67.9%), and 35 were in fresh socket sites (32.1%). Thirty-two out of these 35 implants placed in fresh sockets had the gap filled with bone graft particles. Twenty-six implants received immediate provisionalization. The average MBL was -0.67 ± 0.65 mm in mesial and -0.70 ± 0.63 mm in distal (p = 0.5072). The most important finding was the statistically significant difference comparing the values obtained for MBL between the abutments with different transmucosal height portions, which were better for abutments with heights greater than 2.5 mm. Regarding the abutments' diameter, 58 had 3.5 mm (53.2%) and 51 had 4.5 mm (46.8%). There was no statistical difference between them, with the following means and standard deviation, respectively, -0.57 ± 0.53 mm (mesial) and -0.66 ± 0.50 mm (distal), and -0.78 ± 0.75 mm (mesial) and -0.746 ± 0.76 mm (distal). Regarding the implant dimensions, 24 implants were 3.5 mm (22%), and 85 implants (78%) had 4.0 mm. In length, 51 implants had 9 mm (46.8%), 25 had 11 mm (22.9%), and 33 implants were 13 mm (30.3%). There was no statistical difference between the abutment diameters (p > 0.05). Within the limitations of this study, it was possible to conclude that better behavior and lesser marginal bone loss were observed when using abutment heights greater than 2.5 mm of transmucosal portion and when placed implants with 13 mm length. Furthermore, this type of abutment showed a little incidence of failures within the period analyzed in our study.

Implant Survival in Patients with Chronic Kidney Disease: A Case Report and Systematic Review of the Literature.

BACKGROUND: The aim of this systematic review and case reports was to evaluate osseointegration and implant survival rate in patients with chronic kidney disease. METHODS: The paper screening process was conducted on electronic databases in order to identify clinical studies concerning the study topic. The literature data were evaluated for eligibility and studies were included for the qualitative synthesis. The case report concerned a male subject affected by renal disorders, a candidate for full arch immediate loading procedure. RESULTS: The article screening process reported a total of 54 manuscripts and one paper identified through the manual search. At the end of the review process, a total of 45 articles were excluded while nine manuscripts were included for the descriptive synthesis. No significant complications or events were present during the intraoperative/post-operative phases. The clinical course reported no significant inflammation or symptoms. At follow-up, the rehabilitation was found to be functionally and aesthetically integrated with no complications, probing, or bone resorption. CONCLUSIONS: The available evidence supports the clinical efficacy of the early implant placement protocol. Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri-implant hard tissue compared with immediate implant placement.

Atmospheric Plasma Lingual Frenectomy Followed by Post Operative Tongue Exercises: A Case Series.

The lingual frenulum is a submucosal component significantly involved in the mobility of the tongue. In the case of short lingual frenulum, different surgical approaches have been proposed. Atmospheric plasma is a thermal technique of vaporization or sublimation of the superficial tissues, without going deep, and the resulting fine carbonized layer avoids bleeding. The aim of the present investigation was to evaluate the effectiveness of atmospheric plasma (voltaic arc dermabrasion) for the frenectomy of a short lingual frenulum. A total of 30 patients with an age range between 6−11 years old and a class III/IV Kotlow's ankyloglossia classification were included in the study. The Kotlow's free-tongue, maximal interincisal mouth opening (MIO, mm) and interincisal mouth opening with tongue tip to maxillary incisive papillae at roof of mouth (MOTTIP, mm) were calculated at the baseline, immediately postoperatively (T0), at one week (T1), one month (T2) and two months (T3). A significant increase of Kotlow's measurements, MOTTIP and MIO were detected when comparing the baseline and the T0 (p < 0.05). No significant difference was detected between the T0, T1 and T2 (p > 0.05). The atmospheric plasma demonstrated a very minimal invasive approach for frenectomy, without important or fibrotic complications and with very low recurrence rates.

Randomized Clinical Trial Comparing Insertion Torque and Implant Stability of Two Different Implant Macrogeometries in the Initial Periods of Osseointegration.

Objectives: The present study compared two implants with different macrogeometries placed in healed alveolar sites, evaluating the insertion torque (ITV) and implant stability quotient (ISQ) values at three different periods. Methods: Seventy patients with a total of 100 dental implants were allocated into two groups (n = 50 per group): DuoCone implants (DC group) that included 28 implants in the maxilla and 22 in the mandible, and Maestro implants (MAE group) that included 26 in the maxilla and 24 in the mandible. The ITV was measured during the implant placement, and the ISQ values were measured immediately at implant placement (baseline) and after 30 and 45 days. Results: The mean and standard deviations of the ITV were statistically significant (p < 0.0001), 56.4 ± 6.41 Ncm for the DC group and 29.3 ± 9.65 Ncm for the MAE group. In the DC group, the ISQs ranged between 61.1 ± 3.78 and 69.8 ± 3.86, while the MAE group presented similar values compared with the other group, ranging between 61.9 ± 3.92 and 72.1 ± 2.37. Conclusions: The value of implant insertion torque did not influence the ISQ values measured immediately after implant placement. However, the ITV influenced the ISQ values measured in the two initial periods of osseointegration, with implants installed with lower torques presenting higher ISQ values.

Comparative analysis of the mechanical limits of resistance in implant/abutment set of a new implant design: An in vitro study.

OBJECTIVE: The aim of the present in vitro study was to evaluate the resistance on quasi-static forces and in the fatigue mechanical cycling of a new implant design compared to two other conventional implant designs. MATERIALS AND METHODS: Eighty-eight implants with their respective abutments were tested and distributed into four groups (n = 22 per group): Morse taper connection implant (MT group), conventional external hexagon implant (EH con group), new Collo implant of external hexagon with the smooth portion out of the bone insertion (EH out group), and new Collo implant of external hexagon with the implant platform inserted to the bone level (EH bl group). All the sets were subjected to quasi-static loading in a universal testing machine, and we measured the maximum resistance force supported by each sample. Another 12 samples from each group were submitted to the cyclic fatigue test at 4 intensities of forces (n = 3 per force): 80%, 60%, 40%, and 20%. The number of cycles supported by each sample at each force intensity was evaluated. RESULTS: The three groups of implants with external hexagon connection had similar maximum strength values of the sets (p > 0.05). Meanwhile, samples from the MT group showed the highest resistance values in comparison to the other three groups (p < 0.05). In the fatigue test, the Collo out group supported a smaller number of cycles that led to the fracture than the other 3 groups proposed at loads of 80%, 60%, and 40%, and only at the load value of 20% all groups had the same performance. CONCLUSIONS: Within the limitations of the present in vitro study, the results showed that the new Collo implant performs better when installed at bone level.

Comparative evaluation of two collagen-based biomaterials with different compositions used for bone graft: An experimental animal study.

A large number of materials with different compositions and shapes have been proposed and studied for the purpose of bone tissue regeneration. Collagen-based materials have shown promising results for this application, with improved physicochemical properties. The aim of the present in vivo animal study was to evaluate and compare two commercially available collagen-based biomaterials for bone regeneration, with these being implanted in circumferential bone defects created in the calvarium of rabbits. Twenty rabbits received bilateral parietal osteotomies, performed with the aid of a 6.5 mm diameter trephine. Two groups were created: the BC group, where the defect was filled with a scaffold composed of 90% bovine bone particles and 10% porcine collagen, and the EG group, where the defect was filled with a scaffold composed of 75% hydroxyapatite particles of bovine origin and 25% bovine collagen. Ten animals were sacrificed at 30 days and another 10 at 45 days after implantation, and the samples were processed and histologically analyzed. In the evaluations of the samples at 30 days, no important differences were found in the results. However, in the samples at 45 days after surgery, the EG group showed better results than the BC group samples, mainly in terms of the amount of bone matrix formation (P < 0.0001) and the volume in area measured in each sample, where the EG group had a value 65% higher than that in the BC group samples. Based on the results obtained, we conclude that the amount of collagen and the particle characteristics present in the composition of the scaffolds can directly influence the amount of neoformation and/or bone regeneration.

Effects of insertion torque values on the marginal bone loss of dental implants installed in sheep mandibles.

The aim of the present in vivo study was to analyze and compare the effects on the crestal bone healing of two different implant macrogeometries installed in fresh socket areas and in normal bone areas with different insertion torque values. Two implant macrogeometries were used in the present study, DuoCone implant (DC) and Maestro implant (MAE), forming four groups: group DCws, in which the implants were installed in healing bone (without a socket); group DCfs, in which the implants were installed in post-extraction areas (fresh sockets); group MAEws, in which the implants were installed in healing bone (without a socket); group MAEfs, in which the implants were installed in post-extraction areas (fresh sockets). After 30 and 90 days of implantations in the bilateral mandibles of 10 sheep, eighty implants were evaluated through digital X-ray images and histologic slices. The crestal bone position in relation to the implant platform shoulder was measured and compared. The measured insertion torque was 47.2 ± 4.69 Ncm for the DCws group, 43.4 ± 4.87 Ncm for the DCfs group, 29.3 ± 3.16 Ncm for the MAEws group, and 27.7 ± 4.41 Ncm for the MAEfs group. The radiographic mesio-distal and histological bucco-lingual analyses showed significantly greater vertical bone loss in the implants installed with high torque (DC groups) in comparison to the implants installed with a low torque (MAE groups) (p < 0.05), at both evaluation times. In general, low insertion torque values (Maestro implants) showed better results of MBL when compared to implants installed with higher torque values (Duo Cone implants). Moreover, our results showed that the implants installed in the sites without sockets showed a less MBL in comparison with the implants installed in sites of fresh sockets.

Biomechanical and histological evaluation of four different implant macrogeometries in the early osseointegration process: An in vivo animal study.

This study aims to evaluate the effects of implant macrogeometry on the early period of the osseointegration process, comparing four different implant models through biomechanical and histological analysis after implantation in rabbit tibiae. Twenty New Zealand rabbits were used, evaluated at two different times (21 and 28 days) after installation of the implant. Eighty implants with different macrogeometries were used, forming four groups (n = 20 per group): cylindrical implants Ø4.1 mm and 8 mm in length (STRc group); cylindrical-conical implants Ø4.1 mm and 8 mm in length (STRt group); tapered implants Ø4.3 mm and 8 mm in length (NOBt group); and tapered implants with healing chambers Ø4.0 mm and 8 mm in length (MAEt group). Ten samples from each group were analyzed at each proposed time. The initial implant stability quotient (ISQ) was measured by resonance frequency analysis, both at the time of installation and at the time of sacrifice. In the histological sections, the percentage of bone-implant contact (BIC%), newly formed bone, osteoid matrix, and medullary spaces were measured in the pre-determined cortical and medullary bone portion for each sample. The three tapered implant groups (STRt, NOBt, and MAEt) showed higher values for the analyzed parameters in the early osseointegration period, in comparison with the cylindrical implant group (STRc). In all parameters, the three tapered groups showed no difference (p > 0.05); however, all three tapered groups presented significant differences, when compared to the cylindrical group (p < 0.05). No correlation was detected between the parameters analyzed. Within the limitations of the present study, in all parameters analyzed, the tapered implants demonstrated greater results when compared to the cylindrical implants.

Effects of different switched or not-switched implant and abutment platform designs and marginal bone loss on fracture strength: An in vitro study.

STATEMENT OF PROBLEM: The use of reduced platform sets (implants and abutments) can help to control crestal bone loss around implants, which is essential for optimizing esthetics and biomechanical behavior. However, the information available on the fracture resistance of implants with a reduced platform is sparse. PURPOSE: The purpose of this in vitro study was to analyze the maximum fracture strength value of implants with different platform designs during quasistatic fatigue, followed by a simulation of different bone levels of cervical insertion. MATERIAL AND METHODS: One hundred and twenty sets of dental implants and abutments with different diameters and platform designs were tested. All implants had an internal hexagon connection and conical macrogeometry. Four groups (n=30) were studied: Ø4.0-mm implants with a regular matched platform (rMatch group), Ø4.0-mm implants with a regular switched platform (PSwitch group), Ø5.0-mm implants with a wide matched platform (wMatch group), and Ø5.0-mm implants with a wide switched platform (wSwitch group). Three conditions simulating different levels of bone position around the cervical portion of the implants were proposed: insertion at the implant shoulder level=0 mm (L0), level=3 mm of insertion loss (L3), and level=5 mm of insertion loss (L5). All sets of all groups and proposed insertion level were subjected to a fracture strength test at 30 degrees in relation to the axis of the sets in a universal testing machine. RESULTS: Regardless of the insertion levels tested, the switched platform implants (rSwitch and wSwitch groups) showed similar mean fracture strength values (P>.05), while the implants of matched platforms (rMatch and wMatch groups) showed different fracture strength values for all insertion levels tested (P<.001). CONCLUSIONS: The fracture strength values of the switched platform implants were lower at all insertion levels tested. However, for all insertion levels tested, the implants with a switched platform presented less deformation, whereas, in the matched platform implants, there was significant deformation of the implant structure.