Changes in implant stability using different site preparation techniques: Osseodensification drills versus piezoelectric surgery. A multi-center prospective randomized controlled clinical trial

Influence of implant distribution on the biomechanical behaviors of mandibular implant-retained overdentures: a three-dimensional finite element analysis

OBJECTIVE

To assess stress distribution in peri-implant bone and attachments of mandibular overdentures retained by small diameter implants, and to explore the impact of implant distribution on denture stability.

METHODS

Through three-dimensional Finite Element Analysis (3D FEA), four models were established: three models of a two mandibular implants retained overdenture (IOD) and one model of a conventional complete denture (CD). The three IOD models consisted of one with two implants in the bilateral canine area, another with implants in the bilateral lateral incisor area, and the third with one implant in the canine area, and another in the lateral incisor area. Three types of loads were applied on the overdenture for each model: a 100 N vertical load and a inclined load on the left first molar, and a100N vertical load on the lower incisors. The stress distribution in the peri-implant bone, attachments, and the biomechanical behaviors of the overdentures were analyzed.

RESULTS

Despite different distribution of implants, the maximum stress values in peri-implant bone remained within the physiological threshold for all models across three loading conditions. The dispersed implant distribution design (implant in the canine area) exhibited the highest maximum stress in peri-implant bone (822.8 µe) and the attachments (275 MPa) among the three IOD models. The CD model demonstrated highest peak pressure on mucosa under three loading conditions (0.8188 Mpa). The contact area between the denture and mucosa of the CD model was smaller than that in the IOD models under molar loading, yet it was larger in the CD model compared to the IOD model under anterior loading. However, the contact area between the denture and mucosa under anterior loading in all models was significantly smaller than those under molar loading. The IOD in all three models exhibited significantly less rotational movement than the complete denture. Different implant positions had minimal impact on the rotational movement of the IOD.

CONCLUSION

IOD with implants in canine area exhibited the highest maximum stress in the peri-implant bone and attachments, and demonstrated increased rotational movement. The maximum principal stress was concentrated around the neck of the small diameter one-piece implant, rather than in the abutment. An overdenture retained by two implants showed better stability than a complete denture.

Breakthroughs in Oral and Maxillofacial Surgery

In the field of oral and maxillofacial surgery, continuous advances have ushered in a new era of innovation, profoundly influencing this branch of medicine [...].

The effectiveness of chitosan as a hemostatic in dentistry in patients with antiplatelet/anticoagulant therapy: systematic review with meta-analysis

Hemorrhage control is a crucial aspect of dental procedures, and achieving efficient hemostasis remains a key challenge. The advent of hemostatic dressings has revolutionized the field of dentistry by providing effective and convenient solutions for managing bleeding in vari-ous dental scenarios. This article aims to provide an overview of hemostatic dressings, their mechanisms of action, and their diverse applications in dentistry. We applied the following Pop-ulation, Exposure, Comparator, and Outcomes (PICO) model to assess the document eligibility. A literature search was performed on major search engines, using keywords. At the end of the search, 3 articles were selected that matched the PICO. Three items were selected after the screen-ing process, and bleeding times were analyzed between the control group and the study group. The overall effect showed a substantial and statistically significant difference with bleeding time in favour of HDD-treated patients, showing that this garrison is very useful in controlling bleed-ing for patients taking anticoagulants and antiplatelets (Mean difference - 5.61; C.I. -5.70, - 5.52); Overall, hemostatic dressings have revolutionized the management of bleeding in dentistry, offering a promising solution to achieve optimal hemostasis, improve treatment outcomes, and enhance patient care, particularly Hemcon.

Quality of life in patients in South Korea requiring special care after fixed implants: a retrospective analysis

BACKGROUND

The study on oral health-related quality of life (OHRQoL) of disabled patients is rare but critical for welfare of patients. The aim of this study was to examine the effect of fixed implants in edentulous areas on OHRQoL in Korean disabled patients.

METHODS

The OHRQoL of 63 disabled individuals was evaluated using the Oral Health Impact Profile (OHIP)-14 questionnaires and studied by potential affecting variables such as age, sex, disability severity, and time of disability acquisition. Wilcoxon-signed rank tests were used to examine the OHIP-14 scores for those who had pre/post-fixed implants. Multiple linear regression analysis was used to examine the relationships between factors and OHIP-14 scores before and after implants. A partial correlation analysis was also performed to determine which variables influenced OHIP-14 scores before and after treatment. The Mann-Whitney test was employed for sex and time of disability acquisition analysis (α = 0.05).

RESULTS

Significant improvement was found in OHIP-14 post-implant treatment scores (P < .001). After implant treatment, the severity of disability produced significantly different results (P = .009). Pearson's correlation coefficient between severity of disability and pre/post-implant OHIP-14 scores was 0.265 (P = .030). After controlling for severity of disability, the results showed older patients had lower OHIP-14 scores (P = .032). No differences were found for sex or time of disability acquisition (congenital vs. acquired).

CONCLUSIONS

Fixed implant treatment improved OHRQoL for disabled patients, and the severity of disability was positively correlated with improvement of OHRQoL. For patients with a similar level of disability, the OHRQoL decreased with age.

A randomized controlled trial comparing conventional and piezosurgery methods in mandibular bone block harvesting from the retromolar region

BACKGROUND

Although piezosurgery is now commonly used for various applications in maxillofacial surgery, its advantages over conventional rotary instruments in terms of postoperative edema, ecchymosis, postoperative morbidity, and prolonged osteotomy time have been questioned.

MATERIALS AND METHODS

This study aimed to compare the efficiency, postoperative morbidity, and complication rates of piezosurgery and conventional methods in harvesting autogenous ramus grafts. In this randomized controlled trial, 21 patients (32 sides) underwent autogenous graft harvesting from the ramus area, with 16 sites treated using piezosurgery and 16 using the conventional method. The primary outcomes measured were osteotomy time, total operation time, and postoperative morbidity. Complication rates were also evaluated.

RESULTS

The final analysis encompassed 19 patients, accounting for a total of 30 donor sites, following the exclusion of two patients who were unable to attend the scheduled follow-up visits. A total of 19 patients (30 donor sites) were included in the final analysis. No statistically significant difference was found in the mean osteotomy time between the piezosurgery group (mean: 10.35, SD: 2.74 min) and the conventional group (mean: 8.74, SD: 2.74 min) (95% CI: -3.67 to 0.442, p = 0.119). The total operation time, postoperative pain, and swelling were not significantly different between the two groups (p > 0.05). The complication rates, including wound dehiscence and inferior alveolar nerve exposure, were similar in both groups.

CONCLUSIONS

Piezosurgery can be safely used for harvesting autogenous ramus grafts and does not increase osteotomy or total operation time compared to the conventional method. The postoperative morbidity and complication rates were also similar, indicating that both techniques can be effectively employed in clinical practice.

CLINICAL TRIAL REGISTRATION

The protocol was registered on clinicaltrials.gov (ID: NCT05548049, First registration date: 21/09/2022).

Biomaterials and Clinical Application of Dental Implants in Relation to Bone Density-A Narrative Review

Titanium has been the material of choice for dental implant fixtures due to its exceptional qualities, such as its excellent balance of rigidity and stiffness. Since zirconia is a soft-tissue-friendly material and caters to esthetic demands, it is an alternative to titanium for use in implants. Nevertheless, bone density plays a vital role in determining the material and design of implants. Compromised bone density leads to both early and late implant failures due to a lack of implant stability. Therefore, this narrative review aims to investigate the influence of implant material/design and surgical technique on bone density from both biomechanical and biological standpoints. Relevant articles were included for analysis. Dental implant materials can be fabricated from titanium, zirconia, and PEEK. In terms of mechanical and biological aspects, titanium is still the gold standard for dental implant materials. Additionally, the macro- and microgeometry of dental implants play a role in determining and planning the appropriate treatment because it can enhance the mechanical stress transmitted to the bone tissue. Under low-density conditions, a conical titanium implant design, longer length, large diameter, reverse buttress with self-tapping, small thread pitch, and deep thread depth are recommended. Implant material, implant design, surgical techniques, and bone density are pivotal factors affecting the success rates of dental implant placement in low-density bone. Further study is required to find the optimal implant material for a clinical setting's bone state.

A retrospective study of dynamic navigation system-assisted implant placement

BACKGROUND

To evaluate the accuracy of implant placement assisted by a dynamic navigation system, as well as its influencing factors and learning curve.

METHODS

At Macao We Care Dental Center, 55 cases of implant placement using dynamic navigation were retrospectively evaluated. To evaluate their accuracy, the apex, tip, and angle deviations of preoperatively planned and postoperatively placed implants were measured. The effects of the upper and lower jaws, different sites or lateral locations of dental implants, and the length and diameter of the implants on accuracy were analyzed, as well as the variation in accuracy with the increase in the number of surgical procedures performed by dentists.

RESULTS

The implant had an apex deviation of 1.60 ± 0.94 mm, a tip deviation of 1.83 ± 1.03 mm, and an angle deviation of 3.80 ± 2.09 mm. Statistical differences were observed in the tip deviation of implants at different positions based on three factors: jaw position, lateral location, and tooth position (P < 0.05). The tip deviation of the anterior teeth area was significantly greater than those of the premolar and molar areas. There were no statistically significant differences in apex deviation, tip deviation, or angle deviation between the implants of different diameters and lengths (P > 0.05). There were significant differences in the angle deviation between the final 27 implants and the first 28 implants. Learning curve analysis revealed that angle deviation was negatively correlated with the number of surgical procedures, whereas the regression of apex deviation and tip deviation did not differ statistically.

CONCLUSIONS

The accuracy of dynamic navigation-assisted dental implants meets the clinical needs and is higher than that of traditional implants. Different jaw positions, lateral locations, and implant diameters and lengths had no effect on the accuracy of the dental implants guided by the dynamic navigation system. The anterior teeth area had a larger tip deviation than the posterior teeth area did. As the number of dynamic implantation procedures performed by the same implant doctor increased, the angle deviation gradually decreased.

Effect of Implant Macro-Design and Magnetodynamic Surgical Preparation on Primary Implant Stability: An In Vitro Investigation

BACKGROUND

Macro-geometry and surgical implant site preparation are two of the main factors influencing implant stability and potentially determining loading protocol. The purpose of this study was to assess the initial stability of various implant macro-designs using both magnetodynamic and traditional osteotomy techniques in low-density bone. The parameters examined included peak insertion torque (PIT), implant stability quotient (ISQ), and peak removal torque (PRT).

METHODS

Four groups of 34 implants each were identified in accordance with the surgery and implant shape: T5 group (Five implant and osteotomy using drills); M5 group (Five implant and magnetodynamic osteotomy using Magnetic Mallet); TT group (TiSmart implant and osteotomy with drills); and MT group (TiSmart implant and magnetodynamic osteotomy). Every implant was placed into a low-density bone animal model and scanned using CBCT. The PIT and PRT were digitally measured in Newton-centimeters (Ncm) using a torque gauge device. The ISQ was analyzed by conducting resonance frequency analysis.

RESULTS

The PIT values were 25.04 ± 4.4 Ncm for T5, 30.62 ± 3.81 Ncm for M5, 30 ± 3.74 Ncm for TT, and 32.05 ± 3.55 Ncm for MT. The average ISQ values were 68.11 ± 3.86 for T5, 71.41 ± 3.69 for M5, 70.88 ± 3.08 for TT, and 73 ± 3.5 for MT. The PRT values were 16.47 ± 4.56 Ncm for T5, 26.02 ± 4.03 Ncm for M5, 23.91 ± 3.28 Ncm for TT, and 26.93 ± 3.96 Ncm for MT. Based on our data analysis using a t-test with α = 0.05, significant differences in PIT were observed between TT and T5 (p < 0.0001), M5 and T5 (p < 0.0001), and MT and TT (p = 0.02). Significant differences in the ISQ were found between TT and T5 (p = 0.001), M5 and T5 (p < 0.001), and MT and TT (p = 0.01). The PRT also exhibited significant differences between TT and T5, M5 and T5, and MT and TT (p < 0.0001).

CONCLUSION

Our data showed favorable primary implant stability (PS) values for both implant macro-geometries. Furthermore, the magnetodynamic preparation technique appears to be more effective in achieving higher PS values in low-density bone.

Investigating the impact of diameters and thread designs on the Biomechanics of short implants placed in D4 bone: a 3D finite element analysis

BACKGROUND

Dental implants emerge as a dependable and efficacious alternative for patients experiencing partial or complete tooth loss. The stability of these implants is influenced by surface topography and macro-level design. In cases where the height of the maxillary posterior region is diminished, employing short implants can prove advantageous. With the aim of examining the distribution of von Mises stress, strain, and micromovement in D4 bone quality surrounding platform-switched short implants, measuring 6 mm in length and featuring diameters ranging from 4 to 6 mm, as well as different thread designs, an in-depth finite element analysis was conducted under immediate loading conditions.

METHODOLOGY

A 3D finite element model was constructed to simulate maxillary molar crowns, incorporating an implant with a length of 6 mm and varying diameters and thread designs. The diameters utilized were 4/3.6 mm, 5/4 mm, and 6/4.8 mm, while the thread designs included buttress, square, and triangle patterns. Each model underwent analysis with a 100 N force applied in two directions: vertical and oblique, relative to the long axis of the implant. Stress, strain, and micromovement in the peri-implant region were recorded, employing the Ansys Workbench R v.18.1 software for modelling and analysis.

RESULTS

When comparing all three diameters, the wide diameter (6 mm threads) exhibited the lowest values of peri-implant von Mises stresses (3.3 MPa and 35.1 MPa), strains (194 Ɛ and 484 Ɛ), and micromovements (0.7 μm and 1.3 Ɛ) subjected to axial and non-axial loading of a 100 N force. Notably, square microthreads yielded the most favorable stress parameters among the different thread shapes, manifesting the minimum values of stress, strains, and micromovements in their vicinity.

CONCLUSION

For the treatment of atrophic ridges or in scenarios necessitating extensive surgical preparation of the implant site, a combination of short implants, wide diameters, and platform switching can be employed. In situations with reduced bone height and the requirement for an implant-supported prosthesis to replace a missing permanent maxillary molar, the utilization of wide-diameter platform-switched short implants measuring 6 mm in length, featuring a square thread design, should be taken into consideration.

The Effects of a Biomimetic Hybrid Meso- and Nano-Scale Surface Topography on Blood and Protein Recruitment in a Computational Fluid Dynamics Implant Model

The mechanisms underlying bone-implant integration, or osseointegration, are still incompletely understood, in particular how blood and proteins are recruited to implant surfaces. The objective of this study was to visualize and quantify the flow of blood and the model protein fibrinogen using a computational fluid dynamics (CFD) implant model. Implants with screws were designed with three different surface topographies: (1) amorphous, (2) nano-trabecular, and (3) hybrid meso-spikes and nano-trabeculae. The implant with nano-topography recruited more blood and fibrinogen to the implant interface than the amorphous implant. Implants with hybrid topography further increased recruitment, with particularly efficient recruitment from the thread area to the interface. Blood movement significantly slowed at the implant interface compared with the thread area for all implants. The blood velocity at the interface was 3- and 4-fold lower for the hybrid topography compared with the nano-topography and amorphous surfaces, respectively. Thus, this study for the first time provides insights into how different implant surfaces regulate blood dynamics and the potential advantages of surface texturization in blood and protein recruitment and retention. In particular, co-texturization with a hybrid meso- and nano-topography created the most favorable microenvironment. The established CFD model is simple, low-cost, and expected to be useful for a wide range of studies designing and optimizing implants at the macro and micro levels.

Multicentre Prospective Study Analysing Relevant Factors Related to Marginal Bone Loss: A Two-Year Evolution

INTRODUCTION

The aim of this prospective descriptive study was to analyse the possible variables associated with marginal bone loss in rehabilitated implants (Proclinic S.A.U, Zaragoza, Spain) two years after their prosthetic loading.

MATERIALS AND METHODS

Three clinical centres collaborated for a period of two years after the prosthetic rehabilitation of the implants (Proclinic S.A.U, Zaragoza, Spain), in which marginal bone loss and the possible associated variables were evaluated. The collection form comprised different variables throughout different stages of the implant procedure, from implant insertion to the subsequent prosthetic rehabilitation, over a two-year period. Data of the patients and implant characteristics were studied. Statistical analysis was performed with SPSS for qualitative (univariate logistic regressions, Chi2 test, and Haberman's corrected standardised residuals) and quantitative variables (Kolmogorov-Smirnov test).

RESULTS

The total study sample consisted of 218 implants (Proclinic S.A.U, Zaragoza, Spain). The sample presented a frequency of 99 men (45.4%) and 119 women (54.6%). The mean age of the patients among the reported cases was 58.56 ± 10.12 years. A statistically significant association was found between marginal bone loss 2 years after prosthetic rehabilitation placement and several variables, including age (under 55 years, 0.25 mm ± 0.56; 55-64 years, 0.74 mm ± 0.57; over 65 years, 0.63 mm ± 0.55; p < 0.0001), gender (female, 0.74 mm ± 0.61; male, 0.34 mm ± 0.51; p < 0.0001), bone quality (D1, 0.75 mm ± 0.62; D2, 0.43 mm ± 0.57; D3, 0.65 mm ± 0.60; p < 0.01), implant diameter (up to 4 mm, 0.49 mm ± 0.58; more than 4 mm, 1.21 mm ± 0.30; p < 0.0001), prosthetic connection type (direct to implant, 0.11 mm ± 0.58; transepithelial straight, 0.67 mm ± 0.57; transepithelial angled, 0.33 mm ± 0.25; p < 0001), implant model (internal conical, 0.17 mm ± 0.24; external conical, 0.48 mm ± 0.61; external cylindrical, 1.12 mm ± 0.32; p < 0.0001), prosthetic restoration type (full denture, 0.59 mm ± 0.59; partial denture, 0.50 mm ± 0.85; unitary crown, 0.08 mm ± 0.19; p < 0.05), and insertion torque (>35 N/cm, 0.53 mm ± 0.58; <35 N/cm, 1.04 mm ± 0.63; p < 0.01).

CONCLUSIONS

At 2 years, marginal bone loss following prosthetic rehabilitation was shown to be influenced by multiple factors. Correct implantological planning is of vital importance for successful rehabilitation.

Influence of Multiple Used Implant Drills on Their Cutting Performance and Fracture Resistance

This study aimed to analyze the influence of multiple uses of zirconia implant drills on their cutting performance and bending strength. The hypothesis was that drill usage and sterilization cycles would not affect drilling time or flexural strength. Sixty zirconia twist drills from Z-Systems were used to drill in the angulus mandibulae region of fresh porcine jaws. The drills were divided into four groups based on the cycle count, and the drilling time was measured. Bending strength tests were conducted using a universal testing machine, and statistical analysis was performed using ANOVA tests. The results showed that drilling times followed a normal distribution, and significant differences were observed in drilling times between group 1 and the other groups for the pilot drill. However, no significant differences were found for ø3.75 mm and ø4.25 mm drills, and drilling times also varied significantly among different drill diameters, regardless of the cycle count. Flexural strength did not significantly differ among drill diameters or sterilization cycles. Overall, using and sterilizing zirconia implant drills had no significant impact on drilling time or flexural strength. Nevertheless, drilling times did vary depending on the diameter of the drill. These findings provide valuable insights into the performance and durability of zirconia implant drills, contributing to the optimization of dental implant procedures.

Investigation of the Influence of Roughness and Dental Implant Design on Primary Stability via Analysis of Insertion Torque and Implant Stability Quotient: An In Vitro Study

In the placement of dental implants, the primary fixation between the dental implant and the bone is of great importance and corresponds to compressive mechanical fixation that aims to prevent micromovement of the implant. The aim of this research was to determine the role of roughness and the type of dental implant (tissue-level or bone-level) in implant stability, measured using resonance frequency analysis (RFA) and insertion torque (IT). We analyzed 234 titanium dental implants, placed in fresh calf ribs, at the half-tissue level and half-bone level. The implant surface was subjected to grit-blasting treatments with alumina particles of 120, 300, and 600 μm at a projection pressure of 2.5 bar, resulting in three types of roughness. Roughness was determined via optical interferometry. The wettability of the surfaces was also determined. Implant stability was measured using a high-precision torquemeter to obtain IT, and RFA was used to determine the implant stability quotient (ISQ). The results show that rough surfaces with Sa values of 0.5 to 4 μm do not affect the primary stability. However, the type of implant is important; bone-level implants obtained the highest primary stability values. A good correlation between the primary stability values obtained via IT and ISQ was demonstrated. New in vivo studies are necessary to know whether these results can be maintained in the long term.

Effects of Osseodensification on Primary Stability of Cylindrical and Conical Implants-An Ex Vivo Study

Primary stability is an important factor for dental implant success. In the past years, a new method for bone site preparation was introduced, named osseodensification (OD). OD produces a condensation of the trabecular portion of the bone, increasing bone-to-implant contact and primary stability. This study aims to compare the effect of OD in cylindrical and conical implants to conventional instrumentation. A total of forty implants, divided into four groups, were placed in porcine tibia: cylindrical conventional (1a), cylindrical OD (1b), conical conventional (2a) and conical OD (2b). Each implant was measured for implant stability quotient (ISQ), insertion torque (IT) and removal torque (RT). Group 2b showed the higher values for each of the evaluated parameters; groups 1b and 2b showed better results than 1a and 2a, respectively. Regarding the IT and RT, group 1b achieved higher values than group 2a, but not for ISQ. The inter-group comparison showed significant difference between groups 1a vs 2a, 1a vs 2b and 1b vs 2b for ISQ and 1a vs 1b and 1a vs 2b for RT analysis. OD resulted in improved ISQ, IT and RT of both cylindrical and conical implants.

Evaluation of hydrophilic surface osseointegration in low-density bone: Preclinical study in rabbits

The aim of this study was to evaluate the osseointegration of a hydrophilic surface (blasting + acid etching + immersion in isotonic solution) in comparison with that of a control surface (blasting + acid etching) using an experimental model of low-density bone. To perform the study, 24 rabbits were submitted to the installation of 4 implants in the iliac bone bilaterally: 2 implants with a control surface and 2 implants with a hydrophilic surface. The rabbits were euthanized at 2, 4, and 8 weeks after implant installation. After euthanasia, one implant from each surface was used to perform the removal torque analysis, and the other implant was used for the execution of non-decalcified histological sections and evaluation of the bone implant contact (% BIC) as well as the fraction of bone tissue area between the implant threads (% BBT). The implants with a hydrophilic surface presented higher %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) and % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) in the 2-week period. Furthermore, the hydrophilic surface presented higher removal torque in the 8-week period (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implants with a hydrophilic surface exhibited acceleration in the process of osseointegration, culminating in greater secondary stability in low-density bone than in implants with a control surface.

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.

A Randomized Clinical Trial Comparing Implants Placed in Two Different Biomaterials Used for Maxillary Sinus Augmentation

The objective of this study was to compare marginal bone loss, surgical and clinical complications, and dental implant survival rate in bilateral maxillary sinus augmented by autologous or porcine xenograft. A randomized controlled clinical trial using split-mouth design enrolled 12 consent adult patients (59.7 ± 8.7 years), who received bilateral maxillary sinus floor augmentation for oral rehabilitation with implant-supported prosthesis. Each patient received both the autologous bone from the mandible (control) or porcine xenograft (test) during the random bilateral sinus lift surgery. A total of 39 dental implants were placed in the posterior maxilla of the 12 patients after 6 months, being rehabilitated after the respective osseointegration period. Both graft materials demonstrated a high implant survival rate at 12 months: 95% for the xenograft side, only 1 implant without osseointegration, and 100% for the autologous side. Radiographic bone loss was low and similar for both groups: control group with a mean of 0.063 ± 0.126, and test group with a mean of 0.092 ± 0.163. No major surgical-related complications have occurred. Only one patient had several prosthetic complications due to fractures of prosthetic components. The maxillary sinus augmentation procedure, both with autologous bone and porcine xenograft materials, is an excellent clinical option procedure for the prosthetic rehabilitation of atrophic maxillae, with low marginal bone loss after one year follow-up, few clinical complications, and a high implant survival rate.

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.