Maxillary Posterior Region Research Articles

Three-dimensional digital anatomical measurements of pterygoid plates and posterior maxillary region

BackgroundThe posterior maxilla and skull base is a region with a complex anatomy. Accurate resection of the pterygoid plate is critical during a maxillectomy procedure. However, there is a paucity of functional and anatomical studies on the pterygoid plate and skull base. This study aimed to investigate functional anatomy of the pterygoid plate and its surrounding structures in the posterior maxilla to provide a better understanding of surgical procedures in this region.Methods3D software was used to measure 3D distances, angles, and areas of key anatomical landmarks on CT images of 100 hemifaces. Morphological classification of pterygoid plates was then performed.ResultsResults of comparing right and left pterygoid plates revealed no significant differences in dimensions or angles. Comparisons between sexes revealed that a few parameters were significantly different (P< 0.01), including pterygoid height on the left side, distance from the zygomatico-maxillary buttress to the infraorbital fissure (Zy-IOF), and area of the left lateral pterygoid plate. The morphology of the lateral pterygoid plate was classified into four types based on the shape of the middle region: middle convex (42%), double concave (36%), flattened (10%), and middle concave (12%). The morphology of pterygoid plates was classified based on the divergence of medial and lateral pterygoid plates, with the narrow type (56%) being more common than the wide type in this study cohort.ConclusionsThis 3D digital anatomical study measured key landmarks for maxillary resection. Such measurement has never been reported. This anatomical study provides surgeons with information on the anatomy of the posterior maxilla and allows for safer and more accurate resection of the difficult-to-resect posterior maxilla.

The Use of the Facial Sinus Wall as Bone Shell Onlay Graft for Maxillary Posterior Ridge Reconstruction: A Retrospective Case Series.

To evaluate the performance and clinical outcome of vertical and horizontal bone augmentation (VHBA) in posterior maxillary regions combining lateral window sinus floor elevation (LWSFE) with a horizontal bone shell technique applying the maxillary facial sinus wall as a bone plate. In 18 patients, LWSFE was combined with a horizontal bone shield augmentation procedure utilizing the maxillary facial sinus bone wall as a lateral bone plate. Both the sinus cavity and the lateral bone box created were grafted with a mixture of autogenous bone/venous blood and bovine bone mineral. The primary aim was to assess the performance of combined techniques enabling subsequent implant placement. Using radiographic measurements (preoperative, after VHBA, at implant placement, and at follow-up), bone gain/reduction of augmented horizontal ridge width (HRW) and vertical bone height (VBH) were evaluated. Additionally, clinical outcome assessing implant survival/success rate, marginal bone loss (MBL), and implant health (mucositis/peri-implantitis) was evaluated. For the combined VHBA techniques, HRW and VBH increased significantly (p < 0.001) from preoperative 3.5 ± 1.4 mm/3.6 ± 2.1 mm to 9.7 ± 1.9 mm/18.0 ± 1.6 mm post-augmentation. However, HRW and VBH dimensions decreased up to 8.9 ± 1.8 mm/17.1 ± 1.4 mm at implant placement and 8.6 ± 1.7 mm/16.7 ± 1.3 mm at follow-up evaluation (3.8 ± 1.8 years; p < 0.001, respectively). Augmented bone reduction was significantly higher (-7.7%) between the augmentation procedure and implant placement than in the post-implant-placement period (-2.5%). All implants survived (100%) representing peri-implant MBL of -0.9 ± 0.7 mm, pocket depth of 3.4 + 1.8 mm, and prevalences of 5%/0% for peri-implant mucositis/peri-implantitis. The combination of horizontal bone augmentation using local bone shield transfer from the maxillary facial sinus wall with LWSFE enables sufficient reconstruction of maxillary posterior ridge.

Clinical Outcomes and Cytokine Profile of Standard and Short Implant-supported Prostheses in Diabetics Treated for Periodontal Disease: A 5-year Study.

The present cross-sectional study aimed to assess the clinico-radiographic parameters as well as salivary levels of receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, and tumor necrosis factor-alpha (TNF-α) around standard and short dental implants (SDIs)-supported fixed partial denture in partially dentate type-II diabetes mellitus (T2DM) patients treated for periodontitis. The study comprised 4 groups: group 1 included T2DM patients with standard implants (n = 20); group II included non-T2DM patients with standard implants (n = 20); group III included T2DM patients with SDIs (n = 20); and group IV included non-T2DM patients with SDIs (n = 20). Participants eligible for the study included medically diagnosed T2DM patients with glycated hemoglobin (HbA1c) levels ≥ 6.5%, and non-T2DM participants with HbA1c levels between 4.0% and 5.0%. All had undergone previous periodontal therapy and had at least one standard implant and one SDI in the posterior maxillary or mandibular region. Exclusions were subjects with systemic conditions other than T2DM, recent use of steroids or antimicrobials, pregnancy or lactation, edentulism, misaligned dentition, or alcohol/tobacco use. Treatment involved non-surgical periodontal therapy, implant placement, and prosthetic procedures, with assessments including clinical (plaque index [PI], bleeding on probing [BOP], probing depth [PD]), radiographic (crestal bone loss [CBL]) parameters, and salivary cytokine levels including RANKL, OPG, IL-6, and TNF-α. The study groups, each comprising 20 participants, showed no significant differences in demographics, restoration type, T2DM duration, family history, body mass index, or brushing routine (p>0.05). At baseline and 5-year follow-up, T2DM participants exhibited poorer periodontal parameters compared to non-T2DM, with higher PI (baseline: 62.2 ± 5.8% vs 29.6 ± 3.7%; 5-year follow-up: 69.2 ± 6.1% vs 32.8 ± 3.8%), BOP (baseline: 30.5 ± 3.2% vs 18.2 ± 2.6%; 5-year follow-up: 35.5 ± 3.9% vs 20.5 ± 2.5%), PD (baseline: 5.5 ± 1.1 mm vs 3.1 ± 0.9 mm; 5-year follow-up: 4.2 ± 0.8 mm vs 2.4 ± 0.7 mm), and CBL (baseline: 4.4 ± 0.4 mm vs 2.0 ± 0.2 mm; 5-yearfollow-up: 4.9 ± 0.5 mm vs 2.3 ± 0.3 mm), regardless of implant type. Salivary cytokine levels (RANKL, OPG, IL-6, TNF-α) were consistently higher in T2DM groups than non-T2DM across both implant types. Participants with SDIs showed comparable clinico-radiographic outcomes and salivary levels of cytokines to standard implants. The application of SDI-supported rehabilitation in T2DM and non-diabetics showed comparable clinico-radiographic outcomes and salivary levels of cytokines to standard dental implants. Furthermore, T2DM patients exhibit poorer periodontal health and elevated inflammatory markers in patients with standard implants and SDIs.

Evaluation of the Efficacy of the HaeNaem Zero Bone Loss Kit in Indirect Sinus Lift Using Osseodensification.

Aim The purpose of this study was to evaluate alveolar height at the antral floor following dental implant placement after an indirect sinus lift using osseodensification (OD) with the HaeNaem bur system. Materials and methods A total of 12 patients seeking implant rehabilitation in the maxillary posterior region were selected for the study. Preoperative cone beam CT (CBCT) was performed to measure the residual crestal bone height (RCBH). Patients with an RCBH of 6-8 mm were included in the study. The HaeNaem Zero Bone Loss bur kit was utilized to create an osteotomy site through OD, accompanied by a simultaneous indirect sinus lift. Postoperative CBCT was obtained after four months to assess the difference in bone height and implant stability following implant placement. Results In our study, we performed a comparison of the alveolar ridge height before and after the procedure among the study participants using a paired t-test. This analysis revealed statistically significant differences (p-value <0.01) between the measurements taken before and after the procedure, indicating that the intervention yields effective results. Conclusions Based on the results of this study, it can be inferred that the indirect sinus lift procedure utilizing the OD technique with the HaeNaem Zero Bone Loss bur kit presents an effective treatment alternative for cases with insufficient bone height in the posterior maxilla. This approach is particularly advantageous when considering the increased financial feasibility of treatment options or in situations where advanced and/or time-consuming complex surgeries are contraindicated.

Optimizing Treatment for Severe-Early Childhood Caries: The Role of Groper’s Appliance

Severe-Early Childhood Caries (S-ECC), often leading to serious health issues if left untreated, possesses a great restorative challenge to the pediatric dentist. This case report discusses a comprehensive management of S-ECC in a 5-year-old female patient with high dental caries risk. The patient presented with multiple carious lesions, root stumps, and fenestrated roots, necessitating a staged intervention. Treatment involved restorations with glass ionomer cement, pulpectomy followed by omega loop post build-up on anterior tooth and stainless-steel crowns on posterior teeth. Additionally, extractions were performed and Groper’s appliance was inserted for esthetic rehabilitation and space maintenance on maxillary anterior and posterior regions, respectively. Following completion of the planned treatment, overall risk assessment measured low. This case report emphasizes the importance of rehabilitative interventions in S-ECC, showcasing Groper's appliance as a viable and effective treatment option.

Research trends and mapping knowledge for maxillary sinus augmentation in oral and maxillofacial surgery

BackgroundThe method most frequently employed to alleviate the deficiency of vertical bone volume in the maxillary posterior region is maxillary sinus augmentation. Given its importance in the field of dental implants and its possible impact on implant survival, it is crucial to assess the caliber and bibliometric characteristics of research related to maxillary sinus augmentation. This study aimed to understand the development and trends of studies and guide future studies by performing a bibliometric analysis of research related to maxillary sinus augmentation. MethodsThe Web of Science database was searched on 29.05.2024 with the developed search strategy. Articles were listed in descending order according to the number of citations and analyzed using the Bibliometrix program prepared in R base. The articles were analyzed in four sections: performance analysis, word analysis, collaboration analysis, and thematic analysis. ResultsWang HL is the most frequently listed author on this topic with 24 h-indexes and 1686 total citations. The highest number of articles were published in 2017, with 102 articles with an average of 2.7 citations. The most popular keyword was "dental implants." with 426 usages. Italy and the USA are the countries that have published the most collaborative papers. Clinical Oral Implants Research comes at the top when evaluating the journals that publish on maxillary sinus augmentation based on the h-index. Basic research and technical-oriented studies between 1999 and 2005 have given way to more clinical and patient-oriented research. ConclusionThis bibliometric study will serve as a guide for future research by illustrating the existing state of knowledge and limitations regarding the development of sinus lifting methods, given the constantly growing demand for implant therapy.

Retrospective Radiographic Evaluation of Implant Complications: CBCT-Based Study

Aim: Dental implants are a popular treatment option for patients with one or more missing teeth. With the increase in dental implant treatments, the complications encountered have increased. Therefore, it is very important to plan the implant by evaluating the anatomy of the area where the implant will be placed in three dimensions with cone beam computed tomography (CBCT). The aim of this study is to evaluate the prevalence of implant complications seen in CBCT after implant applications. Material and Methods: CBCT images of 500 patients obtained for different dental reasons were examined; among these, 300 dental implant images were evaluated retrospectively in terms of complications. The number, location and type of identified complications (perforation in the maxillary sinus, mandibular canal, cortical bone, nasal cavity, and mental canal; contact with the adjacent tooth root) were recorded. The data obtained were analyzed statistically using chi-square tests. Results: At least one complication was detected in 65% of the 300 dental implants evaluated. A total of 272 complications (1.4 complications per implant) were observed in 195 dental implants with complications. The number of implants with complications per patient was found to be 3.9. The most observed complication was found to be vertical bone resorption around the implant (45%). Complications were most frequently detected in the maxillary posterior region (40%). Conclusion: Three-dimensional CBCT evaluation of the area where the implant will be applied before and after treatment is very important to prevent possible complications.

Evolving Techniques and Trends in Maxillary Sinus Lift Procedures in Implant Dentistry: A Review of Contemporary Advances.

The most challenging aspects of planning implant rehabilitation for the posterior maxillary region are the pneumatization of the maxillary sinus and the resorption of the residual alveolar ridge. To address the first aspect, there are two primary modalities for sinus augmentation: the direct or lateral window technique and the indirect or crestal technique. Clinicians must possess comprehensive knowledge of the maxillary sinus anatomy and be able to diagnose pathognomonic abnormalities through presurgical imaging and investigations. This skill is essential for performing technique-sensitive augmentation of the maxillary sinus with or without using biomaterials such as bone grafts, membranes, and platelet concentrates. These materials help create a suitable bone bed for either simultaneous or delayed implant placement through various traditional and evolving modified sinus augmentation techniques. It is also critical to effectively elevate the Schneiderian membrane during sinus floor elevation surgery, as complications in this process can adversely affect implant survival and potentially lead to implant failure. This review explores various aspects of maxillary sinus augmentation, ranging from traditional methods to evolving contemporary techniques, and draws on existing literature to examine their advantages, limitations, indications, and contraindications.

Exploring Anatomical Variations in the Bony Architecture of the Greater Palatine Canal in Dry Bones.

Introduction The greater palatine canal (GPC) holds significant clinical importance due to its role in providing access to the branches of the maxillary division of the trigeminal nerve. Anatomical variations within this posterior maxillary region can complicate the surgical anatomy, making the identification of vital structures challenging. Therefore, a thorough understanding of both normal anatomy and common anatomical variations of the GPC is essential to minimize perioperative complications during surgical procedures.This study aims to investigate the bony architecture of the GPC in dry bones to identify anatomical variations and address significant lacunae in our current understanding of this structure. Despite its impact on the management of various dental and surgical procedures, there remains a limited and sometimes inconsistent knowledge of the normal and variant anatomy of the GPC.Existing literature often lacks comprehensive detail regarding the range of anatomical variations and their implications for surgical approaches. By systematically documenting these variations, this study aims to bridge these gaps in knowledge, justify the need for continued research in this area, and highlight its potential clinical implications. Materials and methods In total, 30 dried and intact adult skull specimens were selected, consisting of 19 males (63.3%) and 11 females (36.7%). The selection criteria included an intact hard palate with fully erupted third molars and an intact lateral nasal wall on both sides. The presence of erupted third molars was used to assess the degree of bone resorption, ensuring that only specimens with minimal bone loss were included. The exclusion criteria ruled out specimens with major craniofacial deformities, excessive bone resorption, and signs of advanced age. The bony walls of the GPC were observed by passing a black wire made of rubber material with a consistent diameter (approximately 5 mm), allowing us to qualitatively assess the bore of the canal. Results In four out of 30 specimens (13.3%), significant variations were noted in the bony medial wall of the GPC. Of these, three specimens were male (75%) and one was female (25%). These variations have been categorized into four distinct types for clarity and analysis. Type 1, in a male specimen, showed a deficiency in the lower segment of the bony medial wall of the left GPC above the greater palatine foramen. Type 2, in a male specimen, had a small bar of bone in the left GPC midway between the foramen and the pterygopalatine fossa. Type 3, in a female specimen, exhibited a small bar of bone above the greater palatine foramen on the right side, with no wall above it. Type 4, in a male specimen, displayed a bar of bone above the greater palatine foramen on the right side, with the medial wall completely absent on the left side. Conclusion The study identified anatomical variations in the bony architecture of the GPCbased on dry bone specimens. While these findings offer insights into potential variations that could affect surgical procedures, their clinical implications need validation through patient-based studies. Understanding these variations is crucial for improving preoperative planning and reducing surgical risks, but recommendations should be cautious given the limited sample size. Further research with larger samples and clinical validation is needed to fully understand the embryological basis and potential impact on surgical practice.

A Challenging Case Of Giant Maxillary Ameloblastoma: Navigating Rarity And Complexity In Diagnosis And Treatment

Background: Ameloblastoma is a rare, aggressive, benign odontogenic tumor that most commonly occurs in the jaw. Maxillary occurrences are rarely reported. Case Presentation: We report the case of a 61-year-old male presenting with right-sided unilateral nasal obstruction, characterized by a mass occupying the entire right nasal fossa upon anterior rhinoscopy. A computed tomography (CT) scan, combined with magnetic resonance imaging (MRI), revealed a locally advanced mass centered on the right maxillary sinus. The patient underwent wide excision of the mass, and histopathological analysis confirmed the diagnosis of ameloblastoma. Discussion: Naso-sinus ameloblastomas are rare, benign, and slow-growing tumors, accounting for approximately 0.11% of nasal and sinus tumors. More common in men, they typically present between the ages of 20 and 30. Symptoms include nasal obstruction and epistaxis, with occasional facial swelling or headaches. These tumors often originate in the posterior maxillary region and extend into the maxillary sinuses and nasal cavity. Diagnosis is facilitated by imaging, where the tumors appear as solid, radio-opaque masses. Radical surgical resection is the preferred treatment, as it is essential for preventing recurrence. The prognosis is generally favorable, with no documented cases of malignant transformation or metastasis, and recurrences are rare when appropriate surgical management is performed. Conclusion: Medical imaging plays a crucial role in diagnosis and allows for the evaluation of tumor dissemination and anatomical involvement. The treatment of maxillary ameloblastoma typically involves surgical excision, with the complexity of management often linked to the extent of tumor spread.

Analysis on the relationship between Schneiderian membrane thickening in the posterior maxillary region and periapical lesions by cone beam computed tomography.

This study aimed to evaluate the thickening of sinus membrane, which is also named Schneiderian membrane (SM), in patients and its relationship with periapical lesions (PAL) in the posterior maxillary region to provide reference for the prevention and treatment of odontogenic maxillary sinusitis. A retrospective analysis was conducted on 554 cone beam computed tomography (CBCT) imaging data of maxillary sinuses from 301 patients who met the inclusion criteria to determine the correlation between PAL and SM thickening in the posterior maxillary region. Cases of pathological SM were recorded and classified on the basis of the degree and type of SM thickening. The correlation between SM thickening and the diameter of PAL, the relationship between the upper edge of PAL and the maxillary sinus floor, and its relationship with whether affected teeth with PAL undergo root canal treatment were evaluated. The detection rate of SM thickening in patients with PAL was significantly higher than in those without PAL, so PAL was correlated with SM thickening. Analysis on the correlation between PAL detection indicators and SM thickening degree showed that SM thickening degree was positively correlated with PAL diameter (cone beam computed tomography-periapical index) and not correlated with the three spread effects between the upper edge of PAL and the maxillary sinus floor, as well as whether the teeth with PAL undergo root canal treatment. The correlation analysis between PAL detection indicators and SM thickening types showed that whether the teeth with PAL undergo root canal treatment was not correlated with SM thickening types, and the diameter of PAL, the three spread effects between the upper edge of PAL, and the maxillary sinus floor were not correlated with SM thickening types. The PAL of posterior maxillary teeth is closely related to SM thickening, and the diameter of PAL is positively correlated with the degree of SM thickening. Patients with PAL who have undergone root canal treatment often exhibit SM polyp thickening. In addition, the relationship between the upper edge of PAL and the maxillary sinus floor does not affect the possibility of SM development.

Reamer-scraping and implant-pushing technique for transcrestal sinus floor elevation.

Transcrestal maxillary sinus floor elevation is an effective method to solve the problem of insufficient bone height in the posterior maxillary region. However, current methods, such as osteotome sinus floor elevation, cushioned grind-out technique, Smart Drill technique, etc., require specialized surgical tool boxes. In this article, we introduce a new method of transcrestal maxillary sinus elevation that uses built-in reamers of various implant systems to scrap residual bone at the sinus floor and uses the implant to push the sinus membrane during implant placement. This technique is easy to operate and time saving and has a low rate of sinus membrane perforation. After a one-year follow-up observation of 146 people and 175 implants, the endo-sinus bone gains were 5.00 (4.70, 5.30) mm and 2.10 (1.40, 2.70) mm in the group of 3 mm≤residual bone height (RBH)<5 mm and the group of 5 mm≤RBH<8 mm, respectively, which can meet the clinical requirements of implant stability. This technique is suitable in generalizing dental implantation.

Does alveolar ridge preservation reduce the need for sinus floor elevation: A comparative study to spontaneous healing.

In cases of atrophy in the maxillary posterior region, characterized by reduced vertical bone volume, implant placement becomes challenging. Augmentation procedures like sinus lifts are often needed to address insufficient bone volume. This study aims to explore if alveolar ridge preservation, using a bovine bone substitute and a porcine collagen membrane, significantly decreases the need for sinus lifts compared to natural wound healing after tooth extraction. In this comparative clinical study, 40 patients requiring a total of 53 extractions were assigned to one of the following groups: a test group with bovine bone substitute material (Straumann® XenoFlex) and a porcine collagen membrane (Jason® membrane), or a control group with spontaneous socket healing. After 6 months, digital volume tomography was performed for implant planning. For seven patients from the control group (n = 22 extracted sites) sinus lift augmentations were performed while only four sinus lift procedures were performed in the test group (n = 31 extracted sites), indicating a higher need for sinus augmentation procedures in the control group, however not statistically different on a p value of 0.05 (p = 0.168). In the control group, the mean value of the radiographically measured bone height (mesial and distal) was 11.13 ± 2.12 mm preoperatively before tooth extraction, while it was 11.3 ± 2.17 mm postoperatively after implant placement. In contrast, the mean value in the test group was 11.78 ± 3.09 mm preoperatively and 11.92 ± 2.79 mm postoperatively. Statistical analysis revealed no significant difference between the two groups (odds ratio 0.32; 95% CI: 0.08, 1.26; p = 0.951). The implant survival rate in the control group was 100%, compared to 96.77% in the test group. Within the limits of this study, the use of bovine bone substitute and a porcine resorbable membrane after tooth extraction in the posterior maxilla seems to reduce the need for sinus augmentation in comparison to spontaneous healing although the difference was not statistically significant. Additionally, the Alveolar Ridge Preservation in the test group made external sinus floor elevation unnecessary compared to the control group. The change in radiographically measured bone height pre- and postoperatively showed no significant difference between the two groups.

Unlocking implant success: the impact of surgical techniques on primary stability in the posterior maxilla.

The study conducted by Olmedo-Gaya et al. aimed to investigate the effects of various surgical techniques on the initial stability of implants placed in the posterior maxilla through a randomized controlled clinical trial. The study compared insertion torque (IT) and implant stability quotients (ISQ) among implants placed using under preparation, expanders, and standard surgical instrumentation. The study enrolled 108 patients, each receiving one implant in the posterior maxilla region. Patients were distributed into three groups: group 1 (n = 36) with the under preparation technique, group 2 (n = 36) using the expander technique, and group 3 (n = 36) with conventional drilling. IT was measured using a torque indicator, while ISQ was recorded through resonance frequency analysis immediately post-surgery. The ISQ values were analyzed in relation to the patient's bone quality, categorized into types II, III, and IV. ISQ values varied significantly with bone quality, being highest in type II (76.65) and type III (73.60), and lowest in type IV (67.34) bone, with a significant difference (p < 0.0001). The conventional drilling technique yielded lower ISQ values (69.31) compared to under preparation (74.29) and expander techniques (73.99), with statistical significance (p = 0.008 and p = 0.005, respectively). Surgical technique significantly influences primary stability in low-quality bone. Conventional drilling results in lower ISQ values, suggesting that alternative techniques such as under preparation or expanders should be used in low-quality bone to achieve better primary stability. For implants in low-quality bone, replacing the conventional drilling technique with under preparation or expander techniques can enhance primary stability.

The Effects of using PEEK Coping and Different Restorative Materials on the Stress Distribution in Tooth and Implant- supported Prostheses under Static Loading: 3D FEA.

This study was designed to evaluate the influence of utilizing Polyetheretherketone (PEEK) coping and three different dental restorative materials in the success of tooth and implant-supported fixed partial dentures (TISFPD) in the maxillary posterior region, under static loading by 3-Dimensional Finite Element Analysis (3D FEA). Six 3D FEA models were designed assuming the extraction of maxillary first and second molars. Bone, implant, abutment, PEEK coping, second premolar, periodontal ligament (PDL) and six 3-unit TISFPD with different restorative materials [Porcelain-Fused-to-Metal (PFM), PEEK-Composite (PC), Monolithic Zirconia (MZ)] were modeled. Then, PEEK copings were modeled to be cemented onto the implants as a double-crown system for the first three groups (PFMPEEK, PCPEEK and MZPEEK) whereas, the next three groups (PFM, PC, MZ) excluded a PEEK coping in their designs. The prostheses were loaded twice, vertically and obliquely. From the determined points, 250 N for vertical loading (0o to the long axis) and 200 N for the oblique loading (30o to the long axis) were applied. Von Mises tension, maximum and minimum principal tension value criterias were analyzed. Regardless of the material used for suprastructure, the maximum average stress was reduced by using PEEK coping. Considering the maximum stress distribution, PC appeared to have the highest stresses on the cortical bone, implant and screw. Additionally, the von Mises stresses formed in the PDL for each model were lower when PEEK coping was included in the design of the TISFPD, reducing the risk of intrusion. The stress distribution was positively affected by the PEEK coping in TISFPD design, reducing bone resorption and failure. This elastic material used generated lower stresses in the bone and implant, while no significant effect was found on stresses around natural teeth.

Clinical study of immediate implant placement in posterior maxillary region assisted by dynamic real-time navigation: A randomized controlled trial

ObjectiveTo evaluate the accuracy of the implant accuracy and clinical effect of navigation-assisted immediate implant placement (IIP) in the posterior maxillary tooth region. MethodsThis study included 60 patients with 96 implants undergoing IIP in the posterior maxillary region from January 2021 to December 2022, stratified into dynamic navigation and freehand implant groups. All clinical indicators, including initial stability, implant deviation (entry point deviation, end point deviation, depth deviation and angle deviation), marginal bone resorption and implant success rate, were systematically recorded. ResultsAll implants were successfully placed with an average torque of (24.38 ± 1.84)N.cm. The mean entry point deviation, apex point deviation and angular deviation in the navigation group were significantly smaller than that of the freehand group (P < 0.05). Marginal bone resorption was significantly less in the navigated group than in the freehand group (P < 0.05). All dental implants were considered an operational success and the mean follow-up time was (27.8 ± 8.4) months. ConclusionThe application of dynamic navigation-assisted immediate implant placement in the maxillary posterior region can achieve good implant accuracy and satisfactory clinical results.

A randomized controlled trial of immediate implant placement comparing hydroxyapatite nano-coated and uncoated sandblasted/acid-etched implants using a digital surgical guide

PurposeThis study evaluated the implant stability, volumetric changes, and patient-reported outcome measures (PROMs) of hydroxyapatite (HA) nano-coated sandblasted/acid-etched (SLA) implants compared to uncoated SLA implants.MethodsForty patients were recruited and randomly allocated to HA nano-coated SLA group (test, n = 20) and uncoated SLA group (control, n = 20) using single-blinded/block randomization. Implants were immediately placed in maxillary posterior region using a digital surgical guide. Insertion torque and implant stability quotient (ISQ) were measured at implant surgery and 1, 2, 3, and 4 months postoperatively. Intraoral scans, PROMs and soft tissue inflammation data were collected, and multivariable linear regression analysis of ISQ was performed.ResultsIn total, 48 implants (test; n = 24, control; n = 24) in 37 patients (test; n = 19, control; n = 18) were analyzed. Despite no significant between-group difference at surgery, the test group showed higher ISQ values than the control group at 2 (76.53 ± 4.17 vs. 71.32 ± 4.79, p < 0.01), 3 (77.45 ± 4.41 vs. 73.85 ± 4.69, p < 0.05), and 4 months (79.08 ± 2.96 vs. 73.43 ± 3.52, p < 0.0001) postoperatively. There were no significant differences in linear and volumetric changes, PROMs, and soft tissue inflammation analysis between two groups. The ISQ at implant surgery was influenced by age and diabetes mellitus (DM) at the implant level and DM and predicted total bone-to-implant contact area at the patient level.ConclusionHA nano-coated SLA implants promoted favorable immediate implants stability during early osseointegration phase compared to uncoated SLA implants, but displayed similar dimensional changes, PROMs, and soft tissue inflammation outcomes.Trial registrationClinical Research Information Service (CRIS), KCT0006364. Registered 21 July 2021, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=24221&search_page=L.

Biomechanical Parameters of Implants Placed with Osseodensification Versus Implants Placed with Under-drilling Osteotomy Techniques in Posterior Maxilla: A Comparative Clinical Study

BACKGROUND: To facilitate better implant survival rates in areas with clinically low bone density, osteotomy techniques that provide higher implant stability and improve bone quality are often recommended. The most widely used are under-drilling (UD) and osseodensification (OD). In the UD technique, the diameter of the final osteotomy drill is narrower that the diameter of the placed implant, whereas in the OD technique, special drills that rotate counter-clockwise to condense and densify the bone are used. AIM: The aim of this study was to evaluate the effect of two different implant osteotomy methods – UD versus osseodensification (OD) in terms of implant stability during the period of osseointegration in the posterior maxillary region. MATERIAL AND METHODS: This prospective randomized clinical study included 22 patients who received a total of 37 implants in the posterior maxillary region. They were divided into two groups: In 11 patients, 18 implants were placed using the under-drilling method (UD), while the other 11 patients received 19 implants using the osseodensification method (OD). Within the OD group, 10 implants were placed in areas with the initial height that was insufficient to accommodate implants with a minimal length of 8 mm. In these areas, crestal sinus elevation without bone graft use was performed simultaneously with implant placement, according to the osseodensification protocol proposed by the manufacturer. All implants were placed in a dual-stage manner – completely covered with soft tissue and uncovered 4 months later, at the time of second-stage surgery. The implant stability was determined by measurement of implant stability quotient (ISQ) with instrument that utilizes the method of resonance frequency analysis (RFA) to discover implant stability. The ISQ represents a value on a scale between 0 and 100, with values above 65 indicating high implant stability. ISQ values were measured at two timepoints: At the time of implant placement and at the time of their uncovery. Statistical analysis was performed with Prism 9 statistical program for Mac. The data were analyzed using one-sample t-test, Wilcoxon, and paired two-way ANOVA test. The significance level was set at p ≤ 0.05. RESULTS: The differences between the primary implant stability ISQ values in the UD and osseodensification (OD) groups were not statistically significant. The secondary implant stability was statistically significantly higher in the osseodensification group (p &lt; 0.001) There were no statistically significant differences between secondary implant stability values in implants placed with and without crestal sinus floor lift within the osseodensification group. CONCLUSION: Within the limitations of the study, the conclusion is that osseodensification method of implant osteotomy (OD) results in higher secondary implant stability values that the under-drilling method (UD), which has clinical relevance regarding long-term implant survival. It should be a preferred method of choice for osteotomy in areas with clinically low density of bone due to its predictability and effectiveness.

Prospective observational cohort study of the change of the marginal bone crest in relation to the prosthetic abutment height and the peri-implant vertical mucosal thickness at implants positioned subcrestally.

To evaluate the influence on peri-implant crestal bone loss exerted by the vertical mucosal thickness and the abutment height over 12 months after placement of the restoration on subcrestal implants with change of platform, using a restoration abutment platform smaller than the implant platform. A total of 99 implants were rehabilitated in the maxillary and mandibular posterior regions. A total of 22 implants were rehabilitated in the maxilla and 77 implants in the mandible, using digitally designed customized abutments with Atlantis weborder software, from the commercial house Dentsply Sirona (Dentsply Sirona S.A., Barcelona, Spain), version 4.6.5, adapting the height to the vertical thickness of the mucosa. Clinical and radiographic monitoring begins during the surgical procedure of placement of the implant and ends 12 months afterwards. Crestal bone loss was evaluated through the Carestream® CS8100 3D radiographic equipment. In all cases, the greatest loss of marginal bone occurred between the day of surgery (Tx) and placement of the rehabilitation (To). The average bone loss between both times was greater when the abutment height and vertical mucosal thickness did not exceed 3 mm. Subsequently, bone loss slowed and stabilized at 12 months. The minimum abutment height and the vertical mucosal thickness are factors to take into account when minimizing peri-implant marginal bone loss, the abutment height having the greatest importance according to the clinical data obtained.

Mechanical and modal analysis of different implant strategies for loss of three teeth with bone atrophy in the maxillary posterior region

Purpose: This study aimed to evaluate the stress distribution and secondary stability involved in five implant strategies, including implant-supported prostheses (ISP) and tooth-implant-supported prostheses (TISP), used for bone atrophy in the maxillary posterior region with teeth loss using finite element analysis, and to explore the more desirable implant methods. Methods: Five implant strategies were made to analyze and compare: M1, implant-supported prosthesis consisting of a short implant with a regular implant; M2, implant-supported prosthesis consisting of a tilted implant with a regular implant; M3, cantilever structure; M4, tooth-implant-supported prosthesis consisting of a short implant with a regular implant; M5, tooth-implant-supported prosthesis consisting of a regular implant, and M6, with only the natural teeth as a control group. Dynamic loading of the above models was performed in finite element analysis software to assess the stress distribution of the bone tissue and implants using the von Mise criterion. Finally, the secondary stability of different models was evaluated by modal analysis. Results: The maximum stress distribution in the cortical bone in M1(60 MPa) was smaller than that in M2(97 MPa) and M3(101 MPa), The first principal strain minimum was obtained in M2 (2271 μ ε ). M4 (33 MPa, 10085 Hz) with the best mechanical properties and highest resonance frequency. But increased the loading on the natural teeth. Conclusions: Short implants and tilted implants are both preferred implant strategies, if cantilever construction is necessary, a tooth-implant-supported prosthesis consisting of a short implant and a regular implant is recommended.