Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study.

AIM: To assess the implant stability and amount of marginal bone loss in immediate implant placement (IIP) in mandibular molars by using pre-extractive interradicular implant bed preparation vs conventional post-extractive interradicular implant bed preparation. MATERIALS AND METHODS: This randomized clinical trial was conducted on fourteen patients who had an immediate dental implant at the mandibular molar area by two different techniques. All patients were divided randomly into two equal groups: Group I (control) was treated with conventional post-extractive interradicular implant bed preparation, and group II (test) was treated by pre-extractive interradicular implant bed preparation All surgeries were performed by the same surgeon. All patients were followed up clinically at immediate post-surgery (T0), 7 days (T1), 3 weeks (T2), 90 days (T3), and 3 months after loading (T6) for healing and to evaluate the marginal bone loss radiographically at T0, T3 and T6. Descriptive and bivariate statistics were computed using the SPSS version (SPSS, IBM Inc., Chicago, IL), and p ≤ 0.05 was considered an indicator of statistical significance. RESULTS: A total of 7 female and 7 male patients with a mean age of 32.07 ± 5.87 years. Radiographically, there is no significant statistical difference in comparing between two groups for the marginal bone loss. However, there was a highly significant statistical difference (p < 0.001) in each group between different interval periods (T0, T3, T6) with mean start 5.27 ± 0.53, and 5.19 ± 0.72 at (T0) reaching 7.60 ± 0.89 and 7.09 ± 0.96 at (T3) and slightly decrease of 7.52 ± 0.79 and 7.02 ± 0.79 in (T6) with radiographic evaluation, and it represented clinically in each group with mean 3.57 ± 0.313 and 4.0 ± 0.58 at (T0) increase to 6.55 ± 0.395 and 6.52 ± 0.45 at (T6) for both group respectively. There is no statistically significant difference in soft tissue healing with an average mean of 4.57 ± 0.24 and 3.57 ± 0.509 (p = 0.001) when comparing between both groups respectively. CONCLUSION: Both techniques seem useful for dental implant placement in badly decayed mandibular molars. However, pre-extracted interradicular implant bed preparation for IIP might offer advantages in terms of primary implant stability and bone preservation. However, further studies are needed to confirm these findings. CLINICAL SIGNIFICANCE: Both techniques are alternative methods for the treatment of badly decayed mandibular molars by immediate dental implant except for minor complications that do not interfere with dental implant placement. How to cite this article: Alzaibak LMA, Abdel-Monem TM, Elgohary NM, et al. Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study. J Contemp Dent Pract 2024;25(4):303-312.

Nonionizing diagnostic imaging modalities for visualizing health and pathology of periodontal and peri-implant tissues.

Radiographic examination has been an essential part of the diagnostic workflow in periodontology and implant dentistry. However, radiographic examination unavoidably involves ionizing radiation and its associated risks. Clinicians and researchers have invested considerable efforts in assessing the feasibility and capability of utilizing nonionizing imaging modalities to replace traditional radiographic imaging. Two such modalities have been extensively evaluated in clinical settings, namely, ultrasonography (USG) and magnetic resonance imaging (MRI). Another modality, optical coherence tomography (OCT), has been under investigation more recently. This review aims to provide an overview of the literature and summarize the usage of USG, MRI, and OCT in evaluating health and pathology of periodontal and peri-implant tissues. Clinical studies have shown that USG could accurately measure gingival height and crestal bone level, and classify furcation involvement. Due to physical constraints, USG may be more applicable to the buccal surfaces of the dentition even with an intra-oral probe. Clinical studies have also shown that MRI could visualize the degree of soft-tissue inflammation and osseous edema, the extent of bone loss at furcation involvement sites, and periodontal bone level. However, there was a lack of clinical studies on the evaluation of peri-implant tissues by MRI. Moreover, an MRI machine is very expensive, occupies much space, and requires more time than cone-beam computed tomography (CBCT) or intraoral radiographs to complete a scan. The feasibility of OCT to evaluate periodontal and peri-implant tissues remains to be elucidated, as there are only preclinical studies at the moment. A major shortcoming of OCT is that it may not reach the bottom of the periodontal pocket, particularly for inflammatory conditions, due to the absorption of near-infrared light by hemoglobin. Until future technological breakthroughs finally overcome the limitations of USG, MRI and OCT, the practical imaging modalities for routine diagnostics of periodontal and peri-implant tissues remain to be plain radiographs and CBCTs.

Does an untreated peri-implant dehiscence defect affect the progression of peri-implantitis?: A preclinical in vivo experimental study.

OBJECTIVE: To investigate the early impact of plaque accumulation in a buccal dehiscence defect on peri-implant marginal bone resorption. MATERIALS AND METHODS: In six male Mongrel dogs, four dental implants were placed in the posterior maxilla on both sides (two implants per side). Based on the group allocation, each implant was randomly assigned to one of the following four groups to decide whether buccal dehiscence defect was prepared and whether silk ligation was applied at 8 weeks post-implant placement for peri-implantitis induction: UC (no defect without ligation); UD (defect without ligation); LC (no defect with ligation); and LD (defect with ligation) groups. Eight weeks after disease induction, the outcomes from radiographic and histologic analyses were statistically analyzed (p < .05). RESULTS: Based on radiographs, the exposed area of implant threads was smallest in group UC (p < .0083). Based on histology, both the distances from the implant platform to the first bone-to-implant contact point and to the bone crest were significantly longer in the LD group (p < .0083). In the UD group, some spontaneous bone fill occurred from the base of the defect at 8 weeks after implant placement. The apical extension of inflammatory cell infiltrate was significantly more prominent in the LD and LC groups compared to the UC group (p < .0083). CONCLUSION: Plaque accumulated on the exposed implant surface had a negative impact on maintaining the peri-implant marginal bone level, especially when there was a dehiscence defect around the implant.

Are healing abutments being reused in periodontics residency programs in the United States? A survey-based study.

PURPOSE: Recent studies indicate that reusing healing abutments (HAs) may pose a risk of biomaterial cross contamination among patients. The intent is to investigate whether postgraduate periodontics residency programs in the United States are reusing dental implant HAs and determine if there is a standardization in the decontamination and sterilization protocol of used HAs. METHODS: An electronic survey consisting of-seven multiple choice and/or short answer questions pertaining to the re-use of HAs among postdoctoral periodontics programs was sent to program directors of 57 accredited dental schools in the United States via an online survey system (Qualtrics). Three follow-up remainder emails were sent to programs that did not respond after over a 6-month period. Data were analyzed using descriptive statistics. RESULTS: Of the 57 postdoctoral periodontics program directors contacted, only 14 responded with three programs (3/14, 21%) reported reusing HAs. Approximately, 46% stated their residents place dental implants in two stages, while ∼54% stated they used a one-stage protocol indicating varied time exposure of HA to the oral cavity. Even in a two-stage protocol, the extended time HA remained in situ varied from 4 weeks to 6 months. Each program reusing HAs employed a distinct decontamination approach highlighting a notable lack of standardization in practices. CONCLUSION: The findings from our study suggest that a minority of residency programs in the United States are reusing HAs. However, the limited number of responses leaves uncertainty regarding whether our findings underestimate the prevalence of this practice and accurately reflect the reality. Among those re-using HAs, there seems to be a lack of standardization in their decontamination, potentially leading to cross-contamination of residual biomaterial among patients.

Impact of vertical alveoloplasty on changes in keratinized mucosa width following full-arch immediate implant placement and rehabilitations: A prospective case series.

PURPOSE: This prospective case series aimed to investigate the effect of vertical alveoloplasty on the changes in keratinized mucosa width (KMW) following full-arch immediate implant placement and rehabilitation. MATERIALS AND METHODS: A total of 17 potential edentulous patients were enrolled and received implant placement and full-arch implant-supported immediate rehabilitations. The main outcome was to analyze the effect of vertical alveoloplasty on the changes in KMW. The amount of vertical alveoloplasty during implant surgery as well as the changes in KMW at buccal aspects from the day of surgery to 6 months post-surgery were recorded on the implant-level using a periodontal probe. The secondary outcome was to analyze the other possible factors that affected the changes in KMW. The included factors were the initial KMW, the distribution of implants in the maxilla and mandible, the distribution of implants in the anterior and posterior regions, the distribution of implants in extraction sockets and healed ridges, and gender. Mann-Whitney non-parametric tests and multiple linear regression adjusted by generalized estimating equations (GEE) were used to statistically analyze the data. RESULTS: A total of 121 implant positions were analyzed. The KMW was 4.1± 2.0 mm on the day of the surgery and 4.1± 1.7 mm 6 months post-surgery. The mean changes in KMW following 6 months were -0.1± 1.6 mm (p = 0.824). From the results of GEE, the vertical amount of alveoloplasty had no significant effect on changes in KMW. Both initial KMW and the distribution of implants in the anterior and posterior regions had significant impacts on the changes in KMW (p < 0.0001). CONCLUSION: The amount of vertical alveoloplasty during implant surgery has no significant impact on the KMW. The KMW remained stable from baseline to 6 months after alveoloplasty, implant placement, and immediate rehabilitations in potential edentulous arches. The initial KMW and the distribution of implants in the anterior and posterior regions were the possible factors affecting changes in KMW.

Evaluation of bone apposition on surface modified titanium implant in experimental animal model: A systematic review and meta-analysis.

Purpose: To evaluate the response of peri-implant bone to smooth (machined) surface and surface-modified dental implants in healthy experimental animal models. Materials and Methods: Systematic electronic search was done for using PUBMED, SCOPUS, WEB OF SCIENCE, and EMBASE databases for potentially relevant records from the last 20 years. Duplicate screening and data extraction were performed to formulate the evidence tables and meta-analysis following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The outcome criteria were: 1. Bone Implant Contact (BIC) in percentage, 2. Removal Torque Values (RTV) in Ncm, 3. Implant stability Quotient (ISQ), Quality assessment was done using the ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines and SYRCLE RoB (Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias) tool. Results: Results were expressed as pooled mean difference for the respective groups viz. sandblasted and acid etched, laser modified, acid etched and anodized surface. The surface modified implants revealed somewhat higher BIC over machined surface (P < 0.01). Forest plot were drawn for all the outcome variables. Conclusions: Within the limitations of this study, the authors found a higher degree of osseointegration pertaining to bone to implant interface, RTV, and implant stability quotient (ISQ) with surface modified procedures which seemed to promote bone formation around peri-implant tissue during the early stages of healing. After analyzing all 37 included publications for the outcome of interest (BIC%, RTV, ISQ), a positive outcome was obtained for both subtractive and additive implant surface modifying procedures over machined implant surfaces when the data were pooled together. More advanced research work on healthy animal models needs to be investigated to review the impact of surface modifications on dental implant osseointegration.

Indian Society of Periodontology Good Clinical Practice Recommendations for Peri-implant Care.

Current implant therapy is a frequently employed treatment for individuals who have lost teeth, as it offers functional and biological advantages over old prostheses. Concurrently, active exploration of intervention strategies aims to prevent the progression of peri-implant diseases and manage the existing peri-implant tissue damage. Indian Society of Periodontology has recognized the need for systematic documents to update the everyday clinical practice of general dental practitioners and has provided evidence-based consensus documents, namely good clinical practice recommendations from time to time to raise the oral health-related awareness and standards of oral health-care delivery across the country. The current clinical practice recommendations focused on peri-implant care to bridge the gap between academic theory and clinical practice by compiling evidence-based suggestions for preventing and treating peri-implant diseases. Twenty-eight subject experts across the country prepared these recommendations after a thorough literature review and group discussions. The document has been prepared in three sections covering peri-implant health and maintenance, peri-implant mucositis, and peri-implantitis. It will be a quick and concise reference for oral implant practitioners in patient management. The guidelines provide distinct definitions, signs, and symptoms, treatment required; recall visit specifications for plausible clinical case situations, and home-care recommendations regarding maintaining peri-implant health. The document advocates combined efforts of oral implant practitioners and the population at large with evidence-based, integrated, and comprehensive peri-implant care. By providing accessible, applicable guidance, these guidelines would empower dental professionals to uphold the well-being of implant patients and ensure the long-term success of implant therapy.

Effect of Dental Implant System-Assisted Tooth Intentional Replantation in the Treatment of Anterior Teeth with Pathological Tooth Flaring, Drifting and Elongation in Patients with Stage III/IV Periodontitis: a Case Series.

OBJECTIVE: To investigate the clinical effect of implant-assisted dental intentional replantation (IR) for the treatment of "drifted" anterior periodontally hopeless teeth (PHT). METHODS: The present authors recruited 22 patients with stage III/IV periodontitis who suffered drifting of the maxillary anterior teeth, with a total of 25 teeth. The PHT were extracted for in vitro root canal treatment (RCT). The root surface was smoothed and the shape was trimmed, and the alveolar socket was scratched. The dental implant system was used to prepare the alveolar socket according to the direction, depth and shape of the tooth implantation. The PHT were reimplanted into the prepared alveolar socket. The periodontal indicators were analysed statistically before and after surgery. RESULT: Twenty-two patients who completed the full course of treatment, with a total of 25 PHT, had a successful retention rate of 88%. Mean periodontal probing depth (PPD) decreased by 2.880 ± 0.556 mm and 3.390 ± 0.634 mm at 6 months and 1 year, respectively, and clinical attachment loss (CAL) decreased by 2.600 ± 0.622 mm and 2.959 ± 0.731 mm at the same time points, respectively, showing significant improvement (P < 0.05). CONCLUSION: Dental implant system-assisted IR can effectively preserve "drifted" natural PHT in patients with stage III/IV periodontitis.

Influence of mucosal tissue height on implant crestal bone: A 10-year follow-up of a controlled clinical trial.

OBJECTIVE: To evaluate the 10-year influence of soft tissue height (STH) on crestal bone level changes (CBC) in bone-level implants with non-matching internal conical connections. MATERIAL & METHODS: From the initial 97 patients, 59 (19 men, 40 women, age 55.86 ± 9.5 years) returned for the recall visit. Based on baseline STH, they were categorized into T1 (thin STH ≤2 mm, n = 33), T2 (thin STH augmented with allogenic tissue matrix (ATM), n = 32), and C (thick STH >2mm, n = 32). Implants were placed in the posterior mandible using a one-stage approach and received single screw-retained restorations. Clinical (PPD, BOP, PI) and radiographic examinations were conducted after 10 years, with CBC calculated mesial and distal to each implant. RESULTS: After 10 years, implants in surgically thickened (T2) or naturally thick STH (C) showed bone gains of 0.57 ± 0.55mm and 0.56 ± 0.40mm, respectively (p < 0.0001) shifting from an initial CBC of -0.21 ± 0.33 mm to 0.36 ± 0.29 mm in the thick STH group and -0.2 ± 0.35 mm to 0.37 ± 0.29 mm in the surgically thickened STH group after 10 years. Implants in naturally thin STH yielded a non-significant trend of bone loss (-0.12 ± 0.41mm; p > 0.05). CONCLUSIONS: Implants in thin STH (≤2 mm) exhibited greater CBC over the study period. Significant bone gains were observed in thick STH cases, indicating that naturally thick STH or STH augmentation with ATM and may contribute to maintaining CBC in long-term around implants. CLINICAL SIGNIFICANCE: This is the first long-term follow-up study suggesting that adequate soft tissue height around implants helps maintain stable peri-implant bone levels. While tissue thickness plays a key role, other factors also interact with peri-implant tissue height to sustain crestal bone stability over time.

Microbiological and functional traits of peri-implant mucositis and correlation with disease severity.

Osseointegrated dental implants replace missing teeth and create an artificial surface for biofilms of complex microbial communities to grow. These biofilms on implants and dental surfaces can trigger infection and inflammation in the surrounding tissue. This study investigated the microbial characteristics of peri-implant mucositis (PM) and explored the correlation between microbial ecological imbalance, community function, and disease severity by comparing the submucosal microflora from PM with those of healthy inter-subject implants and intra-subject gingivitis (G) within a group of 32 individuals. We analyzed submucosal plaques from PM, healthy implant (HI), and G sites using metagenome shotgun sequencing. The bacterial diversity of HIs was higher than that of PM, according to the Simpson index. Beta diversity revealed differences in taxonomic and functional compositions across the groups. Linear discriminant analysis of the effect size identified 15 genera and 37 species as biomarkers that distinguished PM from HIs. Pathways involving cell motility and protein processing in the endoplasmic reticulum were upregulated in PM, while pathways related to the metabolism of cofactors and vitamins were downregulated. Microbial dysbiosis correlated positively with the severity of clinical inflammation measured by the sulcus bleeding index (SBI) in PM. Prevotella and protein processing in the endoplasmic reticulum also correlated positively with the SBI. Our study revealed PM's microbiological and functional traits and suggested the importance of certain functions in disease severity.IMPORTANCEPeri-implant mucositis is an early stage in the progression of peri-implantitis. The high prevalence of it has been a threat to the widespread use of implant prosthodontics. The link between the submucosal microbiome and peri-implant mucositis was demonstrated previously. Nevertheless, the taxonomic and functional composition of the peri-implant mucositis microbiome remains controversial. In this study, we comprehensively characterize the microbial signature of peri-implant mucositis and for the first time, we investigate the correlations between microbial dysbiosis, functional potential, and disease severity. With the help of metagenomic sequencing, we find the positive correlations between microbial dysbiosis, genus Prevotella, pathway of protein processing in the endoplasmic reticulum, and more severe mucosal bleeding in the peri-implant mucositis. Our studies offer insight into the pathogenesis of peri-implant mucositis by providing information on the relationships between community function and disease severity.

Xenogeneic Collagen Matrix Versus Free Gingival Graft for Augmenting Peri-Implant Keratinized Mucosa Around Dental Implants: A Systematic Review and Meta-Analysis.

OBJECTIVES: There is a growing evidence to suggest augmenting peri-implant keratinized mucosa in the presence of ≤ 2 mm of keratinized mucosa. However, the most appropriate surgical technique and augmentation materials have yet to be defined. The aim of this systematic review and meta-analyses was to evaluate the clinical and patient-reported outcomes of augmenting keratinized mucosa around implants using free gingival graft (FGG) versus xenogeneic collagen matrix (XCM) before commencing prosthetic implant treatment. MATERIAL AND METHODS: Electronic databases were searched to identify observational studies comparing implant sites augmented with FGG to those augmented with XCM. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. RESULTS: Six studies with 174 participants were included in the present review. Of these, 87 participants had FGG, whereas the remaining participants had XCM. At 6 months, sites augmented with FGG were associated with less changes in the gained width of peri-implant keratinized mucosa compared to those augmented with XCM (mean difference 1.06; 95% confidence interval -0.01 to 2.13; p = 0.05). The difference, however, was marginally significant. The difference between the two groups in changes in thickness of peri-implant keratinized mucosa at 6 months was statistically significantly in favor of FGG. On the other hand, XCM had significantly shorter surgical time, lower postoperative pain score, and higher color match compared to FGG. CONCLUSIONS: Within the limitation of this review, the augmentation of keratinized mucosa using FGG before the placement of the final prosthesis may have short-term positive effects on soft tissue thickness. XCM might be considered in aesthetically demanding implant sites and where patient comfort or shorter surgical time is a priority. The evidence support, however, is of low to moderate certainty; therefore, further studies are needed to support the findings of the present review.

Multi-objective optimization of custom implant abutment design for enhanced bone remodeling in single-crown implants using 3D finite element analysis.

The optimal configuration of a customized implant abutment is crucial for bone remodeling and is influenced by various design parameters. This study introduces an optimization process for designing two-piece zirconia dental implant abutments. The aim is to enhance bone remodeling, increase bone density in the peri-implant region, and reduce the risk of late implant failure. A 12-month bone remodeling algorithm subroutine in finite element analysis to optimize three parameters: implant placement depth, abutment taper degree, and gingival height of the titanium base abutment. The response surface analysis shows that implant placement depth and gingival height significantly impact bone density and uniformity. The taper degree has a smaller effect on bone remodeling. The optimization identified optimal values of 1.5 mm for depth, 35° for taper, and 0.5 mm for gingival height. The optimum model significantly increased cortical bone density from 1.2 to 1.937 g/cm3 in 2 months, while the original model reached 1.91 g/cm3 in 11 months. The standard deviation of density showed more uniform bone apposition, with the optimum model showing values 2 to 6 times lower than the original over 12 months. The cancellous bone showed a similar trend. In conclusion, the depth and taper have a significant effect on bone remodeling. This optimized model significantly improves bone density uniformity.

Efficacy of plasma treatment for surface cleansing and osseointegration of sandblasted and acid-etched titanium implants.

PURPOSE: This study was conducted to evaluate the effects of plasma treatment of sandblasted and acid-etched (SLA) titanium implants on surface cleansing and osseointegration in a beagle model. MATERIALS AND METHODS: For morphological analysis and XPS analysis, scanning electron microscope and x-ray photoelectron spectroscopy were used to analyze the surface topography and chemical compositions of implant before and after plasma treatment. For this animal experiment, twelve SLA titanium implants were divided into two groups: a control group (untreated implants) and a plasma group (implants treated with plasma). Each group was randomly located in the mandibular bone of the beagle dog (n = 6). After 8 weeks, the beagle dogs were sacrificed, and volumetric analysis and histometric analysis were performed within the region of interest. RESULTS: In morphological analysis, plasma treatment did not alter the implant surface topography or cause any physical damage. In XPS analysis, the atomic percentage of carbon at the inspection point before the plasma treatment was 34.09%. After the plasma treatment, it was reduced to 18.74%, indicating a 45% reduction in carbon. In volumetric analysis and histometric analysis, the plasma group exhibited relatively higher mean values for new bone volume (NBV), bone to implant contact (BIC), and inter-thread bone density (ITBD) compared to the control group. However, there was no significant difference between the two groups (P > .05). CONCLUSION: Within the limits of this study, plasma treatment effectively eliminated hydrocarbons without changing the implant surface.

Prediction of lifespan and assessing risk factors of large-sample implant prostheses: a multicenter study.

PURPOSE: This study aimed to analyze factors influencing the success and failure of implant prostheses and to estimate the lifespan of prostheses using standardized evaluation criteria. An online survey platform was utilized to efficiently gather large samples from multiple institutions. MATERIALS AND METHODS: During the one-year period, patients visiting 16 institutions were assessed using standardized evaluation criteria (KAP criteria). Data from these institutions were collected through an online platform, and various statistical analyses were conducted. Risk factors were assessed using both the Cox proportional hazard model and Cox regression analysis. Survival analysis was conducted using Kaplan-Meier analysis and nomogram, and lifespan prediction was performed using principal component analysis. RESULTS: The number of patients involved in this study was 485, with a total of 841 prostheses evaluated. The median survival was estimated to be 16 years with a 95% confidence interval. Factors found to be significantly associated with implant prosthesis failure, characterized by higher hazard ratios, included the 'type of clinic', 'type of antagonist', and 'plaque index'. The lifespan of implant prostheses that did not fail was estimated to exceed the projected lifespan by approximately 1.34 years. CONCLUSION: To ensure the success of implant prostheses, maintaining good oral hygiene is crucial. The estimated lifespan of implant prostheses is often underestimated by approximately 1.34 years. Furthermore, standardized form, online platform, and visualization tool, such as nomogram, can be effectively utilized in future follow-up studies.

Three-dimensional finite element analysis of the biomechanical behaviour of different dental implants under immediate loading during three masticatory cycles.

The study aimed to evaluate the impact of varying modulus of elasticity (MOE) values of dental implants on the deformation and von Mises stress distribution in implant systems and peri-implant bone tissues under dynamic cyclic loading. The implant-bone interface was characterised as frictional contact, and the initial stress was induced using the interference fit method to effectively develop a finite element model for an immediately loaded implant-supported denture. Using the Ansys Workbench 2021 R2 software, an analysis was conducted to examine the deformation and von Mises stress experienced by the implant-supported dentures, peri-implant bone tissue, and implants under dynamic loading across three simulated masticatory cycles. These findings were subsequently evaluated through a comparative analysis. The suprastructures showed varying degrees of maximum deformation across zirconia (Zr), titanium (Ti), low-MOE-Ti, and polyetheretherketone (PEEK) implant systems, registering values of 103.1 µm, 125.68 µm, 169.52 µm, and 844.06 µm, respectively. The Zr implant system demonstrated the lowest values for both maximum deformation and von Mises stress (14.96 µm, 86.71 MPa) in cortical bone. As the MOE increased, the maximum deformation in cancellous bone decreased. The PEEK implant system exhibited the highest maximum von Mises stress (59.12 MPa), whereas the Ti implant system exhibited the lowest stress (22.48 MPa). Elevating the MOE resulted in reductions in both maximum deformation and maximum von Mises stress experienced by the implant. Based on this research, adjusting the MOE of the implant emerged as a viable approach to effectively modify the biomechanical characteristics of the implant system. The Zr implant system demonstrated the least maximum von Mises stress and deformation, presenting a more favourable quality for preserving the stability of the implant-bone interface under immediate loading.

[Determination of the presence of an antibiotic in implant-bone biopsy specimens by Raman spectroscopy in experiment]. / Opredelenie nalichiya antibiotika v implantato-kostnykh bioptatakh metodom ramanovskoi spektroskopii v eksperimente.

THE AIM OF THE STUDY: Was to determine the presence of an amoxicillin-based antibiotic in bone implant biopsies by Raman spectroscopy in an experiment. MATERIALS AND METHODS: Experimental animals (n=10, a miniature pig of the Svetlogorsk breed) were divided into 2 groups of 5 animals. Groups 1 and 2 were injected with amoxicillin 2 ml per 20 kg of body weight 30 minutes before dental implantation surgery, then group 2 was additionally injected with 1 ml per 20 kg of body weight for 5 days. Each animal has 6 implants installed. On the 1st, 3rd, 7th, 14th day, an implant-bone biopsy was removed from each animal, micro-preparations were made and Raman spectroscopy was performed to assess the peak matching of the Raman spectrum. RESULTS: In animals of the 1st and 2nd groups, the main peak of the Raman spectrum, which is closest to the values of the antibiotic spectrum of interest to us, is located closer to 1448 cm-1 and 1446 cm-1, respectively. At the same time, in both observations, the peaks relate to the spectrum of bone tissue, which cannot indicate the content of an antibiotic in the drug. CONCLUSION: No scattering spectra corresponding to the antibiotic molecule were found in any animal from both groups, regardless of the mode of administration and dosage of amoxicillin. The detected peaks corresponded to bone tissue without an antibiotic.

Longevity of different abutments placed on narrow diameter implants: Assessment of structural damage and loosening.

OBJECTIVES: To evaluate structural damage and loosening of abutments placed on narrow diameter implants after cyclic fatigue. METHODS: Sixty Morse taper narrow diameter implants (Neodent, Brazil) received two types of abutments (1PA- one-piece abutment or 2PA- two-piece abutment), which were randomly divided into 3 fatigue experiments (n = 10). The implants were placed into a customized supporting holder and a software-assisted digital torque wrench secured the manufacturer recommended torque for each abutment. Cone beam computed tomography (CBCT) scans were acquired, before and after fatigue, and post-processed (software e-Vol DX) to assess damage and abutment displacement. The boundary fatigue method was adapted to use 2 × 106 cycles, 2 Hz of frequency and constant peak load of 80 N (first experiment) that varied according to the failure rate of previous specimens (second and third experiments). Failure was evaluated using CBCT scans and removal torque values. Data were used to estimate long-term torque degradation, probability of failure and Weibull modulus (software ALTA PRO9). RESULTS: All 2PA specimens became loosen independently of the applied fatigue load, and structural bending was observed in 14 abutments. Eight 1PA got loosen during the fatigue experiment. The Weibull analysis showed a lower modulus (m = 1.0; 0.7, 1.4) for 1PA than for 2PA (m = 2.6; 2, 3.4) resulting in longer predicted lifetimes and slower torque degradation for 1PA than for 2PA specimens. SIGNIFICANCE: 1PA showed greater long-term survival probability than 2PA. Predicting the lifetime and mechanical behavior of implant-abutment systems are useful information to clinicians during the decision-making process of oral rehabilitations.

Full-arch rehabilitation of severely atrophic maxilla with additively manufactured custom-made subperiosteal implants: A multicenter retrospective study.

The aim of this retrospective study was to analyze a series of patients who underwent full-arch rehabilitation of the atrophic maxilla using additively manufactured subperiosteal implants, between August 2018 and January 2023, at the Universities of Sassari and Poznan. In total, 36 patients and 72 implants were included, with no implants lost during follow-up, and a success rate of 90.3%. Seven (9.7%) of the implants showed class 1 exposure. Bleeding on probing was detected in 10.4% of the abutments at 6 months, 7.9% at 1 year, 10% at 2 years, 7% at 3 years, and 11.4% at 4 years. No significant bone resorption under the abutments was detected during the whole observation period. Based on the findings from this study, additively manufactured subperiosteal implants could represent a safe and reliable technique for full-arch rehabilitation in patients with severe maxillary atrophy.

Four-year assessment of masticatory function in mandibular overdenture wearers: A randomised clinical trial comparing two to four implants to retain the prosthesis.

BACKGROUND: Limited data exist on the mid- to long-term masticatory capacity of mandibular overdenture (IOD) wearers, particularly regarding the use of posterior implants to retention. OBJECTIVES: To periodically evaluate mastication of IOD wearers, comparing the effectiveness of two to four implants to retain the prosthesis. METHODS: In a randomised controlled clinical trial, 20 complete edentulous patients (14 women), aged 51-84 years (mean age 69.1 ± 9.6), received new bimaxillary complete dentures (CD). After adaptation, baseline measurements of masticatory performance (X50) and swallowing threshold were conducted using the sieving method. Patients were then randomly assigned to groups: control (two intra-foraminal regular implants) and experimental (two intra-foraminal regular implants and two extra-short posterior implants) (n = 10 each). After 4 months, implants were splinted, and a new mandibular IOD was fabricated with bar/clip retention. Mastication was reassessed after 6, 12, and 48 months, and data analysed with repeated measures ANOVA and Sidak's post hoc (α = 0.05). RESULTS: Despite a loss of two patients per group, masticatory performance significantly improved after mandibular IOD installation (p = .031) in both groups (p = .670). A second improvement was observed after 6 months (p = .027), with no subsequent changes (p > .05). Swallowing threshold improvements were noted with IOD, and no discernible differences between groups were observed (p > .05). CONCLUSION: Masticatory function significantly improved after mandibular IOD installation, with the number of implants demonstrating minimal influence. CLINICAL TRIAL REGISTRATION: The present study was not registered in a public database, as mandated. It is important to note that the recommendation for registration was initiated in 2017 by the Committee of Medical Journal Editors, while patient inclusion in the research took place in 2016. Given that the data presented in this manuscript cover a follow-up period of up to 4 years post-surgical intervention, delayed registration was not feasible.

Application of Hard and Soft Tissue Regenerative Approach in Predictable Management of Peri-Implantitis: A Five-Year Follow-Up Case Report.

As implant dentistry expands, the number of implants being placed increases, and so does the prevalence of associated complications, resulting in implant failure if not timely attended. The present case report aims to discuss the successful regenerative management of peri-implantitis by both hard and soft tissue augmentation with a five-year follow-up. A 60-year-old male reported a chief complaint of purulent discharge, 7 mm peri-implant probing depth, and radiographic bone loss with no pathologic mobility of the dental implant. The reflection of the full-thickness flap revealed a circumferential defect. Guided bone regeneration (GBR) was performed using a combination of autogenous and alloplastic bone grafts around the implant site. To maintain the peri-implant marginal bone level, soft tissue augmentation was done using the vestibular incision subperiosteal tunnel access (VISTA) approach, after six months. A five-year follow-up showed a significant bone fill and stable soft tissue around the implant clinically and radiographically.