Biological performance of a novel bovine hydroxyapatite in a guided bone regeneration model: A preclinical study in a mandibular defect in dogs.

OBJECTIVES: This preclinical model study aims to evaluate the performance and safety of a novel hydroxyapatite biomaterial (Wishbone Hydroxyapatite, WHA) on guided bone regeneration compared to a commercially available deproteinized bovine bone mineral (Bio-Oss, BO). MATERIAL AND METHODS: Twenty-four beagle dogs were allocated to three timepoint cohorts (4, 12, and 26 weeks) of eight animals each. In all animals, four critical-sized, independent wall mandibular defects were created (32 defects/cohort). Each animal received all four treatments, allocated randomly to separated defects: WHA + collagen membrane (M), BO + M, no treatment (Sham, Sh), and Sh + M. At each timepoint, the specimens were harvested for histologic and histomorphometric analyses to determine the newly formed bone and osteoconductivity. RESULTS: At 4 weeks, bone regeneration was significantly higher for WHA + M (46.8%) when compared to BO + M (21.4%), Sh (15.1%), and Sh + M (23.1%) (p < 0.05); at 12 and 26 weeks, regeneration was similar for WHA and BO. Bone-to-material contact increased over time similarly for WHA + M and BO + M. From a safety point of view, inflammation attributed to WHA + M or BO + M was minimal; necrosis or fatty infiltrate was absent. CONCLUSIONS: WHA + M resulted in higher bone regeneration rate than BO + M at 4 weeks. Both BO + M and WHA + M were more efficient than both Sh groups at all timepoints. Safety and biocompatibility of WHA was favorable and comparable to that of BO.

The Effects of Direct Polymethyl Methacrylate and Zirconia-on-Ti-Base Abutments on Peri-implant Soft Tissue Integration: A Study in Minipigs.

PURPOSE: To assess two types of abutment materials routinely used in daily practice-direct polymethyl methacrylate (PMMA) and a zirconia-on-Ti-base abutment-and their effects on peri-implant soft tissues and bone remodeling in a minipig model. MATERIALS AND METHODS: A total of 40 implants were placed in five minipigs in a single-stage surgery. Four different types of abutment materials (n = 10 per group) were used: (1) titanium (control); (2) zirconia (control); (3) PMMA (test 1); and (4) Ti-base (zirconia bonded to a titanium framework; test 2). After 3 months of healing, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attachment) were assessed on each abutment mesially and distally, and the distance from the implant margin to the first bone-to-implant contact (BIC) was measured. RESULTS: No statistically significant differences were found among the four groups regarding soft tissue dimensions (P = .21), and a long junctional epithelium (mean: 4.1 mm) and a short connective tissue attachment (mean: 0.3 mm) were found in the majority of abutments. In some samples, the junctional epithelium extended all the way to the bone level. The measured peri-implant bone remodeling was similar in all four groups (P = .25). CONCLUSIONS: The present findings indicate that both direct PMMA and zirconia-on-Ti-base abutments seem to allow soft tissue integration similar to that of titanium and zirconia abutments. However, clinical studies are warranted to either confirm or refute the observed findings and to further investigate the influence of different materials on mucointegration.

Model-Based Design to Enhance Neotissue Formation in Additively Manufactured Calcium-Phosphate-Based Scaffolds.

In biomaterial-based bone tissue engineering, optimizing scaffold structure and composition remains an active field of research. Additive manufacturing has enabled the production of custom designs in a variety of materials. This study aims to improve the design of calcium-phosphate-based additively manufactured scaffolds, the material of choice in oral bone regeneration, by using a combination of in silico and in vitro tools. Computer models are increasingly used to assist in design optimization by providing a rational way of merging different requirements into a single design. The starting point for this study was an in-house developed in silico model describing the in vitro formation of neotissue, i.e., cells and the extracellular matrix they produced. The level set method was applied to simulate the interface between the neotissue and the void space inside the scaffold pores. In order to calibrate the model, a custom disk-shaped scaffold was produced with prismatic canals of different geometries (circle, hexagon, square, triangle) and inner diameters (0.5 mm, 0.7 mm, 1 mm, 2 mm). The disks were produced with three biomaterials (hydroxyapatite, tricalcium phosphate, and a blend of both). After seeding with skeletal progenitor cells and a cell culture for up to 21 days, the extent of neotissue growth in the disks' canals was analyzed using fluorescence microscopy. The results clearly demonstrated that in the presence of calcium-phosphate-based materials, the curvature-based growth principle was maintained. Bayesian optimization was used to determine the model parameters for the different biomaterials used. Subsequently, the calibrated model was used to predict neotissue growth in a 3D gyroid structure. The predicted results were in line with the experimentally obtained ones, demonstrating the potential of the calibrated model to be used as a tool in the design and optimization of 3D-printed calcium-phosphate-based biomaterials for bone regeneration.

Effect of lab procedures and ultrasonic bath cleaning on customized implant abutment pollution: An in vitro study.

AIM: The aim of this study was to validate the effectiveness of a simplified ultrasonic cleaning protocol to clean customized abutments. The second purpose was to investigate the percentage of pollutants on customized abutments delivered by the implants company and the additional effect of dental laboratory manipulations. MATERIALS AND METHODS: Twenty-four customized abutments were divided in two groups, 12 returning from the implant company and 12 others returning from the dental laboratory. In each group, there were 6 zirconia (Zr02) abutments and 6 titanium (Ti) abutments. For each conditions, half of the samples were clean with the experimental protocol and the other were left as delivered by the company. The two steps cleaning protocol consisted of mechanical treatment with a sterile compress soaked in a detergent over the transgingival part of the abutment followed by 3 successive ultrasound baths for 2 min/bath. The presence of pollutants was quantified by scanning electron microscopy. RESULTS: The suggested cleaning method allowed to significantly decrease the quantity of pollutants (p=0.0006). The abutments returning from the dental laboratory were significantly more polluted than those coming directly from the implant company (p=0.0043). The cleaning effect was highly significant in both groups (p<0.0001). The quantity of pollutants before cleaning were similar in the titanium and in the zirconia groups and the cleaning effect was highly significant in both groups (p=0.0009). CONCLUSION: The tested cleaning protocol was successful on the customized abutments from each group.

How Periodontitis or Periodontal Bacteria Can Influence Alzheimer's Disease Features? A Systematic Review of Pre-Clinical Studies.

BACKGROUND: The negative effects of periodontitis on systemic diseases, including diabetes, cardiovascular diseases, and Alzheimer's disease (AD), have been widely described. OBJECTIVE: This systematic review aimed to gather the current understanding of the pathophysiological mechanisms linking periodontitis to AD. METHODS: An electronic systematic search of the PubMed/MEDLINE, Scopus, and Embase databases was performed using the following PECO question: How can periodontitis or periodontal bacteria influence Alzheimer's disease features?". Only preclinical studies exploring the biological links between periodontitis and AD pathology were included. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO), and the Syrcle and Camarades protocols were used to assess the risk of bias. RESULTS: After a systematic screening of titles and abstracts (n = 3,307), thirty-six titles were selected for abstract reading, of which 13 were excluded (k = 1), resulting in the inclusion of 23 articles. Oral or systemic exposure to periodontopathogens or their byproducts is responsible for both in situ brain manifestations and systemic effects. Significant elevated rates of cytokines and amyloid peptides (Aß) and derivate products were found in both serum and brain. Additionally, in infected animals, hyperphosphorylation of tau protein, hippocampal microgliosis, and neuronal death were observed. Exposure to periodontal infection negatively impairs cognitive behavior, leading to memory decline. CONCLUSIONS: Systemic inflammation and brain metastatic infections induced by periodontal pathogens contribute to neuroinflammation, amyloidosis, and tau phosphorylation, leading to brain damage and subsequent cognitive impairment.

Group 3 ITI Consensus Report: Materials and antiresorptive drug-associated outcomes in implant dentistry.

OBJECTIVES: The aim of Working Group 3 was to address the influence of both material- and anti-resorptive drug- related factors on clinical and biological outcomes and complications in implant dentistry. Focused questions were addressed on (a) implant materials other than titanium (alloy)s, (b) transmucosal abutment materials and (c) medications affecting bone metabolism were addressed. MATERIALS AND METHODS: Three systematic reviews formed the basis for discussion in Group 3. Consensus statements and clinical recommendations were formulated by group consensus based on the findings of the systematic reviews. Patient perspectives and recommendations for future research were also conveyed. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Zirconia is a valid alternative to titanium as material for implant and transmucosal components, allowing soft and hard tissue integration with clinical outcomes-identified by implant survival, marginal bone loss and peri-implant probing depths-up to 5-years comparable to titatnium. However, most of the evidence for zirconia implants is based on 1-piece implants limiting the indication range. Furthermore, based on expert opinion, zirconia transmucosal components might be preferred in the esthetic zone. In patients receiving low-dose bisphosphonate therapy, the rate of early implant failure is not increased, while the long-term effects remain poorly studied. Although it has not been sufficiently addressed, similar outcomes can be expected with low-dose denosumab. A drug holiday is not recommended when considering implant placement in patients treated with low-dose ARD. However, the specific therapeutic window, the cumulative dose and the administration time should be considered. Access to peri-implant supportive care is mandatory to prevent peri-implantitis-related medication-related osteonecrosis of the jaw (MRONJ) or implant-related sequestra (IRS). In patients receiving low-dose anti-resorptive drugs (ARD) therapy, the risk of complications related to implant placement is high, and implant procedures in this specific population should be strictly treated in a comprehensive multidisciplinary center. Finally, healthy dental implants should not be removed before low or high-dose ARD. CONCLUSIONS: Zirconia implants can be an alternative to titanium implants in selected indications. However, the current state of evidence remains limited, especially for 2-piece implant designs. Administration of low-dose ARD did not show any negative impact on early implant outcomes, but careful follow-up and supportive care is recommended in order to prevent peri-implant MRONJ and IRS. Implant placement in high-dose patients must be strictly considered in a comprehensive multidisciplinary center.

An Empirical Model Linking Physico-Chemical Biomaterial Characteristics to Intra-Oral Bone Formation.

Facial trauma, bone resection due to cancer, periodontal diseases, and bone atrophy following tooth extraction often leads to alveolar bone defects that require bone regeneration in order to restore dental function. Guided bone regeneration using synthetic biomaterials has been suggested as an alternative approach to autologous bone grafts. The efficiency of bone substitute materials seems to be influenced by their physico-chemical characteristics; however, the debate is still ongoing on what constitutes optimal biomaterial characteristics. The purpose of this study was to develop an empirical model allowing the assessment of the bone regeneration potential of new biomaterials on the basis of their physico-chemical characteristics, potentially giving directions for the design of a new generation of dental biomaterials. A quantitative data set was built composed of physico-chemical characteristics of seven commercially available intra-oral bone biomaterials and their in vivo response. This empirical model allowed the identification of the construct parameters driving optimized bone formation. The presented model provides a better understanding of the influence of driving biomaterial properties in the bone healing process and can be used as a tool to design bone biomaterials with a more controlled and custom-made composition and structure, thereby facilitating and improving the clinical translation.

The effects of direct polymethylmethacrylate and zirconia-on-Ti-base abutments on peri-implant soft tissue integration: A study in minipigs.

PURPOSE: To assess two types of abutment materials routinely used in daily prac-tice-direct polymethyl methacrylate (PMMA) and a zirconia-on-Ti-base abut-ment-and their effects on peri-implant soft tissues and bone remodeling in a mini-pig model. MATERIALS AND METHODS: A total of 40 implants were placed in five mini-pigs in a single-stage surgery. Four different types of abutment materials (n = 10 per group) were used: (1) titanium (control); (2) zirconia (control); (3) PMMA (test 1); and (4) Ti-base (zirconia bonded to a titanium framework; test 2). After 3 months of healing, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attach-ment) were assessed on each abutment mesially and distally, and the distance from the implant margin to the first bone-to-implant contact (BIC) was measured. RESULTS: No statistically significant differences were found among the four groups regarding soft tissue dimensions (P = .21), and a long junctional epithelium (mean: 4.1 mm) and a short connective tissue attachment (mean: 0.3 mm) were found in the majority of abutments. In some samples, the junctional epithelium extended all the way to the bone level. The measured peri-implant bone remodeling was similar in all four groups (P = .25). CONCLUSION: The present findings indicate that both di-rect PMMA and zirconia-on-Ti-base abutments seem to allow soft tissue integration similar to that of titanium and zirconia abutments. However, clinical studies are war-ranted to either confirm or refute the observed findings and to further investigate the influence of different materials on mucointegration.

Clinical and radiographic assessment of circular versus triangular cross-section neck implants in the posterior maxilla: Five-year follow-up of a randomized controlled trial.

OBJECTIVES: Dental implants with a triangular neck design have been developed in order to maintain peri-implant bone. The primary aim of this randomized controlled trial (RCT) was to assess after 5 years the peri-implant bone stability and the peri-implant soft tissue conditions with this new triangular implant neck design compared to a conventional round neck implant design. MATERIAL AND METHODS: This is a secondary evaluation of a RCT including 34 patients. Patients were recalled after 1, 3, and finally 5 years to assess implant survival and peri-implant bone levels using standardized radiographs. Peri-implant soft tissue health was also evaluated by recording probing depth, plaque index and Bleeding on Probing. Patient Reported Outcome Measures (PROMs) and the Pink Esthetic Score were also assessed. RESULTS: No implant loss occurred during the 5-year follow up period. The mean ± SD proximal bone remodeling after 5 years reached 0.38 ± 0.39 mm for the circular design and 0.29 ± 0.58 mm for the triangular design (p = .49). Peri-implant soft tissue health parameters and PROMs were found to be comparable. Altogether, 80% of implants presented peri-implant mucositis whereas one implant (4%) displayed sings of peri-implantitis. CONCLUSION: The 5-year evaluation of the triangular neck implants showed similar results to the circular neck implants.

Implant connection and abutment selection as a predisposing and/or precipitating factor for peri-implant diseases: A review.

Peri-implant mucosal integration is becoming a critical aspect for long term implant health and can be triggered the selection of implant components. The aim of this review is therefore to investigate the evidence concerning implant connection and abutment characteristics (abutment materials, design, handling) as predisposing or precipitating factor for peri-implant mucositis and peri-implantitis. Although the evidence that these features can directly predispose/precipitate peri-implant diseases is limited, there are -few- studies showing a potential role of the implant connection, trans-mucosal configuration, and handling in the development of early bone loss and/or peri-implantitis. With bone level implants, conical internal connections (with inherent platform switching) might be preferred over internal flat-flat and external connections to decrease the risk of early bone loss and potentially the risk of peri-implant disease. Moreover, there is a trend suggesting moving the prosthetic interface coronally (to the juxta-mucosal level) as soon as possible to reduce the number of disconnections and to limit the risk of cements remnants. This can be achieved by choosing a tissue-level implant or to place a trans-mucosal abutment (one abutment-one time approach) to optimize the peri-implant soft tissue seal. In absence of evidence for the biocompatibility regarding several restorative materials, biocompatible materials such as titanium or zirconia should be preferred in the trans-mucosal portion. Finally, higher implants (≥2mm) with an emergence angle below 30° seem more favourable. It should however be noted that some of this information is solely based on indirect information (such as early bone loss) and more research is needed before making firm recommendations about abutment choice. [Correction added on 13 March 2023, after first online publication: 'longer implants (≥2mm)' was changed to 'higher implants (≥2mm)' in this version.].

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: Five-year clinical outcomes. A prospective case series.

OBJECTIVES: The objective of this study was to assess, over a period of 5 years, implant prosthesis and patient-reported outcomes of complete dentures retained by four implant-supported attachments in the edentulous maxilla facing either natural teeth or fixed rehabilitation in the lower jaw. MATERIALS AND METHODS: Implant, prosthodontic and patient-related outcomes were assessed in 30 patients at 1, 3 and 5 years. Prosthodontic survival, complications or maintenance events as well as implant survival were recorded. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and a visual analogue scale (VAS) before implant placement (baseline) and during the follow-up period. RESULTS: After 5 years, three patients dropped out, 21 implants failed, and four overdentures were replaced leading to a prosthesis survival rate of 85.2% (95% CI: 71.8%-98.6%) and an implant survival rate of 80.6% (95% CI: 73.1%-88.0%). Prosthodontic success rate decreased from 86.2% to 74% between the 1st and the 3rd year and reached 63% after 5 years. OHIP results improved significantly from baseline to 1 year (p < .0001) and to 3 years (p = .036), but, at 5 years, the improvement was no longer significant when compared to baseline (p = .12). The overall VAS score remained significantly higher up to 5 years (p < .001). CONCLUSION: A substantial number of prosthetic complications and replacements occurred over the 5-year follow-up. After 5 years, the OHIP-20 deteriorated and reached again the baseline level. Nonetheless, the VAS results suggest significantly increased patient satisfaction after implant-supported retention was provided for the removable prostheses.

Differential patterns of cross-reactive antibody response against SARS-CoV-2 spike protein detected for chronically ill and healthy COVID-19 naïve individuals.

Immunity to previously encountered viruses can alter response to unrelated pathogens. We reasoned that similar mechanism may also involve SARS-CoV-2 and thereby affect the specificity and the quality of the immune response against the virus. Here, we employed high-throughput next generation phage display method to explore the link between antibody immune response to previously encountered antigens and spike (S) glycoprotein. By profiling the antibody response in COVID-19 naïve individuals with a diverse clinical history (including cardiovascular, neurological, or oncological diseases), we identified 15 highly antigenic epitopes on spike protein that showed cross-reactivity with antigens of seasonal, persistent, latent or chronic infections from common human viruses. We observed varying degrees of cross-reactivity of different viral antigens with S in an epitope-specific manner. The data show that pre-existing SARS-CoV-2 S1 and S2 cross-reactive serum antibody is readily detectable in pre-pandemic cohort. In the severe COVID-19 cases, we found differential antibody response to the 15 defined antigenic and cross-reactive epitopes on spike. We also noted that despite the high mutation rates of Omicron (B.1.1.529) variants of SARS-CoV-2, some of the epitopes overlapped with the described mutations. Finally, we propose that the resolved epitopes on spike if targeted by re-called antibody response from SARS-CoV-2 infections or vaccinations can function in chronically ill COVID-19 naïve/unvaccinated individuals as immunogenic targets to boost antibodies augmenting the chronic conditions. Understanding the relationships between prior antigen exposure at the antibody epitope level and the immune response to subsequent infections with viruses from a different strain is paramount to guiding strategies to exit the COVID-19 pandemic.

Predicting probing depth reduction after periodontal non-surgical treatment in smokers according to the nicotine dependence and the number of cigarette consumed.

Introduction: Smoking is considered as a risk factor for the poor outcomes after periodontitis non-surgical treatment (PNST). The aim of this short communication is to predict probing depth reduction after periodontal non-surgical treatment in smokers according to the nicotine dependence (FTND) and the number of cigarette consumed (NCC). Methods: This work is a post-hoc study of a prospective controlled study on the effect of oral hygiene instructions and PNST on periodontal outcomes. This short communication focused only on the current conventional smokers (N = 34), based on specific smoking indicators, and on probing depth (PD) parameter that were recorded at baseline (time 0), after oral hygiene instruction (time 1) and 3 months after PNST (time 2). Results: The 34 smokers had a mean age 46.5 ± 11.5 years. The NCC- and FTND-based predictions allowed to show in a specific nomogram the PD values 3 months after PNST for each NCC and FTND category. Conclusion: Two nomograms are proposed for prognostic purposes and allow patients to understand the impact of smoking on periodontitis according to the number of cigarette consumed and the level of nicotine dependence. These nomograms might be also used for supporting smoking cessation. Clinical significance: In smoker patients with periodontitis, there is a need to predict, for both patient and clinicians, the impact of the number of cigarettes consumed and the level of nicotine dependence on probing depth after oral hygiene instructions and debridement. Two nomograms are proposed for prognostic purposes.

An individualized approach for a one-abutment one-time protocol using fully guided implant surgery: a 4-year follow-up case series.

AIM: The objective of the present case series was to evaluate the 4-year outcomes of implants placed in the esthetic area using static computer-assisted implant surgery (s-CAIS) and restored with a one-abutment one-time (OAOT) protocol using custom-made zirconia abutments and cemented provisional crowns manufactured prior to surgery. Materials and methods: Ten consecutive implants were placed in the esthetic area. Based on a digital implant and prosthodontic planning, surgical guides were ordered and used for the preparation of definitive custom-made zirconia abutments and polymethylmethacrylate provisional crowns. Implants were placed using the s-CAIS guide, and prosthetic components were placed immediately. Implant outcomes were evaluated at the time of surgery, after 4 months, and after 4 years. RESULTS: All implants were successfully placed with s-CAIS and restored with final abutments and provisional crowns. No major prosthetic adverse events were observed. After 4 years, the implant survival rate was 100%, minor peri-implant bleeding on probing was reported, and very stable peri-implant bone levels were observed. The pink esthetic score showed that the prosthetic components were well integrated, and the peri-implant soft tissue was stable. CONCLUSIONS: Within the limitations of the present case series, these results suggest that emerging digital workflows allow the manufacture of final custom-made abutments and provisional crowns prior to surgery. This individualized OAOT procedure may reduce cement-related complications and improve esthetic outcomes by optimizing soft tissue healing with prosthetic components. However, such protocols have evolved toward fully digital workflows, and comparative clinical trials are needed.

Instrumentation during the second stage of periodontal therapy: a European survey.

OBJECTIVES: To gather practice-based information about instrumentation during the second stage of periodontal therapy among the members of the European Federation of Periodontology. METHODS: This survey was conducted to investigate periodontal instrumentation (e.g., frequency, instruments, their maintenance) during the second stage of periodontal therapy. RESULTS: Questionnaires from 2008 responders actively involved in periodontal therapy (general dental practitioners, periodontists, and dental hygienists) were analyzed. The frequency of use of hand and mechanical instruments was similar during the second stage of periodontal therapy and 94.4% of the participants combined both. The most popular hand instruments were Gracey curettes, and the preferred mechanical devices were ultrasonic scalers. For the latter, mostly the combination of standard and micro/slim inserts was preferred (42.4%) over solely standard inserts (32.1%) or micro/slim inserts (25.5%). The wear of hand instruments was sytematically checked by 46.1% of the respondents and the wear of the inserts by 41.3%. The more experienced the dental professional, the more frequent the wear of the instruments and inserts was checked. CONCLUSION: The most popular periodontal instrumentation technique in clinical practice during the second stage of periodontal therapy is a combination of hand and mechanical instruments. CLINICAL RELEVANCE: Clinicians should check the wear of their instruments systematically to have the most performant instruments possible for periodontal instrumentation. Scientists should see the results of this questionnaire as an incentive to set up studies investigating whether the combination of hand and mechanical instruments, the preferred treatment method of clinicians, is better than either of these instruments alone.

One-stage versus two-stage piezocision-assisted orthodontic tooth movement: A preclinical study based on Nano-CT and RT-PCR analyses.

OBJECTIVE: To evaluate the effect of a second-stage piezocision on the biological response. MATERIALS AND METHODS: 60 rats were randomly allocated to 6 experimental groups of 10 rats. Rats undergoing a one-stage piezocision were sacrified on day 7, 28 and 42 (groups 1-3) while rats undergoing a two-satge piezocision were sacrified on day 42, 63 and 90 (groups 4-6), respectively. The biological response was investigated in 3D at the tissue level using Nano-computed tomography (Nano-CT) and, at the molecular level using the qRT-PCR technique. Bone Volume Fraction (BVF) loss was the primary endpoint. RESULTS: Similar loss of BVF were observed both after the first and second piezocisions. The change in BVF loss between 7 and 28 days after each piezocision were 25.1 ± 13.0 (SE)% and 11.2 ± 11.6 (SE)% respectively and did not differ from each other (p = 0.43). Changes in BVF loss from 7 to 42 days were also comparable in one-stage and two-stage piezocision (4.9 ± 12.3 (SE) vs. -19.9 ± 13.4 (SE), p = 0.19). At the molecular level, all parameters except Translating Ribosome Affinity Purification (TRAP) protein had identical patterns. CONCLUSION: Within the limits of the present study, a second piezocision allowed to re-induce the Regional Acceleratory Phenomenon (RAP) effect. Nevertheless, the relevance of the findings to the clinical effect has not been tested.

The Effects of Abutment Materials on Peri-Implant Soft Tissue Integration: A Study in Minipigs.

PURPOSE: To evaluate, in a minipig model, the soft tissue integration of four different transmucosal materials, as well as the peri-implant bone remodeling. MATERIALS AND METHODS: A total of 40 implants were placed in five minipigs in a single stage surgery, and two of each of the following abutment materials were used in each animal: (1) titanium (Ti; control), (2) polymethylmethacrylate (PMMA), (3) zirconia (Zi), and (4) veneering ceramic (VC). After a healing period of 3 months, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attachment) were assessed on each abutment and the distance from the implant margin to first bone-to-implant contact (BIC) was measured. RESULTS: The mean biological width-characterized by the sum of junctional epithelium and connective tissue measurements-was 3.8 (0.6) mm and no statistically significant difference was found between the four groups (p = 0.41). However, a long junctional epithelium (3.3-3.8 mm) and a very short connective tissue attachment (0.1-0.2 mm) were observed with all abutments. The measured peri-implant bone remodeling was similar in all four groups (p = 0.88). CONCLUSIONS: Within its limitations, this study showed that all tested materials allowed soft tissue integration, consisting of a long junctional epithelium, extending close to the bone level, and a rather short portion of connective tissue.

Digital vs. conventional workflow for one-abutment one-time immediate restoration in the esthetic zone: a randomized controlled trial.

OBJECTIVES: To compare short-term outcomes after immediate restoration of a single implant in the esthetic zone with one-abutment one-time technique comparing a conventional (control) vs. a fully digital workflow (test). MATERIALS AND METHODS: Eighteen subjects were randomly assigned to the two groups, and a digital implant planning was performed for all. In the test group, a custom-made zirconia abutment and a CAD-CAM provisional crown were prepared prior to surgery; implants were placed using a s-CAIS guide allowing immediate restoration after surgery. In the control group, the implant was placed free-handed using a conventional surgical guide, and a custom-made zirconia abutment to support a stratified provisional crown was placed 10 days thereafter, based on a conventional impression. Implant accuracy (relative to the planning), the provisional restoration outcomes, as well as PROMs were assessed. RESULTS: The implant positioning showed higher accuracy with the s-CAIS surgical guide compared to free-handed surgery (angular deviation (AD): 2.41 ± 1.27° vs. 6.26 ± 3.98°, p < 0.014; entry point deviation (CGD): 0.65 ± 0.37 mm vs. 1.27 ± 0.83 mm, p < 0.059; apical deviation (GAD): 1.36 ± 0.53 mm vs. 2.42 ± 1.02 mm, p < 0.014). The occlusion and interproximal contacts showed similar results for the two workflows (p = 0.7 and p = 0.69, respectively). The PROMs results were similar in both groups except for impression taking with intra-oral scanning preferred over conventional impressions (p = 0.014). CONCLUSIONS: Both workflows allowed implant placement and immediate/early restoration and displayed similar clinical and esthetic outcomes. The fully digital workflow was associated with a more accurate implant position relative to planning. CLINICAL RELEVANCE: Our results show that both conventional and digital workflow are predictive and provide similar clinical outcomes, with extra precision provided by digitalisation.

Immediate implant placement combining socket seal abutment and peri-implant socket filling: A prospective case series.

OBJECTIVES: The aim of this prospective case series was to assess the implant outcomes as well as hard and soft tissue dimensional changes of immediate implant placement in posterior sites using a custom-made sealing socket abutment (SSA) combined to peri-implant socket filling (PISF). MATERIAL AND METHODS: Twenty patients were considered for single extraction and immediate implant in upper or lower posterior regions. The remaining peri-implant sockets were filled with Deproteinized Bovine Bone Mineral. Based on intra-oral scans (IOS), custom-made SSAs were placed the same day. Implant survival rate, peri-implant bone changes, peri-implant health and pink esthetic score (PES) were recorded up to 1 year post-implant placement. Moreover, CBCT and IOS were performed to monitor hard and soft tissue dimensional changes. RESULTS: One implant failed to osseointegrate leading to an implant survival rate of 95% after 1 year. Peri-implant bone changes yielded 0.19 ± 0.31 mm and 84.2% of the implants displayed no or mild bleeding on probing. Horizontal bone remodeling was not significant from baseline to 1 year at any levels. Finally, soft tissue profile was stable in the most cervical area while minor changes occurred during the first 6 months below the gingival margin. The absence of mid-buccal recession (0.07 mm) and good PES were found after 1 year. CONCLUSION: Despite its limitations, this study showed that immediate implants in the posterior region using the SSA + PISF protocol resulted in promising implant outcomes with limited hard and soft tissue dimensional changes while decreasing the overall treatment time.

Oral Hygiene Instructions and Methods: A Comparative Survey of European General Dentists, Periodontists and Dental Hygienists.

PURPOSE: To study the practices of general dentists, periodontists and dental hygienists who are members of the European Federation of Periodontology, regarding oral hygiene education, plaque control assessment, recommended dental and interdental hygiene tools, and antimicrobial agents. MATERIALS AND METHODS: A web-based survey was sent to 13,622 members of the European Federation of Periodontology (EFP) through its 29 national member societies. It targeted general dentists (GD), specialists in periodontology (DSP) and dental hygienists (DH). Data were collected between 24 April and 17 May 2015. A data-driven statistical analysis was conducted and differences between professions were explored. RESULTS: A total of 2076 answers were collected. Only the 2009 answers originating from GD, DSP and DH were analysed (67 answers originated from other professions and were excluded). Among those 2009 respondents, 43.2% were DSP and 37.2% were GD. Overall, DH, DSP and GD reported spending 17.1 minutes for the initial teaching of OH, with differences between professions (p < 0.0001). DH, GD and DSP exhibited differences in the type of toothbrushes they recommend (p < 0.0001). DSP recommended electric and manual toothbrushes (TB) equally. DH predominantly recommended electric TB (56.8%). Overall, 95% of DH, DSP and GD recommended interdental brushes, with no statistically significant differences between professions. Low concentration chlorhexidine was considered the most relevant antimicrobial agent for daily oral care of periodontitis patients. Half of GD prescribed antimicrobial mouthrinses for long-term use in 70%-100% of their patients with periodontitis. CONCLUSION: EFP-affiliated practitioners allocate a significant amount of time to educating patients on oral health. Their practices are mostly in line with the current scientific evidence. Some discrepancies were found between the different professions. Similar surveys could be conducted over time to monitor the evolution of practices.