Dental implant and abutment in PEEK: stress assessment in single crown retainers on anterior region.

OBJECTIVE: Stress distribution assessment by finite elements analysis in poly(etheretherketone) (PEEK) implant and abutment as retainers of single crowns in the anterior region. MATERIALS AND METHODS: Five 3D models were created, varying implant/abutment manufacturing materials: titanium (Ti), zirconia (Zr), pure PEEK (PEEKp), carbon fiber-reinforced PEEK (PEEKc), glass fiber-reinforced PEEK (PEEKg). A 50 N load was applied 30o off-axis at the incisal edge of the upper central incisor. The Von Mises stress (σvM) was evaluated on abutment, implant/screw, and minimum principal stress (σmin) and maximum shear stress (τmax) for cortical and cancellous bone. RESULTS: The abutment σvM lowest stress was observed in PEEKp group, being 70% lower than Ti and 74% than Zr. On the implant, PEEKp reduced 68% compared to Ti and a 71% to Zr. In the abutment screws, an increase of at least 33% was found in PEEKc compared to Ti, and of at least 81% to Zr. For cortical bone, the highest τmax values were in the PEEKp group, and a slight increase in stress was observed compared to all PEEK groups with Ti and Zr. For σmin, the highest stress was found in the PEEKc. Stress increased at least 7% in cancellous bone for all PEEK groups. CONCLUSION: Abutments and implants made by PEEKc concentrate less σvM stress, transmitting greater stress to the cortical and medullary bone. CLINICAL RELEVANCE: The best stress distribution in PEEKc components may contribute to decreased stress shielding; in vitro and in vivo research is recommended to investigate this.

Assessment of reproducibility and influence of different dental specialties on functional implant prosthodontic score: A prospective clinical study analyzing single-unit implant crowns.

AIM: Implant therapy in partially edentulous patients has become the most adapted and predictable treatment modality. The success rate of implants has been measured in terms of esthetic, biological, and technical factors such as radiographic bone loss, prosthetic complications, and stability. Despite the existence of several indices for the esthetic assessment of implant crowns, a need for functional evaluation of the implant crown with an objective and reproducible score has arisen. The study aims to validate the reproducibility of the functional implant prosthodontic score (FIPS) and the influence exerted by different dental specialties while evaluating posterior single-unit implant crowns. STUDY SETTING AND DESIGN: This was a prospective clinical study. MATERIALS AND METHODS: Fifteen patients with cement-retained single-implant crowns in the posterior region of the jaws were included. Eight examiners, two prosthodontists, two periodontists, two oral surgeons, and two orthodontists evaluated 15 photographs of single-unit implant crowns during the 1-year follow-up examination. The examiners assessed the photographs for FIPS, which includes five parameters for objectively evaluating the single-unit implant crowns. Assessments were performed twice at a gap of 4 weeks. STATISTICAL ANALYSIS USED: Pearson's correlation with a 95% confidence interval was calculated for the intra-examiner and the Kruskal-Wallis test for inter-examiner reproducibility. RESULTS: The mean total FIPS scores for all included examiners were 7.133 for time T1 and 7.074 for time T2, showing a strong Pearson correlation coefficient for intra-examiner reproducibility. No significant difference was analyzed among different specialties with statistically significant values of the Kruskal-Wallis test. CONCLUSION: Intra- and inter-examiner analysis showed very consistent results during the reproducibility assessment of FIPS. The results validated the use of FIPS as a long-term predictive functional evaluation tool for the single-implant crowns in posterior sites irrespective of the effect of different dental specialties. It could be used for risk estimation and prognosis for long-term survival and performance of implant crowns.

Bone Volume Assessment Around Immediate Dental Implant in the Esthetic Area with Immediate Tooth-Like Single Crown Provisionalization: A Laser and Computed Tomography 1-Year Retrospective Study.

PURPOSE: To examine the remodeling process of both the soft and hard tissue components of the postextraction socket around immediately loaded dental implants after tooth extraction in maxillary esthetic areas. MATERIALS AND METHODS: Subjects underwent immediate placement of single implants in postextraction sockets without bone grafting, and their immediate provisionalization with custom tooth-like interim crowns were fabricated using digital diagnostic impressions and a dental milling machine. Intraoperative and 1-year follow-up layered scans of the postextraction sockets after implantation were acquired using a 3D optical system. In the short term, subjects underwent computed tomographic scans. Digital impressions for gingival contours, originally stored as STL (standard tessellation language) files, were converted to DICOM (Digital Imaging and Communications in Medicine) files with the implant shoulder working as a referral point, which were then superimposed to 3D radiologic images. The observed volumetric and linear outcomes were measured using a program known as DentaScan. The width of the alveolar crest at the level of the implant shoulder and marginal bone levels were acquired. Nonparametric tests were applied with a level of significance set at P < .01. RESULTS: No failure was reported after a follow-up of 1 year. Little or no inflammation of the treated areas was registered, and there were practically no signs of suppuration. The areas showed a significant reduction in the overall volumes for both soft and bone tissue, with a P value < .0001 from the baseline (0.983 ± 0.172 cm3) to the 1-year survey (0.865 ± 0.156 cm3). If the soft and bone tissue changes were separately evaluated, a significant loss (with a P value < .0001) was registered for only the bone tissues (from 0.434 ± 0.075 to 0.355 ± 0.061 cm3). Moreover, changes in gingival tissue from baseline to the 1-year survey (-0.040 ± 0.067) appeared to be significantly different from the overall volume loss (-0.118 ± 0.083 cm3). A shrinkage in width (-0.5 ± 0.7 mm) was found from baseline (12.6 ± 0.6 mm) to the 1-year follow-up (12.1 ± 0.9 mm). Marginal bone levels were 0.97 ± 0.70 mm and 0.39 ± 0.78 mm, respectively, at the mesial and distal aspects of the implants. CONCLUSIONS: The present analysis suggested that immediately customized provisionalization was effective enough to prevent both volume loss and linear shrinkage at the layers of the treated areas. Moreover, the buccal aspects seemed to be the areas most affected by the loss of volume. The mean loss in width, which amounted to roughly 0.5 mm, appeared to be negligible when compared to the overall width measured before surgery.

Implant or tooth? - A cost-time analysis of managing "unrestorable" teeth✰.

OBJECTIVES: Retaining and restoring severely compromised teeth with subcrestal defect extensions or removing and replacing them using implant-supported crowns (ISC) remains controversial, and economic analyses comparing both strategies remain scarce. We performed a cost-time analysis, comparing the expenditures for retaining "unrestorable" teeth using forced orthodontic extrusion and restoration (FOE) versus extraction and ISC, in a clinical prospective cohort study. METHODS: Forty-two patients (n = 21 per group) were enrolled from clinical routine at a university into this study. Direct medical and indirect costs (opportunity costs) were assessed for all relevant steps (initial care, active care, restorative care, supportive care) using the private payer's perspective in German healthcare based on a micro-costing approach and/or national fee items. Statistical comparison was performed with Mann-Whitney-U test. RESULTS: Patients were followed up for at least one year after initial treatment (n = 40). The drop-out rate was 5% (n = 2). Total direct medical costs were higher for ISC (median: 3439.05€) than FOE (median: 1601.46€) with p<0.001. We observed a higher number of appointments (p = 0.002) for ISC (median: 14.5) in comparison to FOE (median: 12), while cumulatively, FOE patients spent more time in treatment (median: 402.5 min) in comparison to ISC (median: 250 min) with p<0.001, resulting in comparable opportunity costs for both treatment groups (FOE: 304.50€; ISC: 328.98€). CONCLUSIONS: ISC generated higher costs than FOE. More in-depth and long-term exploration of cost-effectiveness is warranted. CLINICAL SIGNIFICANCE: ISCs were associated with higher initial medical costs and required more appointments than the restoration of severely compromised teeth after FOE. Treatment time was higher for patients with FOE, resulting in similar opportunity costs for both treatment approaches. Future research needs to investigate long-term cost-effectiveness.

Assessment of the alveolar bone loss in fresh socket implant procedures with immediate implant loading via temporary preformed anatomical healing caps: Comparison of two different lengths of the implant collar.

PURPOSES: The aim of the present clinical and radiologic retrospective study was to evaluate alveolar bone remodeling, in terms of alveolar width and peri­implant bone level, two years after immediate implant positioning (with two different collar lengths, 0.8 mm and 2.0 mm) and loading of preformed healing cap. The Null hypothesis, H0 is: there was no difference between the two groups of implants. METHODS: Patients suffering from single-tooth edentulous areas in premolar, cuspid, and incisive areas were treated with fresh-socket implants and immediate preformed anatomical healing caps. Each final crown restoration was fabricated 3 months later. Primary outcomes (related to loss of the alveolar width and peri­implant bone level) and secondary outcomes (testing adverse events, and measuring implant/prosthesis survival) were acquired and analyzed. RESULTS: A two-year retrospective analysis was conducted on 31 patients (19 female and 12 male), who underwent dental implant placement with implants having two different lengths of the collar: group A, 0.8 mm, and group B, 2.0 mm. As for the width of the alveolar crest, there was a negligible loss (less than half a millimeter) reported for both the groups, anyway reaching a statistical significance. Preoperative alveolar widths (9.50±0.67 mm and 9.45±0.90 mm, respectively for groups A and B) were different from the two-year alveolar widths (9.20±0.74 mm and 8.93±0.99 mm, respectively for groups A and B) with p-values ≤ 0.0049. When the marginal bone loss was assessed, significant differences were registered between the two procedure groups (-1.42±0.34 mm for group A and -0.11±0.15 mm for group B with a p-value < 0.0001). CONCLUSIONS: The proper design of a healing abutment was very important to preserve the emergence profile immediately after extraction and implant placement. The length of the implant collar used with an immediate healing abutment appeared to affect the preservation of the alveolar crest with predictable final results.

Cost-effectiveness analysis: nonsurgical root canal treatment versus single-tooth implant.

BACKGROUND: Economic evaluation of nonsurgical root canal treatment (NSRCT) and single-tooth implant (STI) provides useful information for medical decision. This retrospective study aimed to evaluate the cost-effectiveness of NSRCT versus single-tooth implant (STI) after 5-year treatment in a university affiliated hospital in Beijing, China. METHODS: 211 patients who underwent NSRCT and 142 patients who had STI were included and recalled after 5-year treatment. The propensity scores were used to match the cases of two treatment modalities. At recall, outcomes were determined based on clinical and radiographical examinations. For endodontically treated cases, absence or reduction of radiolucency were defined as success. Marginal bone loss (MBL) ≤ 4 mm were determined as success for implant cases. Direct and indirect costs were calculated in China Yuan (CNY). Patients' willingness to pay (WTP) for each treatment modality was evaluated by questionnaires. A cost-effectiveness analysis was performed from the societal perspective. RESULTS: 170 patients with 120 NSRCT teeth and 96 STI were available at recall. Based on propensity score matching, 76 endodontically treated teeth were matched to 76 implants. Absence of the radiolucency was observed in 58 of 76 endodontically treated teeth (76%) and reduction of the radiolucency in 9 of 76 teeth (12%) and altogether the success rate was 88%. 100% implants were detected with marginal bone loss (MBL) ≤ 4 mm. The cost advantage of NSRCT (4,751 CNY) over STI (20,298 CNY) was more pronounced. Incremental cost effectiveness ratio (ICER) was 129,563 CNY (STI-NSRCT) per success rate gained. It exceeded the patients' willingness to pay value 7,533 CNY. CONCLUSIONS: Clinical outcomes of NSRCT and STI could be predictable after 5-year treatment. NSRCT may be more cost-effective than STI for managing endodontically diseased teeth.

Volume assessment of the external contour around immediate implant with or without immediate tooth-like crown provisionalization: A digital intraoral scans study.

PURPOSES: To examine differences between immediate and delayed dental implant loading in maxillary aesthetic areas. METHODS: In this retrospective controlled analysis, 43 subjects who underwent immediate placement of the dental implant in a post-extraction socket were ranked into either immediate (24 implants loaded with non-occlusal tooth-like profile provisional prostheses fabricated by virtual diagnostic impressions and an in-office dental milling machine) or delayed group (19 implants loaded with conventional cover screws and secondary intention healing). Intraoperatively and then four months later, scans of the external layers were acquired with an optical scanner. The width of the alveolar crest and Jemt papilla index were acquired. Non-parametric tests were applied with a level of significance set at p < 0.01. RESULTS: In both groups, the volumes and areas showed significant reductions from the baseline to the 4-month survey. Reductions in volume appeared to be statistically different between the two groups (-39±31 mm3 for the immediate and 89 ± 30 mm3 for the delayed group). The final Jemt papilla index appeared significantly different between the immediate (mesial, 2.5 and, distal, 3) and delayed groups (2 for both aspects). CONCLUSIONS: Immediate provisionalization significantly reduced volume loss and area shrinkage at the external layer when data were compared to a delayed rehabilitation strategy.

The peri-implant mucosa color: A systematic appraisal of methods for its assessment and clinical significance.

BACKGROUND: Peri-implant mucosa color (PMC) seems to be one of the main parameters affecting the esthetic outcome of implant therapy. However, more emphasis should be given to its assessment and reporting. PURPOSE: To describe the available evidence on methods to assess and report the color of the peri-implant mucosa (PMC) and the respective clinical relevance. MATERIAL AND METHODS: A comprehensive electronic and manual search was performed to identify clinical studies reporting on PMC. RESULTS: A total of 121 studies were included. PMC was evaluated at the time of the follow-up visit (chairside) in 45.5% studies. PMC assessment was performed qualitatively, by comparing PMC with adjacent and/or contralateral gingiva (78.6%) or quantitatively, using spectrophotometry (20.7%) or a software on clinical photographs (0.8%). The most performed method to assess PMC was through esthetic indices (76.9%), either at the time of the follow-up visit (chairside) or at later time point using photographs. Quantitative reporting of PMC included averages of points from esthetic indices or color differences to natural gingiva expressed with the CIELAB color system. PMC assessment allowed describing color discrepancies compared to natural gingiva, evaluating color changes over time, and comparing the outcomes of different treatment modalities. PMC assessment through spectrophotometry was additionally utilized to assess the role of mucosal thickness (MT) on PMC. CONCLUSIONS: Various methods for PMC assessment and reporting were described, including visual assessment, mainly through esthetic indices, and spectrophotometry. PMC evaluation has allowed to demonstrate the factors affecting the color of the peri-implant soft tissue, such as the type of abutment/restoration, MT, and soft tissue augmentation.

Immediate versus delayed implant placement in the esthetic zone: a prospective 3D volumetric assessment of peri-implant tissue stability.

PURPOSE: To evaluate the volumetric stability of peri-implant soft and hard tissue prospectively, this study compared immediate versus delayed implants placed in the anterior esthetic region. METHODS: This non-randomized controlled clinical study included 25 patients, who received an immediate (type 1) or a delayed (type 4) implant placement for the replacement of a single anterior tooth. The anterior maxillae were intraorally scanned at three timepoints: before surgery (S0), 6 months (S1), and 12 months (S2) after surgery. A specific region of interest (ROI), divided into marginal and apical regions, was determined and superimposed for volumetric changes analysis. At 6 and 12 months, the probing depth (PD), bleeding/suppuration on probing (BOP/SUP), modified plaque index (PI), keratinized mucosa (KM) width, mucosal recession (MR), and implant stability (PTV) by means of periotest were recorded. RESULTS: Between S0-S2, tissue surrounding immediate implants was reduced in 0.37 ± 0.31 mm, whereas delayed implants gained 0.84 ± 0.57 mm mean tissue volume. Peri-implant tissue loss at type 1 implants occurred primarily in the marginal section of the ROI (0.42 ± 0.31 mm), whereas tissue gain at type 4 implants occurred mainly in the apical section (0.83 ± 0.51 mm). These values were significantly different between both groups for the entire ROI (p = 0.0452) and the marginal region (p = 0.0274). In addition, the mean buccal KM width around type 1 implants was significantly wider in comparison with the type 4 implants group after 12 months (p = 0.046). There were no significant differences between groups regarding PD, BOP/SUP, or PTV. CONCLUSIONS: The results suggest that type 1 implants placed in the esthetic region experience more tissue loss than type 4 implants, thus marginal tissue remodeling should be considered for planning immediate implants placement in the anterior maxillae.

The Assessment of Different Gingival Management Materials for Immediate Implant Treatment in the Esthetic Zone: A Clinical and Biochemical Study.

PURPOSE: To observe the effect of different prosthetic materials (polymethyl methacrylate [PMMA] and flowable composite [FC]) on marginal bone loss, pink esthetic score (PES), and cytokine levels (receptor activator of nuclear factor kappa-Β ligand [RANKL] and osteoprotegerin [OPG]). MATERIALS AND METHODS: A total of 46 patients (31 women, 15 men) were treated with immediate implant therapy after tooth extraction. For standardization, only the maxillary premolar tooth of each patient was restored, and also, both of the adjacent teeth were present in the dental arch. Provisional crowns were prepared before the surgery on patient models with two different materials (24 PMMA, 22 FC). Following the surgical procedure, provisional crowns were adjusted on polyetheretherketone (PEEK) abutments as nonfunctional in centric and eccentric movements. After the surgery, patients were evaluated monthly for 3 months. At each follow-up, periapical radiography was obtained by the parallel technique, and peri-implant crevicular fluid (PICF) was collected. Pink esthetic scoring was done. MBL was calculated for the mesial and distal sides separately. Cytokine levels were analyzed from PICF. Statistical analyses (Shapiro-Wilk, Mann-Whitney U, independent-samples t test, Wilcoxon t test, paired-samples t test, and Friedman two-way analysis of variance with Bonferroni correction) were completed (α = .05). RESULTS: PES was increased significantly within groups (P < .01). However, there was no statistically significant difference between groups. According to the Mann-Whitney U test, no significant difference was found for the MBL (P > .05). When the RANKL/OPG values were evaluated within the group by using the Friedmann two-way analysis of variance test, no significant difference was found (P > .05). CONCLUSION: Similar pink esthetics, cytokine levels, and bone loss can be achieved using a protocol including immediate implants, particle grafts, soft tissue graft, PEEK abutments, and provisional restorations fabricated using PMMA and FC.

Assessment of Surgical and Radiographic Parameters for Abutment Height Selection: A Prospective Study with 1-Year Follow-up.

PURPOSE: The "one-abutment, one-time" concept entails the placement of a definitive abutment at the time of implant placement, without removal during prosthesis manufacture, with the aim to promote a safer environment for the peri-implant tissues. Identifying surgical and radiographic parameters that can assist with the abutment height selection would facilitate the adoption of the one-abutment, one-time concept. Therefore, the aim of this study was to assess the role of surgical and radiographic parameters as predictive factors for abutment height selection in implant-retained single crowns. MATERIALS AND METHODS: This prospective study assessed the role of surgical and radiographic measurements in the implant survival and success rates and marginal bone loss in implant-retained single crowns. Implants were placed in both healed sites and extraction sockets, and the distances between the implant platform and alveolar bone crest, implant platform and gingival margin, and buccal gap (when present) were recorded using a straight periodontal probe. Digital radiographs were made at implant placement (T0), abutment height selection (Ta), and 1-year follow-up (Tf), and the distance between the implant platform and the alveolar bone crest (mm) was assessed. Linear regression models and Pearson correlation were used to assess the influence of primary and secondary outcomes on abutment height. RESULTS: A total of 130 implants were placed in 68 patients. The mean surgical distance between the bone crest and the implant platform was 1.71 ± 1.01 mm, and the mean distance from the gingival margin to the implant platform was 3.94 ± 1.90 mm, while at the abutment selection appointment, the mean transmucosal height was 3.58 ± 1.50 mm. A high linear correlation was found between the selected abutment height and two primary outcomes: the radiographic implant platform to alveolar bone crest distance at T0 (r2 = 0.66; P < .001) and the transmucosal height at Ta (r2 = 0.81; P < .001). CONCLUSION: Radiographic measurements of the distance between the implant platform and the alveolar bone crest at implant placement can serve as an important parameter to select the abutment height for definitive restorations.

Assessment and aesthetic impact of a long-term vertical discrepancy between the single anterior maxillary implant-supported crown and adjacent teeth: A retrospective cross-sectional study.

OBJECTIVES: To assess the vertical discrepancy between implant-supported crowns and adjacent teeth in the maxillary anterior region at least 8 years after implant placement and to evaluate the influence of this discrepancy on the level of aesthetic awareness of patients. MATERIAL AND METHODS: The sample consisted of 23 adult individuals evaluated at least 8 years after placement of an implant-supported central or lateral single tooth-fixed partial denture. Patients had their crowns delivered at a mean age of 47.8 years (range: 18.9-65.8). The vertical discrepancy was measured by comparing initial and follow-up periapical radiographs using the implant as a stable structure. The patients' satisfaction with their anterior teeth condition and awareness of the possible vertical problem were evaluated using a questionnaire. The aesthetic outcome and patient awareness were related to the objective measurement of the vertical discrepancy. RESULTS: The implant showed a mean infraocclusion of 0.62 mm (range: 0.15-1.63 mm). The vertical discrepancy was not associated with the patient's gender, age at implant placement, and duration between initial and recall radiograph. Patients were generally satisfied with the long-term aesthetic outcome of their smile (mean: 3.9 on a 1-5 scale, 1 unsatisfied, and 5 completely satisfied). Out of 23 patients, 8 noticed the implant infraocclusion and 4 of them found the problem severe enough to be willing to improve the situation. The amount of vertical discrepancy was not associated with the patient's perception of the discrepancy and the pink aesthetic score. CONCLUSION: Implant-supported crowns in the anterior region may suffer infraocclusion over the long term. The amount of vertical discrepancy was not dependent on the gender and age of the patient. Patients were generally satisfied with the aesthetic result of the restoration. The amount of vertical discrepancy, at least in the range we have measured, was not perceived by the patients as a complication.

Vertical eruption of anterior maxillary teeth adjacent to single-implant-supported crowns: An assessment after a 3-year follow-up period.

STATEMENT OF PROBLEM: Vertical eruption of teeth adjacent to an implant has been reported clinically and might affect the esthetic outcome over time. The prevalence of the problem is unclear. PURPOSE: The purpose of this prospective clinical trial was to evaluate the vertical eruption of anterior maxillary teeth adjacent to single-implant crowns after a 3-year follow-up period. MATERIAL AND METHODS: Thirty single dental implants were inserted in maxillary anterior sites including the first premolar. The mean age of the participants at implant-supported crown insertion was 48.4 years (range 23 to 79 years). Each implant was restored with a 1-piece screw-retained ceramic single crown. The vertical changes of 60 adjacent anterior maxillary teeth were evaluated from periapical radiographs and casts at baseline, 6, 12, and 36 months. RESULTS: A global ANOVA test showed statistically significant differences for the outcomes of the distance-implant platform and cement-enamel junction (DPC) (P<.001), crown length distal (P=.021) and mesial (P=.035), implant crown length (P=.022), and incisal edge to edge (P<.001). CONCLUSIONS: Continuous vertical tooth eruption next to a single dental implant was observed in adult participants.

A 5-Year Esthetic RCT Assessment of Anterior Maxillary Single-Tooth Implants with Different Abutment Interfaces.

PURPOSE: This study sought to define the tissue responses at different implant-abutment interfaces by studying bone and peri-implant mucosal changes using a 5-year prospective randomized clinical trial design study. The conus interface was compared with the flat-to-flat interface and platform-switched implant-abutment systems. MATERIALS AND METHODS: One hundred forty-one subjects were recruited and randomized to the three treatment groups according to defined inclusion and exclusion criteria. Following implant placement and immediate provisionalization in healed alveolar ridges, clinical, photographic, and radiographic parameters were measured at 6 months and annually for 5 years. The calculated changes in marginal bone levels, peri-implant mucosal zenith location, papillae lengths, and peri-implant Plaque Index and bleeding on probing were statistically compared. RESULTS: Forty-eight conus interface implants, 49 flat-to-flat interface implants, and 44 platform-switched implants were placed in 141 subjects. Six platform-switched interface and eight flatto- flat interface implants failed, most of them within 3 months. After 5 years, 33 conical interface, 28 flat-to-flat interface, and 27 platform-switched interface implants remained for evaluation. Calculation of marginal bone level change showed a mean marginal bone loss of -0.16 ± 0.45 (-1.55 to 0.65), -0.92 ± 0.70 (-2.90 to 0.20), and -0.81 ± 1.06 (-3.35 to 1.35) mm for conical interface, flat-to-flat interface, and platform-switched interface implants, respectively (P < .0005). The peri-implant mucosal zenith changes were minimal for all three interface designs (0.10 mm and +0.08 mm, P > .60). Only 16% to 19% of the surfaces had presence of bleeding on probing, with no significant differences (P > .81) between groups. Interproximal tissue changes were positive and similar among the implant interface designs. CONCLUSION: Over 5 years, the immediate provisionalization protocol resulted in stable peri-implant mucosal responses for all three interfaces. Compared with the flat-to-flat and platform-switched interfaces, the conical interface implants demonstrated significantly less early marginal bone loss. The relationship of marginal bone responses and mucosal responses requires further experimental consideration.

Assessment of Peri-Implant Soft Tissues Conditions around Short and Ultra-Short Implant-Supported Single Crowns: A 3-Year Retrospective Study on Periodontally Healthy Patients and Patients with a History of Periodontal Disease.

The aim of this retrospective study was to evaluate implant survival, marginal bone loss and peri-implant complications in 326 short and ultra-short implants. Implants were placed in the maxillary and mandibular posterior regions of 140 patients with (PP) and without (NPP) a history of periodontal disease. Clinical and radiographic examinations were performed at 3-year recall appointments. The 8.0, 6.0 and 5.0 mm-length implants placed in PP and NPP were respectively 43.75% and 38.46%, 35.10% and 34.19%, 21.15% and 27.35%; 325 implants (one early failure) were rehabilitated with single crowns in 139 patients. Overall implant survival after 3 years of follow-up was 97.55%, 98.08% and 96.61% for PP and NPP (p = 0.46). Crestal bone level variations were not statistically different among PP and NPP; 15.41% of implants presented signs of mucositis, 14.71% and 16.67% in PP and NPP (p = 0.64). Setting the threshold for bone loss at 2 mm after 36 months, peri-implantitis prevalence was 2.2%, 1.96% and 2.63% in PP and NPP (p = 0.7). Overall implant success was 82.39%, 83.33% and 80.7% for PP and NPP (p = 0.55). Short-term outcomes suggest that short and ultra-short locking-taper implants can successfully be restored with single crowns in the posterior jaws both in PP and NPP.

Immunohistochemical assessment of the peri-implant soft tissue around different abutment materials: A human study.

BACKGROUND: Soft tissue reaction to dental implant abutments influences the sustainability of restoration. Several abutment materials, such as titanium and gold alloy, have been introduced for strength and esthetic solutions. Zirconia and titanium-base abutments have also become popular in recent years due to high esthetic demands. PURPOSE: To investigate the immune cell infiltration into the soft tissue in response to different abutment materials. MATERIALS AND METHODS: Twenty dental implants were placed in the posterior regions of 17 patients. Titanium, zirconia, gold alloy, and titanium-base were randomly selected for each patient on the day of surgery. After 8 weeks of healing, the abutments were removed along with 1 mm of peri-implant soft tissue. Immunohistochemical assessment was performed using labeled streptavidin-biotin to identify T cells, B cells, macrophages, plasma cells, and microvascular infiltration. RESULTS: Gold alloy demonstrated an overall higher inflammatory cell infiltration and highest number of CD3+ , CD20+ , and CD 68+ cells (P value <.05). The number of plasma cell and new microvascular infiltrations among abutment materials was not significantly different. CONCLUSION: Titanium, titanium-base, and zirconia abutments showed comparable infiltration profiles; gold alloy abutments showed the highest B-cell, T cell, and macrophage infiltration. None of the abutment materials caused clinical inflammation; hence, they can be effectively used.

Clinical and radiographic assessment of circular versus triangular cross-section neck Implants in the posterior maxilla: A 1-year randomized controlled trial.

OBJECTIVES: Implants with a triangular neck were recently introduced to limit peri-implant bone loss. The primary objective of this randomized controlled trial was to compare peri-implant bone changes of circular versus triangular cross-section neck implants 1 year after loading. The secondary objectives were to assess buccal hard tissue thickness changes, Pink Esthetic Score (PES), and patient satisfaction. MATERIAL AND METHODS: Thirty four patients requiring replacement of the single, intercalated missing tooth of healed site for at least 4 months in the posterior maxilla were randomized into 2 groups according to the type of implant. Immediately after surgery and 1 year after final restoration, a cone beam CT (CBCT) was performed to assess proximal bone remodeling and buccal bone thickness. Peri-implant soft tissue health, PES, and patient-reported outcome measures (PROMs) were recorded. RESULTS: No implant loss occurred within the follow-up period. The mean ± SD peri-implant proximal bone loss 1 year after loading was 0.22 ± 0.30 mm for triangular and 0.42 ± 0.67 mm for circular implants necks (p = .25). Peri-implant bone loss exceeding 2 mm was observed in a single implant in the circular neck group. Buccal bone thickness remained stable and did not differ different between the 2 groups. The peri-implant soft tissue health, PES, and patient satisfaction were also comparable. CONCLUSIONS: Within the limitations of the present study, patient clinical and radiographic outcomes did not differ between triangular and circular cross-section neck implants in the posterior maxilla.

A Comparative Assessment of Peri-implant Soft and Hard Tissues with Immediate and Delayed Implants.

AIM AND OBJECTIVE: This study was done to assess peri-implant soft tissues and hard tissues in immediate and delayed titanium implants cases. MATERIALS AND METHODS: This study was conducted on 84 patients who were randomly divided into two groups. Group I was immediate implant group (42 patients) and group II was delayed implant group (42 patients). Parameters such as peri-implant esthetic score, crestal bone defect, and densitometry of peri-implant were evaluated after 1 week, 1 month, 3 months, and 6 months. RESULTS: The mean peri-implant esthetic score at first week in group I was 7.4 and in group II was 5.8, at first month in group I was 6.8 and in group II was 4.6, at third month in group I was 6.7 and in group II was 4.5 and at sixth month in group I was 6.4 and in group II was 4.4. The difference was significant (p value < 0.05). The mean peri-implant crestal bone loss (mm) after 1 week, 1 month, 3 months, and 6 months in group I was 0.24, 0.64, 0.86, and 1.04 and in group II was 0.28, 0.70, 0.94, and 1.14, respectively. The difference was nonsignificant (p value > 0.05). The mean peri-implant bone densitometry after 1 week, 1 month, 3 months, and 6 months in group I was 52.4, 45.6, 42.4, and 40.2 and in group II was 64.2, 60.5, 55.2, and 47.6, respectively. The difference was significant (p value < 0.05). CONCLUSION: Instantaneous implants exhibited enhanced esthetic and purposeful result such as healing of peri-implant bone and peri-implant soft tissues when compared to delayed implants. CLINICAL SIGNIFICANCE: Immediate implants can be used to improve esthetic and determined result in healing of peri-implant bone and peri-implant soft tissues.

A multi-center retrospective assessment of monolithic zirconia restorations on posterior teeth and implants / Una evaluación retrospectiva multicéntrica de restauraciones monolíticas de circonio en dientes posteriores e implantes

Objective: the purpose of this multicenter retrospective study was to report on survival, success, and complication rates in monolithic zirconia restorations on teeth and implants. Materials and Methods: data on 671 monolithic zirconia restorations was collected by five prosthodontists from three different specialty practice centers, including a dental school and two private practice centers. Restorations included single crowns and multiple-unit fixed dental prostheses on teeth and implants in the posterior area (premolar and molars). Follow-up time was up to 62 months. Results: mean follow-up time was 28.1±12.9 months. A total of 671 units, 534 single crowns, and 137 multi-unit restorations. Cumulative survival and success rates at 5 years were 97.4%, and 93.8% respectively. Complications presented in 11 restorations out of 671 and included: decementation, abutment screw loosening, restoration crack, restoration fracture, and tooth fracture. No significant differences were observed between tooth-supported and implant-supported restoration (p=0.42), single crowns and multiple-unit restorations (p=0.07), bruxers and non-bruxers (p=0.57). Patients with group function occlusal scheme had significantly less survival rates (p=0.001). Conclusion: the use of monolithic zirconia for restorations on the posterior teeth and implants seems to be promising as it provides a durable solution with a low rate of complications.

Objetivo: el propósito de este estudio retrospectivo multicéntrico fue informar sobre las tasas de supervivencia, éxito y complicaciones en restauraciones monolíticas de circonio en dientes e implantes. Materiales y Métodos: cinco prostodoncistas recolectaron datos de 671 restauraciones monolíticas de zirconia de tres centros de práctica especializados: una escuela de odontología y dos centros de práctica privados. Las restauraciones incluyeron coronas individuales y prótesis dentales fijas de unidades múltiples en dientes e implantes en el área posterior (premolares y molares). El tiempo de seguimiento fue de hasta 62 meses. Resultados: el tiempo medio de seguimiento fue de 28,1±12,9 meses. Un total de 671 unidades, 534 coronas individuales y 137 restauraciones de unidades múltiples. La supervivencia acumulada y las tasas de éxito a los 5 años fueron del 97,4% y del 93,8%, respectivamente. Las complicaciones se presentaron en 11 restauraciones de 671 e incluyeron: fracaso del cementado, aflojamiento del tornillo del pilar, grieta en la restauración, fractura de restauración y fractura de dientes. No se observaron diferencias significativas entre la restauración con soporte dental y con implante (p=0,42), coronas individuales y restauraciones de unidades múltiples (p=0,07), pacientes con bruxismo y sin bruxismo (p=0,57). Los pacientes con esquema oclusal de función grupal tuvieron tasas de supervivencia significativamente menores (p= 0,0 01). Conclusión: el uso de zirconia monolítica para restauraciones en los dientes posteriores y en implantes parece ser prometedor, ya que proporciona una solución duradera con una baja tasa de complicaciones.

Assessment of Peri-implant Soft Tissue Adaptive Pressure and Time After Provisional Restorations.

Using interim restorations to remodel the peri-implant gingiva contour has been a common procedure in esthetic implant treatment. During the interim restoration delivery, the pressure between the restoration and gingiva typically causes ischemia. Adequate restoration should allow the tissue to recover from ischemia over a certain time. To assess the time needed for peri-implant soft tissue recovery, interim restorations were delivered on 25 single implant sites 2 weeks after stage-two surgery, and the gingiva appearance changes after delivery were recorded for 15 minutes using a video camera. Gingiva color changes along the time were measured and analyzed. The color differences between peri-implant mucosa at 10 min and 0 min, as well as between adjacent tooth gingiva, were all within a clinically acceptable range of color difference. The adaptive pressure technique by two-stage contouring exhibited an optimal peri-implant soft tissue profile within 10 minutes of the adaptive time.