This multicenter randomized controlled trial compared the clinical effectiveness of 7.0-mm wide-diameter implants with 5.0-mm conventional-diameter implants placed immediately after molar extraction. Thirty-nine patients needing a single immediate post-extraction implant in a molar site were recruited at five centers. Patients were randomly assigned to receive either a 7.0-mm implant (n = 19) or a 5.0-mm implant (n = 20). Any gaps between bone and implant were grafted with a bone substitute. Definitive zirconia crowns were delivered 4 months after implant placement. Outcomes were assessed 1 year after loading and included implant failures, complications, patient satisfaction, changes in peri-implant marginal bone level (MBL), and pink esthetic score (PES). No patient dropped out. No implant failed in the 7-mm group, whereas one implant failed in the 5-mm group (difference = 5.0%; 95% CI: -4.6% to 14.6%; P = 1.000). Four complications occurred in four patients in the 7-mm group versus zero in the 5-mm group, with the difference being statistically significant (difference = 21.1%; 95% CI: 2.7% to 39.4%; P = 0.047). At loading, mean PES was 5.84 ± 2.34 in the 7-mm group and 6.06 ± 4.04 in the 5-mm group, with no significant difference between groups (mean difference = 0.21; 95% CI: -2.03 to 2.45; P = 0.847). At 1 year, the mean PES score was 9.16 ± 2.22 in the 7-mm group and 9.21 ± 2.88 in the 5-mm group (mean difference = 0.05; 95% CI: -1.64 to 1.75; P = 0.950). Mean peri-implant marginal bone loss was 0.83 ± 1.56 mm and 0.45 ± 1.19 mm, respectively (mean difference = 0.39 mm; 95% CI: -0.53 to 1.30; P = 0.396). Preliminary 1-year data showed similar implant survival, esthetic outcomes, and marginal bone loss between 7-mm and 5-mm diameter implants. However, a higher number of minor complications was observed in the 7-mm group. Given the small sample size, larger randomized clinical trials are needed to confirm these findings.

To evaluate the biomechanical behavior, implant stability, micromotion under loading, and peri-implant bone microstrain of short dental implants (4 mm) compared with longer implants (6, 8, and 10 mm), particularly in high crownto- implant (C/I) ratio scenarios, and to assess the effect of prosthetic splinting as a biomechanical strategy. A total of 50 implants with internal connections (4-, 6-, 8-, and 10-mm implants) were placed in 9 fresh bovine ribs and restored with standardized polymethyl methacrylate (PMMA) crowns to achieve C/I ratios of 1.22 for 10-mm implants, 1.77 for 8-mm implants, 2.7 for 6-mm implants, and 4.55 for 4-mm implants. A maximum of six implants were placed in each rib, with a 6-mm distance between implants in all cases. Using resonance frequency analysis (RFA) and controlled loading (50 N, 6-degree angulation), implant stability and micromotion were evaluated via image-based analysis. Subsequently, a subset of 4-mm implants was tested with a splinted PMMA bridge. Finite element analysis (FEA) using models consistent with the in vitro setup was performed to evaluate bone microstrain, von Mises stress, and displacement. Implant stability (implant stability quotient [ISQ] values) increased significantly with implant length, with the 10-mm group having the highest values (mean ISQ = 68.4) (P < .05). Micromotion and FEA displacement were inversely correlated with implant length and positively correlated with the C/I ratio. The 4-mm implants had significantly higher micromotion and microstrain values, but splinting significantly reduced both parameters and achieved a performance comparable to that of longer implants. Von Mises stress values in the peri-implant bone and abutments were highest in the 4-mm group. Short dental implants correlate with poorer values for implant stability than conventional implants. High C/I ratios in short implants are associated with increased micromovement and microloading of the bone, but splinting improves biomechanical performance and may be advisable when using short implants, especially when implementing immediate loading protocols.

To compare clinical outcomes of short (6 and 8 mm) and standard-length (11 and 13 mm) implants in posterior sites. In this prospective observational study, implant survival and success rates, soft tissue conditions, and marginal bone level change (MBLC) were observed over a period up to 36 months. Short and standardlength OsseoSpeed Astra Tech implants were used to replace two or three missing teeth. A total of 38 patients-with 42 standard-length implants and 64 short implants-were available for follow-up. Data regarding the patients' medical history and clinical and radiographic parameters were analyzed. No implant loss or mobility was recorded throughout the observation period. Regarding an MBLC of ≥ 2 mm, no significant difference in the success rates of short (76.9%) and standard-length (76.2%) implants was found. Considering MBLC in each group, success rates of short (88.7%) and standard-length (100%) implants differed significantly (log-rank test, P = .028). Compromised medical history, implant site location (maxilla or mandible), bone quality, type of prosthetic restoration (single nonsplinted or splinted crowns or fixed partial dentures), and keratinized mucosa width ≥ 2 mm were not associated with MBLC. Premature cover screw exposure and MBLC ≥ 2 mm were significantly associated within short implants (P = .045) but not standard-length implants (P = .853). Short implants in smokers were at a higher risk of MBLC > 3/10 of implant length compared to nonsmokers (P = .022). Short and standard-length implants revealed comparable survival and success rates regarding MBLC ≥ 2 mm but differed significantly considering MBLC > 3/10 of the endosseous implant length. Short implants are more prone to MBLC compared to standard-length implants, especially in smokers or when premature cover screw exposures occur.

To investigate the relationship between the implant micromovements and the torque-depth integral (I) or insertion torque (IT) to test a new reliable primary stability measurement parameter. Cylindrical and tapered-cylindrical implants were placed into monolithic polyurethane foam blocks (Sawbones), featuring three different densities (0.24, 0.32, and 0.48 g/cm3). After both types of implants were placed under three different site preparations (standard, undersized, and oversized), the (I) and the IT were measured via a torque-measuring micromotor. Micromotion was measured by applying a lateral load to abutments mounted on implants and then recording displacement through a tensile testing machine. The relationship between micromotion and (I) [(I)-micromotion] as well as the relationship between micromotion and IT (IT-micromotion) were studied via regression analyses. Significant inverse nonlinear relationships (P < .001) were observed between (I) and micromotion, as well as IT and micromotion, across all implant designs and preparation protocols (according to a negative-power equation). No statistically significant differences were found between the slopes of (I)-micromotion and IT-micromotion curves. Results of the present study provided additional evidence that the torque depth (I) is a reliable primary stability measurement parameter. However, tests should be repeated on materials more similar to bone, and axial loads should be applied instead of lateral loads to implants.

To compare survival and clinical performance of zirconia versus titanium dental implants, with meta-analyses stratified by follow-up period and, where feasible, by study design. This PRISMA-compliant review was registered in PROSPERO (XXXX). MEDLINE, Embase, Scopus, CENTRAL, and Web of Science (until May 2025), along with citation tracking, were searched for comparative human studies. The primary outcome was marginal bone loss (MBL); secondary outcomes were implant survival, probing depth (PD), keratinized tissue width (KTW), Pink Esthetic Score (PES), and patient-reported outcomes (PROMs). Random-effects models were used (Hartung-Knapp); heterogeneity was assessed with I²/Q. Subgroups contrasted one-piece versus two-piece zirconia implants. Prespecified sensitivity analyses included risk-of-bias restriction and leave-one-out influence checks. Publication bias and meta-regression analyses were not undertaken (<10 studies per outcome). Nine studies (six randomized controlled trials, two prospective cohorts, and one cross-sectional) involving 323 patients and 435 implants (222 zirconia and 213 titanium) met the inclusion criteria. Outcome-specific meta-analyses utilized only studies reporting the relevant endpoint (typically 2-6 studies at 1 year and 2-4 studies at ≥5 years). At 1 year, RCTs showed no difference in survival (risk ratio [RR]:0.98; 95% CI: 0.94-1.01; I²=0%). In contrast, observational cohorts were imprecise and heterogeneous (RR 0.78; 0.24-2.57; I²=91.9%). Five RCTs indicated slightly greater MBL around zirconia (mean difference [MD] 0.16 mm; 0.02-0.29; I²=0%), whereas two observational studies suggested a non-significant opposite trend (MD 0.11 mm; -0.73 to 0.51). No significant differences were observed for PD, KTW, PES, or PROMs (2-4 studies per outcome). Subgroup analysis suggested a potential difference in 1-year survival for two piece zirconia (RR 0.94; 0.91-0.97; I²=0%), while one-piece showed no difference (RR 0.99; 0.94-1.03; p<0.001 for subgroup difference). At 3 years, survival did not differ (RR 0.93; 0.86-1.01; I²=0%). At ≥5 years, survival (RR 0.99; 0.91-1.08; I²=0%) and MBL (MD -0.03 mm; -0.14 to 0.08; I²=0%) were comparable; PD slightly favored zirconia (MD 0.29 mm; -0.55 to -0.02; I²=0%), while PES showed no difference. Sensitivity analyses confirmed robustness for ≥5-year outcomes, although the 1-year MBL effect was attenuated after risk-of-bias restriction. In healthy patients, zirconia and titanium implants demonstrate comparable clinical and radiological outcomes over a follow-up period of up to five years. Evidence remains insufficient regarding long-term outcome for zirconia implants, and part of the available data is based on legacy systems that are no longer on the market.

Implant planning in the posterior maxilla is traditionally centered around the maxillary sinus; however, the nasal floor may represent the primary cortical contact in some cases. This study aimed to determine the prevalence of nasal dominance, equal relationship, and sinus dominance patterns using CBCT and to demonstrate the clinical significance of nasal dominance through an illustrative case report. A total of 1993 CBCT images were retrospectively screened. After exclusion criteria, 1133 patients (525 male, 608 female; mean age 37.8 years) were included. Right and left maxillary first molar regions were independently evaluated on coronal CBCT sections, yielding 2266 sites classified as sinus dominance, nasal dominance, or equal relationship. Sinus dominance was the predominant pattern (93.3%), followed by equal relationship (5.2%) and nasal dominance (1.5%). Nasal dominance was approximately four times more frequent in females than males. An illustrative case treated via crestal nasal floor elevation demonstrated stable osseointegration at 70 months. Nasal dominance is a rare but clinically significant variant that may fundamentally alter the surgical approach in posterior maxillary implant planning. CBCT evaluation is essential for its identification. Demographic associations observed in this study should be interpreted cautiously given the limited case numbers.

The aim of this scoping review is to investigate the clinical, microbiological, and histological outcomes of non-surgical and surgical treatments for peri-implant diseases and experimentally induced peri-implant bone defects around zirconia implants. An electronic search was performed up to May 2025 in three databases, including PubMed/MEDLINE, Web of Science and Cochrane Central Register of Controlled Trials. Eligible studies included prospective or retrospective in vivo investigations, such as case series and comparative clinical trials, involving human or animal subjects with zirconia dental implants. Interventions comprised surgical and non-surgical treatments for peri-implant mucositis, peri-implantitis, or experimentally induced peri-implant bone defects. Outcomes assessed included changes in clinical, radiographic, microbiological and/or histological parameters following intervention. Reporting adhered to the PRISMA-ScR statement. Ten studies met the inclusion criteria for this scoping review. Clinical investigations revealed comparable prevalence of peri-implant mucositis and peri-implantitis between zirconia and titanium implants, although some studies reported enhanced mucosal margin stability and reduced plaque accumulation around zirconia implants. In experimental models, zirconia implants elicited a milder inflammatory response and demonstrated greater resistance to bacterial colonization. Across peri-implantitis and buccal dehiscence models, both implant types achieved similar outcomes in bone regeneration and soft tissue healing. Zirconia implants show clinical outcomes comparable to titanium implants regarding survival, peri-implant tissue health, and biological complication response. However, this observation is based on limited and heterogeneous data, predominantly derived from preclinical models and small clinical studies. Current evidence is insufficient to establish clinical equivalence between zirconia and titanium implants, particularly for peri-implant disease treatment and regenerative outcomes. Further well-designed, long-term clinical studies are required.

To evaluate the clinical, digital and histological outcomes of bone regeneration using autologous plasma rich in growth factors (PRGF®) for alveolar ridge preservation (ARP), compared to an anorganic bovine bone (ABB) graft. A randomized clinical trial was conducted in adult subjects requiring tooth extraction and subsequent implant placement. The effect of the therapy was assessed by clinical, intraoral and CBCT scans, and patient-reported outcomes at post-extraction, before implant placement and 1 year after implant loading. Bone core biopsies were also collected four months post-extraction for histological and immunohistochemical analysis. A total of 26 patients were included in this study. IOS and CBCTs demonstrated a reduction of the bone crest over time, with statistically significant differences within but not between groups. The PRGF® group exhibited improved early soft tissue healing, lower inflammation index, and reduced patient-reported discomfort. PRGF® group showed a trend toward higher mineralized tissue and fewer TRAP-positive cells, indicating reduced osteoclastic activity. In addition, soft tissue measurements increased from extraction to implant placement in the PRGF® group, while ABB prevented early bucco-lingual collapse regardless of the thickness of the facial bone. Both ABB and PRGF® yielded similar clinical, digital dimensions, histomorphometric results, and patient-reported outcomes in ARP therapy. PRGF® histology demonstrated no residual material in the grafted area. These findings support the use of PRGF as a biologically active, autologous material for ARP in addition to other options such as xenografts. According to our results, PRGF seems to offer advantages in soft tissue healing and patient-centered outcomes.

Guided sub-crestal implant placement is limited by the lack of visual confirmation, making abutment connection dependent on tactile feedback, which may be compromised by residual bone at the implant crest. A bone leveler can remove excess bone above the implant platform, but no clinical guidelines exist for its use in guided sub-crestal surgery. This in-vitro study evaluated the effect of a bone leveler on prosthetic abutment fit. Ten 3D-printed artificial bone models with irregular cortical morphology were prepared using CAD-CAM technologies from a micro-CT scan obtained from the NIH 3D Print Exchange. Sleeveless surgical guides were digitally designed and additively manufactured, and a 3-mm polyvinyl siloxane layer simulated soft tissue. Guided osteotomies for four implants per model (N = 40) were performed using two protocols: conventional drilling (Control) and conventional drilling plus a bone leveler (Test). Abutments were hand-tightened and assessed for seating by two blinded clinicians through tactile and radiographic evaluation. Inter-rater agreement was quantified via Cohen's Kappa, and Chi-square tests evaluated the effect of the bone leveler on seating outcomes. All abutments were deemed fully seated by tactile assessment of Clinician 1. Independent blinded tactile assessment by Clinician 2 confirmed 80% of abutments in Controls and 85% in Tests as fully seated. Radiographic evaluation revealed 80% fully seated abutments in Test versus only 15% in Controls. The difference was statistically significant (χ² = 7.27, p = 0.007). Inter-rater agreement between tactile and radiographic assessments was poor (C1 vs C2: Kappa = 0; C2 vs R: Kappa = -0.10), highlighting that tactile assessment alone is unreliable. Implants placed in osteotomies prepared with a bone leveler consistently achieved complete abutment seating, whereas those placed without a bone leveler frequently exhibited gaps and were often misclassified as properly fitted. Within the limitations of this in vitro study, incorporating a bone leveler in guided sub-crestal implant placement significantly improves prosthetic abutment fit. Its use should be considered a prerequisite in clinical protocols to enhance prosthetic abutment seating accuracy and improve predictability in guided implant therapy.