The Use of a New Safe Angle Concept for Immediate Implant Placement in the Anterior Maxilla: A Cross-Sectional CBCT Study

PURPOSE: To introduce a new method for labiopalatal positioning and angulation of immediately placed dental implants in the anterior maxilla with relation to the type of abutment used (straight/angled abutment). MATERIALS AND METHODS: CBCT scans from the database of a private practice were searched for patients who received immediate implants in the anterior maxilla. After superimposition of the initial and postoperative scans, the incisor root angle (IRA), incisor implant angle (IIA), and the difference between these angles were measured. An assessment was then made about whether the implant position would be within the safe angle or not. Age, sex, tooth/implant site, and type of prosthetic abutment (straight/angled) were retrieved from the patients' records. RESULTS: A total of 74 patients with 95 immediate implants altogether were selected for analysis. In regard to the type of abutment, 76 (80%) were straight, and 19 abutments (20%) were angled. Regardless of abutment type, 72 implants (75.8%) were placed within the safe angle, while 23 implants (24.2%) were placed outside it. All 19 implants with angled abutments were placed outside the safe angle. There were statistically significant associations between placement within the safe angle and type of abutment (P < .001; OR = 19), IRA (P < .001; effect size = 0.904), difference between IIA and IRA (P < .001; effect size = 1.209), and sex (P < .001; OR = 2.995). There was no statistically significant association between placement within the safe angle and IIA (P = .757, effect size = 0.063), site (P = .200; effect size = 0.184 ), or age (P = .387; effect size = 0.208). There was a statistically significant association between the type of abutment and the IRA (P = .001; effect size = 0.762) as well as the difference between IIA and IRA (P < .001; effect size = 1.056). CONCLUSIONS: The safe angle concept can be used as a reliable planning tool to determine the correct implant positioning for immediate implant placement in the anterior maxilla. Applying the safe angle concept will reduce the need for angled abutments for prosthetic correction.

A Novel Dental Implant Approach for Crestal Sinus Elevation: A Case Series Study.

The aim of this study was to evaluate the radiographic and clinical outcomes of patients undergoing sinus membrane elevation via a minimally invasive crestal approach utilizing the dental implant. Twenty patients having 1 or more missing posterior teeth were included. The maxillary sinus membrane was elevated using dental implant via a crestal approach in areas with insufficient residual bone. CBCT scans were used to measure the amount of newly formed bone, implant length inside the sinus, bucco-palatal sinus width, and bone thickness. Surgical and postsurgical complications along with implant survival were also measured. The mean (±SD) values for the newly formed bone after 1 year were 2.4 (±1.87) mm, while values for implant length inside the sinus were 4 (±1.49) mm. The results showed that percentage of implant length inside the sinus and the palatal bone thickness were statistically significant positive predictors of the newly formed bone. Higher percentage of implant length inside the sinus and increased palatal bone thickness were associated with larger amounts of newly formed bone. A high patient satisfaction was reported along with a 100% implant survival. The utilization of the novel dental implant approach for crestal sinus elevation demonstrated predictable clinical and radiographic outcomes. This novel technique is simple to both patients and clinicians, rendering it a promising and cost-efficient procedure.

Hard and soft tissue alterations using dual-zone concept versus connective tissue graft at maxillary immediate implant placement: A 1-year randomized clinical and volumetric trial.

OBJECTIVES: To evaluate the esthetic outcome, as well as clinical, radiographic, and volumetric tissue alterations 1 year after immediate implant placement (IIP) with connective tissue grafting (CTG) versus dual-zone concept (DZ) at sites with thin labial bone in the esthetic zone. MATERIALS AND METHODS: This randomized clinical trial included 30 patients treated with IIP simultaneous with either CTG or DZ (n = 15 each). Pink esthetic score (PES) was assessed 6 months after crown placement as the primary outcome. Amount of bone labial to the implant, labio-palatal ridge reduction, and crestal bone changes were measured via CBCT after 1 year. Volumetric analysis of linear labial soft tissue contour, interdental, and mid-facial soft tissue level changes, and total volume loss (mm3) were measured after 1 year. RESULTS: Similar PES was observed in the CTG (12.53 ± 1.13) and DZ (12.13 ± 1.55) groups, with no significant difference (p = 0.42). Likewise, there were no statistically significant differences found between the two groups in labio-palatal bone reduction (mm&%), interdental papillae, and mid-facial gingival levels (p > 0.05). However, the mean vertical crestal bone changes in the CTG and DZ groups were -1.1 ± 0.6 mm and 0.2 ± 1.0 mm, respectively, with a statistically significant difference (p = 0.0002). Moreover, CTG revealed less linear and total volume (mm3) loss in the labial soft tissue which was statistically significant compared to DZ (p = 0.007). CONCLUSION: Both groups demonstrated the same PES, nevertheless, volumetric analysis revealed twice total labial volume loss in DZ compared to CTG. It might be concluded that the use of CTG with IIP caused less horizontal reduction in the supra-implant complex compared to the DZ.

Bone dimensional changes after flapless immediate implant placement with and without bone grafting: Randomized clinical trial.

INTRODUCTION: Immediate implant in postextraction sockets requires managing the postextraction alveolar resorption. This randomized clinical trial examined vertical and horizontal changes 1-year following flapless immediate implant with and without xenograft at sites with thin labial plate. METHODS: Forty patients with hopeless teeth in maxillary esthetic zone were randomly assigned to receiving either one immediate implant without bone graft (control) or with bone graft (intervention). Cone beam computed tomography (CBCT) scans were obtained pre-extraction and 1-year postoperatively to measure thickness and dimensional changes of the labial bone. RESULTS: Cone beam computed tomography measurements revealed that a xenograft, when compared to no xenograft, led to 0.2 mm increased fill of the horizontal gap (95% confidence interval (CI): -1.1, 0.7). In both groups, there was a significant reduction in the labio-palatal bone width after 1 year compared to baseline (P ≤ 0.05). There was no significant difference (P > 0.05) between the xenograft when compared to no xenograft regarding the labio-palatal bone collapse % at 0 mm (-0.2, 95% CI: -4.8, 4.5) and 2 mm apical to the labial crest (1.9, 95% CI: -1.8, 5.6). While at 5 mm the ridge was significantly reduced (P ≤ 0.05) in the no xenograft when compared to xenograft (4.5, 95% CI: 0.7, 8.2). The xenograft when compared to no xenograft, led to 1.1 mm less vertical bone changes (95% CI: 0.4, 1.9). Both groups revealed significant positive correlation between labio-palatal socket dimension and bone formed labial to the implant (P ≤ 0.05). [Correction added on 7 February 2023, after first online publication: In the 8th line of this section, the word "collapse" was changed to "ridge" in this version.] CONCLUSION: This investigation suggested that immediate implants with or without grafting the labial gap preserved alveolar bone dimension and that bone formation labial to the implant was related to initial labio-palatal socket dimension.