Survival and tissue maintenance of an implant with a sloped configurated shoulder in the posterior mandible-a prospective multicenter study

Associations between the keratinized mucosa width and the underlying alveolar bone dimensions at partial edentulous molar sites: a retrospective cross-sectional study

BACKGROUND

The assessment of hard and soft tissue at edentulous sites is important for subsequent implant treatment design. The aim of the present study was to explore the associations between the keratinized mucosa width (KMW) and the underlying alveolar bone dimensions at partial edentulous molar sites.

METHODS

In this retrospective study, a total of 110 patients with at least one missing molar were selected. The buccal KMW of the edentulous molar sites was evaluated. Cone-beam computed tomography scans were collected, and the height discrepancy between the alveolar crest and the buccal bone plate (HC-B) as well as the alveolar bone height (ABH) were measured. The KMW was compared among the HC-B and ABH groups at both maxillary and mandibular sites. Linear regression and generalized estimation equations (GEEs) were used to explore the associations between the KMW and alveolar bone dimensions at α = 0.05.

RESULTS

Among the 110 patients, 158 edentulous molar sites were analyzed. The average HC-B and ABH were significantly lower at the maxillary sites (1.26 ± 1.62 mm, 11.62 ± 3.94 mm) than at the mandibular sites (3.67 ± 2.85 mm, 14.91 ± 3.01 mm, p < 0.001). The KMW was significantly lower at sites with HC-B > 2 mm than at sites with HC-B ≤ 2 mm both in the maxilla and mandible (p < 0.001). No significant differences were found between the KMW at sites with ABH < 10 mm and sites with ABH ≥ 10 mm (p > 0.05). Linear regression and GEEs analyses revealed that the HC-B was significantly associated with the KMW (B = -0.339, p < 0.001), while the association between the KMW and the ABH was not statistically significant (B = -0.046, p = 0.352).

CONCLUSIONS

The buccal KMW at edentulous molar sites was significantly associated with the HC-B. Alveolar ridges presenting with a sloped configuration were more prone to possess a narrower band of keratinized mucosa. Both hard and soft tissue augmentation should be considered for implant treatment at these sites. The correlations of dynamic changes between the KMW and alveolar bone dimensions after tooth extraction should be further investigated.

Rehabilitation Using Implants with Sloped Platform Edge vs. Standard Platform with Guided Bone Regeneration: A Randomized Control Clinical Trial

The purpose of this study was to evaluate the vertical bone loss after using different techniques: sloped implants or standard implants with guided bone regeneration. Patients with tooth gap and horizontal bone deficiency were randomly allocated to the test group (implants with sloped platform-SLP) and control group (standard design implants with guided bone regeneration-GBR). The primary outcome was bone loss (6 months after finishing the prosthetic treatment). Secondary outcomes included the following: patient-reported outcome measures (PROMs), post-operative edema, keratinized mucosa width, and pink aesthetic score (PES). The average bone loss at 6 months was 0.23 ± 0.15 mm and 1.03 ± 0.37 mm in the SLP and GBR groups, respectively. The SLP group was characterized by lower pain intensity the first 7 days (p < 0.001), lower post-operative edema (p < 0.001), lower consumption of NSAIDs on days 1, 3, 5, and 7 (p = 0.002, <0.001, <0.001, and 0.008), and lower total OHIP-14 (p = 0.047) on day 7. The keratinized mucosa width was 3.7 (3.4-4.0) mm and 2 (1.4-2.0) mm in the SLP and GBR groups, respectively. The preservation of the mesial, distal papillae, and the level of soft tissue correspondence were significantly higher in the SLP group (p = 0.003, 0.038, <0.001). In the SLP group, more natural color and better texture of soft tissues were found (p = 0.048, p = 0.041). The use of implants with a sloped platform resulted in superior outcomes compared to the standard-design implants with GBR.

Implants placed in an alveolar ridge with a sloped configuration. A 3-year prospective multicenter study

AIM

The aim of the present study was to evaluate soft and hard tissue alterations around implants with a modified marginal portion placed in a healed, sloped ridge over 3 years of follow-up.

MATERIAL AND METHODS

65 patients with a single recipient implant site in an alveolar ridge with a lingual-buccal sloped configuration were recruited. Implants with a modified geometry in the marginal portion were installed in such a way that the sloped part of the device was located at the buccal and most apical position of the osteotomy preparation. Crowns were placed 21 weeks after implant placement. Radiologic examinations were performed at implant installation and at 1 and 3 years of follow-up. Bleeding on probing (BoP), probing pocket depth (PPD), and clinical attachment level (CAL; from the crown margin) were recorded at the insertion of the prosthesis and after 1 and 3 years.

RESULTS

57 patients with 57 implant-supported restorations attended the 3 years follow-up examination. The radiographic analysis revealed a mean marginal bone loss of 0.57 mm during the 3 years period. While the average bone loss between 1 and 3 years amounted to 0.30 mm, approximately 50% of the implants showed no bone loss during this period. The results from the clinical examinations showed a CAL gain of 0.11 ± 0.85 mm between baseline and 3 years of follow-up. About 65% of the implants showed no loss of attachment between 1 and 3 years. BoP and PPD ≥5 mm were identified at <10% of implants at the 3 years examination.

CONCLUSION

Hard and soft tissues formed around dental implants that were designed to match the morphology of an alveolar ridge with a lingual-buccal sloped configuration remained stable over 3 years.

Clinical Evidence on a Novel Macrohybrid Design Dental Implant with 12° Angled Platform: A Systematic Review

Background: Immediate implant placement with immediate esthetics has become a more common procedure over time, though ensuring good emergence of the axis of the implant has been a challenge. A novel macroimplant design with an angled platform (Co-Axis^®) has been developed to ensure exit of the head of the implant in the correct prosthetic position. A systematic literature review was carried to determine the survival rate and marginal bone loss associated with these implants. Material and Methods: An electronic and manual literature search was made in accordance with the PRISMA statement. The search strategy was limited to human studies, retrospective and prospective clinical trials, cross-sectional studies, and cohort studies reporting outcomes of a novel macrohybrid implant with a 12° angled implant connection. Results: Three articles met the inclusion criteria and were reviewed in the analysis. The estimated success rate was 95.9%. The global marginal bone loss was estimated to be −0.17 ± 0.58 mm in an environment characterized by great heterogeneity (I² = 99%). The estimated mean implant stability was 69.6 ± 0.92 (ISQ). As only two studies provided the required information, it was not possible to determine publication bias. Lastly, mean recession was estimated to be practically zero (0.06 ± 0.23 mm), with great heterogeneity. Conclusions: Within the limitations of this systematic review, it can be affirmed that immediate implant treatment with Co-Axis^® implants shows a survival rate of 95.9% at one year of follow-up, with low marginal bone loss values, near-zero soft tissue recession, and favorable papilla index values. Nevertheless, the great heterogeneity of the data requires the findings to be interpreted with caution.

Three interfaces of the dental implant system and their clinical effects on hard and soft tissues

Anatomically, the human tooth has structures both embedded within and forming part of the exterior surface of the human body. When a tooth is lost, it is often replaced by a dental implant, to facilitate the chewing of food and for esthetic purposes. For successful substitution of the lost tooth, hard tissue should be integrated into the implant surface. The microtopography and chemistry of the implant surface have been explored with the aim of enhancing osseointegration. Additionally, clinical implant success is dependent on ensuring that a barrier, comprising strong gingival attachment to an abutment, does not allow the infiltration of oral bacteria into the bone-integrated surface. Epithelial and connective tissue cells respond to the abutment surface, depending on its surface characteristics and the materials from which it is made. In particular, the biomechanics of the implant-abutment connection structure (i.e., the biomechanics of the interface between implant and abutment surfaces, and the screw mechanics of the implant-abutment assembly) are critical for both the soft tissue seal and hard tissue integration. Herein, we discuss the clinical importance of these three interfaces: bone-implant, gingiva-abutment, and implant-abutment.

Comparison of regular- and slope-configured dental implants placed in the edentulous ridge with height discrepancy: A pilot randomized controlled trial

BACKGROUND/PURPOSE

Edentulous ridges with height discrepancies (RHDs) could jeopardize the outcome of implant placement. This study aimed at evaluating the outcomes of placing regular- and slope-configured implants in RHDs.

METHODS

Patients with >1 mm RHDs requesting implant rehabilitation were recruited and randomly assigned to regular- (control) or slope-configured (test) implant treatment using a submerged installation protocol. Thread exposure (TE) and implant stability quotient (ISQ) were evaluated during implant installation (S1) and uncovered surgery (S2), and marginal bone level (MBL) was evaluated after implant installation (T1) and uncovery (T3), and one year after implant placement (T4). Periodontal status and gingival crevicular fluid (GCF) biomarkers of adjacent teeth were evaluated before implant installation (T0), before uncovery (T2), and at T4. Peri-implant clinical status and peri-implant crevicular fluid (PICF) biomarkers of examined implants were evaluated at T4.

RESULTS

Nineteen patients with 17 control and 13 test implants were included. All of the implants survived with acceptable peri-implant health, and PICF biomarkers were at equivalent levels as GCF biomarkers of the adjacent teeth at T4. Compared with the control group, the test group showed reduced TE and equivalent ISQ at S1 and S2, and the loss of MBL was reduced at T4. Regarding the adjacent teeth, all periodontal parameters and GCF biomarkers were slightly decreased from T0 to T2, and the reductions in probing pocket depth and clinical attachment level were slightly greater at T4.

CONCLUSION

Slope-configured implants maintained the implant-supporting structures and minimally altered periodontal status of the adjacent teeth in RHDs.

The effectiveness of immediate implant placement for single tooth replacement compared to delayed implant placement: A systematic review and meta-analysis

AIM

To compare immediate implant placement (IIP) to delayed single implant placement (DIP, ≥3 months post-extraction) in terms of implant survival (primary outcome), surgical, clinical, aesthetic, radiographic and patient-reported outcomes (secondary outcomes).

MATERIALS AND METHODS

Two reviewers independently performed an electronic search in PubMed, Web of Science, EMBASE and Cochrane and a hand search to identify eligible studies up to May 2018. Only randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP to DIP with at least 1 year of follow-up were selected for a qualitative analysis and meta-analysis.

RESULTS

The search identified 3 RCTs and 5 NRSs out of 2,589 titles providing data on 473 single implants (IIP: 233, DIP: 240) that had been in function between 12 and 96 months. One RCT showed unclear risk of bias, whereas all other studies demonstrated high risk. Meta-analysis showed significantly lower implant survival for IIP (94.9%) as compared to DIP (98.9%) (RR 0.96, 95% CI [0.93; 0.99], p = 0.02). All were early implant failures. A subgroup meta-analysis demonstrated a trend towards lower implant survival for IIP when postoperative antibiotics had not been administered (RR: 0.93, 95% CI [0.86; 1.00], p = 0.07). This was not observed among studies including the administration of postoperative antibiotics (RR: 0.98, 95% CI [0.94; 1.02], p = 0.35). Meta-analyses showed similar probing depth (WMD 0.43 mm, 95% CI [-0.47; 1.33], p = 0.35) and aesthetic outcomes as assessed by the pink aesthetic score (standardized WMD -0.03, 95% CI [-0.46; 0.39], p = 0.88) for IIP and DIP. Data on marginal bone loss were conflicting and highly biased. Soft tissue recession was underreported and available data were highly biased. Patient-reported outcomes were underreported, yet both IIP and DIP seemed well tolerated.

CONCLUSION

Immediate implant placement demonstrated higher risk for early implant loss than DIP. There is a need for RCTs comparing IIP to DIP with CBCT analyses at different time points and data on midfacial recession with the preoperative status as baseline. In these studies, the need for hard and soft tissue grafting should also be evaluated.

Minimizing the discrepancy between implant platform and alveolar bone for tilted implants with a sloped implant platform: A clinical report

In a patient with edentulism, distally tilted implants with a novel sloped implant platform were used to minimize the discrepancy between the implant platform and alveolar bone crest and to restore complete-arch monolithic zirconia implant-supported fixed prostheses.