Short (≤6 mm) compared with ≥10-mm dental implants in different clinical scenarios: A systematic review of randomized clinical trials with meta-analysis, trial sequential analysis and quality of evidence grading

AIM

To systematically identify, synthesize and critically summarize the available scientific evidence from randomized controlled trials (RCTs) regarding whether short (≤6 mm) perform as well as long (≥10 mm) implants regarding implant survival, marginal bone loss, and biologic and prosthetic complications in different clinical scenarios.

MATERIALS AND METHODS

Cochrane Collaboration's risk of bias tool and the GRADE approach were applied. Results were synthesized using random-effects meta-analyses assessed by trial sequential analyses.

RESULTS

Forty reports on 19 RCTs comprising 2214 (1097 short; 1117 long) implants were included. Moderate/high certainty/quality evidence demonstrated similar 5-year survival rates for ≤6-mm and ≥10-mm implants in non-augmented bone and full-mouth rehabilitation in either jaw, and for 6-mm implants in the maxilla instead of sinus lift. Nevertheless, the evidence for 5-year survival rates remains inconclusive or insufficient for the remaining combinations of implant lengths and clinical scenarios. They include 4-mm and 5-mm implants as alternatives to sinus lift as well as placing all implant lengths ≤6 mm instead of vertical ridge augmentation with long implants. Marginal bone level and short- and long-term biologic or prosthetic complications were similar.

CONCLUSIONS

Based on moderate/high certainty/quality evidence from 5-year RCTs, implants ≤6 mm may be viable alternatives to ≥10-mm implants in either jaw in native bone and full-arch rehabilitation, and 6-mm implants may be used as an alternative to sinus lift.

TRIAL REGISTRATION

PROSPERO ID: CRD42021254365.

Treatment of Multiple RT1 Gingival Recessions Using a Coronally Advanced Flap Associated with L-PRF or Subgingival Connective Tissue Graft from Maxillary Tuberosity: A Randomized, Controlled Clinical Trial

The goal of plastic periodontal surgery is to obtain complete root coverage, increasing gingival thickness (GT), a positive prognostic factor for gingival margin stability over time. The aim of this study was to compare the effectiveness of the Coronally Advanced Flap (CAF) in RT1 (GR; gingival recession with no loss of interproximal attachment) when associated with a connective tissue graft from the maxillary tuberosity (tCTG) or with leukocyte and platelet-rich fibrin (L-PRF) membranes in obtaining root coverage and increasing the thickness and width of the keratinized tissue, along with aesthetic improvement, taking into account a number of patient-related outcomes. Thirty patients with two adjacent RT1 GRs (GRs with no loss of interproximal attachment) were each treated using CAF associated with tCTG (15 patients) or L-PRF. The main outcome was a GT increase; secondary outcomes were keratinized tissue width (KT), gingival recession (GR), probing depth (PD), clinical attachment level (CAL), root coverage percentage (RC%), complete root coverage (CRC), and root coverage esthetic score (RES). Patient-reported outcomes were discomfort (D), dentine hypersensitivity (DH), patient-related esthetic score (PRES), and overall treatment satisfaction (OTS). After 12 months, clinical and patient-reported parameters did not show significant differences between groups, with the only exception being a GT gain, which was significantly greater in the CAF + tCTG group. Our results showed that both techniques were effective in treating RT1 GRs, with comparable patient-related outcomes. However, the use of tCTG produces significantly thicker tissue, covering the exposed root surface.

Evaluation of Post-Operative Morbidity and Palatal Wound Healing after Implant Uncovering Surgical Procedure Performed with Apically Positioned Flap (APF) and Leukocyte and Platelet-Rich-Fibrin (L-PRF): An Original Technique

Background and Objectives: Dental implants are recognized as an effective treatment in the management of edentulous patients; controversies surround the connection between the sufficiency of keratinized gingiva (KG) and peri-implant health. Maintaining an ample amount of peri-implant KG is crucial for minimizing gingival inflammation, highlighting the need for regular consideration of soft-tissue augmentation. Among the diverse periodontal plastic surgical procedures, the apically positioned flap (APF) is notable for its ability to enhance the width of keratinized tissue while minimizing patient morbidity. The aim of this study was to evaluate the effects of L-PRF on palatal wound healing and patient discomfort after surgery. Materials and Methods: Twenty patients with two adjacent submerged fixtures in the maxilla and buccal keratinized gingiva widths < 2 mm were treated with APF and L-PRF. Clinical evaluations were performed at 1, 2, 3, and 4 weeks post-surgery, focusing on parameters such as complete wound epithelialization (CWE), postoperative discomfort (D), changes in feeding habits (CFH), alteration of sensitivity (AS) around the wound area, and the consumption of analgesics. Results: Our data revealed CWE in 5 patients by the end of the second week, with the remaining 15 achieving CWE by the end of the third week. For D and CHF, a statistically significant improvement was recorded for all cases between the first and second weeks, as well as AS, although less substantial, by the third week. No significant changes were noted for AS over the initial two weeks. Conclusions: These findings suggest that L-PRF may enhance wound healing and decrease patient discomfort following APF for fixture uncovering.

Management of the Lingual Flap During Vertical Augmentation of the Atrophic Anterior Mandible: Anatomical Overview and Description of the Technique

Vertical ridge augmentation in the anterior mandible is a technically delicate procedure that requires knowledge of some anatomical structures to reduce intra- and postoperative complications. Proper soft tissue management is one of the primary aspects to the success of these techniques, enabling tension-free primary wound closure and preventing membrane exposure. This cadaveric and clinical study provides an anatomical overview of the lingual portion of the anterior mandible. Moreover, there is a description of a novel surgical approach for release of the lingual flap that will help clinicians achieve primary closure without incurring intrasurgical complications.

Avoiding implant-related complications in medically compromised patients with or without unhealthy lifestyle/Elevated oxidative stress

Increased human life expectancy broadens the alternatives for missing teeth and played a role in the widespread use of dental implants and related augmentation procedures for the aging population. Though, many of these patients may have one or more diseases. These systemic conditions may directly lead to surgical complications, compromise implant/bone healing, or influence long-term peri-implant health and its response to biologic nuisances. Offering patients credible expectations regarding intra- and postoperative complications and therapeutic prognosis is an ethical and legal obligation. Clear identification of potential types of adverse effects, complications, or errors is important for decision-making processes as they may be related to different local, systemic, and technical aspects. Therefore, the present review structures the underlying biological mechanisms, clinical evidence, and clinical recommendations for the most common systemic risk factors for implant-related complications.

Gingival phenotype changes after different periodontal plastic surgical techniques: a single-masked randomized controlled clinical trial

ABSTRACT: OBJECTIVES: Aim of this clinical study was to evaluate the effects on gingival thickness of three surgical techniques for root coverage: the coronally advanced flap (CAF) alone, with a sub-epithelial connective tissue graft (SCTG) or with leukocyte- and platelet-rich fibrin (L-PRF) membranes.

METHODS

Sixty patients with RT1 single maxillary gingival recession were treated with CAF + L-PRF (20 patients), CAF + SCTG (20 patients) or CAF alone (20 patients). At baseline and 6-month after treatment, gingival thickness (GT), keratinized tissue width (KT), gingival recession (GR), clinical attachment level (CAL), probing depth (PD), PROMs, and the aesthetic outcome were recorded.

RESULTS

CAF + SCTG and CAF + L-PRF groups showed a significantly greater mean GT increase than CAF alone (0.31 ± 0.10 mm) with no significant differences between CAF + SCTG (0.99 ± 0.02 mm) and CAF + L-PRF (0.92 ± 0.52 mm) groups (p = 0.55). CAF + SCTG was associated with a significantly greater KT gain (3.85 ± 1.04 mm), while in CAF + L-PRF (2.03 ± 0.53 mm) and CAF (1.50 ± 0.69 mm) groups, KT was not significantly increased. Both GR and CAL showed a significant within groups' improvement, without among-groups differences. No significant among-groups difference for the aesthetic outcome but greater discomfort and pain-killer consumption in CAF + SCTG group was detected.

CONCLUSION

All investigated surgical techniques produced significant GR reduction and CAL gain. GT was similarly augmented by CAF + L-PRF and CAF + SCTG techniques; however, the CAF + SCTG technique produced a more predictable KT and GT increase.

CLINICAL RELEVANCE

The results of our study suggest that the CAF + SCTG technique represents the most predictable method for the clinician to improve the gingival phenotype, an important factor for long term gingival margin stability.

The added benefit of L-PRF to autogenous bone grafts in the treatment of degree II furcation involvement in mandibular molars

BACKGROUND

Tissue regeneration within the periodontally involved furcation area is one of the most challenging aspects of periodontal surgery. The aim of this study was to evaluate the additional benefit of leukocyte and platelet-rich fibrin (L-PRF) to autogenous bone grafts (ABGs) in the treatment of mandibular molar degree II furcation involvement, comparing the clinical outcomes with those from open flap debridement (OFD)+ABG and OFD alone treatments.

METHODS

Fifty-four patients, exhibiting one buccal or lingual mandibular molar furcation defect, were randomly assigned to three treatment groups: OFD+ABG+L-PRF(n = 18); OFD+ABG (n = 18); and OFD (n = 18). Clinical [probing pocket depth (PPD), horizontal clinical attachment level (HCAL), vertical clinical attachment level (VCAL), gingival recession (GR)] and radiographic [vertical bone level (VBL)] parameters were evaluated at baseline and 6 months after treatment. HCAL change was the primary outcome.

RESULTS

No significant differences within each group were reported for GR changes, but statistically significant improvements in HCAL, VCAL, PPD and VBL were observed in all groups, except for VBL in the OFD group. At 6 months, the mean HCAL gain was 2.29±0.18 mm in the OFD+ABG+L-PRF group, which was significantly greater than that in the OFD+ABG (1.61±0.18 mm) and OFD (0.86±0.18 mm) groups. Both OFD+ABG+L-PRF and OFD+ABG therapies produced a significantly greater clinical and radiographic improvement than OFD.

CONCLUSION

The addition of L-PRF to ABG produces a significantly greater HCAL gain and PPD reduction as compared to OFD+ABG treatment in mandibular degree II furcation involvements. This article is protected by copyright. All rights reserved.

Efficacy of inorganic bovine bone combined with leukocyte and platelet-rich fibrin or collagen membranes for treating unfavorable periodontal infrabony defects: Randomized non-inferiority trial

BACKGROUND

Growing evidence shows the efficacy of platelet concentrates in periodontal therapy. This study aimed to demonstrate that an inorganic bovine bone graft (IBB) in combination with a leukocyte and platelet rich fibrin (L-PRF) is non-inferior to a combination with a collagen membrane (CM) when managing unfavorable infrabony defects (IBDs).

METHODS

All patients exhibited at least one unfavorable IBD; they were randomly assigned to two groups, 31 treated with L-PRF+IBB and 31 with CM+IBB. A clinical and radiographic examination was performed at baseline and 12 months later. Clinical attachment level (CAL), gingival recession (GR), probing depth (PD), and radiographic defect bone level (DBL) post-therapy changes were compared between the two treatments. A non-inferiority margin = 1 mm was set to determine the efficacy of the test treatment (-1 mm for GR); a second non-inferiority margin = 0.5 mm (-0.5 mm for GR) was chosen for clinical relevance.

RESULTS

Twelve months after surgery a significant improvement of clinical and radiographic parameters was observed at both experimental sites. The 90% confidence intervals of the CM+IBB-L-PRF+IBB mean difference for CAL gain (-0.810 mm [-1.300 to -0.319]) and DBL gain (-0.648 mm [-1.244 to -0.052]) were below the 0.5 mm non-inferiority margin; GR increase (1.284 mm [0.764 to 1.804]) remained above the -0.5 mm, while PD reduction (0.499 mm [0.145 to 0.853]) crossed its 0.5-mm margin.

CONCLUSIONS

The L-PRF+IBB treatment of unfavorable IBDs offers non-inferior efficacy for CAL gain, showing less GR and more DBL gain too, while for PD reduction it is inferior to the CM+IBB treatment.

Ascorbic acid enhances bone parameter expression in human gingival mesenchymal stem cells

Ascorbic acid (AS), also known as vitamin C or ascorbate, is an essential dietary nutrient which plays a vital role in biological processes through various different mechanisms, in particular for the biosynthesis of collagen. The aim of the study was to establish the possibility of enhancing the osteogenic differentiation potential by manipulating the cellular micro-environment, through AS supplementation in human gingival mesenchymal stem cells (hGMSCs) at different concentrations, such as 60 and 90 μg/mL, for three weeks. Human GMSCs are considered a stem cell population, easily obtainable and displaying a remarkable immunotherapeutic potential and regenerative repair expression. Osteogenic differentiation level induced from AS was assayed by histochemical characterization, using light microscopy through Alizarin red S staining. The transcript levels of Collagen 1A1 (COL1A1), runtrelated transcription factor 2 (RUNX2), bone morphogenetic protein 2/4 (BMP2/4), osteopontin (OPN) and osteonectin (SPARC) were determined by quantitative RT-PCR. Protein expression of COL1A1, RUNX2, BMP2/4, OPN, SPARC were studied through Western blotting and confocal laser scanning microscopy (CLSM). Our results demonstrate that AS supports osteogenic differentiation in stem cells from gingiva niche as shown by osteogenic marker upregulation and by de novo production of calcium phosphate deposits as revealed by Alizarin red S staining. In summary, the results of the current study provide evidence that hGMSCs undergo osteogenic differentiation with AS treatment, for that reason AS could be a promising candidate for the prevention and healing of bone-related diseases.