Functional profile of oral plaque microbiome: Further insight into the bidirectional relationship between type 2 diabetes and periodontitis.

Increasing evidence support the association between the oral microbiome and human systemic diseases. This association may be attributed to the ability of many oral microbes to influence the inflammatory microenvironment. Herein, we focused our attention on the bidirectional relationship between periodontitis and type 2 diabetes using high-resolution whole metagenomic shotgun analysis to explore the composition and functional profile of the subgingival microbiome in diabetics and non-diabetics subjects with different periodontal conditions. In the present study, the abundance of metabolic pathways encoded by oral microbes was reconstructed from the metagenome, and we identified a set of dysregulated metabolic pathways significantly enriched in the periodontitis and/or diabetic patients. These pathways were mainly involved in branched and aromatic amino acids metabolism, fatty acid biosynthesis and adipocytokine signaling pathways, ferroptosis and iron homeostasis, nucleotide metabolism, and finally in the peptidoglycan and lipopolysaccharides synthesis. Overall, the results of the present study provide evidence in favor of the hypothesis that during the primary inflammatory challenge, regardless of whether it is induced by periodontitis or diabetes, endotoxemia and/or the release of inflammatory cytokines cause a change in precursor and/or in circulating innate immune cells. Dysbiosis and inflammation, also via oral-gut microbiome axis or adipose tissue, reduce the efficacy of the host immune response, while fueling inflammation and can induce that metabolic/epigenetic reprogramming of chromatin accessibility of genes related to the immune response. Moreover, the presence of an enhanced ferroptosis and an imbalance in purine/pyrimidine metabolism provides new insights into the role of ferroptotic death in this comorbidity.

A Minimally Invasive Osseous Resective Surgical Protocol for Pocket Elimination at Maxillary and Mandibular Posterior Sextants: MI-PES.

The purpose of the present study was to describe a novel protocol for a minimally invasive pocket elimination surgery (MI-PES) in the posterior maxilla and mandible, which consists of the combined use of (1) an access flap based on an internally beveled gingivectomy with minimal to no papilla mobilization at the buccal aspect, and (2) a resective procedure with an apically positioned flap on the lingual aspect. The interproximal bone defects were accessed with a single (lingual) flap, and the bone architecture was modified by the adoption of piezoelectric inserts for controlled bone recontouring associated with fiber retention. Mean probing depth (PD) was 5.5 ± 0.8 mm before surgery and 2.7 ± 0.6 mm at the 6-month reevaluation. All treated pockets showed a postsurgical PD < 4 mm. Gingival recession (REC) was 0.3 ± 0.5 mm at baseline and increased to 1.6 ± 0.8 mm at 6 months. When buccal and lingual pockets were analyzed separately, a trend toward a similar PD reduction, less REC increase, and greater clinical attachment level gain was recorded for buccal pockets. These preliminary observations seem to support the use of MI-PES as a valuable option for pocket elimination, at least when residual pockets are associated with a shallow interproximal osseous crater in the posterior maxilla or mandible.

Six-year extension results of a randomized trial comparing transcrestal and lateral sinus floor elevation at sites with 3-6 mm of residual bone.

OBJECTIVES: To comparatively evaluate the 6-year outcomes of transcrestal and lateral sinus floor elevation (tSFE and lSFE, respectively). METHODS: The 54 patients representing the per-protocol population of a randomized trial comparing implant placement with simultaneous tSFE versus lSFE at sites with a residual bone height of 3-6 mm were invited to participate in the 6-year follow-up visit. Study assessments included: peri-implant marginal bone level at the mesial (mMBL) and distal (dMBL) aspects of the implant, proportion of the entire implant surface in direct contact with the radiopaque area (totCON%), probing depth, bleeding on probing, suppuration on probing, and modified plaque index. Also, the conditions of the peri-implant tissues at 6-year visit were diagnosed according to the case definitions of peri-implant health, mucositis, and peri-implantitis from the 2017 World Workshop. RESULTS: Forty-three patients (21 treated with tSFE and 22 treated with lSFE) participated in the 6-year visit. Implant survival was 100%. At 6 years, totCON% was 96% (IR: 88%-100%) in tSFE group and 100% (IR: 98%-100%) in lSFE group (p = .036). No significant intergroup difference in patient distribution according to the diagnosis of peri-implant health/disease was observed. Median dMBL was 0.3 mm in tSFE group and 0 mm in lSFE group (p = .024). CONCLUSIONS: At 6 years following placement concomitantly with tSFE and lSFE, implants showed similar conditions of peri-implant health. Peri-implant bone support was high in both groups and was slightly but significantly lower in tSFE group.

Minimal invasiveness in lateral bone augmentation with simultaneous implant placement: A systematic review.

The presence of a peri-implant bone dehiscence (BD) or fenestration (BF) is a common finding after implant placement in a crest with a reduced bucco-lingual bone dimension. The presence of a residual BD is associated with a relevant incidence of peri-implant biological complications over time. Guided bone regeneration (GBR), performed at implant placement, is the most validated treatment to correct a BD. In the present systematic review, the evidence evaluating factors which could reduce the invasiveness of a GBR procedure with respect to patient-reported outcomes, intra- and post- surgical complications, was summarized. Factors included were: technical aspects, regenerative materials for GBR, and peri- and post-operative pharmacological regimens. The available evidence seems to indicate that the use of membrane fixation and flap passivation by means of a double flap incision technique may reduce the incidence of post-surgical complications. When feasible, the coronal advancement of the lingual flap is suggested. The use of a non-cross linked resorbable membrane positively impacts on patient discomfort. The adjunctive use of autogenous bone to a xenograft seems not to improve BD correction, but could increase patient discomfort. Systemic antibiotic administration after a GBR procedure does not seem to be justified in systemically healthy patients.

Minimal invasiveness in the surgical treatment of intraosseous defects: A systematic review.

The modern approach to regenerative treatment of periodontal intraosseous defects should aim at maximizing the clinical outcomes while minimizing the invasiveness (pain, complications, aesthetic impairment, chair time, and costs) of the procedure. The present systematic review evaluated the effect of flap design, regenerative technology, and perioperative and postoperative adjunctive protocols on invasiveness. Overall, the results of the 13 included trials indicate that: (a) the elevation of a single (buccal or lingual) flap positively influences the intensity of postoperative pain and improves the quality of early wound healing compared with double flaps; (b) while the adjunctive use of a membrane is associated with significantly longer surgery-related chair time and higher postoperative pain, the adjunctive use of enamel matrix derivative at sites receiving a graft significantly reduces postoperative pain; also, graft materials showed no significant impact on invasiveness; (c) open flap debridement performed through the elevation of a single flap may lead to substantial clinical improvements of the lesion with reduced surgery-related chair time and costs, thus representing a promising alternative to regenerative treatment. However, for such an approach, a histological evaluation of the nature of the reconstructed tissues is still lacking, and the presurgery conditions (eg, probing depth, defect severity, and defect morphology), which may benefit in terms of invasiveness, have not yet been defined; and (d) intraoperative and postoperative low-level laser biostimulation of the defect site may favorably modulate the postoperative course.

Effect of lateral bone augmentation procedures in correcting peri-implant bone dehiscence and fenestration defects: A systematic review and network meta-analysis.

PURPOSE: The aim of the present systematic review was to evaluate the effect of different lateral bone augmentation (LBA) procedures on the complete correction of a peri-implant bone dehiscence (BD) or fenestration (BF) from implant placement to implant surgical uncovering. METHODS: Electronic (Medline, Scopus, and Cochrane databases) and hand literature searches were performed for studies including at least one treatment arm where any LBA had been applied to correct a BD/BF at implant placement (T0). Studies where BD/BF was left untreated were also retrieved as negative control. Data from 24 selected articles were used to perform a network meta-analysis. Based on the proportion of nonresolved BD/BF at implant surgical uncovering (T1), a hierarchy of LBA procedures, and was determined. Spontaneous healing (i.e., exposed implant surface covered by a full-thickness flap; SELF) was also included in the hierarchy. Resorbable membrane + bone graft (RM + BG) was used as reference group. An analysis on the effect of nonhuman (NHBS) vs human (HBS) derived bone substitutes was also performed. NHBS was used as the reference group. RESULTS: No statistically significant differences were found among treatments for the proportion of nonresolved BD/BF. SELF performed substantially worse compared to RM + BG (OR: 5.78 × 10, CI: 4.83 × 10 - 1.3 × 1086 ). Treatment based on a combination of a graft material and membrane/periosteum appeared to perform slightly better than treatments using graft material or membrane alone. NHBS appeared to perform better than HBS. SELF had the worst effect among all treatments for both BD/BF height reduction (BDH) and BD/BF width reduction (BDW). Nonresorbable membrane (NRM) and patient's own periosteum (PERI) + BG showed greater increases in buccal bone thickness than RM + BG. CONCLUSION: Reconstructive treatment (including use of graft alone, membrane alone, or combinations of grafts and either membrane or patient's own periosteum) of a BD/BF at implant placement favorably and significantly impacts on the probability to obtain complete correction of the BD/BF at implant uncovering when compared to full-thickness flap repositioning on the BD/BF. When using a bone substitute, a nonhuman derived one may be suggested.

Peri-Implant Bone Augmentation by the Sub-Periosteal Peri-Implant Augmented Layer Technique and a Bovine-Derived Bone Block: A Case Report.

BACKGROUND: When used with deproteinized bovine bone mineral (DBBM) delivered as a particulate, the sub-periosteal peri-implant augmented layer (SPAL) technique was effective in completely correcting up to 92% of peri-implant buccal bone dehiscences. The use of a DBBM block (bDBBM), however, may result in an improvement of the peri-implant bone dehiscence as well as a relevant lateral bone augmentation since its mechanical properties may ensure a better dimensional stability at flap manipulation than particulate DBBM. The aim of the present a proof-of-principle case report is to investigate if SPAL may be successfully used to obtain bone augmentation at peri-implant dehi scence sites when used with bDBBM. CASE PRESENTATION: Lateral bone augmentation was performed using the SPAL technique at two implants showing a buccal peri-implant bone dehiscence immediately after their placement. A partial-thickness flap was elevated, leaving the periosteal layer on the buccal cortical bone plate. The periosteal layer was, in turn, elevated to create a pouch, which was used to stabilize a bDBBM graft at the peri-implant buccal bone dehiscences. At re-entry, exposed implant surfaces were completely covered by new thick hard tissue up to their most coronal portion. A free epithelial-connective tissue graft was used to augment the peri-implant soft tissue phenotype. CONCLUSION: When used to accommodate bDBBM over the most coronal portion of an exposed implant, SPAL may successfully lead to an increase in peri-implant buccal tissue thickness.

Peri-implant tissue conditions at implants treated with Sub-periosteal Peri-implant Augmented Layer technique: A retrospective case series.

OBJECTIVES: To assess peri-implant tissue conditions on the short term in patients receiving the Sub-periosteal Peri-implant Augmented Layer (SPAL) technique and in patients with adequate thickness (≥2 mm) of the peri-implant buccal bone plate (PBBP) at placement. METHODS: Patients where either a dehiscence defect or thin PBBP at implant placement was corrected by SPAL technique (SPALdehiscence and SPALthin groups, respectively) and patients presenting a residual PBBP thickness ≥2 mm at implant placement (control group) were retrospectively selected. The number of peri-implant sites positive to bleeding on probing (BoP) at 6 months following prosthetic loading was the primary outcome. Also, height of keratinized mucosa, marginal soft tissue level, Plaque Index, peri-implant probing depth, suppuration on probing, and interproximal radiographic bone level (RBL) were evaluated. RESULTS: Thirty-four patients (11 in the SPALdehiscence group, 11 in the SPALthin group, and 12 in the control group) were included. In each SPAL group, 10 patients (90.9%) showed peri-implant tissue thickness ≥2 mm at the most coronal portion of the implant at uncovering. The prevalence (number) of BoP-positive sites was 2, 1, and 0 in the SPALdehiscence , SPALthin , and control groups, respectively. RBL amounted to 0.3 mm in the SPALdehiscence group, 0.2 mm in the SPALthin group, and 0 mm in the control group. CONCLUSION: After 6 months of prosthetic loading, patients treated with SPAL technique show limited peri-implant mucosal inflammation in association with shallow PD and adequate KM. At implants receiving SPAL technique, however, interproximal RBL was found apical to its ideal position.

Sub-Periosteal Peri-Implant Augmented Layer Technique to Treat Peri-Implantitis Lesions.

INTRODUCTION: The efficacy of surgical regenerative procedures to treat peri-implantitis lesions has been extensively reviewed. Regenerative treatment showed a variable rate of success, in terms of pocket reduction, gain in bone support, and elimination of signs of infection/inflammation. The aim of the present case report is to illustrate the use of the sub-periosteal peri-implant augmented layer (SPAL) technique to correct peri-implantitis defects CASE PRESENTATION: Surgical treatment of three class Ib and one class Ic peri-implantitis lesions in three patients was performed by means of the SPAL technique. A partial-thickness flap was elevated, leaving the periosteal layer on the buccal cortical bone plate. The periosteal layer was in turn elevated to create a pouch, which was used to stabilize a bovine-derived xenograft (deproteinized bovine bone mineral) at the peri-implant buccal bone defect. No barrier membrane was used. In case of insufficient dimensions of peri-implant mucosa, a connective tissue graft (CTG) was buccally positioned at the most coronal portion of the implant. Treatment resulted in substantial reconstruction of peri-implant support associated with reduced probing depth and absence of inflammation. CONCLUSIONS: SPAL technique with or without additional CTG may be a suitable option to obtain clinical remission of peri-implantitis defects associated with buccal bone dehiscence.

Whole metagenomic shotgun sequencing of the subgingival microbiome of diabetics and non-diabetics with different periodontal conditions.

OBJECTIVE: The aim of this study was to use high-resolution whole metagenomic shotgun sequencing to characterize the subgingival microbiome of patients with/without type 2 Diabetes Mellitus and with/without periodontitis. DESIGN: Twelve subjects, falling into one of the four study groups based on the presence/absence of poorly controlled type 2 Diabetes Mellitus and moderate-severe periodontitis, were selected. For each eligible subject, subgingival plaque samples were collected at 4 sites, all representative of the periodontal condition of the individual (i.e., non-bleeding sulci in subjects without a history of periodontitis, bleeding pockets in patients with moderate-severe periodontitis). The subgingival microbiome was evaluated using high-resolution whole metagenomic shotgun sequencing. RESULTS: The results showed that: (i) the presence of type 2 Diabetes Mellitus and/or periodontitis were associated with a tendency of the subgingival microbiome to decrease in richness and diversity; (ii) the presence of type 2 Diabetes Mellitus was not associated with significant differences in the relative abundance of one or more species in patients either with or without periodontitis; (iii) the presence of periodontitis was associated with a significantly higher relative abundance of Anaerolineaceae bacterium oral taxon 439 in type 2 Diabetes Mellitus patients. CONCLUSIONS: Whole metagenomic shotgun sequencing of the subgingival microbiome was extremely effective in the detection of low-abundant taxon. Our results point out a significantly higher relative abundance of Anaerolineaceae bacterium oral taxon 439 in patients with moderate to severe periodontitis vs patients without history of periodontitis, which was maintained when the comparison was restricted to type 2 diabetics.

A simplified soft tissue management for peri-implant bone augmentation.

PURPOSE: This case series illustrates a simplified soft tissue management, namely, the subperiosteal peri-implant augmented layer (SPAL), to increase hard and soft tissue dimensions at the most coronal portion of an implant. MATERIALS AND METHODS: Twenty-seven implants in 16 patients presenting either a buccal bone dehiscence or a thin (< 1 mm) buccal cortical bone plate (BCBP) were consecutively treated. Briefly, a split-thickness flap (namely, the mucosal layer) was raised on the buccal aspect. Then, the periosteal layer was elevated from the bone crest. A full-thickness flap was elevated on the oral aspect. After implant site preparation, a xenograft was used to fill the space between the periosteal layer and the BCBP and/or exposed implant surface and, if present, to completely correct the bone dehiscence. The periosteal layer was sutured to the oral flap. The mucosal layer was coronally advanced and sutured to submerge both the graft and the implants. At 3 to 6 months, a re-entry procedure for implant exposure was performed. RESULTS: Healing was uneventful, with no signs of infection in all cases. A wound dehiscence was observed in three implants in two patients at 2 weeks postsurgery. Out of 15 implants showing an initial bone dehiscence, 12 implants (80%) showed a complete resolution, with a subperiosteal tissue thickness (SPTT) at the time of re-entry of 3.1 ± 1.0 mm. Three implants presented a residual dehiscence of 1 mm (two implants) or 2 mm (one implant), with a SPTT of at least 2 mm. Out of 12 implants showing a thin BCBP at implant placement, 10 implants (90%) revealed a SPTT ≥ 2 at the time of re-entry. Two implants revealed a SPTT of 1 mm. CONCLUSION: The SPAL technique represents a valuable simplified surgical approach associated with a low rate of complications in the treatment of peri-implant bone dehiscence and in the horizontal augmentation of peri-implant tissue thickness.

Sub-periosteal peri-implant augmented layer technique for horizontal bone augmentation at implant placement.

In the present study, a novel surgical technique, namely the sub-periosteal peri-implant augmented layer (SPAL), to increase hard and soft tissue dimensions at the most coronal portion of an implant will be thoroughly described. The surgical buccal access at the time of implant placement first consisted of a split-thickness flap to raise the most superficial mucosal layer, followed by the elevation of the periosteal layer which was detached from the buccal cortical bone plate (BCBP). A full-thickness flap was elevated on the oral aspect. A xenograft was used to fill the space between the periosteal layer and the BCBP, and the periosteal layer was sutured to the oral flap. The mucosal layer was coronally advanced and sutured to submerge both the graft and the implants. At implant uncovering at 4 months, an increase in the thickness (>2 mm) of the buccal peri-implant tissues was observed. A free gingival graft was used to enhance the dimensions of buccal keratinized mucosa. The SPAL technique may represent a surgical option for the horizontal augmentation of peri-implant tissue thickness.