Efficacy of a collagen matrix for soft tissue augmentation after implant placement compared to connective tissue grafts: A multicenter, noninferiority, randomized controlled trial.

OBJECTIVES: To test whether soft tissue volume augmentation using a collagen matrix (VCMX) leads to noninferior results in terms of gain of mucosal thickness at single implant sites, compared to connective tissue grafts (SCTG). METHODS: The study was designed as a multi-center randomized controlled clinical trial. Subjects in need of soft tissue volume augmentation at single tooth implant sites were consecutively recruited at nine centers. The deficient mucosal thickness at the implant sites (one per patient) was augmented by applying either a VCMX or a SCTG. Patients were examined at 120 days (abutment connection = primary endpoint), 180 days (final restoration), and 360 days (1-year after insertion of the final restoration). Outcome measures included: transmucosal probing of the mucosal thickness (crestal = primary outcome), profilometric measurements of the tissue volume, and patient-reported outcome measures (PROMs). RESULTS: Out of the 88 patients, 79 attended the one-year follow-up. The median increase of the crestal mucosal thickness between pre-augmentation and 120 days was 0.3 ± 2.1 mm in the VCMX group and 0.8 ± 1.6 mm in the SCTG group (p = .455). Non-inferiority of the VCMX compared to the SCTG was not observed. The respective numbers at the buccal aspect amounted to 0.9 ± 2.0 mm (VCMX) and 1.1 ± 1.4 mm (SCTG; p = .431). PROMs including pain perception favored the VCMX group. CONCLUSION: It remains inconclusive whether soft tissue augmentation using a VCMX is noninferior to SCTG in terms of crestal mucosal thickening at single implant sites. However, the use of collagen matrices favors PROMs especially pain perception, while achieving similar buccal volume gains along with comparable clinical and aesthetic parameters to SCTG.

Complications in sinus lifting procedures: Classification and management.

Open and closed sinus lifting procedures are predictable methods to augment the bone needed for appropriate implant placement in the posterior maxilla in cases where available bone is limited. However, these techniques may give rise to complications and associated comorbidities. In the case of open sinus lifting, perforation of the Schneiderian membrane during osteotomy is the most common complication, with an incidence rate of around 20%-25%. Apart from those complications associated with oral surgery in general (such as swelling or hematoma), there are specific complications of open sinus lifting procedures that may arise less frequently (chronic rhinosinusitis, hemorrhage, or ostium blockage by overfilling) but which may nevertheless compromise the viability of the graft and/or the implants and cause substantial discomfort to the patient. Closed sinus lifting is a less invasive approach that allows transcrestal placement of the implants in cases where there is sufficient residual bone height. However, it may also be associated with specific complications, including membrane perforation, benign paroxysmal positional vertigo, and implant displacement to the sinus cavity. New technologies have been proposed to reduce these complications and comorbidities associated with conventional sinus lifting procedures, such as the use of piezoelectric devices and hydraulic sinus lift or reamer burs. The evidence supporting their effectiveness and safety, however, is still lacking. A detailed medical history together with a thorough radiographic and clinical examination are essential prior to any kind of bone regenerative augmentation involving the maxillary sinus. Moreover, it is recommended to employ the most appropriate surgical technique for the specific characteristics of the case and, at the same time, accommodating the experience and skills of the surgeon.

Complications in bone-grafting procedures: Classification and management.

Bone-regenerative interventions aiming to restore deficient alveolar ridges, such as the use of block grafts or through the application of guided bone-regeneration principles, have reported positive outcomes in the published scientific literature. These interventions, however, are invasive, and hence, intraoperative and/or postoperative complications may occur. The types of complications and their severity may vary from the exposure of the biomaterial (membrane or graft) to postsurgical infections, neurosensorial disturbances, occurrence of hemorrhage, and pain, etc. The aim of the present narrative review was to search the available scientific evidence concerning the incidence of these complications, their effect on treatment outcomes, their clinical management and, finally, strategies aimed at prevention. Exposure of the barrier membrane or the block graft is the most common complication associated with oral regenerative interventions. To manage these complications, depending on the extent of the exposure and the presence or absence of concomitant infections, therapeutic measures may vary, from the topical application of antiseptics to the removal of the barrier membrane or the block graft. Regardless of their treatment, the occurrence of these complications has been associated with patient selection, with compliant patients (eg, nonsmokers) having a lower reported incidence of complications. Similarly, surgical factors such as correct flap elevation and a tensionless closure are of obvious importance. Finally, to prevent the incidence of complications, it appears prudent to utilize whenever possible less invasive surgical interventions.

Buccal soft tissue dehiscence defects at dental implants-associated factors and frequency of occurrence: A systematic review and meta-analysis.

AIM: To identify the factors associated with buccal peri-implant soft tissue dehiscences (BSTDs) and their frequency of occurrence. MATERIALS AND METHODS: Randomized controlled trials, controlled clinical trials, cohort studies, and case series assessing the frequency of occurrence of BSTD were included. BSTD was defined as an apical migration of the peri-implant soft tissues of ≥1 mm from the baseline examination (final restoration) or in comparison with the adjacent or contralateral natural tooth. Frequency distributions of BSTD related to the presence or absence of any surgical, prosthetic, or anatomic factor that may have contributed to the development of BSTD were recorded. Random-effects meta-analyses using odds ratios (OR) were performed to investigate the association of certain factors with the development of BSTD. RESULTS: Twenty-four articles were finally included belonging to 22 clinical investigations. Patients at higher risk of developing BSTD were associated with thin biotype (OR = 2.85 [1.40, 5.8], n = 5, p = .003) and with buccally placed implants (OR = 14.37 [4.58, 45.14], n = 3, p ≤ .001). Patients without connective tissue grafting (CTG) had greater odds of developing BSTD (OR = 9.00 [3.11, 26.02], n = 5, p ≤ .001), while buccal bone plate thickness of <1 mm and immediately placed implants were not associated with greater BSTD (OR = 1.29 [0.35, 4.77], n = 2, p = .704 and OR = 1.56 [0.46, 5.26], n = 4, p = .477, respectively). The frequency of occurrence of BSTD varied across the included studies with a range from 0% to 61%. CONCLUSIONS: Thin tissue biotype and buccally placed implants were associated with BSTD, whereas CTG seemed to have a protective effect. Thin buccal plates and immediately placed implants did not demonstrate a higher risk of BSTD.

In vitro effect of different implant decontamination methods in three intraosseous defect configurations.

OBJECTIVES: This in vitro investigation was aimed to evaluate the cleaning ability of four mechanical devices designed for decontaminating implant surfaces. MATERIAL AND METHODS: Ninety-six implants were coated with permanent ink and inserted into 3D-printed resin blocks simulating three different intraosseous defect configurations (types Ib, Ic, and Ie). The four tested mechanical decontamination devices (air-polishing with glycine powder, rotating titanium brush, polyetheretherketone [PEEK]-coated ultrasonic tip, and stainless steel ultrasonic tip) were randomly applied onto the 5 mm exposed implant surface. Standardized photographs were taken from a frontal perspective and with a 30° angle coronally and apically to the implant axis. The area with remnant ink on the implant surface was calculated. RESULTS: Although none of the groups achieved complete ink removal, air-polishing with glycine and titanium brushes demonstrated a higher cleaning ability when compared with ultrasonic devices either with standard or PEEK tips for all three defect configurations. For the three tested models, the best cleaning ability in all groups was shown on implant surfaces without facing an intraosseous wall. Titanium brush was the most effective when the intraosseous walls existed. Cleaning effectiveness diminished in the threads located in the apical third, especially when using air-polishing and ultrasonic devices. CONCLUSIONS: Titanium brushes and air-polishing devices were more effective in removing artificial biofilm using this in vitro model, although their effectiveness was influenced by the presence of the intrabony component.

Occurrence, associated factors and soft tissue reconstructive therapy for buccal soft tissue dehiscence at dental implants: Consensus report of group 3 of the DGI/SEPA/Osteology Workshop.

OBJECTIVES: To systematically assess the literature and report on (1) the frequency of occurrence of buccal soft tissue dehiscence (BSTD) at implants, (2) factors associated with the occurrence of BSTD and (3) treatment outcomes of reconstructive therapy for the coverage of BSTD. MATERIALS AND METHODS: Two systematic reviews addressing focused questions related to implant BSTD occurrence, associated factors and the treatment outcomes of BSTD coverage served as the basis for group discussions and the consensus statements. The main findings of the systematic reviews, consensus statements and implications for clinical practice and for future research were formulated within group 3 and were further discussed and reached final approval within the plenary session. RESULTS: Buccally positioned implants were the factor most strongly associated with the risk of occurrence of BSTD, followed by thin tissue phenotype. At immediate implants, it was identified that the use of a connective tissue graft (CTG) may act as a protective factor for BSTD. Coverage of BSTD may be achieved with a combination of a coronally advanced flap (CAF) and a connective tissue graft, with or without prosthesis modification/removal, although feasibility of the procedure depends upon multiple local and patient-related factors. Soft tissue substitutes showed limited BSTD coverage. CONCLUSION: Correct three-dimensional (3D) positioning of the implant is of utmost relevance to prevent the occurrence of BSTD. If present, BSTD may be covered by CAF +CTG, however the evidence comes from a low number of observational studies. Therefore, future research is needed for the development of further evidence-based clinical recommendations.

Cell Therapy Based on Gingiva-Derived Mesenchymal Stem Cells Seeded in a Xenogeneic Collagen Matrix for Root Coverage of RT1 Gingival Lesions: An In Vivo Experimental Study.

(1) Background: To investigate the effect of a xenogeneic collagen matrix (CMX) seeded with autologous gingiva-derived mesenchymal cells (GMSCs) when combined with a coronally advanced flap (CAF) in the treatment of localized gingival recession type 1 (RT1). (2) Methods: Dehiscence-type defects were created in seven dogs. GMSCs were isolated, transfected with a vector carrying green fluorescent protein (GFP) and expanded. Once chronified, the defects were randomly treated with (1) CAF plus the combination of CMX and GFP+ GMSCs, (2) CAF plus CMX with autologous fibroblasts, (3) CAF plus CMX and (4) CAF alone. Histological and clinical outcomes at 2- and 6-week healing periods were analyzed and compared among groups. (3) Results: Histologically, the addition of autologous cells to the CMX resulted in reduced inflammation and a variable degree of new cementum/bone formation. CMX plus GMSCs resulted in greater mean recession reduction (1.42; SD = 1.88 mm) and percentage of teeth with recession reduction of ≥2 mm (57%) when compared to the other groups, although these differences were not statistically significant. (4) Conclusions: The histometric and clinical results indicated a positive trend favouring the combination of CMX and GMSCs with the CAF when compared to the groups without cells, although these differences were not statistically significant.

Changes in peri-implant soft tissue levels following surgical treatment of peri-implantitis: A systematic review and meta-analysis.

AIM: To assess the changes in peri-implant soft tissue levels after the surgical treatment of peri-implantitis. METHODS: Randomized controlled trials, controlled clinical trials, cohort studies and case series, evaluating the changes in the position of the mucosal margin before and after surgical treatment of peri-implantitis, were searched. Secondary outcomes were changes in keratinized mucosa (KM), radiographic bone levels, probing depths (PD), plaque indices, bleeding on probing and patient perception. Meta-analyses were performed to determine weighted mean differences (WMD) or effects (WME). RESULTS: Twenty-six articles, reporting 20 investigations, were included. Reconstructive approaches yielded significantly less increase in mucosal recession, when compared to access flaps (n = 3, WMD = -1.35 mm, 95% confidence interval [CI] [-2.62; -0.07], p = .038). When comparing among reconstructive surgical interventions similar outcomes were observed irrespective of the use of a barrier membrane (n = 3, WMD = -0.01 mm, 95% CI [-0.15; 0.13], p = .917). When considering the effects over time, limited mucosal recession was observed after reconstructive procedures (n = 23, WME = 0.389 mm, 95% CI [0.204; 0.574]), p = .001), while increased recession was reported with either resective or access flap surgery (n = 6, WME = 1.21 mm, 95% CI [0.70; 1.72], p = <.001; and n = 3, WME = 0.95 mm, 95% CI [0.20; 2.10], p = .106; respectively). When resective and reconstructive approaches were combined the highest values on peri-implant recession were reported (n = 2, WME = 1.97 mm, 95% CI [0.81; 3.14], p < .001). Reconstructive surgical interventions were associated with greater radiographic bone level gains, while similar values were reported for PD reduction when comparing reconstructive, access and resective procedures. CONCLUSIONS: Resective surgical procedures were associated with significant post-surgical recession while minimal recession was observed in regenerative interventions.

Peri-implantitis: Summary and consensus statements of group 3. The 6th EAO Consensus Conference 2021.

OBJECTIVE: To evaluate the influence of implant and prosthetic components on peri-implant tissue health. A further aim was to evaluate peri-implant soft-tissue changes following surgical peri-implantitis treatment. MATERIALS AND METHODS: Group discussions based on two systematic reviews (SR) and one critical review (CR) addressed (i) the influence of implant material and surface characteristics on the incidence and progression of peri-implantitis, (ii) implant and restorative design elements and the associated risk for peri-implant diseases, and (iii) peri-implant soft-tissue level changes and patient-reported outcomes following peri-implantitis treatment. Consensus statements, clinical recommendations, and implications for future research were discussed within the group and approved during plenary sessions. RESULTS: Data from preclinical in vivo studies demonstrated significantly greater radiographic bone loss and increased area of inflammatory infiltrate at modified compared to non-modified surface implants. Limited clinical data did not show differences between modified and non-modified implant surfaces in incidence or progression of peri-implantitis (SR). There is some evidence that restricted accessibility for oral hygiene and an emergence angle of >30 combined with a convex emergence profile of the abutment/prosthesis are associated with an increased risk for peri-implantitis (CR). Reconstructive therapy for peri-implantitis resulted in significantly less soft-tissue recession, when compared with access flap. Implantoplasty or the adjunctive use of a barrier membrane had no influence on the extent of peri-implant mucosal recession following peri-implantitis treatment (SR). CONCLUSIONS: Prosthesis overcontouring and impaired access to oral hygiene procedures increases risk for peri-implantitis. When indicated, reconstructive peri-implantitis treatment may facilitate the maintenance of post-operative peri-implant soft-tissue levels.

Significance of implant design on the efficacy of different peri-implantitis decontamination protocols.

OBJECTIVE: To assess the efficacy of three mechanical decontamination methods in four types of commercially available implants. MATERIAL AND METHODS: Ninety-six implants of four commercial brands with different designs (regarding thread depth and thread pitch) were soaked in a surrogate biofilm (ink) and air-dried. Circumferential standardized peri-implant defects with 6 mm in depth and 1.55 mm in width were custom-made with a 3D printer. Stained implants were inserted in the defects and instrumented with three different methods: a titanium brush (TNB), a metallic ultrasonic tip (IST) and an air abrasive (PF). Standardized photographs were taken vertically to the implant axis (flat view), and with angulations of 60° (upper view) and 120° (lower view) to the implant long axis. The percentage of residual stain (PRS) was calculated with the image analysis software. Scanning electron microscope evaluations were performed on the buccal aspect of the implants at the central level of the defect. RESULTS: The efficacy of PF was significantly inferior to the TNB and IST in all implant designs, while there were no significant differences between TNB and IST. IST showed significantly higher PRS in the implant with the highest thread pitch, while the TNB had the highest PRS in the implant with a marked reverse buttress-thread design. The micro-thread design had the lowest values of PRS for all decontamination methods. The apically facing threads represented the areas with highest PRS for all implant designs and decontamination methods. CONCLUSION: Thread geometry influenced the access of the decontamination devices and in turn its efficacy. Implants with lower thread pitch and thread depth values appeared to have less residual staining. CLINICAL RELEVANCE: Clinicians must be aware of the importance of thread geometry in the decontamination efficacy.

Hard and soft tissue changes after guided bone regeneration using two different barrier membranes: an experimental in vivo investigation.

OBJECTIVE: To assess the contour and volumetric changes of hard and soft tissues after guided bone regeneration (GBR) using two types of barrier membranes together with a xenogeneic bone substitute in dehiscence-type defects around dental implants. MATERIAL AND METHODS: In 8 Beagle dogs, after tooth extraction, two-wall chronified bone defects were developed. Then, implants were placed with a buccal dehiscence defect that was treated with GBR using randomly: (i) deproteinized bovine bone mineral (DBBM) covered by a synthetic polylactic membrane (test group), (ii) DBBM plus a porcine natural collagen membrane (positive control) and (iii) defect only covered by the synthetic membrane (negative control group). Outcomes were evaluated at 4 and 12 weeks. Micro-CT was used to evaluate the hard tissue volumetric changes and STL files from digitized cast models were used to measure the soft tissues contour linear changes. RESULTS: Test and positive control groups were superior in terms of volume gain and contour changes when compared with the negative control. Soft tissue changes showed at 4 weeks statistically significant superiority for test and positive control groups compared with negative control. After 12 weeks, the results were superior for test and positive control groups but not statistically significant, although, with a lesser magnitude, the negative control group exhibited gains in both, soft and hard tissues. CONCLUSIONS: Both types of membranes (collagen and synthetic) attained similar outcomes, in terms of hard tissue volume gain and soft tissue contours when used in combination with DBBM CLINICAL RELEVANCE: Synthetic membranes were a valid alternative to the "gold standard" natural collagen membrane for treating dehiscence-type defects around dental implants when used with a xenogeneic bone substitute scaffold.

Soft tissue stability around dental implants after soft tissue grafting from the lateral palate or the tuberosity area - A randomized controlled clinical study.

AIM: To compare the soft tissue stability (STA) around single implants previously augmented with either subepithelial connective tissue graft (SCTG) from the lateral palate (LP) or from the tuberosity area (TA). MATERIAL AND METHODS: Twenty-nine patients showing 33 implants with buccal volume deficiency randomly received SCTG from LP (control group/CG) or TA (test group/TG). At 4 months (FU-4) the definitive crown was installed and an intra-oral scan performed. At 12 months (FU-12), a new scan was registered. Between FU-4 and FU-12 STA was evaluated by STL image superimposition. Clinical parameters and the modified pink aesthetic score (PES) (Fürhauser et al. 2005) were recorded. RESULTS: After FU-4 both tissues demonstrated a similar STA without statistically significant differences (SSD). The mean soft tissue changes were 0.03 ± 0.22 mm for CG and 0.04 ± 0.23 mm for TG (p = .870). SSD were observed for changes in keratinized tissue (KT) with greater stability for TG (0 ± 0.32 mm) compared with CG (-0.3 ± 0.33 mm) (p = .002). PES resulted in mean values of 8.37 ± 2.46 for CG and 8.54 ± 2.43 for TG (p=.59). CONCLUSIONS: Both groups demonstrated similar STA between the definitive crown placement and 12 months, while greater stability of the KT gained was observed in TG.

Clinical benefits of ridge preservation for implant placement compared to natural healing in maxillary teeth: A retrospective study.

AIM: The purpose of this retrospective study was to determine clinical benefits of ridge preservation in terms of surgical invasiveness of implant placement compared to natural healing in the maxilla. MATERIALS & METHODS: This study included 178 patients with 206 implants placed at ridge-preserved sites and 493 patients with 656 implants placed at naturally healed sites in maxillary anterior and posterior regions. Patient- and implant-related data were collected from electronic dental records including additional augmentation procedures performed before or during implant placement and surgical complications. Cumulative survival rate was assessed using Kaplan-Meier method. The annual peri-implant marginal bone loss between the two groups was compared using the Mann-Whitney U test. RESULTS: The follow-up period was 24.4 ± 18.1 months (mean ± standard deviation) for ridge-preserved sites and 45.7 ± 29.6 months for naturally healed sites. Sinus augmentation was performed at similar frequencies in the two groups, but lateral approach was applied significantly more at naturally healed sites (37.2%) than ridge-preserved sites (8.3%, p ≤ .001). There was no intergroup difference in the cumulative survival rate or annual peri-implant marginal bone loss. CONCLUSION: Ridge preservation can be clinically beneficial for minimizing the invasiveness of implant surgery by simplifying the procedure when sinus augmentation is expected in the maxilla.

Non-surgical therapeutic outcomes of peri-implantitis: 12-month results.

OBJECTIVES: To assess the clinical and radiographic outcomes of implants treated by means of non-surgical debridement with systemic antibiotic therapy. MATERIALS AND METHODS: A prospective case series study evaluating the 12-month clinical and radiographic outcomes of peri-implantitis lesions treated with ultrasonic scaler debridement, a glycine air abrasive, and metronidazole followed by supportive maintenance. Clinical and radiographic variables and success criteria were defined a priori. RESULTS: Overall, 21 patients were included. One implant failed during the study period (implant survival rate 95.24%). Substantial changes occurred at 12 months in all the clinical and radiographic variables, reaching strong statistical significance in the majority of them. According to the success criteria applied, 40.90% of the peri-implantitis were arrested and resolved, while 59.1% presented with at least one probed site with bleeding on probing (BoP). Moreover, 95.45% exhibited peri-implant pocket depth (PPD) < 5 mm at the end of the study. None of the implants presented with progressive bone loss. CONCLUSION: Non-surgical therapy of peri-implantitis is effective to arrest progressive bone loss, reduce PPD and suppuration, and achieve radiographic bone fill in the majority of cases. Nevertheless, it failed to be completely efficacious in the achievement of successful therapeutic outcomes as BoP remained frequently present. CLINICAL RELEVANCE: Non-surgical therapy achieved significant clinical and radiological improvements.

Efficacy of lateral bone augmentation performed simultaneously with dental implant placement: A systematic review and meta-analysis.

OBJECTIVES: To analyse the evidence regarding the efficacy of lateral bone augmentation procedures in terms of defect resolution in cases of horizontal ridge deficiencies after implant placement. MATERIALS AND METHODS: Included studies met the following inclusion criteria: randomized controlled trials (RCTs) or controlled clinical trials (CCTs), re-entry procedure to assess defect resolution, minimum of 10 patients (5 per group). Meta-analyses were performed whenever possible, including subgroup analysis based on membranes and grafting materials. RESULTS: Twenty-eight publications (20 short-term, 8 follow-up studies) were included. The most often used type of intervention was a xenogeneic particulated grafting material (XE) and a resorbable collagen membrane (CM). The mean defect height at baseline amounted to 5.1 mm (range 2.4-7.8) and decreased to a mean of 0.9 mm (range 0.2-2.2) at re-entry, and the mean defect resolution was 81.3% (range 56.4%-97.1%). Defect height reduction was not significantly different using CM+XE as control treatment compared to the combined data of the respective test groups [n = 11; weighted mean difference (WMD) = -0.006 mm; 95% CI, -0.61, 0.60; p = 0.985]. The absence of any lateral bone augmentation was less favourable than the conjunction of a membrane and a bone grafting material (n = 1; MD = -1.96 mm; 95% CI, -3.48, -0.44; p = 0.011). The lack of a grafting material was less favourable than the conjunction of grafting material and membrane (n = 1; MD = -2.44 mm; 95% CI, -4.53, -0.35; p = 0.022), and the addition of a membrane compared to a grafting material alone was more favourable (n = 3; WMD = 0.97 mm; 95% CI, 0.31, 1.64; p = 0.004). CONCLUSIONS: Lateral bone augmentation is a successful treatment modality. For optimal defect height reduction, a barrier membrane and a grafting material should be combined.

Management of the extraction socket and timing of implant placement: Consensus report and clinical recommendations of group 3 of the XV European Workshop in Periodontology.

BACKGROUND: The transition from a tooth requiring extraction to its replacement (with a dental implant) requires a series of clinical decisions related to timing, approach, materials, cost-effectiveness and the assessment of potential harm and patient preference. This workshop focused on the formulation of evidence-based consensus statements and clinical recommendations. METHODS: Four systematic reviews covering the areas of alveolar ridge preservation/bone grafting, immediate early and delayed implant placement and alveolar bone augmentation at the time of implant placement in a healed ridge formed the basis of the deliberations. The level of evidence supporting each consensus statement and its strength was described using a modification of the GRADE tool. RESULTS: The evidence base for each of the relevant topics was assessed and summarized in 23 consensus statements and 12 specific clinical recommendations. The group emphasized that the evidence base mostly relates to single tooth extraction/replacement; hence, external validity/applicability to multiple extractions requires careful consideration. The group identified six considerations that should assist clinicians in clinical decision-making: presence of infection, inability to achieve primary stability in the restoratively driven position, presence of a damaged alveolus, periodontal phenotype, aesthetic demands and systemic conditions. CONCLUSIONS: A substantial and expanding evidence base is available to assist clinicians with clinical decision-making related to the transition from a tooth requiring extraction to its replacement with a dental implant. More high-quality research is needed for the development of evidence-based clinical guidelines.

Ridge alterations after implant placement in fresh extraction sockets or in healed crests: An experimental in vivo investigation.

OBJECTIVES: To study the early and late bone healing around implants placed according to a flapless immediate (test) or flapped delayed (control) implant surgical protocol. MATERIALS AND METHODS: In eight beagle dogs, immediate and delayed implants were placed. Test and control implants were randomly assigned, and horizontal and vertical bone remodelling, as well as bone-to-implant contact (BIC), were assessed with histology at 2 and 8 weeks. Teeth were used as negative controls. RESULTS: Similar results were attained in the two groups when the vertical resorption of the buccal bone crest was evaluated (approximately 0.5 mm). On the other hand, a marked horizontal buccal bone resorption was observed. Immediate implants attained a thinner buccal bone crest as compared to the delayed implant and the tooth. De novo bone formation on the implant surface appeared to be more pronounced at delayed sites at 2 weeks, whereas at 8 weeks, no difference in BIC was observed. CONCLUSIONS: Ridge alterations occurred at both implant placement protocols, with similar limited amounts of vertical buccal bone reduction and a pronounced horizontal bone reduction. The process of horizontal bone remodelling differed between the two surgical protocols.

A retrospective case series evaluating the outcome of implants with low primary stability.

OBJECTIVES: There is a need of more studies on whether low primary implant stability would negatively influence the success of implant therapy. Therefore, this retrospective study analyses outcomes of implants placed with low primary stability and factors that may be related to implant failures. MATERIAL AND METHODS: This retrospective study included 156 patients, restored with 169 implants that presented manual rotation within an observed follow-up time of a minimum of 34 days and a maximum of 9.28 years. Descriptive statistics, survival analyses (life tables and Kaplan-Meier estimates) and radiographic assessment based on marginal bone level measurements were performed. This original study was adherent to STROBE guidelines. RESULTS: Seven implants failed in seven patients, rendering cumulative survival rates of 94.74% (95% CI: 89.11-97.50) and 94.33% (95% CI: 88.30-97.30) at implant and patient levels, respectively. Kaplan-Meier estimates showed implant loss was found only in advanced surgery group (7 implant loss in 82 implants) when compared with simple surgery group (no implant loss in 87 implants; p = 0.005). CONCLUSIONS: Within the limitations of this retrospective study, implant placement with low primary stability might not negatively affect either the survival rates or marginal bone level changes of implants provided that a protected and unloaded healing is guaranteed.

The effect of five mechanical instrumentation protocols on implant surface topography and roughness: A scanning electron microscope and confocal laser scanning microscope analysis.

OBJECTIVE: To evaluate in vitro the changes in implant surface topography and roughness of commercial implants after instrumentation with five decontamination protocols. MATERIAL AND METHODS: Seventy-two titanium implants with a sandblasted and acid-etched (SLA) surface were placed 5 mm supra-crestally. Five groups of twelve implants were instrumented with the following protocols: a metal scaler tip (SCAL), a thermoplastic scaler tip (PEEK), a round titanium brush (RBRU), a tufted brush with titanium bristles (TNBRU), and a glycine-based air-powder abrasive (GLYC). A sixth group with untreated implants was used as control. Scanning electron microscope and confocal laser scanning microscope were utilized to evaluate the changes in the implant surfaces. RESULTS: The SCAL caused pronounced macroscopic alterations and damage of the implant surface, the PEEK left remnants of the plastic tip in the implant surface, and both titanium brush groups flattened the thread profile, while minimal alterations were observed in the GLYC. When compared to the control group, the roughness parameters (Sa) in the buccal aspect increased in the thread area of SCAL, and a minor reduction was observed in the PEEK while in the other groups, these values remained unchanged. In the valley areas, however the RBRU, TNBRU, and GLYC experienced a significant reduction (smoothening) indicating different accessibility of the decontamination protocols to the thread and valley. Similarly, the buccal aspects had more pronounced changes than those in the palatal aspect. CONCLUSION: Within the limitations of this in vitro investigation, the tested protocols induced different macroscopic alterations and surface roughness changes that varied in the thread and valley area.

Digitalized CAD/CAM protocol for the fabrication of customized sealing socket healing abutments in immediate implants in molar sites.

Immediate implant placement in molar sites has the potential to improve patient treatment experience by reducing overall treatment time and the number of appointments. However, primary closure remains a technical challenge. AIM: The objective of this case series was to assess the final clinical outcome at the 2-year follow-up of immediate implant therapy in molar sites using a digitally fabricated sealing socket abutment (SSA) at the time of extraction. MATERIALS AND METHODS: This case series included 29 patients who received immediate implant placement in molar sites. A digital impression was taken at the time of placement, and a chairside CAD/CAM healing abutment was fabricated and delivered in situ to close the alveolar socket. Clinical assessments were reported with a minimum of 2 years of follow-up. RESULTS: All patients reported uneventful postoperative recovery after 1 week of healing. No implant failures were observed. The assessment by an experienced clinician showed healthy and stable periimplant tissue. CONCLUSION: Based on the results of this study, the combination of an immediate implant placement protocol and a customized SSA seems to be a viable treatment alternative, although this needs to be confirmed by future prospective randomized studies.