Efficacy of professionally administered chemical agents as an adjunctive treatment to sub-marginal instrumentation during the therapy of peri-implant mucositis.

AIM: To evaluate the efficacy of professionally administered chemical agents as an adjunctive treatment to sub-marginal instrumentation (SMI) in the therapy of peri-implant mucositis. MATERIALS AND METHODS: The primary outcome criteria were reduction in bleeding on probing (BOP), whereas resolution of disease, elimination of suppuration, including suppuration on probing, reduction of peri-implant probing pocket depth, reduction of plaque, and patient-reported outcome measures were considered as secondary outcome parameters. A literature search was performed on three electronic databases (01/1980 to 05/2022) focused on clinical studies with at least 3 months of follow-up, and meta-analyses were performed when appropriate. RESULTS: From a total of 139 publications, 40 articles were identified for full-text reading, and 5 randomized controlled clinical trials (RCTs) on antimicrobial photodynamic therapy (aPDT), 1 RCT on chlorhexidine (CHX), and 1 RCT on sodium hypochlorite (NaOCl) were included. Three studies had a low risk of bias and four had a mid-level (some concerns) risk of bias. The application of aPDT, 0.95% NaOCl, or 0.12% CHX as an adjunctive treatment to SMI showed no difference in changes in BOP and PD compared with SMI alone (p > .05). CONCLUSIONS: Within the limitations of this review and based on a low level of evidence from seven RCTs, it is concluded that the professional adjunctive topical application of aPDT, 0.95% NaOCl, and 0.12% CHX may not be effective to improve changes for BOP and PD when compared with SMI alone.

Outcome indicators of non-surgical therapy of peri-implantitis: a prospective case series analysis.

OBJECTIVES: This study aims to identify patient and implant indicators influencing the non-surgical therapeutic outcomes of peri-implantitis at 6 months of follow-up. METHODS: This case series involved patients with at least one implant diagnosed with peri-implantitis according to the 2017 World Workshop criteria. Non-surgical therapy consisted of mechanical debridement of the peri-implant pockets combined with metronidazole 500 mg 3 times a day for 7 days. At baseline and at 6 months, clinical and radiographic variables were collected to calculate treatment success (probing pocket depth reduction to 5 mm without bleeding on probing or < 5 mm irrespective of bleeding on probing at all implant sites, and lack of bone loss progression). The primary outcome was treatment success (%) at 6 months. The influence of the patient and implant/prosthetic variables upon disease resolution was assessed through simple and multiple logistic regression analyses at patient and implant level, using generalized estimation equations models. RESULTS: A total of 74 patients and 107 implants were analyzed at 6 months. Disease resolution was established in 25.7% of the patients and 24.1% of the implants. Patients with stage IV and grade C periodontitis, inadequate oral hygiene at baseline, and wide diameter (≥ 4.5 mm) presented significantly greater treatment failure, whereas smokers and former smokers demonstrated a tendency toward failure. At 6 months, there was a significant decrease in probing pocket depth and bleeding on probing of 1.08 ± 1.06 mm and 14%, respectively. Radiographically, a significant gain in marginal bone level of 0.43 ± 0.56 mm was observed. CONCLUSION: Disease resolution after non-surgical treatment of peri-implantitis is negatively influenced by the loss of support of the adjacent periodontium, poor baseline oral hygiene, and wide diameter implants (≥ 4.5 mm). CLINICAL RELEVANCE: This study helps to discriminate the clinical situations in which non-surgical treatment is less likely to achieve treatment success at short term.

Clinical outcomes and associated factors in the treatment of peri-implant mucositis, combining mechanical debridement and prosthesis modification: A 30-month follow-up prospective case series.

AIM: To evaluate the clinical outcome and the associated factors of a treatment protocol for peri-implant mucositis. MATERIALS AND METHODS: Patients were evaluated 30 months after a treatment protocol including professional mechanical debridement and modification of the prosthesis contours to improve access for biofilm control. Clinical performance was assessed by means of probing with an electronic pressure-calibrated periodontal probe. The possible impact of implant- and patient-level factors on the changes in peri-implant mucosal inflammation measured with the modified bleeding index (mBI) was evaluated. RESULTS: Twenty patients and 61 implants were included in the analysis. At the final visit, 50% of the patients presented bleeding on probing, with a mean mBI of 0.22 (SD 0.27). The adjusted linear regression model showed a significant association between patient's compliance with supportive care visits (p = .006) and mucosal inflammation. Similarly, at the implant level, modified plaque index (p < .001) and an irregular use of interdental brushes (p = .017) had a significant impact on final mBI. CONCLUSIONS: Prosthesis modification when needed in association with non-surgical treatment may be an important intervention in the treatment of peri-implant mucositis. Compliance with supportive care visits and the regular use of inter-dental brushes were identified as important factors to achieve mucosal inflammation control.

Intra- and inter-examiner reliability in classifying periodontitis according to the 2018 classification of periodontal diseases.

AIM: To evaluate the inter-examiner reliability in classifying periodontitis using the 2018 classification of periodontal diseases, when used by postgraduate students, academics, and specialist clinicians trained in European Federation of Periodontology (EFP) and American Academy of Periodontology (AAP) postgraduate-accredited programmes. MATERIALS AND METHODS: An online survey including five patients with periodontitis was sent twice to seven specialists in periodontology to provide the staging and grading characteristics. After agreeing on a "gold-standard" classification, the same questionnaire was sent to 16 EFP and 73 AAP postgraduate programmes, to be answered by their faculty, graduates, and students. The responses were compared with the gold-standard classification, and the inter-examiner agreement was calculated. RESULTS: One-hundred and seventy-four participants completed the survey. The inter-examiner agreement resulted in 68.7% in assigning the stage, 82.4% in assigning the grade, and 75.5% in assigning the extent. The academic position and the experience of the participants did not have any significant influence on classifying periodontitis as the gold standard. CONCLUSIONS: The use of the 2018 periodontitis classification resulted in high inter-examiner reliability when used by a specialist group of clinicians, postgraduate students, and academicians, irrespective of their current position and experience. Given the low response rate and potential selection bias, results pertaining to the use of this system in classifying periodontitis should be interpreted with caution.

Efficacy of soft tissue augmentation procedures on tissue thickening around dental implants: A systematic review and meta-analysis.

OBJECTIVES: The first focused question (FQ1) was: What is the efficacy of connective tissue graft (CTG), as compared to the absence of soft tissue grafting procedure, in terms of gain in peri-implant soft tissue thickness (STT) reported by randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs)? The second focused question (FQ2) was: What is the efficacy of CTG, as compared to soft tissue substitutes, in terms of gain in peri-implant STT reported by RCTs or CCTs? MATERIALS AND METHODS: A manual and electronic search was performed for each question to identify RCTs and CCTs published up to July 2020. The primary outcome variable was changes in peri-implant STT and secondary outcomes were marginal bone level (MBL), clinical parameters for the diagnosis of peri-implant health, changes in the position of peri-implant soft tissues, esthetic outcomes, and patient-related outcome measures (PROMs). For primary and secondary outcomes, data reporting mean values and standard deviations for each study were extracted. Weighted mean differences (WMDs) or standardized mean differences as well as 95% confidence intervals (CIs) and prediction intervals (PIs) were calculated. RESULTS: Eight trials were included to answer the first focused question and eight to answer the second one, providing data for 254 and 192 patients, respectively. For the first focused question, a statistically significant difference of 0.64 mm in STT was found in favor of the grafted group (n = 8; 95% CI [0.16; 1.13]; 95% PI [-1.06; 2.35]; p = .01). Moreover, sites treated with CTG exhibited statistically significant less recession than implants without a graft (n = 4; WMD = 0.50 mm; 95% CI [0.19; 0.80]; 95% PI [-0.70; 1.69]; p < .001). For the second focused question, the meta-analysis showed a statistically significant gain of STT in the CTG group when compared to soft tissue substitutes (n = 8; WMD = 0.51 mm; 95% CI [0.28; 0.75]; 95% PI [-0.09; 1.12]; p < .001). Furthermore, the use of CTG resulted in significantly higher pink esthetic score values (n = 3; WMD = 1.02; 95% CI [0.29; 1.74]; 95% PI [-3.67; 5.70]; p = .01) and less recession (n = 2; WMD = 0.50 mm; 95% CI [0.10; 0.89]; 95% PI [not estimable]; p = .014) when compared to soft tissue substitutes. No statistically significant differences between groups were observed for any of the following secondary variables: MBL, clinical parameters for the diagnosis of peri-implant health, position of the interproximal tissues, keratinized mucosa or PROMS (p > 0.05), except for medication intake, which was significantly higher when using CTG as compared to soft tissue substitutes (n = 2; WMD = 1.68; 95% CI [1.30; 2.07]; 95% PI [not estimable]; p < .001). CONCLUSIONS: Soft tissue augmentation procedures are efficacious on soft tissue thickening and, in particular, CTG demonstrated a significant STT gain when compared to no graft or soft tissue substitutes.

Ridge preservation in molar sites comparing xenograft versus mineralized freeze-dried bone allograft: A randomized clinical trial.

OBJECTIVES: The main objective of the study was to compare the dimensional ridge changes and the histological composition after the use of an allograft or xenograft and a resorbable membrane in ridge preservation in molar sites and to evaluate the influence of bone plate thickness on dimensional changes and the need of lateral sinus augmentation following ridge preservation. MATERIALS AND METHODS: Twenty-four patients in need of maxillary or mandibular first or second molar extraction and subsequent implant placement were included and randomly assigned to a group; allograft or xenograft, plus a collagen membrane. Cone-beam computed tomographies were obtained after molar extraction and after 5 months. A bone sample was harvested at the time of implant placement and analyzed by histomorphometry. RESULTS: Bone ridge was reduced significantly. Major changes in width occurred at 1 mm from the bone crest (-2.93 ± 2.28 mm) (p = .0002), while in height, the greatest reduction occurred at the buccal area (-1.97 ± 2.21 mm) (p = .0006). However, differences between groups were not significant. Thicker buccal bone plates exhibited less bone remodeling, while histologically, both biomaterials resulted in similar tissue composition. The resulting available bone height in the implant site measured 7.30 ± 3.53 mm initially and 6.8 ± 3.61 mm after 5 months which allowed implant placement without the need for lateral sinus augmentation in all cases. Still, 55% of the preserved areas needed transcrestal sinus lift. CONCLUSION: Ridge preservation in molar sites using a mineralized allograft or xenograft provides similar dimensional and histomorphometrical results after 5 months.

Effect of peri-implant mucosal thickness on esthetic outcomes and the efficacy of soft tissue augmentation procedures: Consensus report of group 2 of the SEPA/DGI/OF workshop.

OBJECTIVES: The aim of this study was to comprehensively assess the literature in terms of the effect of peri-implant mucosal thickness on esthetic outcomes and the efficacy of soft tissue augmentation procedures to increase the mucosal thickness with autogenous grafts or soft tissue substitutes. MATERIAL AND METHODS: Two systematic reviews (SR) were performed prior to the consensus meeting to assess the following questions. Review 1, focused question: In systemically healthy patients with an implant-supported fixed prosthesis, what is the influence of thin as compared to thick peri-implant mucosa on esthetic outcomes? Review 2, focused question 1: In systemically healthy humans with at least one dental implant (immediate or staged implant), what is the efficacy of connective tissue graft (CTG), as compared to absence of a soft tissue grafting procedure, in terms of gain in peri-implant soft tissue thickness (STT) reported by randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs)? Review 2, focused question 2: In systemically healthy humans with at least one dental implant (immediate or staged implant), what is the efficacy of CTG, as compared to soft tissue substitutes, in terms of gain in peri-implant STT reported by RCTs or CCTs? The outcomes of the two SRs, the consensus statements, the clinical implications, and the research recommendations were discussed and subsequently approved at the consensus meeting during the group and plenary sessions. CONCLUSIONS: There was a tendency of superior esthetic outcomes in the presence of a thick mucosa. The connective tissue graft remains the standard of care in terms of increasing mucosa thickness.

Bifunctional metal-organic frameworks for the hydrogenation of nitrophenol using methanol as the hydrogen source.

This work reports the reduction of 4-nitrophenol to 4-aminophenol using UiO-66(Zr) as a bifunctional photocatalyst and hydrogenation catalyst using methanol as the hydrogen source. In particular, a series of UiO-66(Zr)-X (X: NH2, NO2 and H) and MIL-125(Ti)-NH2 catalysts have been screened as bifunctional catalysts for this process. UiO-66(Zr)-NH2 was found to be the most active material to promote light-assisted nitro hydrogenation under both UV-Vis and simulated sunlight irradiation. The tandem reaction occurs via hydrogen generation from a water/methanol mixture in the first step and, then, reduction of 4-nitrophenol to 4-aminophenol. UiO-66(Zr)-NH2 acts as a truly heterogeneous catalyst and can be reused several times without significant loss of activity, maintaining its crystallinity. This work shows the possibility of using MOFs as solar-driven bifunctional catalysts to promote the hydrogenation of organic compounds using methanol as the hydrogen source.

On the biocompatibility of graphene oxide towards vascular smooth muscle cells.

Graphene and its derivatives have shown fascinating potential in biomedical applications. However, the biocompatibility of graphene with vascular smooth muscle cells (VSMCs) and applications to vascular engineering have not been explored extensively. Using a rat aortic smooth muscle cell line, A7r5, as a VSMC model, we have explored the effects of graphene oxide (GO) on the growth and behaviours of VSMCs. Results demonstrated that GO had no obvious toxicity to VSMCs. Cells cultured on GO retained the expression of smooth muscle cell-specific markers CNN1, ACTA2 and SMTN, on both mRNA and protein levels. A wound healing assay demonstrated no effect of GO on cell migration. We also found that small-flaked GO favoured the proliferation of VSMCs, suggesting a potential of using surface chemistry or physical properties of GO to influence cell growth behaviour. These results provide insight into the suitability of GO as a scaffold for vascular tissue engineering.

Keratinized tissue gain after free gingival graft augmentation procedures around teeth and dental implants: A prospective observational study.

AIM: The primary goal was to compare the amount of keratinized tissue width (KTW) gain after free gingival graft (FGG) procedures around implants and teeth after 6 and 12 months of healing. MATERIALS AND METHODS: Patients with mucogingival defects (<2 mm of KT) around teeth and implants underwent a gingival augmentation procedure by means of a FGG. Clinical measurements were performed with an individual stent to determine keratinized tissue width (KTW), length (KTL), graft shrinkage (GS) and gingival margin position (GMP) at 2 weeks, 6 weeks, 3 months, 6 months and 12 months after surgery. RESULTS: Twenty-nine patients (35 sites) participated in this prospective study. After surgery, KTW decreased and GS increased significantly in both treatment groups during the whole follow-up period, but the biggest changes were observed at 6 weeks. When comparing both treatment groups, implant sites showed significantly more reduction in KTW and more GS. Thus, at 12 months, KTW and GS reduced 2.03 ± 2.1 mm and 36.74 ± 38.2% in the teeth group and 2.91 ± 12.03 mm and 61.8 ± 36.25% around implants, respectively. CONCLUSIONS: A significantly greater reduction in KTW and more GS might be expected at implant sites.

Implant failure and associated risk indicators: A retrospective study.

OBJECTIVES: To evaluate early and late implant loss rates in a sample of patients who had received implant therapy in a university setting as well as patient- and implant-related variables for implant failure. MATERIAL AND METHODS: This is a retrospective analysis in a cohort of patients who were treated with implant-supported restorative therapy during the period 2001-2012. Patients were randomly selected from an electronic database and scheduled for an appointment to record subject and implant characteristics. The primary study outcome was implant loss (i.e., early and late implant failure). RESULTS: A total of 190 patients and 710 implants were included. The mean time in function was 8.2 (SD 2.4) years. Four implants (0.6%) failed in four patients (2.1%) prior to connection of the restoration within a mean period of 1.5 (SD 1.3) months after surgical procedure. Moreover, 17 subjects (8.9%) exhibited late implant failure, representing 26 implants (3.7%), after a mean follow-up of 5 years (SD 2.2) from prosthesis connection. The final multivariable model indicated three factors related to late implant failure: subjects <55 years (OR = 3.62; 95% CI 1.46-10.22; p = .002), smokers/former smokers (OR = 6.25; 95% CI 1.70-17.52; p = .005), and implants with no access to interproximal hygiene (OR = 7.25; 95% CI 2.20-28.25; p < .001). CONCLUSIONS: The rate for early and late implant failure in a sample of 190 patients who had received implant therapy in a university setting was 2.1% and 8.9%, respectively, at subject level. Subjects <55 years and smokers/former smokers as well as implants with inadequate access to interproximal hygiene were significantly associated with late implant failure.

Clinical and esthetic outcomes of immediate implant placement compared to alveolar ridge preservation: a systematic review and meta-analysis.

AIM: The aim of this systematic review was to evaluate the efficacy of immediate implant placement (IIP) compared to implants placed after alveolar ridge preservation (ARP) in terms of clinical, esthetic, and patient-reported outcomes. METHODS: A manual and electronic search (National Library of Medicine) was performed for controlled clinical trials, with at least 12 months of follow-up. Primary outcome variable was implant survival and secondary outcomes were marginal bone level (MBL) (change), pink esthetic score (PES), mid-facial mucosal level (change), papilla index score, complications, and patient-reported outcomes. RESULTS: A total of 10 publications were included (7 randomized clinical trials and 3 controlled clinical trials). The results from the meta-analyses showed that survival rate was significantly lower in the IIP group compared to ARP group [RR = 0.33; 95% CI (0.14; 0.78); p = 0.01]. No significant differences between the two groups were observed regarding radiographic MBL, PES scores, or mid-facial mucosal level (p > 0.05). CONCLUSION: The results from this systematic review and meta-analysis showed that IIP had lower survival rates and similar esthetic results when compared to ARP. CLINICAL RELEVANCE: Clinicians should weigh the benefits and disadvantages of each intervention to select the optimal timing of implant placement.

Plasma-Induced Defects Enhance the Visible-Light Photocatalytic Activity of MIL-125(Ti)-NH2 for Overall Water Splitting.

Defect engineering in metal-organic frameworks is commonly performed by using thermal or chemical treatments. Herein we report that oxygen plasma treatment generates structural defects on MIL-125(Ti)-NH2 , leading to an increase in its photocatalytic activity. Characterization data indicate that plasma-treated materials retain most of their initial crystallinity, while exhibiting somewhat lower surface area and pore volume. XPS and FT-IR spectroscopy reveal that oxygen plasma induces MIL-125(Ti)-NH2 partial terephthalate decarboxylation and an increase in the Ti-OH population. Thermogravimetric analyses confirm the generation of structural defects by oxygen plasma and allowed an estimation of the resulting experimental formula of the treated MIL-125(Ti)-NH2 solids. SEM analyses show that oxygen plasma treatment of MIL-125(Ti)-NH2 gradually decreases its particle size. Importantly, diffuse reflectance UV/Vis spectroscopy and valence band measurements demonstrate that oxygen plasma treatment alters the MIL-125(Ti)-NH2 band gap and, more significantly, the alignment of highest occupied and lowest unoccupied crystal orbitals. An optimal oxygen plasma treatment to achieve the highest efficiency in water splitting with or without methanol as sacrificial electron donor under UV/Vis or simulated sunlight was determined. The optimized plasma-treated MIL-125(Ti)-NH2 photocatalyst acts as a truly heterogeneous photocatalyst and retains most of its initial photoactivity and crystallinity upon reuse.

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.

Stability of the gingival margin after an aesthetic crown lengthening procedure in the anterior region by means of a replaced flap and buccal osseous surgery: a prospective study.

OBJECTIVES: The main objective of this study was to assess changes in the position of the gingival margin (GM) after performing an aesthetic crown lengthening (ACLP) by means of submarginal incisions, buccal osseous surgery, and a replaced flap after a healing period of 6 months. METHODS: Twenty-one patients who needed a surgical crown lengthening in the maxillary anterior teeth were included. An individual stent was fabricated to record changes in the position of the GM. Clinical measurements were recorded pre-surgically; immediately post-surgically (baseline); and at 42, 90, and 180 days. RESULTS: After the ACLP, the GM displacement did not change significantly after 42, 90, and 180 days (4.32 ± 1.17 mm, 4.29 ± 1.14 mm, and 4.26 ± 1.11 mm, respectively). Tissue rebound seems to be related to the distance from the GM to the alveolar bone (AB) at the time of suturing (GM-AB(X)). When GM-AB(X) was ≤ 2 mm, 3 mm, and ≥ 4 mm, the GM rebound at 6 months was 0.94 ± 0.53 mm, 0.10 ± 0.28 mm, and - 0.26 ± 0.40 mm, respectively. These differences were statistically significant (P < 0.001). CONCLUSIONS: An ACLP releasing the flap up to the mucogingival junction, with a ≥ 3-mm distance from the bone crest to the gingival margin can lead to a stable GM position at 42, 90, and 180 days. CLINICAL RELEVANCE: This article focuses on variables affecting the stability of the GM, which is a critical factor that may compromise the biological and aesthetic long-term outcomes.

Adjunctive effect of modifying the implant-supported prosthesis in the treatment of peri-implant mucositis.

AIM: To evaluate the adjunctive effect of modifying the implant-supported prosthesis to facilitate access to oral hygiene when treating peri-implant mucositis. MATERIAL AND METHODS: A 6-month randomized clinical trial was designed. Patients with peri-implant mucositis were treated by implant surface debridement with plastic curettes and a plastic tipped ultrasonic device. Then, they were randomly assigned to either modifying their prosthesis to allow for better oral hygiene (test group) or not (control group). Subsequently in both groups, individualized oral hygiene instructions were provided. Clinical and radiographical outcomes were evaluated at baseline and 1, 3 and 6 months after treatment. RESULTS: 48 patients were included, and 45 completed the clinical trial (24 test and 21 control patients). After 6 months, changes in the modified bleeding index between the control and test groups were 0.50 (standard deviation -SD = 0.70) and 1.14 (SD = 0.96), respectively (p = 0.01). The changes in implant probing pocket depth at 6 months were -0.02 (SD = 0.61) and 0.31 (SD = 1.20) mm, respectively (p = 0.04). CONCLUSIONS: Modifying the contour of the prostheses to improve access for oral hygiene significantly improved the clinical outcomes after standard mechanical treatment of peri-implant mucositis.

The adjunctive effect of a titanium brush in implant surface decontamination at peri-implantitis surgical regenerative interventions: A randomized controlled clinical trial.

AIM: To evaluate an additional mechanical approach, a titanium brush, in the implant surface decontamination performed during the regenerative surgical therapy of peri-implantitis. MATERIAL AND METHODS: A randomized double-blinded clinical trial, with a 1-year follow-up, was carried out. After a hygienic phase, peri-implantitis-affected implants were randomly assigned to a control or to a test group. In the control group, implant surface was decontaminated both mechanically and chemically with 3% H2 O2 and plastic ultrasonic scalers, respectively, while in the test group, a titanium brush was also applied. Intrabony defects in both groups were filled with an alloplastic material (ß-tricalcium phosphate and hydroxyapatite) and covered with a collagen membrane. The primary outcome was the reduction in probing pocket depth (PPD) at the deepest site. RESULTS: Thirty patients were included, 15 in each group. At 12 months, reduction in PPD was 4.87 (standard deviation [SD] 1.55) mm and 2.85 (SD: 1.91) mm, respectively (p = 0.009). The correspondent figures for residual PPD were 3.6 (SD: 0.91) and 4.92 (SD: 1.26) mm, respectively (p = 0.007). CONCLUSIONS: The additional use of a titanium brush during regenerative treatment of peri-implantitis resulted in statistically significant benefits in terms of PPD reduction after 12 months.

Influence of surfactants of different nature and chain length on the morphology, thermal stability and sheet resistance of graphene.

The effects of surfactants of different nature (anionic, cationic and non-ionic) and chain length on the morphology, microstructure, thermal stability and electrical resistivity of liquid exfoliated graphene (G) were investigated. Microscopic (SEM and AFM) observations revealed that the thickness of G in the dispersions depended on the surfactant nature: non-ionic surfactants rendered the highest level of exfoliation, whilst dispersions in the cationic ones exhibited fully-covered thicker sheets; the flake thickness increased with increasing surfactant chain length. X-ray diffraction studies indicated an increased interlamellar G spacing with increasing surfactant content. Raman spectra showed an increase in the ID/IG ratio with decreasing G loading. Larger upshifts of the G, 2D and D + G bands were found with increasing surfactant concentration, particularly for dispersions in the cationic surfactants. For the same G/surfactant weight ratio, the electrical resistivity of the dispersions followed the order: cationic > non-ionic > anionic, consistent with the amount of surfactant adsorbed onto G calculated via TGA. It is demonstrated herein that the thermal and electrical properties of liquid exfoliated G can be tuned by varying the surfactant concentration, nature and chain length, which is of great importance for numerous applications like solar power harvesting, high-temperature devices and flexible nanoelectronics.

Influence of suturing technique on wound healing and patient morbidity after connective tissue harvesting. A randomized clinical trial.

OBJECTIVES: The aims of this randomized clinical trial were to investigate the influence of the suturing technique and the thickness of the pre- and postoperative palatal and flap mucosa on the early healing of the palate after harvesting a connective tissue graft. Furthermore, patient pain perception was evaluated. MATERIAL AND METHODS: A subepithelial connective tissue graft was obtained from the palate with a single horizontal incision technique. Patients were randomly assigned to continuous interlocking suture group or criss-cross suture group. The thickness of the palatal mucosa and residual palatal flap was measured; however, these variables were not randomized. One week postoperatively, the donor site wound healing was recorded by the modified rate of early healing index (EHI). Patient's pain perception was assessed by a visual analogue scale. RESULTS: Thirty-six patients were evaluated. No statistically significant differences were found between suturing technique and wound healing (p = 0.215). Statistically significant differences were found between postoperative flap thickness and EHI at 1, 3 and 6 mm from the incision line (p < 0.001). Negative correlations reaching statistical significance were found between the number of days of discomfort and residual flap thickness measured at 1, 3 and 6 mm. CONCLUSIONS: No association between the suture technique and the EHI was observed. Moreover, postoperative palatal flap thickness was associated with early wound healing of the donor site. Finally, the greater the postoperative palatal flap thickness, the less intensity of the pain perceived by patients.

Influence of implant neck surface and placement depth on crestal bone changes and soft tissue dimensions around platform-switched implants: A histologic study in dogs.

OBJECTIVES: To analyse bone remodelling and peri-implant soft tissues around platform-switching implants with and without a machined collar placed at different levels in relation to bone crest. MATERIAL AND METHODS: All mandibular premolars and the first molars were extracted in five dogs. At 6 months, six implants with and without a machined neck (MACH and GBAE implants, respectively) were randomly inserted in each hemimandible positioning the implant-abutment interface in either a supracrestal (+1.5 mm), equicrestal, or subcrestal (-1.5 mm) position. After 6 months, animals were killed for histomorphometric analysis. RESULTS: When net bone loss (primary outcome variable) was compared between MACH and GBAE groups, the multivariable regression analysis revealed no significant differences between implants inserted at the same vertical position. The dimensions of the peri-implant mucosa were greater in MACH implants compared with GBAE implants; however, these differences failed to reach statistical significance. Regarding the number of inflammatory cells and collagen fibre orientation, no statistically significant differences were found between MACH and GBAE groups. CONCLUSIONS: The surface treatment of the implant neck does not seem to have an influence on net bone loss, and there were no statistically significant differences in the peri-implant soft tissues between platform-switching implants with and without a machined neck.