Root coverage with tunneling technique or modified advanced flap associated with acellular dermal matrix: results from 6 months randomized clinical trial.

OBJECTIVES: This study compared two surgical techniques using acellular dermal matrix (ADM) for the treatment of multiple gingival recessions. MATERIAL AND METHODS: Twenty patients, with bilateral RT1 gingival recessions, were selected. One side received a modified extended coronally advanced flap (MECAF), and the contralateral side a supra-periosteal flap (TUN). The evaluated parameters were probing depth (PD), relative clinical attachment level, gingival index, gingival recession height (GR), width of keratinized tissue, keratinized tissue thickness, and gingival recession area at baseline and 6 months postoperative. Pain was evaluated weekly, using a visual analog scale (VAS) during first month postoperative. RESULTS: Both groups were effective in reducing GR (ΔGR: MECAF 2.28 mm; TUN 1.93 mm), without significant differences. The % of root coverage was numerically superior favoring MECAF (MECAF 61.24%; TUN 56.07%), without significant differences between groups. VAS scale failed to provide differences between groups. CONCLUSIONS: Both treatment were effective in root coverage and might be valuable for the treatment of multiple gingival recessions. The use of vertical releasing incisions and a flap design including the papillae did not hamper root coverage. CLINICAL RELEVANCE: This study compared two techniques for use of ADM in large multiple gingival recessions. Within its limitations, both treatments successfully achieved root coverage and were able to reduce gingival recession. It is expected a partial root coverage when using these techniques in large gingival recessions. The study failed to provide significant differences between groups. The use of modified extended coronally advanced flap may be advisable for the treatment of multiple gingival recessions, specially involving large defects when using ADM, to avoid early matrix exposure.

Effects of Bifidobacterium probiotic on the treatment of chronic periodontitis: A randomized clinical trial.

AIM: This randomized placebo-controlled clinical trial evaluated the effect of Bifidobacterium animalis subsp. lactis (B. lactis) HN019-containing probiotic lozenges as adjuvant to scaling and root planing (SRP) in patients with generalized chronic periodontitis. MATERIALS AND METHODS: Forty-one chronic periodontitis patients were recruited and monitored clinically, immunologically, and microbiologically at baseline (before SRP) and 30 and 90 days after SRP. All patients were randomly assigned to a Test (SRP + Probiotic, n = 20) or Control (SRP + Placebo, n = 21) group. The probiotic lozenges were used twice a day for 30 days. The data were statistically analysed. RESULTS: The Test group presented a decrease in probing pocket depth and a clinical attachment gain significantly higher than those of the Control group at 90 days. The Test group also demonstrated significantly fewer periodontal pathogens of red and orange complexes, as well as lower proinflammatory cytokine levels when compared to the Control group. Only the Test group showed an increase in the number of B. lactis HN019 DNA copies on subgingival biofilm at 30 and 90 days. CONCLUSION: The use of B. lactis HN019 as an adjunct to SRP promotes additional clinical, microbiological, and immunological benefits in the treatment of chronic periodontitis (NCT03408548).

Evaluation of a bone substitute covered with a collagen membrane for ridge preservation after tooth extraction. Clinical and tomographic randomized controlled study in humans.

OBJECTIVE: To evaluate the use of a synthetic bone substitute covered with a collagen membrane for ridge preservation after tooth extraction, by clinical and tomographic analysis. MATERIAL AND METHODS: Fifteen patients, presenting at least two maxillary anterior teeth indicated for extraction, were selected: in the test group (TG), post-extraction sockets were filled by a synthetic bone substitute; in the control group (CG), by blood clot. In both groups, the sockets were covered by a collagen membrane. Cone-beam computerized tomography (CBCT) scans were acquired immediately after and 6 months post-surgically, and horizontal and vertical dimensional bone changes were quantified. RESULTS: Transurgical clinical analysis presented no statistically significant differences between TG and CG (p > .05). CBCT intragroup evaluation presented statistically significant reduction for the buccal alveolar measurement (TG = 1.58 mm or 21.82%, and CG = 1.66 mm or 24.08%) and horizontal cervical measurement (TG = 0.55 mm or 8.30% and CG = 1.30 mm or 17.68%), and not significant for palatal alveolar measurement (TG = 0.44 mm or 3.42% and CG = 0.26 mm or 3.89%). For alveolar height and horizontal apical measurements, this decrease was significant only for the CG, with reductions of 1.03 mm and 0.50 mm, respectively, compared to a decrease of 0.57 mm and 0.19 mm for the TG. The intergroup analysis showed significant difference for cervical horizontal measurement after 6 months (p < .05). CONCLUSION: The results showed that the use of the bone substitute covered with a collagen membrane resulted in less changes in vertical and horizontal alveolar ridge dimensions than the collagen membrane alone.

Effect of surgical periodontal treatment associated to antimicrobial photodynamic therapy on chronic periodontitis: A randomized controlled clinical trial.

AIM: This randomized controlled clinical trial evaluated the effects of an adjunctive single application of antimicrobial photodynamic therapy (aPDT) in Surgical Periodontal Treatment (ST) in patients with severe chronic periodontitis (SCP). MATERIAL AND METHODS: In a split-mouth design, 20 patients with SCP were treated with aPDT+ST (Test Group, TG) or ST only (Control Group, CG). aPDT was applied in a single episode, using a diode laser and a phenothiazine photosensitizer. All patients were monitored until 90 days after surgical therapy. Levels of 40 subgingival species were measured by checkerboard DNA-DNA hybridization at baseline, 60 and 150 days. Clinical and microbiological parameters were evaluated. RESULTS: In deep periodontal pockets depth (PPD ≥5 mm), Test Group presented a significantly higher decrease in PPD than Control Group at 90 days after surgical therapy (p < .05). Test Group also demonstrated significantly less periodontal pathogens of red complex (Treponema denticola) (p < .05). CONCLUSION: A single episode of aPDT used in adjunct to open flap debridement of the root surface in the surgical treatment of SCP: i) significantly improved clinical periodontal parameters; ii) eliminates periodontal pathogens of the red complex more effectively (NCT02734784).

Antimicrobial photodynamic therapy as an alternative to systemic antibiotics: results from a double-blind, randomized, placebo-controlled, clinical study on type 2 diabetics.

AIM: This double-blind, placebo-controlled clinical study compared multiple applications of the antimicrobial photodynamic therapy (aPDT) treatment protocol, to systemic doxycycline as adjuvant to scaling and root planing (SRP) on type 2 diabetic patients on clinical, systemic and immune-inflammatory outcomes. MATERIALS AND METHODS: Thirty patients with Hba1c >7% were allocated in two groups, SRP + Doxy (n = 15) using systemic doxycycline 100 mg/day (14 days) and SRP + aPDT (n = 15) with multiple applications (0, 3, 7 and 14 days). Primary outcome was glycated haemoglobin levels (HbA1c). Clinical parameters: plaque score (PS), bleeding on probe, probing depth, suppuration, gingival recession, and clinical attachment level, percentage of pockets with desired clinical endpoint were measured at baseline and 3 months after therapy. Cytokine profile was assessed at 0, 1 and 3 month to measure IL1-ß, TNF-α and TGF-ß on gingival crevicular fluid. RESULTS: No significant difference was detected on HbA1c, between treatments. The SRP + aPDT group showed advantage on reducing moderate pockets in single-rooted teeth at 3 months. SRP + aPDT presented better results at 3 months on IL1-ß levels. There were no significant differences between TNF-α and TGF-ß. CONCLUSIONS: Both treatments improved clinical and systemic outcomes (Hba1c). SRP + aPDT performed better in moderate probing pocket depth on single-rooted teeth, reduced favourably inflammation in short term, and may be an alternative to systemic antibiotics. (Clinicaltrials.org ID NCT01595594).

Influence of periodontal tissue thickness on buccal plate remodelling on immediate implants with xenograft.

AIM: To evaluate the influence of gingival thickness and bone grafting on buccal bone plate remodelling after immediate implant placement in sockets with thin buccal bone, using a flapless approach. MATERIALS AND METHODS: The gingiva of eight dogs was thinned at one side of the mandible, mandibular premolars were extracted without flaps, and four implants were installed on each side at 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). After 12 weeks the dogs were sacrificed and the samples were processed for histological analysis. RESULTS: All animals exhibited a thin buccal bone initially. In all the experimental groups the buccal gap was filled with newly formed bone and the buccal bone level was slightly apical to the implant shoulder. There were no statistically significant differences among the groups for the histomorphometric parameters. CONCLUSIONS: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The gingival thickness or the addition of a biomaterial in the gap did not influence the results.

The influence of the periodontal biotype on peri-implant tissues around immediate implants with and without xenografts. Clinical and micro-computerized tomographic study in small Beagle dogs.

OBJECTIVE: Soft tissues and buccal bone plate remodeling after immediate implantation in sockets with thin buccal bone, using the flapless approach with or without bone graft into the buccal gap, was compared between sites with thin and normal gingiva. MATERIAL AND METHODS: Eight dogs had the gingiva of one side of the mandible thinned, the mandibular premolars were extracted without flaps, and 4 implants were installed in each side, positioned 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). Buccal bone thickness (BBT), thickness of keratinized tissue (TKT), alveolar thickness (AT), gingival recession (GR), and probing depth (PD) were clinically evaluated. Within 12 weeks the dogs were sacrificed and the samples were analyzed by micro-computerized tomography. RESULTS: A thin BBT was observed in all the dogs. The presurgical procedures reduced TKT in the test group, with minimal changes of the AT. There were no statistically significant differences among the groups for the clinical parameters and the tomographic analysis showed similar linear and tri-dimensional bone reduction in all the groups. CONCLUSION: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The decrease in gingival thickness or the addition of a biomaterial in the gap did not influence the results.

Adjunctive effect of antimicrobial photodynamic therapy to nonsurgical periodontal treatment in smokers: a randomized clinical trial.

The aim of this study was to investigate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to scaling and root planing (SRP) in smokers with chronic periodontitis. Twenty subjects had two contralateral teeth randomly assigned to receive SRP (SRP group) or SRP + a single episode of aPDT (SRP + aPDT group), with a diode laser and a phenothiazine photosensitizer. Plaque index, bleeding on probing, probing depth (PD), clinical attachment level (CAL), and gingival recession were recorded, and gingival crevicular fluid was collected for assay of IL-1ß and matrix metalloproteinase (MMP)-8 levels. There was a significant PD reduction (SRP 1.81 ± 0.52 mm/SRP + aPDT 1.58 ± 1.28 mm; p < 0.001) and a significant CAL gain (SRP 1.60 ± 0.92 mm/SRP + aPDT 1.41 ± 1.58 mm; p < 0.001) for both groups. Significant differences were not observed in between-group comparisons. IL-1ß level in gingival crevicular fluid was higher in SRP group after 1 week (SRP 24.65 ± 18.85 pg/µL/SRP + aPDT 34.07 ± 24.81 pg/µL; p = 0.048), and MMP-8 level was higher in SRP group after 12 weeks (SRP 303.31 ± 331.62 pg/µL/SRP + aPDT 534.23 ± 647.37 pg/µL; p = 0.024). There were no statistically significant differences in intragroup comparisons. The adjunctive effect of aPDT did not warrant improvements on clinical parameters in smokers. However, it resulted in a suppression of IL-1ß and MMP-8 when compared with SRP alone.

A modified surgical flap for root coverage in association with grafting materials.

PURPOSE: To clinically evaluate in humans the effectiveness of a modified flap for root coverage associated with connective tissue graft or acellular dermal matrix graft after a postoperative period of 12 months. MATERIALS AND METHODS: Thirty bilateral gingival recessions were selected and randomly assigned into experimental groups. All of them were treated with a modified surgical flap, with the releasing incisions placed on the mesial and distal line angles of the adjacent teeth, distant from the main defect, providing a broader flap. One site was treated with the autograft and the contralateral site, with the allograft. Probing depth, clinical attachment level, gingival recession, and keratinized tissue width were measured at baseline and after 12 months. RESULTS: Both procedures significantly improved the clinical parameters evaluated, without statistically significant differences between them. While the autograft group had a mean gingival recession reduction from 3.15 to 0.67 mm, in the allograft group, it was from 3.47 to 0.93 mm. CONCLUSION: The extended flap technique can improve the root coverage results using the subepithelial connective tissue graft or the acellular dermal matrix. CLINICAL SIGNIFICANCE: Graft survival plays a decisive role in mucogingival therapy results and the selection of the appropriate surgical technique is important to achieve it. This 12-month randomized study showed that an extended flap is able to improve the results of root coverage of localized gingival recessions not only when using the acellular dermal matrix as shown in a previous study, but also when using the subepithelial connective tissue. On this basis, this surgical technique can be suggested as the procedure of choice for treating this type of defect.

Buccal bone plate remodeling after immediate implants with or without synthetic bone grafting and flapless surgery: a histomorphometric and fluorescence study in dogs.

OBJECTIVE: The aim of this study was to evaluate the buccal bone plate remodeling after immediate implantation using the flapless approach with or without bone graft into the gap between the implant and the buccal bone. MATERIAL AND METHODS: Eight dogs had the mandibular bicuspids extracted without flaps, and four implants were installed on each side, totaling eight implants per animal. Randomly, in one side, the implants were positioned at the bone crest level (equicrestal), and on the opposite side, the implants were positioned 2 mm subcrestal. All the implants were positioned 2.0 mm from the buccal bone plate (gap) and associated or not with grafting material. Therefore, the following treatments were performed: implants subcrestal test (SCTG) with bone graft and control (SCCG) without bone graft, and equicrestal test (ECTG) with bone graft and control (ECCG) without bone graft. One week following the surgeries, metallic prostheses were installed. Bone markers were administered 1, 2, 4, and 12 weeks after implant placement for fluorescence analysis. Ground sections were prepared from 12-week healing biopsies, and histomorphometry was performed. RESULTS: The histomorphometric evaluation presents significant better results for the ECTG in the vertical crestal bone resorption, but the other parameters showed better results for the SCCG. The fluorescence evaluation in adjacent areas showed numerically different results between groups with a small decrease at 12 weeks, except for the SCCG, which was higher at this time. The distant area showed a continuous increase in the marked bone. CONCLUSION: The equicrestally placed implants presented little or no loss of the buccal bone wall. The subcrestally positioned implants presented loss of buccal bone, regardless of the use of bone graft. However, the buccal bone was always coronal to the implant shoulder. Both the equicrestal and subcrestal groups were benefited in the early stages of bone healing as evidenced by the fluorescence analysis.

Additional effects of aPDT on nonsurgical periodontal treatment with doxycycline in type II diabetes: a randomized, controlled clinical trial.

The association of doxycycline and periodontal treatment in non-controlled diabetes mellitus (DM) has shown positive results on clinical and metabolic parameters. Antimicrobial photodynamic therapy (aPDT) is a local and painless antimicrobial treatment that can be applied in periodontal treatment without systemic risks. The aim of this study was to evaluate the potential improvement of aPDT on clinical and metabolic effects in patients with type 2 diabetes mellitus in conjunction with nonsurgical periodontal treatment plus doxycycline. Thirty patients with type 2 diabetes and diagnosis of chronic periodontitis were treated with scaling and root planning (SRP; N = 15) or SRP plus phenothiazine chloride photosensitizer-induced aPDT (SRP + aPDT, N = 15). Patients of both groups took doxycycline (100 mg/day) for 2 weeks and plaque index, bleeding on probe (BOP), probing pocket depth (PPD), suppuration, clinical attachment level (CAL), and glycated hemoglobin levels (HbA1c) were measured at baseline and 3 months after therapy. An improvement in clinical parameters such as PPD, CAL, S, and BOP between groups was observed but without statistical significance (p > 0.05). Intragroup analysis showed a significant reduction of HbA1c (8.5 ± 0.9 to 7.5 ± 0.1, p < 0.01) in the SRP + aPDT group. The differences of HbA1c between baseline and 3 months were greater for the SRP + aPDT (11.4 %) than SRP (10 %) (0.87 ± 0.9 and 0.4 ± 0.84 respectively; p < 0.05). A single application of the aPDT as an adjunct to periodontal treatment did not show additional benefits in the clinical parameters but resulted in a slight greater decrease in HbA1c.

Buccal bone remodeling after tooth extraction using the flapless approach with and without synthetic bone grafting. A histomorphometric study in dogs.

OBJECTIVE: The aim of this study was to evaluate buccal bone remodeling of fresh sockets following tooth extraction using the flapless approach, with or without synthetic graft materials. MATERIAL AND METHODS: Eight dogs had the mandibular bicuspids extracted without flaps, and two alveoli on each side (total of 4) were selected. The following groups were devised: one socket on each side received a grafting material (test group), and the other remained only with a blood clot (control group). Ground sections were prepared from 12-week healing biopsies, and histomorphometry was performed. RESULTS: The buccal crest level (BCL) relative to the new bone (i), in the test group, showed numerically better data when compared with the control group, but without statistical relevance. The BCL relative to the old bone (ii) was very similar for the groups without statistical relevance. The alveolar ridge width (ARW) showed similar results without statistically significant difference between the groups. The total bone area (TBA) showed statistically significant differences between the test (38.60%) and control (47.18%) groups. The new bone area (NBA) presents a numerical difference between the test (15.62%) and control (22.24%), but without statistically significant differences. The old bone and the bone marrow were similar for both groups. CONCLUSION: It was observed that there was no loss of the buccal bone crest in relation to the lingual bone crest, especially in the test group.

Arterial hypertension perpetuates alveolar bone loss.

Few studies have focused on the impact of hypertension on the progression of periodontitis (PD). The purpose of this study was to evaluate whether hypertension affects PD by enhancing bone loss even after the stimulus for PD induction is removed. Ligature-induced PD was created on the first mandibular molars of spontaneously hypertensive rats (SHR) and normotensive rats (Wistar Kyoto-WKY). The animals were assigned to non-ligated controls (C) and PD groups: WKY-C, WKY-PD, SHR-C, and SHR-PD. After 10 days, five animals of each group were killed and the ligatures of the other animals were removed. On the 21st day (11 days without PD induced), the remaining animals were killed. The jaws were defleshed and the amount of bone loss was measured. After 10 days, the PD groups showed more bone loss than its controls (P < .05); SHR-PD = 0.72 ± 0.05 mm, SHR-C = 0.39 ± 0.04 mm, WKY-PD = 0.75 ± 0.04 mm, and WKY-C = 0.56 ± 0.04 mm. The cumulative bone loss on day 21 (0.94 ± 0.13 mm) was significantly worse than on day 10 only in SHR-PD group (P < .05). The final bone loss differences between PD and C groups accounted for 102% (SHR) and 26% (WKY) increase in comparison with the initial control levels. Hypertension is associated with progressive alveolar bone loss even when the stimulus for PD induction is removed and it may be speculated that host condition perpetuates alveolar bone loss.

A Randomized comparative clinical study of two surgical procedures to improve root coverage with the acellular dermal matrix graft.

AIM: This randomized, controlled, clinical study compared two surgical techniques for root coverage with the acellular dermal matrix graft (ADMG) to evaluate which procedure could provide better root coverage and greater amounts of keratinized tissue. MATERIALS AND METHODS: Fifteen pairs of bilateral Miller Class I or II gingival recessions were treated and assigned randomly to the test group, and the contra-lateral recessions were assigned to the control group. The ADMG was used in both groups. In the control group, the graft and flap were positioned at the level of the cemento-enamel junction (CEJ), and in the test group, the graft was positioned 1 mm apical to the CEJ and the flap 1 mm coronal to the CEJ. The clinical parameters were taken before the surgeries and after 6 months. The gingival recession area, a new parameter, was measured in standardized photographs through a special device and software. RESULTS: There were statistically significant differences favouring the proposed technique for all parameters except for the amount of keratinized tissue at 6 months. CONCLUSIONS: The proposed test technique is more suitable for root coverage procedures with ADMG, and the new parameter evaluated appears valuable for root coverage analysis. (Clinicaltrials.gov Identifier: NCT01175720).

Acellular dermal matrix graft with or without enamel matrix derivative for root coverage in smokers: a randomized clinical study.

AIM: The aim of this randomized controlled clinical study was to compare the use of an acellular dermal matrix graft (ADMG) with or without the enamel matrix derivative (EMD) in smokers to evaluate which procedure would provide better root coverage. MATERIAL AND METHODS: Nineteen smokers with bilateral Miller Class I or II gingival recessions ≥3 mm were selected. The test group was treated with an association of ADMG and EMD, and the control group with ADMG alone. Probing depth, relative clinical attachment level, gingival recession height, gingival recession width, keratinized tissue width and keratinized tissue thickness were evaluated before the surgeries and after 6 months. Wilcoxon test was used for the statistical analysis at significance level of 5%. RESULTS: No significant differences were found between groups in all parameters at baseline. The mean gain recession height between baseline and 6 months and the complete root coverage favored the test group (p = 0.042, p = 0.019 respectively). CONCLUSION: Smoking may negatively affect the results achieved through periodontal plastic procedures; however, the association of ADMG and EMD is beneficial in the root coverage of gingival recessions in smokers, 6 months after the surgery.

Antimicrobial photodynamic therapy in the non-surgical treatment of aggressive periodontitis: microbiological profile.

The aim of this trial was to investigate changes occurring in the subgingival microbiological composition of subjects with aggressive periodontitis, treated with antimicrobial photodynamic therapy (aPDT), in a single episode, or scaling and root planing (SRP), in a split-mouth design on -7, 0, and +90 days. Ten patients were randomly assigned to either aPDT using a laser source in conjunction with a photosensitizer or SRP with hand instruments. Subgingival plaque samples were collected and the counts of 40 subgingival species were determined using checkerboard DNA-DNA hybridization. The data were analyzed using the method of generalized estimating equations (GEE) to test the associations between treatments, evaluated parameters, and experimental times (α = .05). The results indicated that aPDT and SRP affects different bacterial species, with aPDT being effective in reducing numbers of A. actinomycetemcomitans than SRP. On the other hand, SRP was more efficient than aPDT in reducing the presence of periodontal pathogens of the Red Complex. Additionally, a recolonization in the sites treated by aPDT was observed, especially for T. forsythia and P. gingivalis. Under our experimental conditions, this trial demonstrates that aPDT and SRP affected different groups of bacteria, suggesting that their association may be beneficial for the non-surgical treatment of aggressive periodontitis.

Enamel matrix derivative and transforming growth factor-beta1 in Class III furcation defects. A histomorphometric study in dogs.

The objective of this study was to evaluate histomorphometrically, in dogs, the effect of enamel matrix derivative (EMD), with or without transforming growth factor-beta1 (TGF-beta1), in a periodontal Class III furcation model. Class III furcation defects were created in P3 and P4 of six dogs. The defects were allowed to stabilize for 21 days. Four experimental conditions were established: G1: control (propylene glycol alginate); G2: EMD; G3: TGF-beta1 and G4: EMD + TGF-beta1. After 12 weeks, the dogs were euthanized. Their jaws were removed, fixed, decalcified, dehydrated and embedded in paraffin. Semi-serial sections were obtained, stained and examined with light microscopy. The furcation defects were not completely closed in any specimen, with downgrowth of the junctional epithelium into the furcation area. The morphologic characteristics of the newly formed tissues in the test groups were similar to the control group, with slight differences in average values, but with no statistically significant differences between the groups. This study was not able to provide histological evidence that EMD, TGF-beta1 and EMD + TGF-beta1 present additional advantages in periodontal bone formation in a Class III furcation model in dogs.

Buccal bone plate remodeling after immediate implant placement with and without synthetic bone grafting and flapless surgery: radiographic study in dogs.

Recent studies in animals have shown pronounced resorption of the buccal bone plate after immediate implantation. The use of flapless surgical procedures prior to the installation of immediate implants, as well as the use of synthetic bone graft in the gaps represent viable alternatives to minimize buccal bone resorption and to favor osseointegration. The aim of this study was to evaluate the healing of the buccal bone plate following immediate implantation using the flapless approach, and to compare this process with sites in which a synthetic bone graft was or was not inserted into the gap between the implant and the buccal bone plate. Lower bicuspids from 8 dogs were bilaterally extracted without the use of flaps, and 4 implants were installed in the alveoli in each side of the mandible and were positioned 2.0 mm from the buccal bone plate (gap). Four groups were devised: 2.0-mm subcrestal implants (3.3 × 8 mm) using bone grafts (SCTG), 2.0-mm subcrestal implants without bone grafts (SCCG), equicrestal implants (3.3 × 10 mm) with bone grafts (ECTG), and equicrestal implants without bone grafts (ECCG). One week following the surgical procedures, metallic prostheses were installed, and within 12 weeks the dogs were sacrificed. The blocks containing the individual implants were turned sideways, and radiographic imaging was obtained to analyze the remodeling of the buccal bone plate. In the analysis of the resulting distance between the implant shoulder and the bone crest, statistically significant differences were found in the SCTG when compared to the ECTG (P = .02) and ECCG (P = .03). For mean value comparison of the resulting linear distance between the implant surface and the buccal plate, no statistically significant difference was found among all groups (P > .05). The same result was observed in the parameter for presence or absence of tissue formation between the implant surface and buccal plate. Equicrestally placed implants, in this methodology, presented little or no loss of the buccal bone. The subcrestally positioned implants presented loss of buccal bone, even though synthetic bone graft was used. The buccal bone, however, was always coronal to the implant shoulder.

Evaluation of Bone Response to a Nano HA Implant Surface on Sinus Lifting Procedures: Study in Rabbits.

The aim of this study was to evaluate the bone response to two different implant surfaces on sinus lift procedures in rabbits. Bilateral sinus lifting with inorganic bovine bone associated with collagen membrane and immediate implantation were performed in 16 rabbits. Custom mini-implants were randomly installed in the prepared sites: one side received a double acid-etched (DAE) surface and the other a nano-hydroxyapatite (NHA) surface. The animals were euthanized 30 and 60 days after surgery, and biopsies were collected for microtomographic and histomorphometric analysis. After 30 days, no intra- and inter-group statistical differences were observed in microtomographic analysis, while at 60 days, bone analysis showed statistically significant differences between groups (p < 0.05) for all the evaluated parameters. Histomorphometric analysis showed, after 30 days, mean % of Bone-to-Implant Contact (BIC) for DAE and NHA of 31.70 ± 10.42% vs. 40.60 ± 10.22% (p > 0.05), respectively; for % of Bone Area Fraction Occupancy (BAFO), mean values were 45.43 ± 3.597% for DAE and 57.04 ± 5.537% for NHA (p < 0.05). After 60 days, mean %BIC and %BAFO for DAE and NHA implants were statistically significant (p < 0.05). The NHA surface showed superior biological features compared to the DAE treatment, promoting higher bone formation around the implants in an experimental model of bone repair in a grafted area.

Gingival crevicular fluid levels of MMP-8, MMP-9, TIMP-2, and MPO decrease after periodontal therapy.

BACKGROUND: This study aimed at comparing the levels of matrix metalloproteinase (MMP)-8, tissue Inhibitor of MMPs (TIMP)-1 and TIMP-2, Myeloperoxidase (MPO), and MMP-9 in the gingival crevicular fluid (GCF) of chronic periodontitis (CP) patients and controls at baseline and 3 months after non-surgical therapy. MATERIALS AND METHODS: GCF was collected from one site of 15 control subjects and 27 CP patients. MMP-8, MMP-9, TIMP-1, and TIMP-2 were determined by Enzyme-linked immunoabsorbent assay; different forms of MMP-9, by gelatin zymography; and MPO, colorimetrically. RESULTS: At baseline, higher levels of MMP-8, TIMP-2, MPO, and the 87 kDa-MMP-9 were found in patients compared with controls (p<0.001), and these molecules decreased after therapy (p<0.03). There were no differences between the groups with respect to the higher molecular forms of MMP-9 (180, 130, 92 kDa) or total MMP-9 at baseline. No differences were observed in TIMP-1 levels. In controls, decreased levels of TIMP-2 and the higher molecular forms of MMP-9 (180, 130, 92 kDa) were found 3 months after therapy compared with baseline (p<0.01). CONCLUSIONS: Higher levels of MMP-8, TIMP-2, MPO, and 87 kDa MMP-9 were found in the GCF of patients compared with controls, and these markers decreased 3 months after periodontal therapy.