Analysis of osseointegration of implants with hydrophilic surfaces in grafted areas: A Preclinical study.

OBJECTIVES: The aim of this study was to evaluate the effect of a hydrophilic surface on the osseointegration in grafted areas with deproteinized bovine bone (DBB) and with biphasic ceramics of hydroxyapatite/ß-tricalcium phosphate (HA/TCP). MATERIAL AND METHODS: Fifty-six rats were randomly allocated to four groups with 14 animals each: DBB: DBB+Machined surface; HA/TCP: HA/TCP+Machined surface; DBB-H: DBB+Hydrophilic surface; HA/TCP-H: HA/TCP+Hydrophilic surface. The bone defects were performed at the proximal epiphysis of the tibia. Then, the defects were filled with the biomaterials. After 60 days, the implants were placed in the grafted areas. The animals were submitted to euthanasia at periods of 15 and 45 days after the implants' placement. The osseointegration was assessed by biomechanical, microtomographic, and histometric analyses. In addition, the expression of bone morphogenetic protein-2 (BMP-2), alkaline phosphatase (ALP), and osteocalcin (OCN) was evaluated by immunohistochemistry. RESULTS: The HA/TCP-H group presented higher removal torque values and more mineralized tissue in the vicinity of the implants compared with the HA/TCP group. The DBB-H and HA/TCP-H groups presented higher values of bone-implant contact (at 15 and 45 days), of bone between the threads (45 days), and expression of BMP-2 (45 days) than the DBB and HA/TCP groups. Furthermore, the DBB-H group presented a higher expression of ALP than the DBB group (15 days). CONCLUSION: In conclusion, implants with a hydrophilic surface improve osseointegration in grafted areas compared to implants with machined surfaces in a rat tibia model.

Effect of low-level laser therapy on the healing of sites grafted with coagulum, deproteinized bovine bone, and biphasic ceramic made of hydroxyapatite and ß-tricalcium phosphate. In vivo study in rats.

OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the healing of biomaterial graft areas (i.e., coagulum, deproteinized bovine bone, and biphasic ceramics comprising hydroxyapatite and ß-tricalcium phosphate). MATERIAL AND METHODS: Ninety rats were divided into two groups according to laser irradiation use (λ 808 nm, 100 mW, φ ∼600 µm, seven sessions with 28 J of irradiation dose in total): a laser group and a control group. Each of these groups was divided into three subgroups of 15 animals each according to the type of biomaterial used: Coagulum (COA), deproteinized bovine bone (DBB), and hydroxyapatite/ß-tricalcium phosphate (HA/ßTCP). Biomaterials were inserted into Teflon domes, and these domes were grafted to the lateral aspect of the mandibular branch of the rats. The animals were sacrificed after 30, 60, and 90 days. Scarring patterns were evaluated by microtomography and histometry. The expression levels of BMP2, osteocalcin (OCN), and alkaline phosphatase (ALP) were evaluated by immunohistochemistry. The mRNA expression levels of ALP, BMP2, Jagged1, Osterix, Runx2, and TGFß1 were determined by RT-qPCR. RESULTS: The animals treated with LLLT exhibited increased mineralized tissues and bone, particularly after 90 days. These increases were associated with increased BMP2, OCN, and ALP protein expression and ALP, BMP2, and Jagged1 mRNA expression. CONCLUSION: LLLT improved the osteoconductive potential of DBB and HA/ßTCP grafts and bone formation in ungrafted areas. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Intrusion of teeth with class III furcation: a clinical, histologic and histometric study in dogs.

AIM: To assess orthodontic intrusion effects on periodontal tissues in dogs' pre-molars with class III furcations treated with open flap debridement (OFD) or with guided tissue regeneration (GTR) associated to bone autograft (BA). MATERIAL AND METHODS: Class III furcations were created in the pre-molars of seven mongrel dogs. After 75 days, teeth were randomly treated with OFD or GTR/BA. After 1 month, metallic crowns were assembled on pre-molars and connected apically to mini-implants by nickel-titanium springs. Teeth were randomly assigned to orthodontic intrusion (OFD+I and GTR/BA+I) groups or no movement (OFD and GTR/BA) groups. Dogs were sacrificed after 3 months of movement and 1 month retention. RESULTS: All class III furcations were closed or reduced to class II or I in the intrusion groups, while 50% of the lesions in non-moved teeth remained unchanged. Intruded teeth presented higher probing depth and lower gingival marginal level than non-moved teeth (p<0.01). Clinical attachment gain was reduced in the intrusion groups by the end of retention (p<0.05). OFD+I presented smaller soft tissue area and larger bone tissue area than other groups (p<0.05). CONCLUSION: Orthodontic intrusion with anchorage via mini-implants improved the healing of class III furcation defects after OFD in dogs. GTR/BA impaired those results.

The effect of a supragingival plaque-control regimen on the subgingival microbiota in smokers and never-smokers: evaluation by real-time polymerase chain reaction.

BACKGROUND: The aim of the present study was to evaluate the effect of strict supragingival plaque control on the subgingival microbiota in smokers and never-smokers. Research into the impact of supragingival plaque control on the number of subgingival bacteria has resulted in contradictory findings. Real-time polymerase chain reaction (PCR) has been suggested as a valid alternative to current microbiologic methods based on bacteria cultures. METHODS: Forty-five subjects with chronic periodontitis were selected. Twenty-four of them had never smoked, and 21 were active smokers. Four sites per patient were selected for sampling. Supragingival debridement was performed at baseline, and the subjects received weekly instructions on oral hygiene for 180 days. A clinical examination and subgingival plaque sampling were carried out at baseline and at 30, 90, and 180 days. A real-time PCR assay was used to detect and quantify Porphyromonas gingivalis, Parvimonas micra (previously Peptostreptococcus micros or Micromonas micros), Dialister pneumosintes, Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), and the total bacteria load (eubacteria) in the subgingival samples. Statistical analysis was performed using linear models adjusted for the clustering of observations within individuals. RESULTS: Smokers and never-smokers exhibited a similar and significant reduction in total bacteria counts over time. Irrespective of smoking status, deep sites consistently harbored greater quantities of total bacteria throughout the study. Higher numbers of the bacteria investigated were associated with bleeding on probing. CONCLUSION: Supragingival plaque control markedly reduced subgingival microbiota counts in smokers and never-smokers.

Periodontal status in smokers and never-smokers: clinical findings and real-time polymerase chain reaction quantification of putative periodontal pathogens.

BACKGROUND: Smoking is a well-known risk factor for destructive periodontal disease, but its relationship with periodontal status and subgingival microbiota remains unclear. Inherent limitations of microbiological methods previously used may partly explain these mixed results, and real-time polymerase chain reaction (PCR) has been presented as a valid alternative. The aim of the present study was to investigate the clinical condition and microbiological profile of patients with chronic periodontitis as related to the habit of smoking. METHODS: Fifty patients (33 to 59 years old), 25 smokers and 25 never-smokers, constituted the sample. The visible plaque index (VPI), gingival bleeding index (GBI), bleeding on probing (BOP), periodontal probing depth (PD), clinical attachment loss (CAL), and gingival crevicular fluid (GCF) volume were recorded. Real-time PCR quantified Porphyromonas gingivalis, Micromonas micros, Dialister pneumosintes, Actinobacillus actinomycetemcomitans and total bacteria in subgingival samples. RESULTS: Smokers and never-smokers showed similar values for VPI, GBI, and BOP. Smokers had deeper PD in buccal/lingual sites and higher CAL independently of the tooth surface. The GCF volume was smaller in smokers, independent of the PD. Similar amounts of total bacteria and P. gingivalis were observed for both groups. Significantly higher numbers of D. pneumosintes and M. micros were present in smokers and associated with moderate and deep pockets. When heavy smokers were considered, higher counts of total bacteria, M. micros, and D. pneumosintes were observed. CONCLUSIONS: Smoking seems to have a detrimental impact on the periodontal status and microbiological profile of patients with periodontitis. Compared to never-smokers, smokers had deeper pockets, greater periodontal destruction, and higher counts of some putative periodontal pathogens.

Root coverage stability of the subepithelial connective tissue graft and guided tissue regeneration: a 30-month follow-up clinical trial.

OBJECTIVES: The aim of this study was to compare the long-term clinical effects produced by subepithelial connective tissue graft (SCTG) and guided tissue regeneration combined with demineralized freeze-dried bone allograft (GTR-DFDBA) in the treatment of gingival recessions in a 30-month follow-up clinical trial. METHODS: Twenty-four defects were treated in 12 patients who presented canine or pre-molar Miller class I and/or II bilateral gingival recessions. GTR-DFDBA and SCTG treatments were performed in a randomized selection in a split-mouth design. The clinical measurements included root coverage (RC), gingival recession (GR), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KTW). These clinical parameters were evaluated at baseline and after 6, 18 and 30months post-surgery. RESULTS: The changes in RC, GR, PD and CAL did not show significant differences between groups (p>0.05). Both procedures promoted similar RC (GTR-DFDBA: 87% and SCTG: 95.5%) and similar reduction in GR (GTR-DFDBA: 3.25mm and SCTG: 3.9mm), PD (GTR-DFDBA: 1.6mm and SCTG: 1.2mm) and CAL (GTR-DFDBA: 4.9mm and SCTG: 5.0mm). The increase in KTW was significantly higher (p=0.02) in the SCTG group (3.5mm) than in the GTR-DFDBA group (2.4mm). CONCLUSIONS: Both techniques for treatment of gingival recession (SCTG and GTR-DFDBA) lead to favourable and long-term stable results, but SCTG promoted a more favourable increase in keratinized tissue.

Local application of tetracycline solution with a microbrush: an alternative treatment for persistent periodontitis.

OBJECTIVE: Topical antibiotics may overcome shortcomings of mechanical therapy for localized persistent periodontitis. This double-center, single-blind, randomized controlled study aimed to evaluate the microbiologic profile and clinical parameters of persistent periodontal pockets after treatment with tetracycline solution. METHOD AND MATERIALS: Thirty-seven patients who had at least 4 non-adjacent sites of persistent periodontal pockets with probing depth of at least 5 mm and bleeding on probing were randomly assigned to test and control groups. In the test group, 2 teeth received 4 applications of tetracycline solution (100 mg/mL) with a microbrush(T), while the other 2 teeth received the same treatment plus 1 session of scaling and root planing(SRP+T). In the control group, 2 teeth received 1 session of scaling and root planing(SRP), and the other 2 teeth received 4 applications of saline with a microbrush plus 1 session of scaling and root planing(SRP+S). Clinical parameters of probing depth, bleeding on probing, visible plaque index, gingival bleeding index, gingival recession, as well as clinical attachment level and subgingival plaque samples (evaluated by polymerase chain reaction) were measured at baseline and 1, 3, and 6 months. RESULTS: All therapies yielded statistically significant data on clinical measurements with no significant differences among groups. Presence of bacteria decreased in both groups, but only in the test group was a significant decrease of Porphyromonasgingivalis,Tannerellaforsythia, and Actinobacillusactinomycetemcomitans noted up to 6 months. CONCLUSION: Tetracycline applied with a microbrush may be an alternative treatment for persistent periodontitis that can probably be mediated by reduction of microorganism proliferation