Carbon nanotubes functionalized with sodium hyaluronate: Sterilization, osteogenic capacity and renal function analysis.

AIM: This study determined the optimum gamma irradiation dosage to sterilize sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and CNT functionalized with HY (HY-SWCNT and HY-MWCNT), evaluated the structural integrity of the materials and assessed whether sterilized materials kept biological properties without affecting renal function. MAIN METHODS: Materials were submitted to dosages of 100 gγ to 30 Kgγ and plated onto agar mediums for colony forming units (CFUs) counting. Sterilized samples were inoculated with 107Bacillus clausii, submitted again to gamma irradiation, and plated in agar mediums for CFUs counting. Scanning electron microscope was used for structural evaluation of sterilized materials. Tooth sockets of rats were treated with sterilized materials for bone formation assessment and renal function of the animals was analyzed. KEY FINDINGS: The optimum gamma dosage for sterilization was 250 gγ for HY and 2.5 Kgγ for the other materials without meaningful structural changes. Sterilized materials significantly increased bone formation (p < 0.05) and they did not compromise renal function and structure. SIGNIFICANCE: Gamma irradiation efficiently sterilized HY, SWCNT, MWCNT, HY-SWCNT and HY-MWCNT without affecting structural aspects while maintaining their desirable biological properties.

Quality assessment of systematic reviews regarding immediate placement of dental implants into infected sites: An overview.

STATEMENT OF PROBLEM: With the increased number of published systematic reviews and in view of their wide clinical applicability, these studies must be carefully assessed before professionals begin to use their recommendations in daily practice, and above all, the methodological quality of this study design must be considered. In implant dentistry, one topic that has been arousing particular interest is the immediate placement of dental implants into infected sites. PURPOSE: The purpose of this systematic review was to determine the methodological quality of systematic reviews that evaluated the immediate placement of dental implants into infected sites. MATERIAL AND METHODS: A systematic search was performed by 2 independent reviewers of PubMed, LILACS, and ISI Web of Knowledge up to March 2016. All selected articles were published in the English language. Systematic reviews of original papers that assessed the immediate placement of dental implants into infected sites were eligible for the overview. Narrative reviews, randomized clinical trials, and case reports were excluded. Methodological quality assessment was performed using A Measurement Tool to Assess Systematic Reviews. RESULTS: Of the 5 selected systematic reviews, 3 were low methodological quality and 2 were assessed as moderate. None were high methodological quality. The first systematic review of the topic was published in 2010, and the most recent, published in 2015, was the only one that performed meta-analysis. CONCLUSIONS: The systematic reviews that assessed the immediate placement of dental implants into infected sites were assessed as low or moderate methodological quality. The topic focus remains controversial because the implant survival rate, the main outcome considered for the implant placement prognosis, presents contradictory results.

Ridge preservation of extraction sockets with chronic pathology using Bio-Oss® Collagen with or without collagen membrane: an experimental study in dogs.

OBJECTIVES: This study aimed to evaluate the dynamics of newly bone formation and dimensional change in diseased extraction sockets using Bio-Oss® Collagen with or without a collagen membrane. MATERIAL AND METHODS: In six beagle dogs, right and left 3rd and 4th mandibular premolars were hemisected and the distal roots were removed. Combined endodontic-periodontic lesions were induced in all sites using black silk, collagen sponge, endodontic files, and application of Porphyromonas gingivalis. After 4 months, among 4 premolars, three teeth were randomly selected per dog and allocated to the following experimental groups: Control group (no treatment but debridement), Test 1 group (only Bio-Oss® Collagen graft), and Test 2 group (Bio-Oss® Collagen graft with a collagen membrane). After 7 months from the baseline, the beagle dogs were sacrificed for histomorphometric and Micro-CT analysis. RESULTS: The vertical distance between buccal and lingual crests in the Control group (2.22 ± 0.26 mm) and Test 2 group (1.80 ± 0.16 mm) was significantly different. The socket of the Test 2 group (27.04 ± 5.25%) was occupied by a greater quantity of bone graft compared to the Test 1 group (18.49 ± 2.11%). CONCLUSION: Ridge preservation in diseased extraction sockets could compensate for buccal bone resorption by contact osteogenesis surrounding the bone graft particles at the bucco-coronal area during socket healing, and the application of a collagen membrane at the entrance of the socket is useful for preserving graft material at the coronal part of the socket.

Levels of bacterial contamination in fresh extraction sites after a saline rinse.

PURPOSE: To determine the level of bacterial contamination in immediate implantation or augmentation sites vs pristine bone, before and after saline rinses. MATERIALS AND METHODS: Bacterial samples were taken from fresh extraction sites (17 patients) and pristine bone (15 patients) before performing implant dentistry surgical procedures. Levels of bacterial contamination were estimated before and after saline rinses. Samples from the socket were placed on an agar plate for total bacterial account and on selective plates for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis counts. RESULTS: The level of bacterial contamination before saline rinse was 1.2 × 10(4) units of bacterial colony (CFU)/mL in fresh extraction sites (study group) and 5 × 10(2) CFU/mL in pristine bone sites (control group). After a saline rinse, the bacterial level was lowered significantly to 5.2 × 10(3) CFU/mL in the study group and to zero in the control group (P < .05). Levels of bacterial contamination were higher in the mandibular sockets (7.5 × 10(3) CFU/ml) than in the maxillary sockets (5.6 × 10(3) CFU/mL), and the difference was statistically significant (P = .034). All implanted/augmented fresh or pristine sites survived in the follow-up period. CONCLUSION: Fresh extraction sockets with clinical signs of infection show bacterial presence. Pristine bone shows a lower bacterial level. Saline rinse in addition to a decontamination protocol may reduce the level of bacterial contamination significantly both in fresh extraction sites and pristine bone.

Effect of antimicrobial photodynamic therapy on periodontally infected tooth sockets in rats.

The aim of the present study was to evaluate the antimicrobial effect of antimicrobial photodynamic therapy (aPDT) in alveolar treatment of areas with induced periodontitis. Thirty male Wistar rats were subjected to ligature-induced periodontal disease (PD) in the first left inferior molars, while the right side molars did not receive ligatures. After 7 days of PD evolution, ligatures were removed from the left side, and the first left and right mandibular molars were extracted. Afterwards, animals were divided into groups according to the following treatments: control (C)--no treatment; mechanical debridement (MD)--mechanical debridement and irrigation with saline solution; and aPDT--mechanical debridement, irrigation with toluidine blue O (TBO), and 1 min of laser irradiation (GaAlAs, 660 nm, 30 mW, 32 J/cm(2), 60 s). Ligatures were removed and samples of the alveolar content after extraction and after each treatment were collected for microbial processing by real-time polymerase chain reaction with specific primers for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Treponema denticola. Data were submitted to statistical analysis by multiple comparison tests (McNemar test; p < 0.05). T. denticola was not found in the collected samples. A. actinomycetemcomitans and P. gingivalis were found in ligature samples. Tooth socket samples without periodontitis induction presented lesser microbial charge than samples with induced periodontitis (p < 0.05). aPDT significantly reduced A. actinomycetemcomitans levels on the left side (p < 0.05). It was concluded that aPDT was an effective antimicrobial treatment for tooth sockets in areas affected by induced periodontitis.

Outcome of single immediate implants placed in post-extraction infected and non-infected sites, restored with cemented crowns: a 3-year prospective study.

OBJECTIVES: To compare the survival of immediate implants placed in postextraction infected and non-infected sites, restored with cemented crowns. METHODS: Thirty-six implants were immediately placed in non-infected sockets (control group (CG), n=18), and in infected alveoli (test group (TG), n=18) that had been debrided, curetted, cleaned with 90% hydrogen peroxide, irradiated with yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser, and irrigated with a sterile solution. Guided bone regeneration was performed under antibiotic coverture. All study patients had both a CG and a TG site. The implant osteotomy sites were extended 3-4 mm beyond the apical extent of the sockets to achieve primary stability for the implants. The prosthetic phase occurred 4.5 months after surgery. Success criteria were accepted as the presence of implant stability, absence of a radiolucent zone around the implants, absence of mucosal suppuration, and lack of pain. Clinical evaluations were performed at baseline, and at 12, 24, and 36 months of follow-up. RESULTS: All of the implants were osseointegrated 3 months after surgery. The 3-year survival rate was 94.44% for TG, and 100% for CG. The clinical and radiographic variables tested yielded no significant differences among groups at 36 months. CONCLUSIONS: Under the tested conditions, immediate implant placement can be considered a predictable treatment option for the restoration of fresh postextraction infected sockets. CLINICAL SIGNIFICANCE: Immediate implants may be indicated for replacing teeth lost due to chronic periapical lesions with endodontic failure history when appropriate preoperative procedures are taken to clean and decontaminate the surgical sites.

Analysis of the intraimplant microflora of two-piece dental implants.

OBJECTIVE: Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing. MATERIALS AND METHODS: Ten patients (six men and four women; average age = 66.7 years; age range = 58-78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing. RESULTS: Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples. CONCLUSIONS: Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci. CLINICAL RELEVANCE: These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities.

Comparison of effects of clodronate and zoledronic acid on the repair of maxilla surgical wounds - histomorphometric, receptor activator of nuclear factor-kB ligand, osteoprotegerin, von Willebrand factor, and caspase-3 evaluation.

BACKGROUND: The aim of this study was to compare clodronate and zoledronic acid regarding their influence on the repair of surgical wounds in maxillae (soft tissue wound and tooth extraction) and their relation to osteonecrosis. MATERIAL AND METHODS: Thirty-four Wistar rats were allocated into three groups according to the treatment received: (i) 12 animals treated with zoledronic acid, (ii) 12 animals treated with clodronate and (iii) 10 animals that were given saline solution. All animals were subjected to tooth extractions and surgically induced soft tissue injury. Histological analysis of the wound sites was performed by means of hematoxylin-eosin (H&E) staining and immunohistochemical staining for receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG), von Willebrand factor, and caspase-3. RESULTS: The zoledronic acid group showed higher incidence of non-vital bone than did the clodronate group at the tooth extraction site. At the soft tissue wound site, there were no significant differences in non-vital bone between the test groups. RANKL, OPG, von Willebrand factor, and caspase-3 did not show significant differences between the groups for both sites of surgical procedures. CONCLUSION: Both of the bisphosphonates zoledronic acid and clodronate are capable of inducing maxillary osteonecrosis. Immunohistochemical analysis suggests that the involvement of soft tissues as the initiator of osteonecrosis development is less probable than has been pointed out.

Microbiologic evaluation of compromised periodontal sites before and after immediate intrasocket implant placement.

This study aimed to elucidate the changes in subgingival microflora before the extraction of severely periodontally involved teeth and 1 year after immediate implant placement and provisionalization without flap elevation. Clinical parameters were recorded for 20 maxillary anterior teeth from 10 individuals before and after implant treatment. The clinically observed improvement in the soft tissues was found to be compatible with a less pathogenic flora. Concentrations of periodontopathogens in the periodontal sites were heavily reduced when transformed into peri-implant sites, whereas the relevant counts of the beneficial microorganisms were increased.

Implant therapy and apical actinomycosis: case report.

Treatment of periapical actinomycosis includes extraction of the involved tooth; however, indications for and timing of implant therapy remain unclear. In this case report, we describe treatment of apical actinomycosis in a 63-year-old woman following tooth extraction. After monitoring the patient for 6 months, implant therapy was carried out and remained successful after 1 year follow-up.

Experimental alveolitis in rats: microbiological, acute phase response and histometric characterization of delayed alveolar healing.

UNLABELLED: The pathogenesis of alveolitis is not well known and therefore experimental situations that mimic some features of this disease should be developed. OBJECTIVE: In this study, the evolution of the experimentally induced infection in rat sockets is characterized, which leads to clinical signs of suppurative alveolitis with remarkable wound healing disturbs. MATERIAL AND METHODS: Non-infected (Group I) and experimentally infected sockets in Rattus novergicus (Group II) were histometrically evaluated regarding the kinetics of alveolar healing. In addition, the characterization of the present bacteria in inoculation material and the serum levels of C-reactive protein (CRP) were performed. The detected species were Capnocytophaga ochracea, Fusobacterium nucleatum ss nucleatum, Prevotella melaninogenica, Streptococcus anginosus, Treponema socranskii and Streptococcus sanguis. RESULTS: All experimentally infected rats developed suppurative alveolitis, showing higher levels of CRP in comparison to those non-infected ones. Furthermore, infected rats presented a significant delayed wound healing as measured by the histometric analysis (higher persistent polymorphonuclear infiltrate and lower density of newly formed bone). CONCLUSION: These findings indicate that rat sockets with experimentally induced infection produced higher levels of serum CRP, showing the potential of disseminated infection and a disturb in the alveolar repair process in an interesting experimental model for alveolitis studies.

Immediate implantation in infected tooth sockets.

Although immediate implantation has not been previously recommended in infected sites, it is now becoming a procedure of choice in modern implant dentistry. We report a case of a 65-year-old male patient, who required multiple tooth extractions in the lower jaw and fabrication of a new overdenture in the lower jaw and a complete denture in the upper jaw. Immediate implantation in infected tooth sockets followed extraction. Two NobelReplace Tapered implants (Nobel BioCare, Zürich, Switzerland), one 13 mm long and 4.3 mm wide and the other 13 mm long and 5.0 mm wide, were placed in the position 33 and 43. The site was sutured and a temporary denture was fabricated by adjusting the old denture. After a period of three months the implant site was reopened and healing abutments were placed. Impressions were made using the Impregum Penta Soft (3M ESPE, St. Paul, Minn, USA) polyether material. Ball Abutment Titanium" was used as a patrix attachment and a matrix was inserted into the denture. Clinical examination and x-ray analysis after six months showed no significant changes of the implants. Bone resorption was within standard values. Although it is still a controversial subject, immediate implantation in infected sites can be a safe and predictable procedure if surgical protocols are followed. However, further research is needed to draw firm conclusions.

Experimental alveolitis in rats: microbiological, acute phase response and histometric characterization of delayed alveolar healing

The pathogenesis of alveolitis is not well known and therefore experimental situations that mimic some features of this disease should be developed. OBJECTIVE: In this study, the evolution of the experimentally induced infection in rat sockets is characterized, which leads to clinical signs of suppurative alveolitis with remarkable wound healing disturbs. MATERIAL AND METHODS: Non-infected (Group I) and experimentally infected sockets in Rattus novergicus (Group II) were histometrically evaluated regarding the kinetics of alveolar healing. In addition, the characterization of the present bacteria in inoculation material and the serum levels of C-reactive protein (CRP) were performed. The detected species were Capnocytophaga ochracea, Fusobacterium nucleatum ss nucleatum, Prevotella melaninogenica, Streptococcus anginosus, Treponema socranskii and Streptococcus sanguis. RESULTS: All experimentally infected rats developed suppurative alveolitis, showing higher levels of CRP in comparison to those non-infected ones. Furthermore, infected rats presented a significant delayed wound healing as measured by the histometric analysis (higher persistent polymorphonuclear infiltrate and lower density of newly formed bone). CONCLUSION: These findings indicate that rat sockets with experimentally induced infection produced higher levels of serum CRP, showing the potential of disseminated infection and a disturb in the alveolar repair process in an interesting experimental model for alveolitis studies.

Maintenance of class III trifurcated molars versus implant placement in regenerated extraction sockets: long-term results of 2 cases.

Studies to date have reached differing conclusions regarding the long-term prognosis of teeth with class III furcation involvement. Replacement of such teeth with implants could be an alternative. This report compares the treatment outcomes of 2 cases with similar disease progression: 1 treated by implant therapy and 1 maintained with nonsurgical periodontal treatment. Two patients with advanced chronic periodontitis and class III furcation involvement of all molars were treated. Case 1 received a conservative periodontal and antibiotic treatment, followed by 15 years of maintenance. In case 2, the molars were extracted and replaced with implants, and the implants were observed for 7 years. Clinical attachment level (CAL), probing attachment level (PAL), bleeding on probing, plaque index, and periodontal pathogens were recorded. Despite good compliance of case 1, periodontal pathogens were not eliminated and tissue destruction was not halted. The PAL outcomes of case 2 improved over time; mean PAL loss reached 0.35 mm/y in the first 3 years and then decreased to 0.01 mm/y. While CAL outcomes did not change in case 2, case 1 showed increased CAL loss after 8 years. Based on the limited findings of this case report, extraction of molars with class III furcation involvement and subsequent implant placement may render a better predictability of treatment outcomes than nonsurgical periodontal therapy in the cases of infection with periodontal pathogens.

Immediate implant placement into infected sites: bacterial studies of the Hydroacoustic effects of the YSGG laser.

This article describes the use of an erbium laser to use photoacoustics to reduce the bacteria in osteotomy sites that were infected by apical pathology. The author shows reduced bacterial counts by performing bacterial cultures following laser treatment. Swabs were taken after the extraction of the tooth and then after the laser was placed into the osteotomy site. The results showed a noticeable reduction of bacteria and no traces of virulent bacteria.

[Immediate implant placement in endodontically infected sites: an alternative treatment for compromised teeth].

In certain clinical conditions when endodontic treatment is either impractical or unlikely to improve the previous results, tooth extraction and replacement with a dental implant becomes a viable alternative. Although the presence of active infection has long been considered a major contraindication to the insertion of implants immediately following tooth extraction, several articles assessing this treatment modality reported excellent and promising results. The aim of this literature review is to evaluate and discuss the clinical outcome of implants placed immediately following extraction in endodontically infected sockets. A Medline and EMBASE search was performed to identify articles published from 1966 to 2010 using the keywords "dental implants", "immediate implant", "extraction socket", "infected teeth", "infected site", "infected socket". No restrictions were placed regarding the study design. Only clinical articles with at least 6 months of follow-up were included. The available relevant literature concerning this topic was limited, and based on relatively low level of evidence study designs with limited follow-up periods. However, the data analysis of the selected articles showed that an immediate implant insertion in endodontically infected sites following tooth extraction and careful debridement of the socket, could be a predictable viable technique. Additional large scaled, well-designed studies are required in order to further assess the clinical applications of this treatment alternative.

Bacterial persistence in dentoalveolar bone following extraction: a microbiological study and implications for dental implant treatment.

BACKGROUND: The microbiological status of apparently healed alveolar bone implant sites is unknown. Implant success may be compromised by site-specific persistence of bacterial biofilm co-aggregations contaminating healed alveolar bone. PURPOSE: The purpose of the present study was to investigate whether extraradicular infection can persist in apparently healed alveolar bone and to develop a surgical debridement strategy that favors implant osseointegration. MATERIALS AND METHODS: The study was conducted on 32 private practice patients. Seventy-seven microbiological samples were taken from 16 pre-implant extraction sockets, 56 healed post-extraction osteotomies at fixture placement, and five failed fixtures. Two of the healed osteotomy samples were healed retreatment sites. Tissue fluid and bone samples were analyzed by either anaerobic/aerobic culturing or DNA molecular techniques. All patients were treated ad modum Brånemark, with a two-stage sterile surgical procedure. A search of the medical and dental literature revealed no evidence-based or best practice recommendations for the use of debridement in implant therapy. Thus, we developed a new technique for the debridement of alveolar bone found to be contaminated by persistent biofilm or planktonic bacteria. RESULTS: The results of the microbiological analysis of 77 bone and effusion samples from 47 implant sites of the 32 patients showed that overall, 32% (n = 25) had bacteria present in the sample. In 16 pre-implant extraction sockets, 69% of samples were positive for the presence of bacteria (n = 11). Of 56 osteotomies with a minimum 3-month healing at fixture placement, 21% revealed a positive culture (n = 12). Two-stage failed fixtures had 100% positive cultures (n = 5) and it was evident from radiographs that all of these failed fixtures had the apical ends close to the former tooth root end. Based on these findings, we have developed a microbiologically based surgical debridement strategy to successfully re-treat early infective failures and to place successful two-stage fixtures. CONCLUSION: Bacteria can persist as a contaminant in apparently healed alveolar bone following extraction of teeth with apical or radicular pathosis. A new technique for surgical debridement to reduce and limit this bacterial contamination has been described.

Decontamination of autogenous bone grafts collected from dental implant sites via osteotomy: a review.

Autogenous bone particles can be obtained with bone collectors during implant osteotomy; however, collected bone particles contain oral microorganisms that may cause infectious complications. The purpose of this review was to summarize the clinical studies that have evaluated the degree of this contamination and the effectiveness of different decontamination methods. Stringent aspiration protocol, preoperative oral chlorhexidine rinse, and antibiotic prophylaxis are important precautions to be implemented when collected bone particles are to be implanted. Despite reducing contamination of collected bone particles, none of the methods described in the literature can completely decontaminate collected bone particles or prevent the risk of infectious complications. Further research is needed to identify more effective decontamination methods.

Influence of local tetracycline on the microbiota of alveolar osteitis in rats.

The aim of the present study was to evaluate the effects of local tetracycline on the occurrence of alveolar osteitis in rats, and on the microbiota associated to this infection. Forty Wistar rats were randomly assigned to 4 groups (n=10): I - the rats had the maxillary right incisor extracted and the alveolar wound did not receive any treatment; II - adrenaline and Ringer-PRAS were introduced into the alveolar wound; III - the alveolar wound was irrigated with sterile saline; and IV - the alveolar wound was irrigated with an aqueous solution of tetracycline. Microbial samples from the alveolar wounds were collected 2 days after surgery and inoculated on blood agar (with and without 8 microg/mL of tetracycline) and other selective media, and were incubated in either aerobiosis or anaerobiosis at 37 degrees C, for 2 to 14 days. It was verified that tetracycline reduced the occurrence of alveolar osteitis in the rats and caused significant changes in the microbiota of the surgical sites, decreasing the number of anaerobes and increasing the participation of tetracycline-resistant and multi-resistant microorganisms.