Effects of probiotics in rats with experimental metabolic syndrome and periodontitis: An investigation of the intestine-adipose tissue axis.

BACKGROUND: This study evaluated the systemic (intestine and adipose tissue) and local (periodontal tissues) impact of probiotic therapy in rats with metabolic syndrome (MS) associated or not with periodontitis (PE). METHODS: Forty-eight rats received a high-fat diet for induction of MS for 16 weeks. They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) receiving probiotics (PROB): MS (-**), MSP (-*), MSPE (+**), and MSPEP (+*). PROB administration (Bifidobacterium animalis subsp. lactis HN019) started on the 8th week of the study and PE was induced on the 14th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16th week. Biomolecular, immunoenzymatic assays, and histomorphometric analyses were performed. The data obtained were statistically analyzed (ANOVA, Tukey, p < 0.05). RESULTS: The MSPEP group exhibited reduced alveolar bone loss when compared with the MSPE group, as well as lower levels of hepatic steatosis and proteinuria (p < 0.05). In the intestinal environment, the MSPE group exhibited significantly lower villus height and crypt depth, as well as a greater increase in Bacillota when compared with the MSPEP group (p < 0.05). The MSPEP group showed lower adipokine gene expression (LEPR, NAMPT, and FABP4) in adipose tissue than the MSPE group (p < 0.05). CONCLUSION: The probiotic B. lactis HN019 reduced the severity of experimental periodontitis and modulated the expression of lipogenic genes and intestinal morphological and microbiological parameters in rats with MS.

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.

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.

Sub-antimicrobial doses of doxycycline decreased bone loss related to ligature-induced periodontitis in hypertensive rats.

BACKGROUND/OBJECTIVE: The beneficial effects of sub-antimicrobial dose doxycycline (SDD) associated with nonsurgical periodontal therapy are well documented. Recently, the effects of SDD on metalloproteinases have been investigated in the treatment of hypertension. The aim of this study was to evaluate the effects of SDD on ligature-induced periodontitis in spontaneously hypertensive rats (SHR). METHODS: Fifty-four adult male rats were divided into three groups: SHR-C, SHR-L and SHR-L-DOX (C - Control; L - Ligature). In group SHR-L-DOX, animals were treated with daily 5 mg/kg SDD administration. In L groups, a ligature remained around mandibular first molars for the first 10 days. Each group was divided for euthanasia at 10 or 21 days. Microtomographic and histometric analyses were performed. Osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP) assay and gene expression of 84 inflammatory mediators by polymerase chain reaction (PCR) array. RESULTS: Group SHR-L-DOX presented reduced systolic blood pressure when compared with group SHR-L at both 10 and 21 days (p < 0.05). Group SHR-L-DOX showed decreased bone and attachment loss in comparison with group SHR-L at both 10 and 21 days (p < 0.05). SDD treatment reduced the amount of TRAP-positive cells at 10 days (p < 0.05). Group SHR-L-DOX showed a downregulated inflammatory genes profile in comparison with SHR-L at 10 and 21 days. CONCLUSION: SDD therapy exerted systemic modulatory effect on inflammation with reduced periodontal tissue destruction in hypertensive rats.

Impact of Different Implant Surfaces Topographies on Peri-Implant Tissues: An Update of Current Available Data on Dental Implants Retrieved from Human Jaws.

The high success range obtained with the implant-supported restorations has improved its applicability on routine of the daily clinical practice. This elevated percentage of success is related to the previous pre-clinical data obtained from animal and in vitro studies that evaluated the impact of implant surface topographies on bone tissue. However, the histological evaluation of human bone tissue is scarce. Therefore, the aim of this review is to depict an actual panorama of the data available on boneto- implant contact (BIC) of retrieved implants from human jaws. Some aspects of implant surface topography as well as systemic conditions as osteoporosis and smoking habit were demonstrated to have a strong impact, suggesting that the data obtained from human bone tissue is still valuable for the better understanding of the osseointegration process. This article also highlighted that most data in humans are difficult to interpret, due to the lack of detailed information about the surfaces found in retrieved implants. Without the definition of the surface characteristics, it is difficult to link exactly the surface patterns to specific clinical observations, and all observations remain de facto incomplete. As a conclusion, data from implants retrieved from human jaws are very important for our understanding, however the studies remain scarce and data is fragmented. This important approach should be improved, completed and developed in the future.

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.

The effect of a single episode of antimicrobial photodynamic therapy in the treatment of experimental periodontitis. Microbiological profile and cytokine pattern in the dog mandible.

The purpose of this study was to evaluate the effect of a single application of antimicrobial photodynamic therapy (aPDT) on microbiological profile and cytokine pattern in dogs. Periodontal disease was induced by placing 3.0 silk ligatures around the mandibular pre-molars bilaterally during 8 weeks. The dogs were randomly treated with aPDT using a dye/laser system, scaling and root planning (SRP), or with the association of treatments (SRP + aPDT). Plaque samples were collected at baseline, 1, 3, and 4 weeks, and the mean counts of 40 species were determined using DNA-DNA hybridization. Gingival biopsies were removed and the expression of tumor necrosis factor alpha (TNF-α), receptor activator of NF-kB ligand (RANKL), osteoprotegerin (OPG), matrix metalloproteinase (MMP-1), interleukin (IL) 6, IL-10 and total bacterial load by analysis of 16 S rRNA gene were evaluated through real-time PCR. The results shows that the levels of the majority of the species were reduced 1 week post-therapy for all treatments, however, an increase in counts of Prevotella intermedia (p = 0.00), Prevotella. nigrescens (p = 0.00) and Tannerella forsythia (p = 0.00) was observed for aPDT and SRP + aPDT. After 4 weeks, a regrowth of Porphyromonas gingivalis (p = 0.00) and Treponema denticola (p = 0.00), was observed for all treatments. Also, a strikingly reduction of counts on counts of Aggregatibacter actinomycetemcomitans was observed for the aPDT (p = 0.00). For the cytokine pattern, the results were similar for all treatments, and a reduction in the expression of cytokines and bacterial load was observed throughout the study. Our results suggest that SRP, aPDT in a single application, and SRP + aPDT affects different bacterial species and have similar effects on the expression of cytokines evaluated during the treatment of ligature-induced periodontitis.

The effect of bone condensation and crestal preparation on the bone response to implants designed for immediate loading: a histomorphometric study in dogs.

PURPOSE: The aim of this study was to evaluate the influence of bone condensation and crestal preparation on the bone response of implants designed to promote osseocompression. MATERIALS AND METHODS: In the first phase, the mandibular premolars of 6 dogs were extracted bilaterally. After 8 weeks, each dog received 8 Xive implants (4 per hemimandible). One hemimandible was randomly assigned to the experimental group and the other to the control group. The implant site was prepared using conventional standard drills. Prior to implant placement the crestal drill was used in the experimental group but not in the control group. After 12 weeks, the animals were sedated and sacrificed. The hemimandibles were removed and prepared for histomorphometric analysis of bone-implant contact (BIC) and bone density of areas adjacent to and further from the implant surface. RESULTS: The mean +/- SD percentages of BIC attained were 71.1% +/- 11.8% and 45.1% +/- 16.1% for the experimental and control groups, respectively. The bone density analysis revealed that in the control group, percentage BIC was a mean of 55.6% +/- 11.3% adjacent to the implant and 50.7% +/- 17.9% distant from the implant. In the experimental group, percentage BIC was a mean of 71.1% +/- 8.6% adjacent to the implant and 55.6 +/- 11.3 distant from the implant. The difference between the experimental and control groups was statistically significant for both parameters, BIC and bone density, in the adjacent areas (P < .0001). CONCLUSION: Crestal preparation is of fundamental importance for this implant system, since it led to better bone response, represented by the improved BIC and bone density.

Titanium membranes in prevention of alveolar collapse after tooth extraction.

BACKGROUND AND PURPOSE: The resorption of alveolar bone following tooth extraction results in a narrowing and shortening of the residual ridge, which leads to esthetic and restorative problems, and reduces the bone volume available for implant therapy. The aim of this study was to evaluate the prevention of alveolar collapse after tooth extraction, using titanium membrane (Frios Boneshield; DENTSPLY Friadent, Mannheim, Germany), associated (or not) with autologous bone graft. MATERIALS AND METHODS: A total of 10 nonsmoking healthy subjects, ranging from 35 to 60 years old, were selected for this study. Each patient had a minimum of 2 uni-radicular periodontally hopeless teeth, which were scheduled for extraction. After the procedure, 2 titanium pins were fixed on the vestibular bone surfaces that were used as references for the initial measures (depth, width, and height) of the socket. Of the sockets,1 was randomly chosen to be filled with autologous bone graft (test) removed from superior maxillary tuber, and the other one did not receive the graft (control). A titanium membrane was adapted and fixed, covering the sockets, which remained for at least 10 weeks. After a 6-month healing, the final measures were performed. RESULTS: There was exposure of the membrane in 5 of the 10 treated subjects. Average bone filling (+/-standard deviation) among the 10 subjects was 8.80 +/- 2.93 mm (range 4-13) in the control group and 8.40 +/- 3.35 mm (range 4-13) in the test group. Average bone loss in width in both group was 1.40 +/- 1.97 mm (range -4-1) in the control group and 1.40 +/- 0.98 mm (range -4-0) in the test group. There was no significant statistical difference between groups considering the evaluated standards. CONCLUSION: The use of titanium membrane, alone or in association with autogenous bone, favored the prevention of alveolar ridge after tooth extraction. This membrane seems to be a possible and safe alternative to other nonresorbable membranes when the prevention of alveolar ridge resorption is the objective.

Crestal bone loss minimized when following the crestal preparation protocol: a histomorphometric study in dogs.

Initial breakdown of the implant-tissue interface generally begins at the crestal region in successfully osseointegrated implants. The purpose of this study was to evaluate the effect on crestal bone loss (CBL) around implants specially developed for immediate loading with a unique crestal drill. After 8 weeks postextraction, 6 young male mongrel dogs received 48 implants (XiVE) in the region corresponding to the 4 mandibular premolars. The implant sites were prepared according to the manufacturer's protocol with conventional standard drills. Before implant placement, the crestal drill was used in the experimental group but not in the control group. After a healing period of 12 weeks, the dogs were sedated and euthanized. Through linear measurements, from the top of the implant to the first bone-implant contact, the amount of CBL was determined. The histomorphometric results of CBL (mean +/- SEM) were 0.88 +/- 0.13 mm (range 0.0-3.0 mm) in the experimental group and 1.69 +/- 0.17 mm (range 0.0-4.2 mm) in the control group. The difference was statistically significant (P < .05) when the implants were used as the experimental units. The statistical analysis also revealed significance when the dogs were used as the experimental units (P < .05). When the median was used for analyses, the CBL was 0.44 mm for the experimental group and 1.91 mm for the control group. Crestal bone loss was minimized when the crestal preparation protocol was carefully followed by using the osseocondensating XiVE implant system.

Comparative study of enamel matrix derivative with or without GTR in the treatment of class II furcation lesions in dogs.

Chronic Class II furcation lesions were created in four dogs. After 21 days, group I remained as a control, group 2 was treated with membranes and enamel matrix derivative (EMD), and group 3 received EMD alone. Healing in group 1 was characterized by a long junctional epithelium and discrete bone formation; group 2 showed reduced bone formation; and group 3 showed significant bone regeneration (area of new bone = 67.36%+/-3.93%; distance from furcation roof to bone crest = 0.57+/-0.15 mm). The EMD led to significant regeneration of the furcation lesions, and the association with membranes was detrimental.