Impact of a modified implant macrogeometry on biomechanical parameters and bone-related markers in rats.

This study investigated the impact of a modified implant macrogeometry on peri-implant healing and its effect on bone-related molecules in rats. Eighteen rats received one implant in each tibia: the control group received implants with conventional macrogeometry and the test group received implants with modified macrogeometry. After 30 days, the implants were removed for biomechanical analysis and the bone tissue around them was collected for quantifying gene expression of OPN, Runx2, ß-catenin, BMP-2, Dkk1, and RANKL/OPG. Calcein and tetracycline fluorescent markers were used for analyzing newly formed bone at undecalcified sections of the tibial implants. These fluorescent markers showed continuous bone formation at cortical bone width and sparse new bone formed along the medullary implant surface in both groups. However, higher counter-torque values and upregulation of OPN expression were achieved by test implants when compared to controls. The modified macrogeometry of implants optimized peri-implant healing, favoring the modulation of OPN expression in the osseous tissue around the implants.

Influence of partially exposed nonabsorbable membrane for alveolar ridge preservation: A randomized controlled trial.

AIM: This randomized controlled trial evaluated the impact of a partially exposed non-absorbable membrane (dPTFE) in Alveolar Ridge Preservation (ARP) procedures on clinical, tomographic, immunoenzymatic, implant-related, and patient-centered outcomes. MATERIALS AND METHODS: Patients with a hopeless maxillary single-rooted tooth demanding rehabilitation with implants were included. Patients were randomized into two groups: dPTFE (n = 22)-tooth extraction followed by ARP using a partially exposed dPTFE membrane; USH (n = 22)-unassisted socket healing. Clinical and tomographic analyses were performed at baseline and after 3 months. After 3 months, patients received one dental implant. Implant stability quotient was obtained following implant placement. Bone-related markers were analyzed in bone biopsies using an immunoenzymatic assay. RESULTS: Greater gain in Keratinized Mucosa Width (KMW) was observed in the dPTFE (1.33 ± 0.98 mm) compared to USH (0.59 ± 0.98 mm) (Mann-Whitney test, Z = 2,28, p < 0.05). USH showed a reduction of pain/discomfort, edema, and interference with daily life from the seventh day (Friedman/Wilcoxon test, maxT = 7.48, 8.00, and 5.92, respectively, p < 0.05). dPTFE presents a reduction of edema and interference with daily life from the 7th day and pain/discomfort from the 14th day (Friedman/Wilcoxon test, maxT = 5.40, 5.26, and 4.78, respectively, p < 0.05). The dPTFE group presented higher pain/discomfort in the 35 and 42 days and higher edema from 7 to 42 days postoperatively than USH group (Mann-Whitney test, p < 0.05). No differences between groups were observed in the tomographic measures, immunoenzymatic analysis, and implant stability (p > 0.05). CONCLUSION: dPTFE was superior to USH by increasing KMW gain. However, dPTFE without bone graft presented similar bone loss compared to USH. This clinical trial was not registered prior to participant recruitment and randomization (NCT04329351).

Resveratrol for preventing medication-related osteonecrosis of the jaws in rats.

This study evaluated the effect of resveratrol (RES) on the prevention of medication-related osteonecrosis of the jaws (MRONJ) in ovariectomized (OVX) rats treated with zoledronate (ZOL). Fifty rats were distributed in five groups: SHAM (n = 10): non-ovariectomy + placebo; OVX (n = 10):ovariectomy + placebo; OVX + RES (n = 10):ovariectomy + resveratrol; OVX + ZOL (n = 10):ovariectomy + placebo + zoledronate; and OVX + RES + ZOL (n = 10):ovariectomy + resveratrol + zoledronate. The mandibles left sides were analyzed with micro-CT, histomorphometry, and immunohistochemistry. On the right side, bone markers gene expression was analyzed by qPCR. ZOL increased the percentage of necrotic bone and reduced the neo-formed bone compared to groups not receiving ZOL (p < 0.05). RES impacted the tissue healing pattern in OVX + ZOL + RES, reduced inflammatory cell infiltrate, and improved bone formation in the extraction site. Osteoblasts, alkaline phosphatase (ALP)-, and osteocalcin (OCN)-immunoreactive cells were lower in OVX-ZOL than in SHAM, OVX, and OVX-RES. The OXV-ZOL-RES had fewer osteoblasts and ALP- and OCN-cells than the SHAM and OVX-RES. The tartrate-resistant acid phosphatase (TRAP)-positive cells were reduced in the presence of ZOL (p < 0.05), while the TRAP mRNA levels increased with ZOL treatment, with or without resveratrol, compared with the other groups (p < 0.05). RES alone increased superoxide dismutase levels compared to OVX + ZOL and OVX + ZOL + RES (p < 0.05). In conclusion, resveratrol reduced the tissue impairment severity induced by ZOL; however, it could not prevent the occurrence of MRONJ.

Does resveratrol favor peri-implant bone repair in rats with ovariectomy-induced osteoporosis? Gene expression, counter-torque and micro-CT analysis.

This study investigated the influence of resveratrol on peri-implant repair and its effects on bone-related markers in ovariectomy-induced osteoporosis in rats. Animals were divided into: OVX+PLAC (n = 10): ovariectomized animals treated with placebo; OVX+RESV (n = 10): OVX treated with resveratrol; OVX+PLAC+ZOL (n = 10): OVX treated with PLAC and zoledronate; OVX+RESV+ZOL (n = 10): OVX treated with RESV and ZOL; and SHOVX+PLAC (n = 10): sham ovariectomy treated with PLAC. RESV and PLAC were administrated after ovariectomy and ZOL after six weeks after OVX, until the end of experiment. One implant was inserted in each tibiae of animals 18 weeks after ovariectomy. After 4 weeks, one implant was removed for counter-torque, and peri-implant tissue was collected for mRNA quantification of several osteogenic markers by PCR. The other tibia was submitted to micro-computed tomography analysis. Reduced counter-torque values, bone-implant contact (BIC) and bone volume fraction (BV/TV), and higher bone porosity (BP) were detected in OVX+PLAC group when compared to SHOVX+PLAC (p < 0.05). OVX+RESV rats presented lower BIC, BV/TV, and trabecular number (Tb.N), and augmented BP and trabecular spacing (Tb.Sp) when compared to SHOVX+PLAC (p < 0.05). Higher Tb.N and connectivity density (Conn.Dn) and reduced Tb.Sp were observed in OVX rats treated with ZOL, independently of RESV, when compared to OVX+PLAC and OVX+RESV groups (p < 0.05), whereas the combination ZOL+RESV promoted lower BP when compared to OVT+PLAC and OVX+RESV (p < 0.05). Gene expression was not influenced by RESV (p > 0.05), whereas ZOL promoted up-regulation of BMP-2 (p<0.05). RESV did not improve peri-implant bone repair in rats with ovariectomy-induced osteoporosis.

Comparison between flapless-guided and conventional surgery for implant placement: a 12-month randomized clinical trial.

OBJECTIVES: The study was aimed at comparing implants installed with guided and conventional surgery. MATERIAL AND METHODS: Twenty-nine total edentulous patients were selected, and maxillary contralateral quadrants were randomly assigned to static computer-aided implant surgery (S-CAIS): flapless computer-guided surgery, and conventional surgery (CS): flap surgery with conventional planning. Tomography scans were performed at baseline and 10 days after the surgery for deviation measurement, and radiography was done at baseline and after 6 and 12 months, for peri-implant bone level (PIBL) analysis. Peri-implant fluid and subgingival biofilm were collected to evaluate bone markers and periodontal pathogens. RESULTS: S-CAIS showed less linear deviation at the apical point and the midpoint and less angular deviation (p < 0.05), with greater depth discrepancy in the positioning of the platform (p < 0.05). Higher values of vertical PIBL were observed for the S-CAIS group at baseline (p < 0.05), while lower values of horizontal PIBL were observed for CS (p < 0.05). Bone markers and Tf presented higher levels in CS (p < 0.05). Flapless S-CAIS allowed smaller linear and angular deviations than the conventional technique. CONCLUSION: However, PIBL was higher in S-CAIS; the conventional technique led to a greater angiogenic and bone remodeling activity by elevating the angiogenic levels and bone markers. CLINICAL RELEVANCE: Evaluating the different implant insertion techniques can guide clinical and surgical regarding the accuracy, the release pattern of bone markers, and the peri-implant bone level. TRIAL REGISTRATION: ReBEC-RBR-8556fzp.

Impact of a modified implant macrogeometry on biomechanical parameters and bone-related markers in rats

Abstract This study investigated the impact of a modified implant macrogeometry on peri-implant healing and its effect on bone-related molecules in rats. Eighteen rats received one implant in each tibia: the control group received implants with conventional macrogeometry and the test group received implants with modified macrogeometry. After 30 days, the implants were removed for biomechanical analysis and the bone tissue around them was collected for quantifying gene expression of OPN, Runx2, β-catenin, BMP-2, Dkk1, and RANKL/OPG. Calcein and tetracycline fluorescent markers were used for analyzing newly formed bone at undecalcified sections of the tibial implants. These fluorescent markers showed continuous bone formation at cortical bone width and sparse new bone formed along the medullary implant surface in both groups. However, higher counter-torque values and upregulation of OPN expression were achieved by test implants when compared to controls. The modified macrogeometry of implants optimized peri-implant healing, favoring the modulation of OPN expression in the osseous tissue around the implants.

Does resveratrol favor peri-implant bone repair in rats with ovariectomy-induced osteoporosis? Gene expression, counter-torque and micro-CT analysis

Abstract This study investigated the influence of resveratrol on peri-implant repair and its effects on bone-related markers in ovariectomy-induced osteoporosis in rats. Animals were divided into: OVX+PLAC (n = 10): ovariectomized animals treated with placebo; OVX+RESV (n = 10): OVX treated with resveratrol; OVX+PLAC+ZOL (n = 10): OVX treated with PLAC and zoledronate; OVX+RESV+ZOL (n = 10): OVX treated with RESV and ZOL; and SHOVX+PLAC (n = 10): sham ovariectomy treated with PLAC. RESV and PLAC were administrated after ovariectomy and ZOL after six weeks after OVX, until the end of experiment. One implant was inserted in each tibiae of animals 18 weeks after ovariectomy. After 4 weeks, one implant was removed for counter-torque, and peri-implant tissue was collected for mRNA quantification of several osteogenic markers by PCR. The other tibia was submitted to micro-computed tomography analysis. Reduced counter-torque values, bone-implant contact (BIC) and bone volume fraction (BV/TV), and higher bone porosity (BP) were detected in OVX+PLAC group when compared to SHOVX+PLAC (p < 0.05). OVX+RESV rats presented lower BIC, BV/TV, and trabecular number (Tb.N), and augmented BP and trabecular spacing (Tb.Sp) when compared to SHOVX+PLAC (p < 0.05). Higher Tb.N and connectivity density (Conn.Dn) and reduced Tb.Sp were observed in OVX rats treated with ZOL, independently of RESV, when compared to OVX+PLAC and OVX+RESV groups (p < 0.05), whereas the combination ZOL+RESV promoted lower BP when compared to OVT+PLAC and OVX+RESV (p < 0.05). Gene expression was not influenced by RESV (p > 0.05), whereas ZOL promoted up-regulation of BMP-2 (p<0.05). RESV did not improve peri-implant bone repair in rats with ovariectomy-induced osteoporosis.

Peri-Implant Repair Using a Modified Implant Macrogeometry in Diabetic Rats: Biomechanical and Molecular Analyses of Bone-Related Markers.

DM has a high prevalence worldwide and exerts a negative influence on bone repair around dental implants. Modifications of the microgeometry of implants have been related to positive results in bone repair. This study assessed, for the first time, the influence of an implant with modified macrodesign based on the presence of a healing chamber in the pattern of peri-implant repair under diabetic conditions. Thirty Wistar rats were assigned to receive one titanium implant in each tibia (Control Implant (conventional macrogeometry) or Test Implant (modified macrogeometry)) according to the following groups: Non-DM + Control Implant; Non-DM + Test Implant; DM + Control Implant; DM + Test Implant. One month from the surgeries, the implants were removed for counter-torque, and the bone tissue surrounding the implants was stored for the mRNA quantification of bone-related markers. Implants located on DM animals presented lower counter-torque values in comparison with Non-DM ones, independently of macrodesign (p < 0.05). Besides, higher biomechanical retention levels were observed in implants with modified macrogeometry than in the controls in both Non-DM and DM groups (p < 0.05). Moreover, the modified macrogeometry upregulated OPN mRNA in comparison with the control group in Non-DM and DM rats (p < 0.05). Peri-implant bone repair may profit from the use of implants with modified macrogeometry in the presence of diabetes mellitus, as they offer higher biomechanical retention and positive modulation of important bone markers in peri-implant bone tissue.

Impact of resveratrol in the reduction of the harmful effect of diabetes on peri-implant bone repair: bone-related gene expression, counter-torque and micro-CT analysis in rats.

OBJECTIVE: Investigate the impact of resveratrol (RESV) on peri-implant repair and its effect on bone-related markers in rats with induced diabetes mellitus (DM). MATERIAL AND METHODS: Ninety rats were divided into: DM + RESV (n = 18); DM + placebo (PLAC) (n = 18); DM + insulin (INS) (n = 18); DM + RESV + INS (n = 18); Non-DM (n = 18). Diabetes was induced by streptozotocin. One screw-shaped titanium implant was inserted in each tibiae of animals. Treatments were administered during 30 days. After, one of the implants was removed for counter-torque and the peri-implant tissue was collected for mRNA quantification of BMP-2, OPN, Runx2, Lrp-5, Osx, ß-catenin, Dkk1, OPG, and RANKL by Real-time PCR. The other tibia was submitted to MicroCT analysis to measure: bone volume (BV/TV), trabecular thickness (Tb.Th) and bone-implant contact (BIC). RESULTS: Higher counter-torque values were observed for implant removal in DM + RESV, DM + RESV + INS and Non-DM groups when compared to DM + PLAC (p < .05). Augmented Tb.Th was observed in DM + RESV and Non-DM when compared to DM + PLAC group (p < .05), whereas higher BIC was detected in DM + RESV, DM + RESV + INS and Non-DM animals when compared to DM + PLAC (p < .05). Levels of RANKL were downregulated by the RESV and/or INS therapy, whereas only the association of RESV and INS upregulated the levels of Runx2 (p < .05). CONCLUSIONS: The therapy with RESV may favour peri-implant bone repair improving bone formation around implants.

Resveratrol and insulin association reduced alveolar bone loss and produced an antioxidant effect in diabetic rats.

BACKGROUND: The present investigation studied the effects of systemic administration of resveratrol (RSV) on the development of experimental periodontitis (EP) and on the release of markers of inflammation, bone metabolism, and oxidative stress in diabetic rats. METHODS: Seventy-five male rats were divided into five groups: DM+PLAC: Diabetes Mellitus + placebo solution; DM+INS: DM + insulin therapy; DM+RSV: DM + RSV; DM+RSV+INS: DM + RSV and insulin; NDM: non-diabetic. Streptozotocin was used to induce DM and EP was induced by the placement of a ligature at the fist mandibular and the second maxillary molars. Euthanasia occurred 30 days after the initiation of the study and mandible specimens were subjected for morphometric analysis of bone level. Gingival tissues from mandibular molars were collected for quantification of inflammatory and oxidative stress markers by multiplex assay system and ELISA assay, respectively. Maxillary gingival tissues were processed for real-time polymerase chain reaction (real-time PCR) assessment of markers of bone metabolism and oxidative stress. RESULTS: Morphometric analysis revealed greater bone loss in DM+PLAC and DM+INS in comparison to the other treatments (P < 0.05). RSV used in conjunction with INS reduced the levels of interleukin (IL)-1ß, IL-6, IL-17, interferon-gamma (IFN-γ) and superoxide dismutase 1 (SOD) (P < 0.05). RSV alone reduced nicotinamide adenine dinucleotide phosphatase oxidase (NADPH oxidase) levels, in comparison to DM+INS and DM+RSV+INS (P < 0.05). All treatments upregulated mRNA levels for osteoprotegerin (OPG) in comparison to PLAC (P < 0.05). Sirtuin 1 (SIRT) mRNA levels were lower in PLAC when compared to DM+RSV, DM+RSV+INS and NDM (P < 0.05). CONCLUSION: RSV reduced the progression of EP and the levels of NADPH oxidase. Co-treatment with RSV and insulin reduced the levels of pro-inflammatory factors (either proteins or mRNA) and increased the levels of SOD. The data also demonstrated that treatment with RSV and INS alone or in combination had beneficial effects on bone loss.

Effect of resveratrol on the progression of experimental periodontitis in an ovariectomized rat model of osteoporosis: Morphometric, immune-enzymatic, and gene expression analysis.

OBJECTIVE: This study aimed to determine the role of resveratrol (RESV) on the progression of experimental periodontitis (EP) in ovariectomy rats (OVT). BACKGROUND: Estrogen deficiency is the main cause of osteoporosis and is related to higher periodontal attachment loss and reduction of alveolar bone. Zoledronate (ZLD) is an antiresorptive drug used to control osteoporosis but can lead to osteonecrosis of the jaw. RESV, a natural product, can reduce bone loss and control and prevent osteoporosis. Thus, this study aimed at investigating the effect of RESV on the progression of EP in estrogen-deficient rats. MATERIAL AND METHODS: The animals were subjected to the OVT or sham surgery to induce estrogen-deficiency and then were divided into the groups: OVT + RESV (n: 10); OVT + PLAC (n: 10): OVT + placebo; OVT + ZLD +PLA (n: 10); OVT + RESV +ZLD (n: 10): OVT + RESV and ZLD; SHAM (n: 10): non-ovariectomized animals + placebo. To induce estrogen deficiency, the rats were subjected to ovariectomy. Experimental periodontitis was induced by the placement of a ligature at the second maxillary molars. Daily administration of the placebo solution, resveratrol (10 mg/kg), and ZLD (0.1 mg/kg) was carried out for a period 42 days prior to initiation of EP, and then for another 28 days following ligature placement. After euthanasia, the specimens were processed for micro-CT and morphometric analysis of bone loss (linear measurement), and the gingival tissue surrounding the maxillary second molar was collected for the quantification of inflammatory markers using Luminex/MAGPix, of oxidative stress markers using ELISA assay, and gene expression analysis of bone markers, by real-time PCR. RESULTS: Morphometric and micro-CT analysis showed higher bone loss and lower bone density, respectively, in OVT + PLAC when compared to the other groups (P < .05). ZLD treated groups had lower alveolar bone loss, as well as, higher density and percentage of bone volume, when compared to OVT + RESV and SHAM + PLAC groups (P < .05). IL-4 levels were significantly lower in the OVT + PLAC group versus OVT + ZLD +RESV and SHAM + PLAC (P < .05). NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) levels were significantly lower OVT + RESV group when compared to OVT + PLAC (P < .05). OPG mRNA levels were lower in OVT + PLAC compared with the SHAM + PLAC group (P < .05). CONCLUSION: It can be concluded that resveratrol modulated alveolar bone loss during experimental periodontitis progression in estrogen-deficient rats by downregulating NADPH oxidase levels.

Impact of history of periodontitis on gene expression of bone-related factors in young patients.

Although dental implants and bone regenerative procedures are important approaches for the reestablishment of esthetics and function in young patients with a history of generalized aggressive periodontitis (GAP), no predictable outcomes have been reported, and the host osteo-immunoinflammatory response may play a relevant role in this context. In view of the lack of molecular investigations into the bone tissue condition of young patients with periodontitis, the aim of this study was to evaluate the gene expression of bone-related factors in this population. Bone biopsies were obtained from the posterior mandible in 16 individuals previously diagnosed with GAP and on periodontal support therapy and from 17 periodontally healthy (PH) patients. The gene expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß, receptor activator of the NF-κB ligand (RANKL), osteoprotegerin (OPG), osteocalcin (OC), bone sialoprotein (BSP), and type I collagen (COL-I), important biomarkers of bone turnover, was evaluated by qRT-PCR. Lower TGF-ß and OPG mRNA levels were observed in GAP patients compared to PH individuals (p ≤ 0.05). There were no between-group differences in levels of TNF-α, BSP, RANKL, OC, or COL-I mRNA (p>0.05). In young adults, a history of periodontal disease can negatively modulate the gene expression of important bone-related factors in alveolar bone tissue. These molecular outcomes may contribute to the future development of therapeutic approaches to benefit bone healing in young patients with history of periodontitis via modulation of osteo-immuno-inflammatory biomarkers.

Novel 20% doxycycline-loaded PLGA nanospheres as adjunctive therapy in chronic periodontitis in type-2 diabetics: randomized clinical, immune and microbiological trial.

OBJECTIVE: This study evaluated the clinical, microbiological, and immunological results of poly lactic-co-glycolic acid (PLGA) nanospheres containing 20% doxycycline (DOXY) in the treatment of type-2 diabetic patients (DM-2) with chronic periodontitis (CP). MATERIAL AND METHODS: A parallel, double-blind, randomized, placebo-controlled clinical trial was conducted in DM-2 presenting severe and generalized CP. All patients received one-stage full-mouth ultrasonic debridement (FMUD) and they were randomly divided into two groups: PLAC (n = 20)-local application of placebo PLGA nanospheres, and DOXY (n = 20)-local application of doxycycline-loaded nanospheres; both in six non-contiguous sites. Clinical, metabolic (fasting plasma glucose level-FPG and glycated hemoglobin-HbA1c), cytokine pattern (multiplexed bead immunoassay) and microbiological assessments were performed at baseline, and 1, 3, and 6 months after treatment. RESULTS: Both groups showed clinical improvement in all parameters after treatment (p < 0.05). Deep pockets showed improvements in bleeding on probing-BoP (3 and 6 months), PD (at 3 months), and CAL gain (at 1 and 3 months) favoring DOXY (p < 0.05). The percentage of sites presenting PD reduction and CAL gain ≥ 2 mm was higher in DOXY at 3 months (p < 0.05). DOXY group exhibited a significant increase in the levels of anti-inflammatory interleukin (IL)-10 and a reduction in IL-8, IFN-y, IL-6, and IL-17 (p < 0.05), significant reduction in periodontal pathogens (p < 0.05), and a lower mean percentage of HbA1C at 3 months (p < 0.05). CONCLUSION: DOXY nanospheres may be considered a potential adjunct to mechanical debridement in the therapy of periodontitis in DM-2, offering additional benefits in deep pockets, improving the cytokine profile, and reducing periodontal pathogen levels. CLINICAL RELEVANCE: The use of locally applied doxycycline nanospheres may represent an adjunctive therapeutic approach in the treatment of periodontal disease in type-2 diabetic patients, achieving additional benefits in the local modulation of cytokines, microbial reduction, and clinical parameters, especially in deep pockets.

Impact of history of periodontitis on gene expression of bone-related factors in young patients

Abstract Although dental implants and bone regenerative procedures are important approaches for the reestablishment of esthetics and function in young patients with a history of generalized aggressive periodontitis (GAP), no predictable outcomes have been reported, and the host osteo-immunoinflammatory response may play a relevant role in this context. In view of the lack of molecular investigations into the bone tissue condition of young patients with periodontitis, the aim of this study was to evaluate the gene expression of bone-related factors in this population. Bone biopsies were obtained from the posterior mandible in 16 individuals previously diagnosed with GAP and on periodontal support therapy and from 17 periodontally healthy (PH) patients. The gene expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, receptor activator of the NF-κB ligand (RANKL), osteoprotegerin (OPG), osteocalcin (OC), bone sialoprotein (BSP), and type I collagen (COL-I), important biomarkers of bone turnover, was evaluated by qRT-PCR. Lower TGF-β and OPG mRNA levels were observed in GAP patients compared to PH individuals (p ≤ 0.05). There were no between-group differences in levels of TNF-α, BSP, RANKL, OC, or COL-I mRNA (p>0.05). In young adults, a history of periodontal disease can negatively modulate the gene expression of important bone-related factors in alveolar bone tissue. These molecular outcomes may contribute to the future development of therapeutic approaches to benefit bone healing in young patients with history of periodontitis via modulation of osteo-immuno-inflammatory biomarkers.

Host response and peri-implantitis.

Considering the absence of predictable and effective therapeutic interventions for the treatment of peri-implantitis, scientific evidence concerning the host response profile around dental implants could be important for providing in the future a wider preventive and/or therapeutic window for this peri-implant lesion, indicating biomarkers that provide quantifiable measure of response to peri-implant therapy. Moreover, a better knowledge of pattern of host osteo-immunoinflammatory modulation in the presence of peri-implantitis could either benefit the early diagnostic of the disease or to cooperate to prognostic information related to the status of the peri-implant breakdown. Finally, new evidences concerning the host profile of modulators of inflammation and of osseous tissue metabolism around dental implants could explain the individual susceptibility for developing peri-implant lesions, identifying individuals or sites with increased risk for peri-implantitis. The focus of this chapter was, based on a systematically searched and critically reviewed literature, summarizing the existing knowledge in the scientific research concerning the host osteo-immunoinflammatory response to the microbiological challenge related to periimplantitis.

Deproteinized bovine bone derived with collagen improves soft and bone tissue outcomes in flapless immediate implant approach and immediate provisionalization: a randomized clinical trial.

OBJECTIVES: This study aimed at evaluating soft and hard tissue dimensions after immediate implant placement and immediate temporization with or without alveolar preservation at the maxillary anterior region. MATERIALS AND METHODS: Twenty-two patients needing maxillary incisor extraction and with the possibility of immediate implant placement were randomly assigned to the following groups: test (n = 11): immediate implant placement + deproteinized bovine bone derived with collagen inserted into the alveolus or control (n = 11): immediate implant placement without biomaterial. All soft tissue measurements were evaluated at baseline, 3 months, and 6 months after implant therapy. Cone beam tomography was performed at baseline and at 6 months after implant placement to evaluate hard tissue dimension. RESULTS: The test group presented higher height of soft tissue at mesiobuccal and distobuccal sites at 3 months and 6 months when compared to the control group (p < 0.05). Regarding the bone tissue, the test group showed higher buccolingual ridge dimension at 6 months when compared to the control group (p < 0.05). CONCLUSIONS: It can be concluded that the use of deproteinized bovine bone derived with collagen together with immediate dental implants results in better soft and bone tissue outcomes than immediate implants alone. CLINICAL RELEVANCE: The use of deproteinized bovine bone derived with collagen may enhance the results regarding soft and bone tissue in combination with immediate implant and temporization.

Resveratrol reverses the negative effect of smoking on peri-implant repair in the tibia of rats.

OBJECTIVES: Innovative approaches capable to improve peri-implant bone repair are relevant in the presence of smoking, a risk factor for healing around implants. This study investigated the effect of resveratrol (RESV) on peri-implant repair, and its influence on bone-related markers in rats submitted to cigarette smoking inhalation (CSI). MATERIALS AND METHODS: One titanium implant was inserted in each tibiae of rats assigned to CSI+RESV (n:18); CSI+placebo (n:18); and non-CSI (n:18). One implant was removed for counter torque, and the peri-implant tissue was collected for mRNA quantification of BMP-2, OPN, Runx2, Lrp-5, Osx, ß-catenin, Dkk1, OPG, and RANKL. The other tibia was submitted to microCT to measure: bone volume, bone porosity, trabecular spacing, trabecular thickness, and bone-implant contact (BIC). RESULTS: No differences were detected between counter torque in CSI+RESV and non-CSI group (p > 0.05), whereas CSI+placebo group presented lower values when compared to the others (p < 0.05). RESV improved the BIC in CSI rats without differences when compared to non-CSI group (p > 0.05), whereas CSI+placebo showed reduced BIC when compared to the other groups (p < 0.05). RESV reduced RANKL/OPG and Lrp-5 levels and increased ß-catenin in CSI rats when compared to CSI+placebo (p < 0.05). CONCLUSION: Although further investigations should be considered using oral models of dental implants, within the limits of the present study, it was concluded that RESV reverses the negative effects of smoking in the peri-implant repair, benefiting the modulation of bone-related markers.

Resveratrol attenuates oxidative stress during experimental periodontitis in rats exposed to cigarette smoke inhalation.

OBJECTIVES: This study aimed at investigating the effect of the systemic administration of resveratrol (RESV) on oxidative stress during experimental periodontitis in rats subjected to cigarette smoke inhalation. MATERIAL AND METHODS: Experimental periodontitis (EP) was induced in 26 male Wistar rats by the insertion of a ligature around one of the first mandibular and maxillary molars. The animals were assigned randomly to the following groups: cigarette smoke inhalation (CSI; 3 times/d, 8 minutes/d) + resveratrol (10 mg/Kg), that is, SMK + RESV (n = 13) and cigarette smoke inhalation + placebo, that is, SMK + PLAC (n = 13). The substances were administered daily for 30 days (19 days prior and 11 days following EP induction), and then, the animals were euthanized. The maxillary specimens were processed for morphometric analysis of bone loss, and the tissue surrounding the first maxillary molars was collected for mRNA quantification of Sirtuin 1 (SIRT1) by real-time PCR. The gingival tissues surrounding the mandibular first molars were collected for quantification of superoxide dismutase 1 (SOD1) and nicotinamide adenine dinucleotide phosphatase oxidase (NADPH) using an ELISA assay. RESULTS: Reduced bone loss was demonstrated in animals in the SMK + RESV group as compared to those in the SMK + PLAC (P < 0.05) group on the basis of morphometric analysis. Resveratrol promoted higher levels of SIRT and SOD (P < 0.05) as well as reduced levels of NADPH oxidase (P < 0.05) were found in tissues derived from animals in the SMK + RESV group when compared to those in the SMK + PLAC group. CONCLUSION: Resveratrol is an efficient therapeutic agent that reduces exacerbation of bone loss found in animals with EP that were also exposed to smoke. The results suggest that its effects could be mediated, at least in part, by its antioxidant and anti-inflammatory properties which attenuate the effects of oxidative stress on EP in the presence of cigarette smoke.

Host response and peri-implantitis

Abstract Considering the absence of predictable and effective therapeutic interventions for the treatment of peri-implantitis, scientific evidence concerning the host response profile around dental implants could be important for providing in the future a wider preventive and/or therapeutic window for this peri-implant lesion, indicating biomarkers that provide quantifiable measure of response to peri-implant therapy. Moreover, a better knowledge of pattern of host osteo-immunoinflammatory modulation in the presence of peri-implantitis could either benefit the early diagnostic of the disease or to cooperate to prognostic information related to the status of the peri-implant breakdown. Finally, new evidences concerning the host profile of modulators of inflammation and of osseous tissue metabolism around dental implants could explain the individual susceptibility for developing peri-implant lesions, identifying individuals or sites with increased risk for peri-implantitis. The focus of this chapter was, based on a systematically searched and critically reviewed literature, summarizing the existing knowledge in the scientific research concerning the host osteo-immunoinflammatory response to the microbiological challenge related to periimplantitis.