Minimal invasiveness in nonsurgical periodontal therapy.

Periodontal treatment is quickly moving towards a philosophy consisting of a less invasive approach. In this context, minimally invasive nonsurgical therapy (MINST) is a promising option. This paper reviews the concepts behind minimal invasiveness in nonsurgical periodontology and reports the state-of the art evidence for this topic. Instruments used and protocols suggested for these applications are introduced and discussed. The original papers reviewed show probing pocket depth (PPD) reductions and clinical attachment level (CAL) gains ranging from 2 to 4 mm between baseline and 6 months to 5 years posttreatment for intrabony defects and from 1.5 to 3 mm between baseline and 2-6 months of follow-up for full-mouth results. These clinical outcomes are accompanied by statistically significant reductions in radiographic bone defect depth and increases in intrabony defect angles posttreatment. Wound healing mechanisms following MINST are presented, and clinical applications and directions for future research are suggested.

Impact of natural curcumin on the progression of experimental periodontitis in diabetic rats.

OBJECTIVE: To evaluate the role of natural curcumin (CURC) on experimental periodontitis (EP) in animals with diabetes mellitus (DM). MATERIAL AND METHODS: One hundred rats were assigned to DM + placebo (PLA); DM + CURC; DM + insulin (INS); DM + CURC + INS; and Non-DM. Diabetes was induced by streptozotocin. After 3 days, they were initiated CURC and PLAC solutions and insulin administrations, daily for 30 days. This included a period of 19 days prior to EP induction (ligature at the first mandibular and the second maxillary molar) and then additional 11 days. Specimens from the mandible were processed for morphometric examination of bone level. Gingival tissues from mandibular molars were collected for quantification of IL-1ß, IL-4, IL-6, IL-17, IFN-γ, and TNF-α using a Luminex/MAGpix assay. Gingivae from maxillary molars were subjected to RT-PCR for assessment of Runx2, RANKL, OPG, SIRT, Dkk1, and Sost levels. RESULTS: Lower linear bone loss was detected in ligated molars of DM + CURC + INS vs DM + PLAC and DM + INS groups (P < 0.05). In ligated sites from DM rats treated with CURC + INS, IL-6, IL-1ß, INF-γ, and TNF-α levels were the lowest in comparison with PLAC and/or INS and CURC as monotherapies (P < 0.05). CURC, independently of INS, increased Runx2 and SIRT when compared to DM + PLAC (P < 0.05) in ligated sites, whereas only CURC + INS reduced the RANKL/OPG ratio when compared to DM + PLAC (P < 0.05). CONCLUSION: Natural CURC, when associated with INS, reduces the DM-induced loss of supporting alveolar bone and promotes favorable modulation on osteo-immune-inflammatory mediators.

Experimental and clinical studies on regenerative periodontal therapy.

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Smoking habit modulates peri-implant microbiome: A case-control study.

BACKGROUND AND OBJECTIVE: Smoking is a recognized risk factor for peri-implant disease and leads to microbiological changes in mucositis and peri-implantitis. However, there is no knowledge about the impact of smoking in healthy peri-implant tissue. The aim of the study was to evaluate the microbiome in a peri-implant environment in smokers with healthy peri-implant conditions. METHODS: Peri-implant biofilm was collected around single clinically healthy, screwed-retained, teeth-surrounded implants in 12 non-smoker (NSMK) and 12 smoker (SMK) non-periodontitis subjects (no bleeding and probing depth <4 mm). Bacterial DNA was isolated and 16S ribosomal RNA gene libraries were sequenced using pyrosequencing, targeting the V3-V4 region. Datasets were processed using the Quantitative Insights into Microbial Ecology, Greengenes and the Human Oral Microbiome Database databases. RESULTS: An evident difference in the SMK peri-implant microbiome was observed compared to the NSMK microbiome, with a large abundance of species, even with a healthy peri-implant. The SMK core-microbiome showed an abundance of Fusobacterium, Tannerella and Mogibacterium, while the NSMK core revealed an abundance of Actinomyces, Capnocytophaga and Streptococcus, genera that are usually related to periodontal health. The microbiome inter-relationship was shown to be more inter-generic in SMK then in NSMK, indicating different microbiome cohesion. CONCLUSION: Smoking negatively affected the peri-implant microbiome, leading to a disease-associated state, even in clinically healthy individuals.

Esthetic treatment of gingival hyperpigmentation with Nd:YAG laser or scalpel technique: a 6-month RCT of patient and professional assessment.

This double-masked, randomized controlled trial with a split-mouth design aimed to compare patient- and professional-centered outcomes using different therapeutic approaches-neodymium-yttrium aluminum garnet (Nd:YAG) laser or scalpel technique-for gingival depigmentation. Patients presenting bilateral melanin gingival hyperpigmentation and who requested cosmetic therapy were recruited. Contralateral quadrants were randomly assigned to receive Nd:YAG laser (settings: 6 W, 60 mJ/pulse, and 100 Hz) or scalpel technique. Patient morbidity experienced at intratherapy and during the first postoperative week was evaluated. In addition, after 6 months, the cosmetic results achieved for the different therapeutic approaches were evaluated by patients and professionals. The chair time of each technique was also calculated. Patient-oriented outcomes concerning intratherapy morbidity did not demonstrate any differences between groups (p > 0.05), although a higher extent of discomfort/pain was experienced in the side treated by the scalpel technique compared to the Nd:YAG laser procedure during the first posttherapy week (p < 0.05). Regarding to cosmetic outcomes, no differences between techniques were observed for patient and professionals (p > 0.05). Significantly higher chair time was required for the scalpel technique than for the Nd:YAG laser therapy (p < 0.05). The Nd:YAG laser or the scalpel technique may be successfully used for the treatment of melanin gingival hyperpigmentation. However, the use of the Nd:YAG laser has presented advantages in terms of less discomfort/pain during the posttherapy period and a reduction of treatment chair time.

Photodynamic therapy in the treatment of class II furcation: a randomized controlled clinical trial.

AIM: To investigate the effect of photodynamic therapy (PDT) as adjunct to mechanical therapy in furcations. MATERIALS AND METHODS: A double-blind, parallel, randomized controlled clinical trial was conducted in subjects presenting class II furcations. The subjects were randomly allocated to a test (PDT; n = 16) or control group (non-activated laser/only photosensitizer; n = 21). At baseline, 3 and 6 months, clinical, microbiological and cytokine pattern evaluation was performed. Clinical attachment level was defined as the primary outcome variable. RESULTS: Clinical parameters improved after both therapies (p < 0.05) with no differences between groups at any time point (p > 0.05). At 6 months, real-time PCR evaluation showed a decrease in Porphyromonas gingivalis and Tannerella forsythia only in the PDT group (p < 0.05) with no inter-group differences. Regarding cytokines, IL-4 and IL-10 levels increased in both groups at 6 months. GM-CSF, IL-8, IL-1ß and IL-6 levels decreased only in the PDT group after 3 months (p < 0.05). At 3 months, inter-group analyses showed that GM-CSF, IFN-γ, IL-6 and IL-8 levels were lower in the PDT group. At 6 months, lower IL-1ß levels were also observed in the PDT group (p < 0.05). CONCLUSION: Photodynamic therapy did not promote clinical benefits for class II furcations; however, advantages in local levels of cytokines and a reduction in periodontopathogens were demonstrated.

The adjunctive effect of photodynamic therapy for residual pockets in single-rooted teeth: a randomized controlled clinical trial.

Residual pockets are challenging sites that require additional periodontal therapy. The aim of this study was to evaluate the effect of a single photodynamic therapy (PDT) as an adjunct to scaling and root planning (SRP) in residual pockets in single-rooted teeth. A blind, split-mouth, randomized controlled clinical trial was conducted in systemically healthy subjects presenting at least two residual pockets (probing pocket depth (PPD) ≥ 5 mm with bleeding on probing (BoP)) in single root teeth in supportive periodontal therapy. The selected sites were assigned to receive (1) PDT + SRP or (2) SRP. In sites treated by PDT as adjunctive to SRP, the laser system included a handheld battery-operated diode laser with a wavelength of 660 nm, a power output of 60 mW, and energy density of 129 J/cm(2), together with methylene blue as a photosensitizer (10 mg/ml). Clinical parameters were assessed at baseline and 3 months post-therapies. Clinical parameters improved significantly after both therapies (p < 0.05), whereas higher probing pocket depth reduction and clinical attachment level gain were observed in the PDT + SRP group at 3 months (p < 0.05). In addition, sites treated by the combined approach yielded a significant reduction in the number of sites with PPD <5 mm without BoP after 3 months compared to sites treated by conventional SRP alone (p < 0.05). PDT as an adjunctive to mechanical debridement demonstrated additional clinical benefits for residual pockets in single-rooted teeth and may be an alternative therapeutic strategy in supportive periodontal maintenance.

Clinical and microbiological changes after minimally invasive therapeutic approaches in intrabony defects: a 12-month follow-up.

OBJECTIVES: This 12-month randomized, controlled trial evaluated the clinical effects and microbiological changes of minimally invasive nonsurgical and surgical approaches for the therapy of intrabony defects. MATERIALS AND METHODS: Twenty-nine subjects with intrabony defects in single-rooted tooth were randomly assigned to; (1) minimally invasive nonsurgical technique (MINST) or (2) minimally invasive surgical technique (MIST). Quantities of Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Porphyromonas gingivalis, determined by using real-time PCR, were evaluated at baseline, 3, 6, and 12 months after the treatments. Clinical recordings--probing depth (PD), position of the gingival margin (PGM), and relative clinical attachment level (RCAL)--were obtained at baseline and 12 months post-therapy. The primary outcome variable of the study was RCAL. RESULTS: Both treatment modalities resulted in an improvement in all clinical recordings, with significant PD reductions (p < 0.05), RCAL gains (p < 0.05), and no change in the PGM (p > 0.05) after 12 months in both MINST and MIST groups. No clinical differences were observed between groups (p > 0.05). Regarding the microbiological outcomes, at the re-examinations, a significant decrease was observed for T. forsythia and P. gingivalis when compared with baseline (p < 0.05) for both treatments. The amount of A. actinomycetemcomitans did not reduced decrease throughout the study (p > 0.05). Intergroup differences in the microbiological assay were not found at any time point (p > 0.05). CONCLUSIONS: Both MINST and MIST provided comparable clinical results and microbiological changes in the treatment of intrabony defects over 12 months follow-up. CLINICAL RELEVANCE: This randomized, controlled, parallel trial revealed that both therapeutic modalities may promote clinical and microbiological benefits at 12 months post-therapy.

Impact of a triclosan-containing toothpaste during the progression of experimental peri-implant mucositis: Clinical parameters and local pattern of osteo-immunoinflammatory mediators in peri-implant fluid.

BACKGROUND: This study evaluated the influence of a triclosan-containing toothpaste in the profile of osteo-immunoinflammatory mediators in peri-implant crevicular fluid (PICF) and in clinical parameters during progression of peri-implant mucositis. METHODS: Twenty-two clinically healthy patients with an implant-supported single-unit crown were enrolled in this double-blind, randomized, crossover study carried out in two phases of 21 days each. During an experimental 3-week period of undisturbed plaque accumulation in the implants, patients were randomly assigned to use three times/day: triclosan (n = 11), triclosan/copolymer/fluoride toothpaste; or placebo (n = 11), fluoride toothpaste. After a professional prophylaxis, a washout period of 30 days was established. Clinical parameters and 15 osteo-immunoinflammatory mediators in the PICF were evaluated at baseline and at 3, 7, 14, and 21 days. RESULTS: Both groups showed increase in plaque index at implant sites from the 3rd until the 21st day (P < 0.05). Only triclosan treatment was able to avoid an increase in bleeding on probing (BOP) throughout the follow-ups (P > 0.05), whereas a significant intensification in BOP was observed from the 14th day in the placebo-treated sites (P < 0.05). Lower interleukin (IL)-10 concentrations were detected in the placebo group at the 21st day when compared with triclosan-treated implant sites (P < 0.05). IL-10 levels were reduced and IL-1ß concentrations were increased at 21 days when compared with baseline only in placebo-treated sites (P < 0.05). Osteoprotegerin levels significantly increased from the 14th until the 21st day only in triclosan-treated sites (P < 0.05). CONCLUSION: Triclosan-containing toothpaste controls clinical inflammation and interferes positively in the profile of osteo-immunoinflammatory mediators during progression of experimental peri-implant mucositis.

Occurrence of peri-implant diseases and risk indicators at the patient and implant levels: A multilevel cross-sectional study.

BACKGROUND: High prevalence rates of peri-implant diseases have been reported; however, the lack of standardization of definition criteria has lead to variations in the observed estimates. In addition, scarce data are available concerning patient and implant related factors associated to peri-implantitis. The aim of this study was to determine the prevalence of peri-implant diseases and their risk indicators at the patient and implant levels. METHODS: One hundred forty-seven patients with 490 dental implants were included. Dental implants were clinically and radiographically evaluated to determine their peri-implant conditions. Patient-related conditions and implant and prosthetic-related factors were recorded. Multivariable Poisson regression was fitted and prevalence ratios (PR) were reported. RESULTS: 85.3% of implants (95%CI 80.2 to 90.4) had mucositis and 9.2% (95%CI 4.7 to 13.7) had peri-implantitis. 80.9% (95%CI 73.8 to 86.8), and 19.1% (95%CI 12.6 to 25.5) of patients had mucositis and peri-implantitis. At the patient level, it was observed an increased probability of peri-implantitis in individuals with pocket depths ≥6 mm (PR = 2.47) and with ≥4 implants (PR = 1.96). Smoking increased the probability of peri-implantitis by three times (PR = 3.49). The final multilevel Poisson regression model at the implant level indicated that platform switching reduced the probability of peri-implantitis (PR = 0.18) and implants in function for ≥5 years increased this probability (PR = 2.11). The final model including patient and implant level indicators demonstrated that higher time of function (PR = 2.76) and smoking (PR = 6.59) were associated with peri-implantitis. CONCLUSION: Peri-implant diseases are highly prevalent in the studied sample, and factors associated with the occurrence of peri-implantitis were presence of pockets ≥6 mm, smoking, time of function, and type of platform.

Resveratrol Inhibits Periodontitis-Related Bone Loss in Rats Subjected to Cigarette Smoke Inhalation.

BACKGROUND: Alternative therapeutic approaches have been explored to modulate host response to periodontal disease. Knowledge of new strategies to treat periodontitis is particularly relevant in patients presenting augmented risk to periodontitis, such as smokers. The aim of this study is to investigate the impact of resveratrol (RESV) on progression of experimental periodontitis (EP) in the presence of cigarette smoke inhalation (CSI). METHODS: Rats were assigned to one of three groups: 1) CSI+RESV (n = 20); 2) CSI+placebo (n = 20); and 3) non-CSI (n = 20). CSI was initiated 1 week prior to initiation of RESV or placebo administration (systemically for 30 days) and was continued until the end of the study. EP was induced around the first mandibular and second maxillary molars using ligatures. Specimens from the mandible were processed for morphometric and microcomputed tomography examination of bone volume/levels. Gingival tissues surrounding mandibular molars were collected for quantification of interleukin (IL)-1ß, IL-4, IL-6, IL-17, and tumor necrosis factor-α using an assay system. Additional analyses of immunoinflammatory mediator performance (T-helper Type 17 [Th17]/Th2 and Th1/Th2 cell levels) were performed according to Th cell responses in gingival tissues. Gingival tissues of maxillary molars were subjected to real-time polymerase chain reaction for assessment of osteoprotegrin, runt-related transcription factor-2, receptor activator of nuclear factor-kappa B ligand (RANKL), sclerostin, and Dickkopf Wnt signaling pathway inhibitor 1 levels. RESULTS: Higher linear alveolar bone loss (ABL) and lower interradicular bone density were detected in ligated molars in the CSI+placebo group (P <0.05). IL-4 level was the highest, and Th17/Th2 levels were the lowest in RESV-treated rats compared with placebo rats (P <0.05). RESV reduced expression of messenger RNA for RANKL in animals receiving CSI (P <0.05). CONCLUSION: RESV inhibits EP and CSI-induced supporting ABL and has a beneficial effect on osteo-immunoinflammatory markers.

Selective cyclooxygenase-2 inhibitor may impair bone healing around titanium implants in rats.

BACKGROUND: The aim of this study was to investigate the effect of a selective cyclooxygenase-2 inhibitor, meloxicam, on bone healing around titanium implants in rats. METHODS: Thirty-one adult male Wistar rats were included in this study, and one screw-shaped titanium implant was inserted in the tibiae of each rat. The animals were randomly assigned to one of the following groups for daily subcutaneous injections: control (N = 14): saline solution; and test (N = 17): 3 mg/kg of meloxicam, each administered daily for 60 days. After the treatment, animals were sacrificed, and undecalcified sections were obtained. Bone-to-implant contact (BIC) and bone area (BA) within the limits of implant threads and bone density (BD) in a 500 mum-wide zone lateral to the implants were obtained and arranged for cortical (zone A) and cancellous (zone B) bone regions. RESULTS: Intergroup comparisons demonstrated that meloxicam significantly reduced bone healing around implants. For zone A, significant differences were observed regarding BIC (47.01 +/- 10.48 A; 35.93 +/- 12.25 B), BA (86.42 +/- 3.66 A; 61.58 +/- 12.09 B), and BD (96.86 +/- 0.96 A; 91.06 +/- 3.05 B) for control and test groups, respectively (P <0.05). For zone B, data analysis also showed significant differences among groups for BIC (30.76 +/- 13.80 A; 16.86 +/- 11.48 B), BA (34.83 +/- 8.18 A; 25.66 +/- 9.16 B), and BD (15.76 +/- 7.05 A; 7.73 +/- 4.61 B) for control and test groups, respectively (P <0.05). CONCLUSION: Meloxicam may negatively influence bone healing in the cortical and cancellous bone around titanium implants inserted in rats after continuous administration.

Open-flap versus flapless esthetic crown lengthening: 12-month clinical outcomes of a randomized controlled clinical trial.

BACKGROUND: Excessive gingival display (EGD) has a negative impact on a pleasant smile. Minimally invasive therapeutic modalities have become the standard treatment in many dentistry fields. Therefore, the aim of this study is to compare the clinical outcomes of open-flap (OF) and minimally invasive flapless (FL) esthetic crown lengthening (ECL) for the treatment of EGD. METHODS: A split-mouth randomized controlled trial was conducted in 28 patients presenting with EGD. Contralateral quadrants received ECL using OF or FL techniques. Clinical parameters were evaluated at baseline and 3, 6, and 12 months post-surgery. The local levels of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) were assessed by enzyme-linked immunosorbent assay at baseline and 3 months. Patients' perceptions regarding morbidity and esthetic appearance were also evaluated. Periodontal tissue dimensions were obtained by computed tomography at baseline and correlated with the changes in the gingival margin (GM). RESULTS: Patients reported low morbidity and high satisfaction with esthetic appearance for both procedures (P >0.05). RANKL and OPG concentrations were increased in the OF group at 3 months (P <0.05). Probing depths were reduced for both groups at all time points, compared with baseline (P <0.05). There were no differences between groups for GM reduction at any time point (P >0.05). CONCLUSIONS: FL and OF surgeries produced stable and similar clinical results up to 12 months. FL ECL may be a predictable alternative approach for the treatment of EGD.

Does Lip-Repositioning Surgery Improve Long-Term Smile Outcome and Dental Esthetics in Patients With Excessive Gingival Display? A Review of the Current Literature.

Focused Clinical Question: In patients with normal crown dimensions and excessive gingival display, does lip-repositioning surgery improve long-term smile outcome and dental esthetics? Clinical Scenario: A 27-year-old systemically healthy female presents with the chief complaint of "excessive gingival display when smiling" (Fig. 1). She reports that orthodontic treatment was performed and that she was referred for orthognathic surgery to correct the maxillary vertical excess and altered passive eruption. Clinically, the patient is periodontally healthy with favorable long-term periodontal prognosis. She is unsatisfied with her smile and states that it is "compromising her self-esteem." However, she refuses to accept the orthognathic surgery because of the extensiveness and morbidity of the procedure. She inquires about alternative solutions for her esthetic problem and whether it is possible to solve her gummy smile with a less invasive procedure. Lip-repositioning and anatomic crown-lengthening surgeries are presented as treatment options. The patient decides to pursue these treatment options. Lip-repositioning surgery is performed as described by Rosenblatt and Simon1 and Simon et al.,2 and healing is uneventful. Anatomic crown lengthening is performed 6 months after the previous surgery. The patient is pleased with the reduction of the excessive gingival display after these procedures (Fig. 2). However, there is lack of clinical evidence regarding the long-term stability of this surgical procedure.

Photodynamic therapy during supportive periodontal care: clinical, microbiologic, immunoinflammatory, and patient-centered performance in a split-mouth randomized clinical trial.

BACKGROUND: This study investigates the effect of photodynamic therapy (PDT) as monotherapy during supportive periodontal therapy. METHODS: A split-mouth, randomized controlled trial was conducted in patients with chronic periodontitis (N = 22) presenting at least three residual pockets (probing depth [PD] ≥5 mm with bleeding on probing [BOP]). The selected sites randomly received the following: 1) PDT; 2) photosensitizer (PS); or 3) scaling and root planing (SRP). At baseline and 3 and 6 months, clinical, microbiologic (real-time polymerase chain reaction analyses), cytokine pattern (multiplexed bead immunoassay), and patient-centered (regarding morbidity) evaluations were performed. RESULTS: All therapies promoted similar improvements in clinical parameters throughout the study (P <0.05), except that BOP was not reduced in the PS protocol (P >0.05). Lower levels of Aggregatibacter actinomycetemcomitans were observed in the PDT and SRP protocols at 3 months when compared with the PS protocol (P <0.05). An inferior frequency detection of Porphyromonas gingivalis was observed in the PDT protocol at 3 and 6 months and in the SRP protocol at 6 months from baseline (P <0.05). In addition, PDT protocol presented inferior frequency of P. gingivalis at 3 months when compared with the other therapies (P <0.05). Only patients in the PDT protocol exhibited augmented levels of anti-inflammatory interleukin (IL)-4 and reduced proinflammatory IL-1ß and IL-6 throughout the study (P <0.05). Intergroup analyses showed reduced IL-10 and increased interferon-γ and IL-1ß levels in the PS protocol when compared with the other therapies during follow-ups (P <0.05). No differences in morbidity were observed between the therapies (P >0.05), although the need for anesthesia was higher in SRP-treated sites (P <0.05). CONCLUSION: PDT as an exclusive therapy may be considered a non-invasive alternative for treating residual pockets, offering advantages in the modulation of cytokines.

Resveratrol decreases periodontal breakdown and modulates local levels of cytokines during periodontitis in rats.

BACKGROUND: Resveratrol (3,4',5-trihydroxystilbene) is a naturally occurring product found in numerous plants. Among its biologic properties, resveratrol may promote immunomodulatory effects on the host response. This study investigates the effect of continuous administration of resveratrol on the progression of experimental periodontitis in rats. METHODS: Periodontitis was induced in rats in one of the first molars chosen to receive a ligature. Animals were assigned to one of two groups: 1) daily administration of the placebo solution (control group) or 2) 10 mg/kg resveratrol (RESV group). The therapies were administered systemically for 30 days: for 19 days before periodontitis induction and then for another 11 days. Then, the specimens were processed for morphometric analysis of bone loss, and the gingival tissue surrounding the first molar was collected for quantification of interleukin (IL)-1ß, IL-4, and IL-17 using a multiplexing assay. RESULTS: Intergroup comparisons of the morphometric outcomes revealed higher bone loss values in ligated molars and unligated teeth in the control group than the RESV group (P <0.05). The immunoenzymatic assay of the gingival tissue showed a lower concentration of IL-17 in the RESV group than the control group (P <0.05), whereas no differences in the IL-1ß and IL-4 levels of the groups were observed (P >0.05). CONCLUSIONS: Continuous administration of resveratrol may decrease periodontal breakdown induced experimentally in rats. In addition, lower levels of IL-17 were found in the RESV group. Future studies are important to confirm the mechanism through which resveratrol exerts its effects.

The expression of antioxidant enzymes in the gingivae of type 2 diabetics with chronic periodontitis.

OBJECTIVES: There is controversial evidence regarding the levels of antioxidant molecules in type 2 diabetes periodontitis patients. Thus, the aim of the present study was to evaluate the gene expression of antioxidant enzymes in the gingival tissue of poorly and well-controlled type 2 diabetic subjects with chronic periodontitis (CP). DESIGN: Gingival biopsies were harvested from systemically and periodontally healthy subjects (n=12), systemically healthy subjects with CP (n=15), well-controlled (n=8) and poorly controlled (n=14) diabetic subjects with CP. The messenger RNA (mRNA) levels of peroxiredoxin (PRDX) 1 and 2, catalase (CAT), glutathione peroxidase (GPX1) and superoxide dismutase (SOD) 1 and 2 were measured by quantitative polymerase chain reaction (qPCR). RESULTS: The results showed that PRDX1 and GPX1 were up-regulated by periodontitis (p<0.05), independently of the glycaemic status, whilst PRDX2 and SOD2 genes were slightly influenced by periodontitis, but significantly induced when periodontitis was associated with DM, especially under a poor glycaemic control (p<0.05). Moreover, CAT and SOD1 expressions were not significantly influenced by any of these inflammatory disorders (p>0.05). CONCLUSION: In conclusion, both PRDX1 and GPX1 were overexpressed in CP whilst PRDX2 and SOD2 were up-regulated especially in the poorly controlled diabetic group with CP.

Clinical and patient-centered outcomes after minimally invasive non-surgical or surgical approaches for the treatment of intrabony defects: a randomized clinical trial.

BACKGROUND: The present study aims to compare the performance of minimally invasive non-surgical and surgical approaches for the therapy of intrabony defects. METHODS: Twenty-nine patients who presented with intrabony defects were randomly assigned to: 1) a minimally invasive non-surgical technique (MINST) group, or 2) minimally invasive surgical technique (MIST) group. The chair time of each therapeutic procedure was calculated. The probing depth (PD), position of the gingival margin (PGM) and relative clinical attachment level (RCAL) were evaluated at 3 and 6 months after treatments. The patient perception of discomfort/pain experienced during and after therapy and patient satisfaction regarding treatments were also evaluated. RESULTS: Significant PD reductions, RCAL gains, and no changes in the PGM were obtained at 3 and 6 months in MINST and MIST groups (P <0.05). No differences were observed between groups at any time points (P >0.05). Patient-oriented outcomes did not demonstrate differences between therapeutic approaches (P >0.05). Significant higher chair times were required in the MIST group than in the MINST group (P <0.05). CONCLUSIONS: Minimally invasive non-surgical and surgical approaches were successfully used for the treatment of intrabony defects and achieved periodontal health in association with negligible morbidity and suitable patient satisfaction. However, non-surgical therapeutic modality presented an advantage in terms of a reduction of treatment chair time.

The role of enamel matrix derivative protein in minimally invasive surgery in treating intrabony defects in single-rooted teeth: a randomized clinical trial.

BACKGROUND: This study investigates the impact of enamel matrix derivative (EMD) proteins on the outcome of a minimally invasive surgical technique (MIST) for the treatment of intrabony defects. METHODS: Thirty patients who presented with intrabony defects were randomly assigned to treatment with: 1) MIST plus EMD or 2) MIST alone. Probing depth (PD), position of the gingival margin (PGM), and relative clinical attachment level (RCAL) were evaluated at 3 and 6 months after treatment. Radiographs and markers in gingival crevicular fluid associated with periodontal regeneration were also evaluated. RESULTS: Significant PD reductions, RCAL gains, and no changes in PGM were obtained at 3 and 6 months in both groups. Clinical and radiographic evaluations and levels of mediators of wound healing did not present differences between therapies at any time. CONCLUSION: The use of EMD did not provide superior benefits on the outcome of the minimally invasive surgical approach for the treatment of intrabony defects.

Periosteum-derived cells as an alternative to bone marrow cells for bone tissue engineering around dental implants. A histomorphometric study in beagle dogs.

BACKGROUND: The aim of this study is to investigate the potential use of periosteum-derived cells (PCs) for tissue engineering in peri-implant defects. METHODS: Bone marrow cells (BMCs) and PCs were harvested from seven adult beagle dogs, cultured in vitro, and phenotypically characterized with regard to their osteogenic properties. The animals were then subjected to teeth extraction, and 3 months later, two implant sites were drilled, bone dehiscences created, and dental implants placed. Dehiscences were randomly assigned to one of two groups: PCs (PCs + carrier) and BMCs (BMCs + carrier). After 3 months, the animals were sacrificed and the implants with adjacent hard tissues were processed for undecalcified sections. Bone-to-implant contact, bone fill within the limits of implant threads, and new bone area in a zone lateral to the implant were histometrically obtained. RESULTS: In vitro, phenotypic characterization demonstrated that both cell populations presented osteogenic potential, as identified by the mineral nodule formation and the expression of bone markers. Histometrically, an intergroup analysis showed that both cell-treated defects had similar bone fill within the limits of implant threads and bone-to-implant contact (P >0.05), and although a trend toward higher new bone area values was found for the PC group, there was no significant difference between the experimental groups (P >0.05). CONCLUSIONS: Periosteal and bone marrow cells presented a similar potential for bone reconstruction. As such, periosteum may be considered as an alternative source of osteogenic cells in implant dentistry.