Semilunar coronally positioned flap or subepithelial connective tissue graft for the treatment of gingival recession: a 30-month follow-up study

BACKGROUND

The objective of this prospective, controlled clinical trial was to evaluate the long-term outcomes of subepithelial connective tissue graft (SCTG) or semilunar coronally positioned flap (SCPF) for the treatment of Miller Class I gingival recession defects.

METHODS

Seventeen patients with bilateral Miller Class I gingival recessions (< or =4.0 mm) in maxillary canines or premolars were selected. The recessions were randomly assigned to receive SCPF or SCTG. Recession height (RH), recession width (RW), width of keratinized tissue (WKT), thickness of keratinized tissue (TKT), probing depth (PD), and clinical attachment level (CAL) were measured at baseline and at 6 and 30 months post-surgery. Patient satisfaction with esthetics and root sensitivity was also evaluated.

RESULTS

The root-coverage outcomes obtained at 6 months were maintained throughout the study. At the 30-month examination, the average percentage of root coverage was 89.25% for SCPF and 96.83% for SCTG (P >0.05); complete root coverage was observed in 58.82% and 88.24% of patients, respectively. SCTG maintained a statistically significant increase in TKT (P <0.05) at 30 months. At this time, there were no significant differences between the two groups with regard to RH, RW, WKT, PD, and CAL. The evaluation of the esthetic outcome by the patient showed a preference for the SCTG treatment. Furthermore, in this group, no patient complained of residual or additional root hypersensitivity. In the SCPF group, three patients had this complaint at 30 months.

CONCLUSIONS

SCPF and SCTG can be successfully used to treat Class I gingival recession, presenting outcomes with long-term stability. However, patient-oriented outcomes, such as esthetics and root sensitivity, favor SCTG therapy.

Povidone-Iodine Used as an Adjunct to Non-Surgical Treatment of Furcation Involvements

BACKGROUND

The aim of this clinical trial was to evaluate the effect of topically applied povidone-iodine (polyvinylpyrrolidone and iodine [PVP-I]) used as an adjunct to non-surgical therapy of furcation involvements.

METHODS

Forty-four patients presenting at least one Class II furcation involvement that bled on probing with probing depth (PD)>or=5 mm were recruited. Patients were stratified into two treatment groups: 1) subgingival instrumentation by an ultrasonic device using PVP-I (10%) as the cooling liquid (test); and 2) identical treatment using distilled water as the cooling liquid (control). The following clinical outcomes were evaluated: plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PD, and relative horizontal attachment level (RHAL). The N-benzoyl-L-arginine-p-nitroanilide (BAPNA) test was used to analyze the trypsin-like activity in dental biofilm. The clinical and biochemical parameters were evaluated at baseline and 1, 3, and 6 months after therapy.

RESULTS

Both groups had similar means of PD reduction and RAL and RHAL gain. At 6 months, these variables were, respectively, 2.31, 1.17, and 1.00 mm in the control group and 2.31, 1.23, and 1.02 mm in the test group. There was also no difference between groups regarding the number of furcation sites presenting RAL gain>or=2 mm. The results of the BAPNA test failed to demonstrate significant differences between groups.

CONCLUSION

Non-surgical therapy can effectively treat Class II furcation involvements, and the use of topically applied PVP-I as an adjunct to subgingival instrumentation does not provide additional benefits.

Effect of curcumin on bone tissue in the diabetic rat: repair of peri-implant and critical-sized defects

This study determined the effect of curcumin on bone healing in animals with diabetes mellitus (DM). One hundred rats were divided into five groups: DM+PLAC, DM+CURC, DM+INS, DM+CURC+INS, and non-DM (CURC, curcumin; PLAC, placebo; INS, insulin). Critical calvarial defects were created and titanium implants were inserted into the tibiae. Calvarial defects were analyzed histometrically, and BMP-2, OPN, OPG, RANKL, Runx2, Osx, β-catenin, Lrp-5, and Dkk1 mRNA levels were quantified by PCR. The implants were removed for a torque evaluation, the peri-implant tissue was collected for mRNA quantification of the same bone-related markers, and the tibiae were submitted to micro-computed tomography. The DM+CURC+INS and non-DM groups exhibited greater closure of the calvaria when compared to the DM+PLAC group (P<0.05). Increased retention of implants was observed in the DM+CURC, DM+CURC+INS, and non-DM groups when compared to the DM+PLAC group (P<0.05). CURC improved bone volume and increased bone-implant contact when compared to DM+PLAC (P<0.05). In calvarial samples, CURC favourably modulated RANKL/OPG and Dkk1 and improved β-catenin levels when compared to DM+PLAC (P<0.05). In peri-implant samples, Dkk1 and RANKL/OPG were down-regulated and BMP-2 up-regulated by CURC when compared to DM+PLAC (P<0.05). CURC reverses the harmful effects of DM in bone healing, contributing to the modulation of bone-related markers.

Guided tissue regeneration may modulate gene expression in periodontal intrabony defects: a human study

BACKGROUND AND OBJECTIVE

Guided tissue regeneration has been shown to lead to periodontal regeneration, however, the mechanisms involved remain to be clarified. The present study was carried out to assess the expression of genes involved in the healing process of periodontal tissues in membrane-protected vs. nonprotected intrabony defects in humans.

MATERIAL AND METHODS

Thirty patients with deep intrabony defects (> or = 5 mm, two or three walls) around teeth that were scheduled for extraction were selected and randomly assigned to receive one of the following treatments: flap surgery alone (control group) or flap surgery plus guided tissue regeneration (expanded polytetrafluorethylene (e-PTFE) membrane) (test group). Twenty-one days later, the newly formed tissue was harvested and quantitatively assessed using the polymerase chain reaction assay for the expression of the following genes: alkaline phosphatase, receptor activator of nuclear factor-kappa B ligand, osteoprotegerin, osteopontin, osteocalcin, bone sialoprotein, basic fibroblast growth factor, interleukin-1, interleukin-4, interleukin-6, matrix metalloproteinase-2 and matrix metalloproteinase-9.

RESULTS

Data analysis demonstrated that mRNA levels for alkaline phosphatase, receptor activator of nuclear factor-kappa B ligand, osteoprotegerin, osteopontin, bone sialoprotein, basic fibroblast growth factor, interleukin-1, interleukin-6, matrix metalloproteinase-2 and matrix metalloproteinase -9 were higher in the sites where guided tissue regeneration was applied compared with the control sites (p < 0.05), whereas osteocalcin mRNA levels were lower (p < 0.05). No difference was observed in interleukin-4 mRNA levels between control and test groups.

CONCLUSION

Within the limits of this study, it can be concluded that genes are differentially expressed in membrane barrier-led periodontal healing when compared with flap surgery alone, and this may account for the clinical outcome achieved by guided tissue regeneration.

Guided tissue regeneration with a bioabsorbable polylactic acid membrane in gingival recessions. A histometric study in dogs

BACKGROUND

The goal of this investigation was to histologically and histometrically evaluate the healing process of gingival recessions treated by guided tissue regeneration with bioabsorbable polylactic acid membranes (GTR group) and to compare it to that obtained with coronally positioned flaps (CPF group).

METHODS

Gingival recessions were surgically created on the buccal aspect of the upper cuspids of 5 mongrel dogs. The defects (5x7 mm) were exposed to plaque accumulation for 3 months. The contralateral defects were then randomly assigned to each group. After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, and defect coverage.

RESULTS

The extension of the epithelium was 1.9 +/- 0.8 mm for the GTR-group and 3.0 +/- 0.9 mm for the CPF-group (P = 0.16). The connective tissue adaptation was 0.1 +/- 0.1 and 0.8 +/- 0.5 mm in the GTR group and CPF group, respectively (P = 0.051). The new cementum was 3.8 +/- 1.5 mm and 2.4 +/- 0.3 mm in the GTR group and CPF group, respectively (P= 0.16). Bone formation was 1.1 +/- 0.5 mm in the GTR group and 1.4 +/- 0.2 mm in the CPF group (P = 0.53). Histologically, the defect coverage observed was similar, 90.5% and 91.9% for the GTR group and the CPF group, respectively. No statistical differences in any of the parameters could be detected.

CONCLUSIONS

Within the limits of this study, it can be concluded that both procedures resulted in a favorable healing response with no significant difference between the treatments.

Root surface defect produced by hand instruments and ultrasonic scaler with different power settings: an in vitro study

The aim of this study was to evaluate the root surface defect produced by hand curettes and ultrasonic tips with different power settings. Forty root surfaces were divided into 4 groups according the treatment: Gracey curettes, ultrasonic scaler at 10% power, ultrasonic scaler at 50% power and ultrasonic scaler at 100% power. Each specimen was instrumented with 15 strokes and the and divided in the middle to evaluate: (1) the defect depth produced by the instrumentation and (2) contact area of the instrument tips, which was analyzed by scanning electron microscopy. ANOVA and Tukey's test were used for statistical analysis (a=0.05). The results (mean ± SD) of the contact area showed significantly greater defects (p<0.05) for the hand instrumented groups (2092.9 ± 482) compared to the ultrasonic groups (606.8 ± 283.0; 858.6 ± 422.5; 1212.0 ± 366.7, respectively), independently of the power setting. The values for the defect depth on root surface showed no statistically significant difference (p<0.05) between hand instrumentation (66.1 ± 34.0) and ultrasonic scaling at 10%, 50% or 100% power settings (52.4 ± 22.1; 72.0 ± 29.9; 77.7 ± 37.7, respectively). The findings of this study demonstrate that ultrasonic instrumentation produced a similar defect depth to that of hand instrumentation, with a smaller tip contact area, independently of the power setting used for scaling.

Effect of two different approaches for root decontamination on new cementum formation following guided tissue regeneration: a histomorphometric study in dogs

BACKGROUND AND OBJECTIVE

The aim of the present study was to evaluate comparatively the effect of two different approaches for root decontamination on new cementum formation following guided tissue regeneration (GTR).

MATERIAL AND METHODS

Nine mongrel dogs were used to obtain bilateral chronic class III furcation defects by placing cotton ligatures around both third mandibular premolars. The teeth were randomly assigned to receive one of the following treatments: scaling and root planing, by means of hand and rotatory instruments, in order to remove soft and hard deposits as well as all root cementum (group A); or removal of only soft microbial deposits, by polishing the root surface with rubber cups and polishing paste, aiming for maximum root cementum preservation (group B). Both groups were treated with GTR, with the use of resorbable polyglycolic-lactic acid membranes (RESOLUT XT).

RESULTS

Four months later, data analysis showed that a superior length (mm) (3.59 +/- 1.67 and 6.20 +/- 2.26 for groups A and B, respectively; p = 0.004) and a thicker layer (microm) (18.89 +/- 9.47 and 52.29 +/- 22.48 for groups A and B, respectively; p = 0.001) of new cementum was achieved by keeping the root cementum in place during root decontamination (group B). Regardless of the treatment modality, the new cementum was predominantly of a reparative, cellular extrinsic and intrinsic fiber type.

CONCLUSION

Within the limits of the present study, it may be concluded that root cementum preservation may affect the new cementum formation following GTR in class III furcation defects, and the treatment modality did not influence the type of newly formed cementum.

Age-related and surgically induced estrogen deficiencies may differently affect bone around titanium implants in rats

BACKGROUND

Valuable information has been obtained using the ovariectomy model; however, clinical studies have indicated that such a model may not be appropriate to parallel with the postmenopausal condition and titanium implants. Thus, this study aimed to comparatively evaluate, by histometric analysis, the influence of age-related (ARED) and surgically induced (OVX) estrogen deficiencies on bone around titanium implants inserted in rats.

METHODS

Single screw-shaped titanium implants were placed in rat tibiae and animals were then assigned to one of the following groups: SHAM (N = 15): bilateral sham ovariectomies in 90-day-old rats, 21 days before implant placement; OVX (N = 15): bilateral ovariectomies in 90-day-old rats, 21 days before implant placement; and ARED (N = 15): implant placement in reproductive aged rats (22 months old). After 60 days, the animals were sacrificed and undecalcified sections obtained. Bone-to-implant contact (BIC) and bone area (BA) within the limits of implant threads and bone density (BD) in a 500 microm-wide zone lateral to the implant were obtained and arranged for cortical (zone A) and cancellous (zone B) bone regions.

RESULTS

For zone A, intergroup analysis showed no significant differences regarding BIC and BA (P >0.05). In contrast, ARED negatively influenced BD around the implants (P <0.05). In zone B, OVX negatively affected BIC and BA (P <0.05), and both ARED and OVX groups demonstrated lower BD than the SHAM group (P <0.05).

CONCLUSION

Within the limits of this study, it can be concluded that ARED mainly affects preexisting bone while OVX more significantly affects both newly formed and preexisting bone.

Impact of an Anti-Inflammatory Therapy and Its Withdrawal on the Progression of Experimental Periodontitis in Rats

BACKGROUND

Anti-inflammatory agents have been reported as a bone loss mediator in periodontitis. This study aimed to investigate in rats the impact of a selective cyclooxygenase-2 inhibitor (meloxicam) on bone loss in ligature-induced periodontitis and its post-treatment effect after administration withdrawal.

METHODS

Seventy-five adult male Wistar rats were included. After anesthesia, a mandibular first molar was randomly assigned to receive the cotton ligature in the sulcular position, while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following five treatment groups (15 animals each), including daily subcutaneous injections: 1) saline solution for 15 days; 2) saline solution for 45 days; 3) 3 mg/kg of meloxicam for 15 days; 4) 3 mg/kg of meloxicam for 45 days; or 5) 3 mg/kg of meloxicam for 15 days followed by saline solution for 30 days. The animals were sacrificed and the specimens routinely processed. The volume of bone loss was histometrically measured and statistical analysis performed.

RESULTS

Intergroup comparisons demonstrated that the drug may significantly reduce periodontitis-related bone loss (group 3: 5.83 +/- 2.04); however, this effect is less evident when the drug is administered in a short period (group 4: 3.59 +/- 1.57). Moreover, after drug withdrawal, no residual effect was observed (6.86 +/- 3.59, 6.09 +/- 2.66, groups 2 and 5, respectively) (P > 0.05).

CONCLUSIONS

Within the limits of the present study, it can be concluded that selective cyclooxygenase-2 inhibitors may reduce bone loss associated with experimental periodontitis and that no remaining effect can be expected after its withdrawal.

Periodontal Surgery and Glass Ionomer Restoration in the Treatment of Gingival Recession Associated With a Non-Carious Cervical Lesion: Report of Three Cases

BACKGROUND

Buccal gingival recession is a prevalent problem in populations with a high standard of oral hygiene and is very often associated with a non-carious cervical lesion, complicating treatment. The purpose of this report is to show three cases treated by an integrated periodontal and restorative dentistry approach.

METHODS

Three patients with Miller Class I gingival recessions associated with non-carious cervical lesions were enrolled for treatment. One patient received a coronally positioned flap and a resin-modified glass ionomer restoration, and two patients were treated with a coronally positioned flap, resin-modified glass ionomer restoration, and connective tissue graft. Probing depth (PD), relative gingival recession (RGR), and clinical attachment level (CAL) were measured at baseline and at 6 and 8 months after surgery.

RESULTS

After the healing period, all patients showed CAL gain and reduction in RGR. No difference was observed on PDs compared to baseline. No signs of gingival inflammation or bleeding on probing were seen. The patients were satisfied with the final esthetics and had no more dentin hypersensitivity.

CONCLUSION

This report indicates that teeth with Miller Class I gingival recessions associated with non-carious cervical lesions can be successfully treated by an integrated periodontal and restorative dentistry approach; however, longitudinal randomized controlled clinical trials must be performed to support this approach.

Comparative Study of Ultrasonic Instrumentation for the Non-Surgical Treatment of Interproximal and Non-Interproximal Furcation Involvements

BACKGROUND

The aim of this clinical trial was to compare the outcome of non-surgical treatment of interproximal and non-interproximal Class II furcation involvements.

METHODS

Thirty-eight patients presenting at least one Class II furcation involvement that bled on probing with a probing depth (PD) > or = 5 mm were recruited. Furcation involvements were grouped as either buccal and lingual furcation involvements (BLFI) or interproximal furcation involvements (IFI). The following clinical outcomes were evaluated: visible plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PD, and relative horizontal attachment level (RHAL). N-benzoyl-l-arginine-p-nitroanilide (BAPNA) testing was used to analyze trypsin-like activity in dental biofilm. All parameters were evaluated at baseline and 1, 3, and 6 months after non-surgical subgingival instrumentation.

RESULTS

Six months after treatment, both groups had similar means of RAL and RHAL gain (P >0.05). These variables were 1.22 and 1.07 mm in the IFI group and 1.38 and 1.20 mm in the BLFI group, respectively. The PD reduction was significantly greater in the BLFI group than in the IFI group (2.59 and 2.11 mm, respectively; P <0.05). The BLFI group presented fewer sites with PD > or = 5 mm than the IFI group at all post-treatment periods. At 6 months, the BAPNA test showed that only the BLFI group had values significantly different from baseline. This means that the BLFI group had significantly lower BAPNA values compared to the IFI group at 6 months.

CONCLUSION

Buccal and lingual Class II furcation involvements respond better to non-surgical therapy compared to interproximal Class II furcation involvements.

Use of enamel matrix protein derivative with minimally invasive surgical approach in intra-bony periodontal defects: clinical and patient-centered outcomes

This case series evaluated the clinical performance and patient-centered outcomes after a minimally invasive surgical technique (MIST) associated with enamel matrix protein derivative (EMD), for the treatment of intra-bony defects. Twelve patients presenting teeth with probing depth >5 mm and bleeding on probing associated with radiographic evidence of intra-bony defect were treated by MIST associated with EMD. Clinical parameters were measured at baseline, 3 and 6 months. Patient perception during the intraoperative period and during the first postoperative week was evaluated. The use of MIST with EDM promoted significant improvements in clinical parameters, minimal pain/discomfort and maximum esthetics satisfaction. Within of limits of the present study, it could be shown that MIST combined with EMD for the treatment of intra-bony defects promotes satisfactory clinical and patient-centered outcomes.

Cigarette smoke inhalation increases the alveolar bone loss caused by primary occlusal trauma in a rat model

BACKGROUND AND OBJECTIVE

Occlusal trauma (OT) and smoking are both factors that alter alveolar bone metabolism and therefore could synergistically act on alveolar bone loss. The aim of this experimental study was to evaluate the influence of short-term cigarette smoke inhalation (CSI) on inter-radicular alveolar bone loss promoted by primary OT in a rat model.

MATERIAL AND METHODS

Forty-eight animals were randomly assigned to one of three groups based on treatment type: OT + CSI (n = 16), animals were exposed to CSI three times per day, for 8 min per exposure, and they concomitantly received unilateral vertical augmentation creating an occlusal interference inducing experimental OT; OT (n = 16), animals received only unilateral vertical augmentation; negative control (NC; n = 16), animals maintained for equal periods to achieve periodontal baseline values of periodontal ligament dimension. Each group was divided into two subgroups (n = 8) based on treatment length: 7 or 14 d.

RESULTS

After 7 d, the OT + CSI group exhibited significantly higher bone loss compared to the NC group (p = 0.0022). After 14 d, the OT (p < 0.0001) and OT + CSI (p < 0.0001) groups presented significantly higher bone loss compared to the NC group, and OT + CSI resulted in significantly higher bone loss than OT alone (p = 0.0241). The number of tartrate-resistant acid phosphatase-positive cells on the linear surface of the bone crest after 7 d was significantly higher in the OT + CSI group as compared to the NC and OT groups (p < 0.0001 and p = 0.0045, respectively) and remained significantly higher in the OT + CSI group after 14 d, compared to the OT group (p < 0.0001).

CONCLUSION

Short-term CSI increases early bone loss in association with OT after 7 d, and this worsens in severity after 14 d of exposure.

Characterization of the release profile of doxycycline by PLGA microspheres adjunct to non-surgical periodontal therapy

The aim of this pilot study was to assess the release of locally delivered doxycycline by poly (l-lactide-co-glycolide) (PLGA) microspheres in the periodontal pocket of patients with chronic periodontitis, treated by non-surgical periodontal therapy. Nineteen sites of non-adjacent teeth of four different patients were evaluated. Five milligram of PLGA microspheres loaded with 16 doxycycline hyclate (DOX) was administered per periodontal site. To quantify DOX released into the periodontal pocket, gingival crevicular fluid (GCF) was collected from the sites on days 2, 5, 7, 10, 15, and 20 after DOX application, and high-performance liquid chromatography was performed. Data were statistically assessed by ANOVA/Tukey test. At days 2, 5, and 7, the DOX concentration was stably sustained (23.33 ± 1.38, 23.4 ± 1.82, and 22.75 ± 1.33 μg/mL, respectively), with no significant differences over these assessment times (p > 0.05). At days 10 and 15, a tendency was observed toward a decrease in DOX concentration (21.74 ± 0.91 and 20.53 ± 4.88 μg/mL, respectively), but a significant decrease in GCF drug concentration (19.69 ± 4.70 μg/mL) was observed only on day 20. The DOX delivery system developed demonstrated a successful sustained release after local administration, as an adjunct to non-surgical periodontal therapy.

Comparative in vitro study of root roughness after instrumentation with ultrasonic and diamond tip sonic scaler

Objective:

The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips.

Materials and Methods:

Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope.

Results:

Significant statistical differences (p<0.05) were observed when comparing the control group (0.48±0.07mm) to the treated groups (hand - 1.246±0.279mm, ultrasonic - 1.468±0.177mm and sonic instrumentation - 1.576±0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p>0.05).

Conclusion:

The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

Non-surgical instrumentation associated with povidone-iodine in the treatment of interproximal furcation involvements

Objective

The aim of this controlled clinical trial was to evaluate the effect of topically applied povidone-iodine (PVP-I) used as an adjunct to non-surgical treatment of interproximal class II furcation involvements.

Material and methods

Thirty-two patients presenting at least one interproximal class II furcation involvement that bled on probing with probing pocket depth (PPD) ≥5 mm were recruited. Patients were randomly chosen to receive either subgingival instrumentation with an ultrasonic device using PVP-I (10%) as the cooling liquid (test group) or identical treatment using distilled water as the cooling liquid (control group). The following clinical outcomes were evaluated: visible plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PPD and relative horizontal attachment level (RHAL). BAPNA (N-benzoyl-Larginine-p-nitroanilide) testing was used to analyze trypsin-like activity in dental biofilm. All parameters were evaluated at baseline and 1, 3 and 6 months after non-surgical subgingival instrumentation.

Results

Six months after treatment, both groups had similar means of PPD reduction, RAL and RHAL gain (p>0.05). These variables were, respectively, 2.20±1.10 mm, 1.27±1.02 mm and 1.33±0.85 mm in the control group and 2.67±1.21 mm, 1.50±1.09 mm and 1.56±0.93 mm in the test group. No difference was observed between groups at none of the posttreatment periods, regarding the number of sites showing clinical attachment gain ≥2 mm. However, at 6 months posttreatment, the test group presented fewer sites with PPD ≥5 mm than the control group. Also at 6 months the test group had lower BAPNA values than control group.

Conclusion

The use of PVP-I as an adjunct in the non-surgical treatment of interproximal class II furcation involvements provided limited additional clinical benefits.

Enamel matrix derivative versus guided tissue regeneration in the presence of nicotine: a histomorphometric study in dogs

AIM

The goal of this histometric study was to compare the healing process of dehiscence-type defects treated by enamel matrix derivative (EMD) or guided tissue regeneration (GTR) under the effect of nicotine in the dog model.

MATERIALS AND METHODS

Eight mongrel dogs were used. Buccal osseous dehiscences were surgically created on the mesial roots of the mandibular third and fourth pre-molars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: open flap debridement (OFD), EMD or GTR with a resorbable membrane. During 4 months, the dogs received subcutaneous administration of nicotine (2 mg/kg twice a day with a 12 h interval between the applications). After this period, the animals were killed and the blocks were processed. The histometric parameters evaluated included gingival recession, epithelial length, connective tissue adaptation, new cementum and new bone.

RESULTS

A superior length of new cementum was observed in the sites treated by EMD in comparison with OFD (p< or =0.05). No statistically significant differences were observed between GTR and the other groups.

CONCLUSIONS

In the presence of nicotine, EMD may promote more new cementum formation than OFD while GTR failed to provide a significant difference.

Cigarette smoke inhalation influences bone healing of post-extraction tooth socket: a histometric study in rats

The aim of this study was to evaluate, histometrically, the bone healing of the molar extraction socket just after cigarette smoke inhalation (CSI). Forty male Wistar rats were randomly assigned to a test group (animals exposed to CSI, starting 3 days before teeth extraction and maintained until sacrifice; n=20) and a control group (animals never exposed to CSI; n=20). Second mandibular molars were bilaterally extracted and the animals (n=5/group/period) were sacrificed at 3, 7, 10 and 14 days after surgery. Digital images were analyzed according to the following histometric parameters: osteoid tissue (OT), remaining area (RA), mineralized tissue (MT) and non-mineralized tissue (NMT) in the molar socket. Intergroup analysis showed no significant differences at day 3 (p>0.05) for all parameters. On the 7(th) day, CSI affected negatively (p<0.05) bone formation with respect to NMT and RA (MT: 36%, NMT: 53%, RA: 12%; and MT: 39%, NMT: 29%, RA: 32%, for the control and test groups, respectively). In contrast, no statistically significant differences (p>0.05) were found at days 10 and 14. It may be concluded that CSI may affect socket healing from the early events involved in the healing process, which may be critical for the amount and quality of new-bone formation in smokers.

Rethinking the decision-making process to treat gingival recession associated with non-carious cervical lesions

The presence of a tooth-surface defect, such as a non-carious cervical lesion (NCCL), associated with sites of gingival recession (GR) defects creates a combined soft tissue/tooth defect (CD) that requires a different treatment plan. This study aimed to critically review the literature regarding the available treatment protocols for CDs and suggest a new decision-making process. NCCLs were classified as Class A-: the cementoenamel junction (CEJ) was visible and the root surface discrepancy was < 0.5 mm (no step); Class A+: CEJ was visible and the root surface discrepancy was > 0.5 mm (with a step); Class B-: unidentifiable CEJ without a step; Class B+: unidentifiable CEJ with a step. NCCLs affecting both root and crown surfaces (Class B) lead to CEJ destruction and consequently eliminate an important landmark used before and after root coverage procedures. The depth of the root surface discrepancy is vital owing to its possible impact on soft tissue adaptation after healing, which, in turn, may influence the treatment options, namely the use of graft and/or composites to compensate for the discrepancy. Clinically, a step with horizontal depth greater than 0.5 mm should be recognized as the minimum threshold value to define this condition. Extremely deep defects tend to assume a V-shaped topography. Therefore, extremely deep V-shaped defects were classified into subclasses A+V, a V-shaped defect, and B+V, a V-shaped defect with loss of CEJ, for management considerations. The treatment options, supported by the literature, and a decision-making process to deal with each condition are presented.

Clinical and Microbiological Evaluation of Surgical and Nonsurgical Treatment of Aggressive Periodontitis

The present study aimed to evaluate clinical and microbiological effects of surgical and nonsurgical periodontal therapy in generalized aggressive periodontitis (GAgP) treatment. Sixteen GAgP patients were included in this randomized split-mouth design clinical trial. Maxillary quadrants were allocated into two groups: Nonsurgical Therapy (NST) and Surgical Therapy (ST). The following clinical parameters were assessed: plaque index (PI), bleeding on probing index (BoP), probing depth (PD), clinical attachment level (CAL) and gingival margin position (GMP). Concentrations of Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) in the subgingival biofilm were also determined. Clinical and microbiological parameters were assessed at baseline (n=16), 3 (n=15), 6 (n=15) and 12 months (n=8) after treatment. ST was able to promote higher PD reduction compared to NST in deep pockets at 12 months (p<0.05) and in posterior teeth at 6 months (p<0.05). In addition, higher gingival recession was observed in posterior teeth of the ST group at the 6th month (p<0.05). However, ST failed to promoted additional CAL gain in any timepoint (p>0.05). Moreover, microbiological evaluation showed no statistical difference in levels of Aa and Pg for both groups at all follow-up periods. Surgical therapy promoted similar clinical benefits to GAgP therapy. Moreover, both therapies failed to reduce Aa and Pg levels at different follow-up times.

Selective COX-2 inhibitor reduces bone healing in bone defects

Anti-inflammatory agents have been reported to regulate bone healing. The aim of this study was to investigate the effect of a selective cyclooxygenase-2 inhibitor (meloxicam) on bone healing in calvarial defects in rats. Thirty-six adult male Wistar rats were included. After anesthesia, a linear incision was made through the skin of the scalp, a full-thickness flap was reflected and a 4 mm round defect was made with a trephine drill. The animals were randomly assigned to one of the following 4 treatment groups (9 animals each), including daily subcutaneous injections: A: saline solution for 15 days; B: saline solution for 45 days; C: 3 mg/kg of meloxicam for 15 days and D: 3 mg/kg of meloxicam for 45 days. The animals were sacrificed and the specimens, routinely processed. The bone filling was histometrically measured and statistical analysis, performed. Intergroup comparisons demonstrated that the meloxicam groups presented a significant reduction in bone healing when compared to their respective controls (group A, 44.5 ± 5.75%, against group C, 57.5 ± 7.25%, p < 0.05; group B, 40.25 ± 13.75%, against group D, 52.25 ± 17.25%). Within the limits of the present study, it can be concluded that selective cyclooxygenase-2 inhibitors may reduce bone healing in calvarial defects in rats after continuous administration.