Long-term stability of gingival margin and periodontal soft-tissue phenotype achieved after mucogingival therapy: A systematic review.

BACKGROUND: The aim of this systematic review was two-fold: (i) to evaluate the long-term (≥5 years) stability of the gingival margin position, keratinized tissue width (KTW) and gingival thickness (GT) in sites that underwent root coverage (RC) or gingival augmentation (GA); and (ii) to assess the influence of different local variables on the long-term stability of dental and gingival tissues. MATERIALS AND METHODS: Randomized controlled trials (RCTs) and non-RCTs reporting short-term (i.e., 6-12 months after baseline surgical intervention) and long-term (≥5 years) follow-up data after surgical treatment of adult patients presenting single or multiple mucogingival deformities, defined as sites presenting gingival recession defects (GRDs) and/or (KTW) deficiency (i.e., <2 mm), were considered eligible for inclusion. MEDLINE-PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases were searched for articles published up to 15 May 2023. Mixed-effects multiple linear regression was used to assess the association between KTW, type of surgical procedure and time (i.e., independent variables) on the stability of the gingival margin in sites that received RC or GA therapy. RESULTS: Of the 2569 potentially eligible records, 41 (reporting 40 studies) met the eligibility criteria. Graphical estimates including data from all RC procedures found an upward trend in recession depth (RD) increase over time. Conversely, it was observed that in 63.63% of RC studies and in 59.32% of RC treatment arms KTW increased over time, particularly in sites treated with subepithelial connective tissue grafts (SCTGs). Conversely, sites that underwent GA procedures generally exhibited an overall reduction of KTW over time. However, sites treated with free gingival grafts (FGGs) showed a decrease in RD after 10 years of follow-up. Three main findings derived from the pooled estimates were identified: (i) Gingival margin stability was associated with the amount of KTW present during short-term assessment (i.e. the greater the KTW at 6-12 months after treatment, the more stable the gingival margin). (ii) The use of autogenous soft-tissue grafts was associated with lower RD increase over time. (iii) Treatment approaches that contribute to the three-dimensional enhancement of the gingival phenotype, as clearly demonstrated by FGG, were associated with gingival margin stability. CONCLUSIONS: The extent of apical migration of the gingival margin appears to be directly related to the amount of KTW and GT upon tissue maturation. Interventions involving the use of autogenous grafts, either SCTG or FGG, are associated with greater short-term KTW gain and lower RD increase over time.

Critical-size defects reconstruction with four different bone grafts associated with e-PTFE membrane: A histomorphometric experimental in vivo study.

OBJECTIVES: The goal of this study was to assess the newly formed bone and the remnant biomaterial by comparing four different bone grafts used to treat critical-size defects, associated or not with the non-resorbable membrane. MATERIALS AND METHODS: Two calvaria critical-size bone defects were created in 50 male Wistar rats. They were divided into blood (G1), autogenous (G2), bioglass (G3), hydroxyapatite (G4), and xenograft (G5) groups, associated or not with e-PTFE. The experimental periods were 15 and 45 days. Sections were prepared for histomorphometric assessment. All data were analyzed by the mixed-effects model with multiple comparisons (significance level, p < .05). RESULTS: A similar level of new bone was observed for all groups, associated with a high level of vascularization. G1 and G2 ensured sovereignty over the greater quantity of new bone. A non-significant result was reported comparing groups with and without membranes. No significant result was found between the experimental synthetic biomaterials (G3 and G4). G5L achieved 22.0% of new bone after 45 days (p > .05). All groups had a stable volume of biomaterial kept in the short term (p > .05). G2 was the best material for new bone formation and final volume of biomaterial, followed by G4 < G5 < G3. Thus, it is possible that G4 had a better degradation profile among the experimental groups. CONCLUSIONS: The best results were found in the autogenous group, with higher resorption and integration; non-significative new bone was found among the experimental groups; and the regeneration of critical bone defects using an e-PTFE barrier did not present significant results on new bone formation.

Root coverage of multiple gingival recessions treated with coronally advanced flap associated with xenogeneic acellular dermal matrix or connective tissue graft: a 6-month split-mouth controlled and randomized clinical trial.

OBJECTIVES: This study aimed to compare xenogeneic dermal matrix (XDM) to connective tissue graft (CTG) associated with coronally advanced flap (CAF) in treating Miller's class I and II (RT1) multiple gingival recession in a split-mouth randomized clinical trial. MATERIALS AND METHODS: Fifteen patients with bilateral Miller's class I and II multiple recessions were selected. The patient's side receiving each treatment was randomly allocated to receive XDM or CTG. The clinical parameters were measured at baseline and 6 months of follow-up. RESULTS: At 6 months, no significant difference in the root coverage (RC) (95.28 ± 6.89% for CTG and 92.68 ± 7.35% for XDM) and the keratinized tissue (KT) gain (0.91 ± 0.46 mm for CTG and 0.74 ± 0.39 mm for XDM) was observed between groups (p > 0.05). The CTG group presented higher complete root coverage (CRC) than XDM (60% and 33%, respectively) (p = 0.045). Multiple logistic regression indicated that the XDM (p = 0.01) and the XDM and KT interaction (p = 0.02) negatively interfered in the CRC. A 1-mm increase in the baseline KT when using XDM increases almost 6 times the chance of achieving CRC, and XDM reached a similar CRC probability to CTG when the receptor area presented at least 2 mm of KT. CONCLUSIONS: Both treatments were effective for treating multiple gingival recession; similar KT gain, GR reduction, and RC were obtained for CTG and XDM, while CTG promoted higher CRC than XDM. Moreover, the amount of KT at baseline was determinant for CRC when treating multiple gingival recession with XDM. CLINICAL RELEVANCE: XDM produces limited CRC in sites with a reduced amount of KT. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (REBEC) number RBR-56NZQ6.

Influence of Transmucosal Height on Loss of Prosthetic Abutment Torque After Mechanical Cycling.

The aim of this study was to measure and record the universal transmucosal abutment height, and then evaluate whether it influenced loosening of the abutment screw by analyzing the torque and detorque values after mechanical cycling. Thirty-six implants, model CM Unitite, with internal conical connections (3.5 × 10 mm) and respective universal prosthetic abutments (n = 36, 3.25 × 6 mm), were divided into three groups (n = 12 each) with respective transmucosal heights of 0.8, 3.5, and 5.5 mm. Insertion torque of 20 Ncm was used in accordance with the manufacturer's specifications. Afterward, the samples were submitted to fatigue tests consisting of 500,000 cycles at a frequency of 2Hz, a dynamic compressive load of 120N, and an angle of 30°. The detorque values were measured with a digital torque meter and tabulated to perform statistical analyses; a level of significance of 5% was adopted. The mean detorque values (SD) obtained were 22.83 (6.30), 22.5 (5.45), and 19.41 (4.69) Ncm for transmucosal abutments with heights of 0.8, 3.5, and 5.5 mm, respectively, and showed no statistically significant difference ( P = .262). The authors of this study concluded that the transmucosal height of prosthetic abutments submitted to mechanical fatigue did not influence the detorque values.

In Vitro Microbiological Analysis of Bacterial Seal in Hybrid Zirconia Abutment Tapered Connection.

PURPOSE: The aim of this study was to evaluate the bacterial seal at the implant-hybrid zirconia abutment interface and Morse taper-type connections through in vitro microbiological analysis. MATERIALS AND METHODS: Sixteen implants and their respective abutments were divided into 3 groups: test (10 sets), positive control (3 sets), and negative control (3 sets). In the test group, 10 implants were contaminated with Escherichia coli using a sterile inoculating loop to the inner portion of the implants, followed by torque application to the abutment (30 N·cm). The positive controls were also contaminated, but no torque was applied to the abutment screw. The negative control consisted of uncontaminated sets. All specimens were immersed in test tubes containing 5 mL brain heart infusion (BHI) broth, maintained in a microbiological incubator for 14 days at 37°C under aerobic conditions, and monitored every 24 hours for evidence of bacterial growth. RESULTS: During the 14 days of incubation, no significant increase in the number of cloudy culture media was observed in the test group (P = 0.448). No significant difference in broth turbidity ratio was observed (P > 0.05). CONCLUSION: Hybrid zirconia abutments can create an effective seal at the tapered abutment-implant interface with a 30-N·cm installation torque.

Biomechanical and histomorphometric analysis of osseodensification drilling versus conventional technique: a systematic review and meta-analysis.

OBJECTIVES: This systematic review aimed to search the literature for the answer to the following questions. In human studies: Does the osseodensification technique increase the resonance frequency analysis given in implant stability quotient value and the insertion torque value compared to the conventional technique? In animal studies: Does the osseodensification technique increase implant stability quotient, bone-to-implant contact, and bone area fraction occupancy values over the conventional technique? DATA SOURCES: A search for studies was carried out in eight databases until August 2021. Out of the 447 publications found, 11 were included. RESULTS: In human studies, osseodensification technique showed better results for implant stability quotient values with a summarized median difference of 8.57. As for secondary stability, there was no significant difference, with summarized median difference of 4.49 in favor of the osseodensification technique. In animal studies, all results were favorable to the osseodensification technique. Regarding insertion torque, bone-to-implant contact, and bone area fraction occupancy between counterclockwise osseodensification technique vs conventional, the mean difference was 46.79 for insertion torque, 2.17 for bone-to-implant contact, and 2.11 for bone area fraction occupancy. High heterogeneity was observed between the studies. The risk of bias in humans was moderate in three studies and low in one; and in animal studies, four presented moderate risk, two low risk, and one high risk. The certainty of evidence ranged from low to moderate. CONCLUSION: The osseodensification technique showed improvement concerning the resonance frequency and the insertion torque value of implants in human studies. In addition, it increased the values of bone-to-implant contact, bone area fraction occupancy, and implant stability quotient in animal studies, when compared to the conventional technique.

Clinical and histomorphometric soft tissue assessment comparing free gingival graft and a collagen matrix as alveolar-sealer materials: a randomized controlled pilot clinical trial.

OBJECTIVE: This study aimed to compare the alveolar sealing performance between free gingival graft (FGG) and porcine collagen membrane (MS) and qualitatively assess patient-centered outcomes via a visual analog scale. METHOD AND MATERIALS: Eighteen patients were randomly divided into control (FGG) and test (MS) groups. After extraction, all the alveoli were filled with bovine bone grafts (small granules) and sealed. Follow-up was during the immediate postoperative period and after 3, 7, 15, 30, 60, 90, and 120 days. After 180 days, before implant placement, tissue samples were obtained for histologic analysis. The epithelial tissues were morphometrically measured for each sample. Qualitative information on the patient's perception of the treatment was collected after 7 days. RESULTS: A faster healing was observed for the MS group. After 60 days, all the sites from the MS were partially healed, in contrast with only five from the FGG. The histologic results after 120 days showed for the FGG group a predominant acute inflammatory process, whereas chronic processes were observed for the MS group. The mean epithelial heights found for the FGG and MS were 535.69 µm and 495.33 µm, respectively (P = .54). The intragroup analysis showed significant variance among the data (P < .001) for both groups. The qualitative result showed statistically more significative comfort for the MS group (P < .05). CONCLUSION: Within the limitations of the study, both techniques effectively promote alveolar sealing. However, the visual analog scale result was superior and more significant for the MS group, with faster wound healing and lower discomfort.

A Lip Repositioning Technique Using Polyester Threads for Gummy Smile Treatment.

A new technique is proposed in this study to correct the gummy smile (GS) with myotomy, combining lip repositioning with the insertion of polyester threads at the surgical site to act as a physical barrier and control relapse. 11 patients were clinically assessed (30.2 ± 7.43 years old, 90.9% females and 9.10% males). All patients presented gingival display (GD) greater than 4 mm. Hypermobile upper lip (HUL), vertical maxillary excess (VME) + HUL, altered passive eruption (APE) + HUL, and VME + APE were the etiologies identified. Three polyester threads were inserted in each patient one month after the surgery. The GS was measured before, 6 months, and 12 months after the surgery. The results showed a reduction in the mean GD of the patients, 4.42 mm after 6 months (p value = 0.000) and 4.13 mm after 12 months (p value = 0.000). The largest relapse was 0.29 mm and was not statistically significant (p value = 0.07). The Friedman test with pairwise comparisons was used to determine the existence of statistically significant differences in GD between the periods analyzed. The results showed that the proposed technique was successful in treating GS, presenting significant reductions in the GD 12 months after surgery and controlling the relapse.

Histologic and histomorphometric analysis of two biomaterials of xenogenous origin for maxillary sinus elevation: a clinical study.

Objective: This study analyzed two xenogenous biomaterials based on deproteinized bovine bone mineral applied for maxillary sinus elevation. Method and materials: Fourteen patients were submitted to maxillary sinus augmentation with one of the following biomaterials: Criteria Lumina Bone Porous (test group) or Geistlich Bio-Oss (control group), both of large granules (1 to 2 mm). After 6 months, trephine biopsies were collected at the time of implant placement: 27 samples (11 patients) in the test group; 7 samples (3 patients) in the control group. Biopsies were analyzed by descriptive histology and histomorphometry, in which the percentages of newly formed bone, residual biomaterial particles, and connective tissue were evaluated. Results: Histomorphometry showed means for test and control groups, respectively, of 32.41% ± 9.42% and 26.59% ± 4.88% for newly formed bone, 22.89% ± 4.58% and 25.00% ± 4.81% for residual biomaterial, and 44.70% ± 9.54% and 48.41% ± 3.36% for connective tissue. There were no differences between groups (P > .05). Conclusion: This study concluded that Criteria Lumina Bone Porous presented similar histologic and histomorphometric characteristics to Geistlich Bio-Oss 6 months after sinus elevation surgery, identifying the tested biomaterial as an interesting alternative for bone augmentation in the maxillary sinus.

Guided bone regeneration in staged vertical and horizontal bone augmentation using platelet-rich fibrin associated with bone grafts: a retrospective clinical study.

BACKGROUND: The use of guided bone regeneration (GBR) for vertical and horizontal bone gain is a predictable approach to correct the bone defects before implant installation; however, the use of different protocols is associated with different clinical results. It is suggested that platelet-rich fibrin (PRF) could improve the outcomes of regenerative procedures. Thus, this study aimed to describe the bone gain associated with GBR procedures combining membranes, bone grafts, and PRF for vertical and horizontal bone augmentation. MATERIALS AND METHODS: Eighteen patients who needed vertical or horizontal bone regeneration before installing dental implants were included in the study. The horizontal bone defects were treated with a GBR protocol that includes the use of a mixture of particulate autogenous and xenogenous grafts in the proportion of 1:1, injectable form of PRF (i-PRF) to agglutinate the graft, an absorbable collagen membrane covering the regenerated region, and leukocyte PRF (L-PRF) membrane covering the GBR membrane. The vertical bone defects were treated with the same grafted mixture protected by a titanium-reinforced non-resorbable high-density polytetrafluoroethylene (d-PTFE-Ti) membrane and covered by L-PRF. The bone gain was measured using a cone-beam computed tomography at baseline and after a period of 7.5 (± 1.0) months. RESULTS: All patients underwent surgery to install implants after this regenerative protocol. The GBR produces an increase in bone thickness (p < 0.001) and height (p < 0.005) after treatment, with a bone gain of 5.9 ± 2.4 for horizontal defects and 5.6 ± 2.6 for vertical defects. In horizontal defects, the gain was higher in the maxilla than in mandible (p = 0.014) and in anterior than the posterior region (p = 0.033). No differences related to GBR location were observed in vertical defects (p > 0.05). CONCLUSION: GBR associated with a mixture of particulate autogenous and xenogenous grafts and i-PRF is effective for vertical and horizontal bone augmentation in maxillary and mandibular regions, permitting sufficient bone gain to future implant placement. TRIAL REGISTRATION: REBEC, RBR-3CSG3J . Date of registration-19 July 2019, retrospectively registered. http://www.ensaiosclinicos.gov.br/rg/RBR-3csg3j/.

DC-STAMP and TACE Levels are Higher in Patients with Periodontitis.

Although periodontitis is one of the commonest infectious inflammatory diseases in humans, the mechanisms involved with its immunopathology remain ill understood. Numerous molecules may induce inflammation and lead to bone resorption, secondary to activation of monocytes into osteoclasts. TACE (TNF-α converting enzyme) and DC-STAMP (dendritic cell-specific transmembrane protein) appear to play a role on bone resorption since TACE induces the release of sRANKL (soluble receptor activator of nuclear factor kappa-ß ligand) whereas DC-STAMP is a key factor in osteoclast induction. The present study evaluated the levels of TACE and DC-STAMP in patients with and without periodontitis. Twenty individuals were selected: 10 periodontally healthy participants undergoing gingivectomy for esthetic reasons and 10 diagnosed with periodontitis. Protein levels of such molecules in gingival tissue were established using Western blotting. Protein levels of both TACE and DC-STAMP were higher in the periodontitis group than in the control group (p<0.05; Student t-test). In conclusion, TACE and DC-STAMP protein levels are elevated in patients with periodontitis, favoring progression of bone resorption.

Viability and collagen secretion by fibroblasts on titanium surfaces with different acid-etching protocols.

BACKGROUND: From the consolidation of surface treatments of dental implants and knowledge on the cellular mechanisms of osseointegration, studies have highlighted the importance of a connective tissue seal against the implant to prevent contamination from the oral environment and consequent biofilm formation. OBJECTIVE: This in vitro study aimed to evaluate whether different titanium surface treatments using acid solutions promoted an increase in collagen secretion, proliferation, and viability of fibroblasts. MATERIAL AND METHODS: Commercially pure grade-4 titanium disks (6 × 2 mm) were treated with different acid solutions (hydrochloric, nitric, and sulfuric) for 20 and 60 min, respectively, obtaining mean surface roughness of 0.1 to 0.15 µm and 0.5 to 0.7 µm. Human fibroblasts were seeded onto different surfaces and assessed after 24 h, 48 h, and 72 h for cell proliferation and viability using Trypan blue staining and MTT, respectively, as well as the secretion of type I collagen on to such surfaces using ELISA. Machined titanium surfaces were used as controls. Data were statistically analyzed using one-way ANOVA and Fisher's LSD test for multiple comparisons, adopting a significance level of 5%. RESULTS: No significant difference was observed in cell proliferation for the different surfaces analyzed. Cell viability was significantly lower on the machined surface, after 48 h, when compared to the groups treated with acid for 20 or 60 min, which did not differ from each other. The expression of type I collagen was lowest on the acid-treated surfaces. CONCLUSION: The results showed that the acid treatment proposed did not promote fibroblast proliferation and viability nor favor type I collagen synthesis.

Peri-implant bone loss around posterior mandible dental implants placed after distraction osteogenesis: preliminary findings.

BACKGROUND: The present study evaluates implant survival and peri-implant bone loss around posterior mandible dental implants placed at sites of distraction osteogenesis. METHODS: On removal of the distraction devices, 34 dental implants were inserted into 14 posterior mandible sites in 10 healthy, non-smoking female patients. Prosthetic treatment was performed 4 months after implant placement using fixed implant prostheses. After 6 to 16.5 months, periapical radiographs were taken and evaluated for peri-implant bone loss and radiolucency. The distance between the implant margin and the first visible bone-implant contact was measured on the mesial and distal aspects of the implants using imaging software. Radiographic dimensional distortion was corrected as a function of the known true dimension of the implant. RESULTS: Of the 34 implants placed, two (5.9%) failed to integrate at reentry surgery. Both were replaced and restored during the course of the study so that a total of 34 implants was followed for 12.1 +/- 3.8 months post-restoration and 16.1 +/- 3.8 months post-insertion. Mean loss of marginal bone height was 2.6 +/- 1.0 mm. During the follow-up period, radiolucent lines along the implant surface were absent. CONCLUSIONS: The mean peri-implant bone loss in areas of alveolar bone distraction was 1.9 mm/year. A high implant survival rate was observed.

Coronally positioned flap with subepithelial connective tissue graft for root coverage: various indications and flap designs.

Aesthetic concerns and functional abnormalities, such as dentin hypersensitivity, are often associated with gingival recession defects. Root coverage procedures aim to restore both gingival aesthetics and function in recession defects. The coronally positioned flap combined with the subepithelial connective tissue graft is one of the most widely used root coverage procedures. The present report illustrates four different indications where this procedure has been successfully employed. An isolated Miller class II recession defect associated with frenum pull, multiple adjacent Miller class I defects in the aesthetic zone, an isolated Miller class I defect associated with dentin hypersensitivity, and an isolated Miller class II defect on a retained deciduous tooth are the four diverse conditions treated by periodontal plastic surgery. Different approaches were used to create the coronally positioned flap. Treatment resulted in complete root coverage, resolution of hypersensitivity, and satisfaction of the patients' aesthetic concerns. An effective and predictable treatment modality, such as the coronally positioned flap combined with the subepithelial connective tissue graft, should be considered when treatment planning for gingival recession defects.

Microbiological Seal of Two Types of Tapered Implant Connections.

Tapered implant connections have gained wide popularity for being more resistant to fatigue and for promoting a better seal against bacterial infiltration than conventional connections. The aim of this study was to evaluate the bacterial seal at the implant-abutment interface using two Morse taper implant models, by in vitro microbiological analysis. Eleven non-indexed and 11 indexed abutments were selected and connected to their respective implants with a 20 N torque, according to manufacturer's recommendation. Microbiological analysis was carried out using colonies of Escherichia coli transported directly from a culture dish to the prosthetic component. For control, one non-contaminated abutment-implant set from each group (negative control) and one contaminated implant with no abutment (positive control) were used. The specimens were immersed in BHI broth and maintained in an incubator at 37 °C for 14 days to assess the development of bacterial contamination. The results revealed that 36.4% (n=4) of the indexed components and 90.9% (n=10) of the non-indexed components allowed bacterial leakage, with significant difference between groups (p=0.0237). In conclusion, both tapered components failed to provide adequate sealing to bacterial leakage, although the indexed type components showed a superior seal compared with non-indexed components.

Clinical and radiographic evaluation of soft and hard tissue changes around implants: a pilot study.

BACKGROUND: The aim of this study was to evaluate the clinical and radiographic changes in the peri-implant tissues around one-stage implants with different smooth neck portion lengths before and after functional prosthetic loading. METHODS: Twelve one-stage implants were placed in adult patients with bilateral edentulous posterior mandibular ridges. The sites were randomly assigned into two groups of six each: group 1: 2.8 mm neck implants and group 2: neck implants. The parameters plaque index (PI), gingival index (GI), probing depth (PD), gingival margin level (GML), relative clinical attachment level (r-CAL), and optical density (OD) were measured at loading (4 months) and 12 months after implant placement. The radiographic parameter osseous level (OL) was measured at implant placement, loading, and at 12 months. Analysis of variance and the paired Student t test were used to detect difference over time and between groups. RESULTS: The results showed significant differences (P<0.05) for both groups for PD, r-CAL, and OL for intragroup comparisons over time. However, no significant differences were found for PI, GI, PD, GML, OD, and OL for between-group comparisons. CONCLUSION: Bony loss occurred before loading, supporting the soft tissues and maintaining the biologic width irrespective of the smooth portion length.

Root coverage using the coronally positioned flap with or without a subepithelial connective tissue graft.

BACKGROUND: Various surgical techniques have been proposed for treating gingival recession. This randomized clinical trial compared the coronally positioned flap (CPF) alone or in conjunction with a subepithelial connective tissue graft (SCTG) in the treatment of gingival recession. METHODS: Eleven non-smoking subjects with bilateral and comparable Miller Class I recession defects were selected. The defects, at least 3.0 mm deep, were randomly assigned to the test (CPF + SCTG) or control group (CPF alone). Recession depth (RD), probing depth (PD), clinical attachment level (CAL), width of keratinized tissue (KT), and gingival/mucosal thickness (GT) were assessed at baseline and 6 months postoperatively. RESULTS: Recession depth was significantly reduced 6 months postoperatively (P<0.05) for both groups. Mean root coverage was 75% and 69% in the test and control groups, respectively. There were no significant differences between the two groups in RD, PD, or CAL, either at baseline or at 6 months postoperatively. However, at 6 months postoperatively, the test group showed a statistically significant increase in KT and GT compared to the control group (P<0.05). CONCLUSIONS: The results indicate that both surgical approaches are effective in addressing root coverage. However, when an increase in gingival dimensions (keratinized tissue width, gingival/mucosal thickness) is a desired outcome, then the combined technique (CPF + SCTG) should be used.

Clinical and radiographic evaluation of periodontal intrabony defects treated with guided tissue regeneration. A pilot study.

BACKGROUND: The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans. METHODS: Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical Pi and GI < 10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone (control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test. RESULTS: Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P < 0.0 1). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P < 0.01). Both therapies were effective in improving the clinical parameters assessed. CONCLUSION: Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR.

[Comparison between gingival and periodontal ligament fibroblasts from the same subject]. / Comparação entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo.

The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.

Clinical analysis of the stability of dental implants after preparation of the site by conventional drilling or piezosurgery.

We used resonance frequency analysis to evaluate the implant stability quotient (ISQ) of dental implants that were installed in sites prepared by either conventional drilling or piezoelectric tips. We studied 30 patients with bilateral edentulous areas in the maxillary premolar region who were randomised to have the implant inserted with conventional drilling, or with piezoelectric surgery. The stability of each implant was measured by resonance frequency analysis immediately after placement to assess the immediate stability (time 1) and again at 90 days (time 2) and 150 days (time 3). In the conventional group the mean (SD) ISQ for time 1 was 69.1 (6.1) (95% CI 52.4-77.3); for time 2, 70.7 (5.7) (95% CI 60.4-82.8); and for time 3, 71.7 (4.5) (95% CI 64.2-79.2). In the piezosurgery group the corresponding values were: 77.5 (4.6) (95% CI 71.1-84.3) for time 1, 77.0 (4.2) (95% CI, 69.7-85.2) for time 2, and 79.1 (3.1) (95% CI 74.5-87.3) for time 3. The results showed significant increases in the ISQ values for the piezosurgery group at each time point (p=0.04). The stability of implants placed using the piezoelectric method was greater than that of implants placed using the conventional technique.