Efficacy of conventional cord versus cordless techniques for gingival displacement: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Unsatisfactory adaptation of restorations with subgingival margins can cause problems such as accumulation of biofilm, secondary caries, and inflammation of the periodontal tissue. Therefore, special attention should be given to gingival displacement and impression procedures to optimize marginal fit. PURPOSE: The purpose of this systematic review and meta-analysis was to compare gingival displacement with conventional cords and cordless techniques and determine the reliability of the measurement methodologies. MATERIAL AND METHODS: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and identified studies through September 2018. The studies were submitted to the Cochrane risk-of-bias assessment. The gingival displacement was evaluated by using the Review Manager Software. RESULTS: Nine studies were selected, and the most common risks of bias were random sequence generation, blinding of outcome assessment, and absence of sample size calculation. Most of the studies reported obtaining a width greater than 0.2 mm. CONCLUSIONS: The cord technique resulted in increased displacement when compared with the cordless technique. The evaluation of sulcular width with digital microscope images obtained from sectioned gypsum casts is an adequate and versatile experimental methodology for measuring displacement.

Relationship Between Clinical and Histologic Periodontal Biotypes in Humans.

Histologic and histomorphometric evaluations of gingival biopsy samples of patients presenting either a thick or a thin gingival biotype were performed. Full-thickness gingival biopsy samples were obtained and processed for histologic and histometric evaluations. Thickness of the keratinized mucosa or gingiva was found to be increased in the thick biotype. Specifically, the connective tissue layer was thicker with no change in epithelial thickness. In conclusion, gingival transparency appears to be an adequate, clinically useful method to classify the gingival biotype. The thin gingival biotype is manifested by reduced connective tissue thickness; therefore, biotype conversion or enhancement may be based on augmentation of the connective tissue portion of the gingival tissues.

Platelet-Derived Growth Factor-Mediated Guided Bone Regeneration in Immediate Implant Placement in Molar Sites with Buccal Bone Defects.

This study compared the clinical outcomes of recombinant human platelet-derived growth factor BB and beta-tricalcium phosphate (rhPDGF-BB/ßTCP) with guided bone regeneration (GBR) in immediate implant placement in molar extraction sockets with buccal bone defects versus conventional implant placement. Twenty-eight implants were placed in fourteen patients. Clinical and radiographic evaluations assessed peri-implant soft and hard tissue parameters after 12 months. No implants were lost during the 1-year observation period, yielding a survival rate of 100%. Similar clinical and radiographic parameters were observed for both treatment groups. Use of rhPDGF-BB/ßTCP and GBR in immediate implants in molars was as successful as conventional implant placement in fully healed extraction sites.

Correção do zênite gengival no manejo estético pré-restaurador por gengivectomia dupla combinada / Combined double-gingivectomy procedure for gingival zenith position correction in restorative esthetic management

As intervenções odontológicas atuais visam, além do restabelecimento funcional, alternativas terapêuticas para contemplar as necessidades estéticas de nossos pacientes. A crescente exigência por altos padrões estéticos alavanca uma integração entre as diversas especialidades, propondo um tratamento global que objetive a previsibilidade e resolução dos casos clínicos. Nesse contexto, as abordagens periodontais assumem um importante papel, sobretudo em casos em que alterações no complexo dentogengival estão presentes. Além das recessões gengivais, as assimetrias no contorno gengival e exposição excessiva de tecido gengival podem interferir diretamente na composição estética de um sorriso. Diante do exposto, o objetivo do presente trabalho foi relatar um caso clínico em que um procedimento de aumento de coroa clínica foi realizado para promover a harmonia do sorriso no planejamento estético integrado da exposição excessiva de tecido gengival, e hiperplasia gengival dos dentes anteriores inferiores. Foram realizados procedimentos cirúrgicos periodontais para definir o posicionamento da nova margem gengival, proporcionar uma arquitetura gengival fisiológica e obter ambiente mais favorável para que o recondicionamento dentário com resina composta pudesse ser realizado nos dentes superiores.

A clinical comparison of guided bone regeneration with platelet-derived growth factor-enhanced bone ceramic versus autogenous bone block grafting.

PURPOSE: The objective of this study was to evaluate the efficacy of guided bone regeneration (GBR) employing recombinant human platelet-derived growth factor-BB (rhPDGF-BB) incorporated into a beta-tricalcium phosphate (ß-TCP)/hydroxyapatite (HA) carrier as a graft material and to compare it to autogenous bone block grafting. MATERIALS AND METHODS: Adult patients with a site that required bone grafting to increase the thickness of the alveolar bone ridge were treated. After mucoperiosteal flap elevation, experimental bone defects were treated by GBR with rhPDGF incorporated into ß-TCP/HA, and control defects were treated with autogenous bone. Primary tension-free wound closure was obtained for all treated sites. RESULTS: Thirty patients were treated. No significant differences were observed between the groups for any of the parameters evaluated, including the amount of bone regeneration and a need for additional grafting. CONCLUSION: A composite bone ceramic graft that incorporated rhPDGF appears to be a suitable substitute for autogenous bone block grafting when employed in conjunction with GBR in humans.

Influence of endodontic treatment in the post-surgical healing of human Class II furcation defects.

BACKGROUND: Treatment of molar furcation defects remains a considerable challenge in clinical practice. The degree of success in the management of furcation involvement is highly variable and related to the baseline clinical status of these defects. The identification of clinical parameters influential to the treatment outcomes is critical to optimize the results of surgical periodontal therapy. The impact of the endodontic treatment (ET) of the tooth on the healing potential of the periodontium is controversial. Therefore, the objective of this study is to evaluate the clinical response of buccal Class II furcation defects to open-flap debridement (OFD) and to determine the influence of ET in the clinical outcomes of therapy. METHODS: Sixty patients were divided into two treatment groups (n = 30): 1) OFD; and 2) OFD in endodontically treated teeth (OFD + ET). The clinical variables evaluated were plaque (full-mouth plaque score), bleeding on probing, gingival recession, probing depth (PD), and vertical (VAL) and horizontal (HAL) attachment levels. Reevaluation was performed 12 months after the surgical procedures. RESULTS: Both treatments resulted in improvements in all the clinical variables evaluated. Postoperative measurements from OFD-treated and OFD + ET-treated sites showed, respectively, 1.2 ± 1.2 and 1.3 ± 1.3 mm reduction in PD, 0.6 ± 0.8 and 0.7 ± 0.6 mm VAL gains, and 0.7 ± 1.1 and 0.8 ± 1.6 mm HAL gains. No significant differences were found between the groups. CONCLUSION: The present findings demonstrate that adequate endodontic therapy performed ≥6 months before surgical treatment does not significantly influence the clinical parameters of healing of human mandibular buccal Class II furcation defects.

A clinical comparison of two flap designs for coronal advancement of the gingival margin: semilunar versus coronally advanced flap.

BACKGROUND: The semilunar incision was introduced in oral surgery more than a century ago. The semilunar coronally re-positioned flap (SLCRF) is one of the variants of this procedure; however, no previous controlled clinical study has evaluated the SLCRF performed as originally described. The objective of the present study was to compare the clinical outcomes of the SLCRF and coronally advanced flap (CAF) procedure in the treatment of maxillary Miller class I recession (GR) defects. MATERIALS AND METHODS: Twenty-two patients, with 22 contra-lateral Miller class I GR defects, were randomly assigned to CAF or SLCRF. Clinical parameters assessed included recession height, width of keratinized tissue, probing depth, vertical clinical attachment level, visual plaque score and bleeding on probing. Clinical recordings were performed at baseline and 6 months later. Inter-measurements differences were analysed with a chi(2) or a paired t-test, with significance set at alpha<0.05. RESULTS: Both flap designs were effective in obtaining and maintaining a coronal displacement of the gingival margin. The CAF resulted in clinical improvements significantly better than SLCRF for percentage of root coverage (RC), frequency of complete RC and gain in clinical attachment level. RC obtained in the immediate post-surgical period of SLCRF-treated sites was not maintained throughout the subsequent evaluations. CONCLUSION: RC is significantly better with CAF compared with the original SLCRF technique in the treatment of shallow maxillary Miller class I GR defects.

Clinical evaluation of single-stage advanced versus rotated flaps in the treatment of gingival recessions.

BACKGROUND: Several procedures have been reported for the surgical correction of gingival recession (GR), including the laterally positioned flap (LPF) and the coronally advanced flap (CAF), performed as single- or two-stage procedures without or with, respectively, the preceding placement and healing of a free gingival graft. The objective of the present report was to compare the efficacy of single-stage LPF and CAF techniques in the treatment of localized maxillary GR defects. METHODS: Thirty-six patients, 10 men and 26 women, with average age of 34 + or - 9 years with Miller Class I GR defects were randomly assigned to be treated by either a CAF (n = 18) or LPF (n = 18). Clinical parameters, including recession height, the width of keratinized tissue (WKT), probing depth, and vertical clinical attachment level were assessed at the mid-buccal site. Visual plaque score and bleeding on probing were also assessed dichotomously. Clinical recordings were performed at baseline and 6 months later. Intermeasurements differences were analyzed with a chi-square or a Wilcoxon test, with significance set at alpha<0.05. RESULTS: Both flap designs were effective in treating recession defects resulting in similar improvements for percentage of root coverage, frequency of complete root coverage, and gain in clinical attachment level. The LPF resulted in significantly more gains in WKT than the CAF. CONCLUSION: The results obtained by CAF in the treatment of Miller Class I maxillary GR are clinically similar to the LPF albeit with more limited gains in WKT.

Efficacy of combined regenerative treatments in human mandibular class II furcation defects.

BACKGROUND: The treatment of molar furcation defects remains a considerable challenge in clinical practice. The degree of success in the management of furcation involvement is highly variable and inversely related to initial probing depth (PD) measurements in these lesions. The identification of clinical measurements influential to the treatment outcomes is critical to optimize the results of surgical periodontal therapy. Therefore, the objective of this study was to evaluate the clinical response of mandibular buccal Class II furcation lesions to a combined regenerative treatment modality. METHODS: Sixty patients were divided into two (n = 30) treatment groups. An experimental combined regenerative therapy (ET) was compared to open flap debridement (OFD). The ET was a combination of a composite graft consisting of bioabsorbable hydroxyapatite and tetracycline (3:1), a guided tissue regeneration barrier, and a coronally advanced flap. The clinical variables evaluated were plaque, bleeding on probing, gingival recession, PD, vertical attachment level (VAL), horizontal attachment level (HAL), furcation vertical height, furcation horizontal depth, and the amount of tissue under the barrier membrane at uncovering. Reevaluation was performed 12 months after the surgical procedure. RESULTS: Both treatments resulted in improvements in all clinical variables evaluated. Postoperative measurements revealed a reduction in PD of 3.65 +/- 0.6 mm and 0.60 +/- 1.0 mm; VAL gains of 3.05 +/- 0.6 mm and 0.65 +/- 0.6 mm and HAL gains of 3.45 +/- 1.3 mm and 0.55 +/- 0.7 mm in the ET and OFD groups, respectively. In the ET group, significant positive correlations were found between baseline PD and PD reduction at 12 months, and the initial VAL correlated positively with PD reduction and HAL gain. The horizontal furcation depth and amount of tissue formed under the membrane at uncovering correlated positively with PD reduction and HAL and VAL gains. For the OFD group, the initial PD correlated positively with PD reduction and VAL and HAL gains and correlated negatively with recession. Initial VAL correlated positively with PD reductions and VAL and HAL gains. The initial HAL correlated negatively with recession at 12 months. CONCLUSIONS: ET exhibited significantly better clinical results, with more PD reduction, HAL and VAL gains, and a higher frequency of furcation closure compared to OFD and showed promise as a regenerative treatment technique. The ability to predict a response to treatment based upon pretreatment parameters was not consistent between groups; thus, prediction of treatment outcomes based on pretreatment measurements should be carefully evaluated for each treatment modality.

Efficacy of vascularized periosteal membranes in providing soft tissue closure at grafted human maxillary extraction sites.

PURPOSE: Soft tissue closure is mandatory for optimal healing of extraction sites treated via guided bone regeneration. The objective of this study was to evaluate the efficacy of a flap design based on the extension of palatal tissues to obtain and maintain soft tissue coverage over grafted extraction sockets. MATERIALS AND METHODS: Adult patients (n = 22) with at least two teeth indicated for extraction were treated. After atraumatic extraction, control sockets were filled with a composite graft (1:1) containing demineralized freeze-dried bone allografts and Bio-Oss. Experimental sockets were treated identically, except that an Atrisorb absorbable barrier membrane was also placed over the graft material before flap closure, which was obtained, in all sockets, by the coronal extension of a vascularized pedicle dissected from the periosteal aspect of the palate. RESULTS: Primary tension-free wound closure was achieved at all treated sites. Exfoliation of the graft material during healing was not observed in either treatment group. High levels of soft tissue closure were maintained throughout the study period for both treatment groups, and membrane exposure was observed in only 7% of treated sites. CONCLUSION: On the basis of this study it appears that the reported technique was an adequate method of achieving and maintaining complete soft tissue coverage and promoting healing by primary intention in grafted extraction sockets in humans.

A quantitative evaluation of the spatial displacement of the gingival zenith in the maxillary anterior dentition.

BACKGROUND: The appearance of gingival tissues plays an important role in the esthetics of the anterior maxillary region of the mouth. The gingival zenith (GZ) is defined as the most apical point of the marginal gingival scallop; however, its quantitative orientation in the apico-coronal (AC) and mesio-distal (MD) directions has not been reported. Thus, this study aimed to quantify the specific spatial displacement of the GZ in the maxillary anterior dentition. METHODS: Bilateral measurements, taken with a digital caliper in maxillary stone casts from periodontally healthy volunteers, were recorded to the nearest 1/100th millimeter in the canine (C), lateral incisor (LI), and central incisor (CI) teeth to evaluate the MD displacement of the GZ in relation to the long axis of the crowns and the AC displacement of the GZ of LI teeth in relation to CI and C teeth. Intermeasurement differences were analyzed with the chi(2) or paired t test, with significance set at alpha <0.05. RESULTS: The GZ was distally displaced between 0.06 and 0.96 mm in 12%, 70%, and 96% of the C, LI, and CI teeth, respectively. The majority of the population (70%) presented with the GZ of LI teeth positioned 0.75 +/- 0.60 mm coronally to the GZ of the ipsilateral C and CI. CONCLUSIONS: The GZ is not universally displaced toward the distal aspect. The frequency and magnitude of distal displacement is tooth-dependent and larger in CI than in LI, which, in turn, is larger than in C. Consideration of these findings may improve clinical management of the dentogingival complex and enhance periodontal and restorative procedures in the anterior maxillary dentition.

Controlled release of fibroblast growth factor 2 stimulates bone healing in an animal model of diabetes mellitus.

PURPOSE: Bone formation and the healing of calvarial defects in mice is diminished in chemically induced type 1 diabetes. The present study investigated whether controlled local release of fibroblast growth factor 2 (FGF-2) stimulates bone defect healing in this model of diabetes. MATERIALS AND METHODS: First, in vitro release kinetics of different doses of recombinant human FGF-2 (rhFGF-2) from polyglycolate:polylactide membranes was determined over a 14-day period by incubating loaded membranes in PBS with constant shaking. The amount of FGF-2 was measured by enzyme-linked immunosorbent assay. Then, the effects of rhFGF-2-loaded and control membranes on calvarial defect healing over a 14-day healing period were determined in diabetic and nondiabetic mice. The degree of healing was determined by histomorphometric analyses of bone area percentage and by area measurements. The significance of the data was determined by statistical analyses, including analysis of variance. RESULTS: Kinetic release data in vitro showed that membranes loaded with 5 microg FGF-2 released measurable levels of growth factor for more than 14 days. Data from the in vivo study supported the previous finding that diabetes inhibits bone formation. Membranes containing rhFGF-2 significantly (P < .05) stimulated bone formation in diabetic animals to near normal levels during the healing period. CONCLUSION: FGF-2-loaded membranes may be useful in further studies aimed at developing therapeutic strategies for correcting deficient bone healing in patients with diabetes.

Relationship between position of probe tip and periodontal tissues after periodontal surgery in dogs.

The aim of this study was to investigate postsurgical periodontal probe penetration by using clinical information and histometric data. Thirty-eight three-walled defects were created in four dogs, then maintained for 3 months. Subsequently, 26 defects were subjected to periodontal surgery (surgical group), while 12 defects served as controls. The dogs were sacrificed at 4, 8, 12, and 16 weeks. Immediately before sacrifice, endodontic silver points were placed in the gingival crevices as substitutes for periodontal probes and fixed on the teeth. Following block sections, histologic and histomorphometric evaluations were undertaken: location of the probe tip in relation to the apical termination of the junctional epithelium, length of new junctional epithelium in relation to the apical junctional epithelium, and mean length of connective tissue adhesion in relation to the apical junctional epithelium. Probe tips were located -1.37 +/- 1.73 mm and -0.20 +/- 0.15 mm apical to the apical junctional epithelium for the surgical and control groups, respectively, at 4 weeks, while the probe tip was located 0.58 +/- 0.31 mm and 0.40 +/- 0.20 mm coronal to the apical junctional epithelium, respectively, at 16 weeks. Length of new junctional epithelium in relation to apical junctional epithelium was significantly less for the surgical than the control group at 4 weeks (0.73 +/- 0.60 mm vs 1.19 +/- 0.02 mm) and 8 weeks (1.77 +/- 0.52 mm vs 2.15 +/- 0.00 mm). There were no significant differences between the groups in regard to connective tissue relationship to the apical junctional epithelium. Periodontal probing is not recommended for at least 2 months after surgical procedures; before this stage, probing forces may damage the soft tissue-tooth interrelationship.

Morphometric analysis of the furcation anatomy of mandibular molars.

BACKGROUND: Successful treatment of molar furcation defects remains a challenge in clinical practice. Knowledge of anatomic factors facilitates predictable management of furcation involvement lesions. The degree of success in managing furcation involvement is inversely related to the horizontal probing depth. The depth of the horizontal component of attachment loss can vary depending on the external tooth-surface reference points used. However, the anatomical factors affecting horizontal component of attachment loss have not been previously assessed. Therefore, this study determined the bucco-lingual measurements of the cemento-enamel junction and the mesial and distal roots and at the level of root separation. METHODS: One hundred extracted permanent human mandibular first (N = 50) and second (N = 50) molars were studied. Four horizontal bucco-lingual widths were measured with calibrated calipers: 1) furcation entrance/roof (FE); 2) cemento-enamel junction level (CEJ); 3) mesial root width (MRW); and 4) distal root width (DRW). RESULTS: The mean widths at FE, CEJ, MRW, and DRW were, respectively, 5.53 +/- 0.45 mm, 8.71 +/- 0.54 mm, 8.57 +/- 0.54 mm, and 7.97 +/- 0.65 mm in the first molars and 5.61 +/- 0.65 mm, 8.40 +/- 0.65 mm, 7.95 +/- 0.88 mm, and 7.16 +/- 0.84 mm in the second molars. Analysis of variance revealed significant differences between FE and the other variables tested. The results showed that the bucco-lingual width of the furcation roof is considerably shorter than the MRW and DRW. The difference in the mean bucco-lingual dimension between FE and the other measurements occurred in all teeth evaluated and varied between 0.7 and 4.30 mm. CONCLUSIONS: Our findings demonstrate that clinical measurements of horizontal probing depth that use the external surfaces of roots as reference points overestimate the true anatomical component of furcation involvement in mandibular molars. Conversely, positive treatment outcomes in these teeth may be underestimated. This has implications not only for clinical practice but also for clinical research studies evaluating treatment outcomes.

A role for lysyl oxidase regulation in the control of normal collagen deposition in differentiating osteoblast cultures.

Differentiation of phenotypically normal osteoblast cultures leads to formation of a bone-like extracellular matrix in vitro. Maximum collagen synthesis occurs early in the life of these cultures, whereas insoluble collagen deposition occurs later and is accompanied by a diminished rate of collagen synthesis. The mechanisms that control collagen deposition seem likely to include regulation of extracellular collagen biosynthetic enzymes, but expression patterns of these enzymes in differentiating osteoblasts has received little attention. The present study determined the regulation of lysyl oxidase as a function of differentiation of phenotypically normal murine MC3T3-E1 cells at the level of RNA and protein expression and enzyme activity. In addition, the regulation of BMP-1/mTLD mRNA levels that encodes procollagen C-proteinases was assayed. The role of lysyl oxidase in controlling insoluble collagen accumulation was further investigated in inhibition studies utilizing beta-aminopropionitrile, a specific inhibitor of lysyl oxidase enzyme activity. Results indicate that lysyl oxidase is regulated as a function of differentiation of MC3T3-E1 cells, and that the maximum increase in lysyl oxidase activity precedes the most efficient phase of insoluble collagen accumulation. By contrast BMP-1/mTLD is more constitutively expressed. Inhibition of lysyl oxidase in these cultures increases the accumulation of abnormal collagen fibrils, as determined by solubility studies and by electron microscopy. Taken together, these data support that regulation of lysyl oxidase activity plays a key role in the control of collagen deposition by osteoblast cultures.

A role for advanced glycation end products in diminished bone healing in type 1 diabetes.

The effect of type 1 diabetes on bone healing and bone formation in standardized craniotomy defects created in BALB/cByJ mice was determined. The hypothesis that advanced glycation end products (AGEs) contribute to diminished bone healing in diabetes was evaluated by assessing for the presence of the receptor for advanced glycation end products (RAGE) by immunohistochemistry in healing craniotomy defects in diabetic animals. The effect of local application of a known RAGE protein ligand, N(epsilon)-(carboxymethyl)lysine (CML)-mouse serum albumin (MSA), on craniotomy defect healing in normal animals was then assessed and compared to the effects of control MSA. Finally, evidence in support of the expression of RAGE mRNA and protein in osteoblastic cells was obtained. The results indicated that craniotomy defects in diabetic animals healed approximately 40% of the degree to which they healed in nondiabetic animals (P < 0.05). RAGE was expressed at higher levels in healing bone tissues in diabetic compared to control animals. Further studies in nondiabetic animals indicated that bone healing was reduced by 63 and 42% in lesions treated with 900 and 90 micro g CML-MSA, respectively, compared to in animals treated with MSA alone (P < 0.05). Evidence for the expression of RAGE was obtained in mouse and rat osteoblastic cultures. These results support the contribution of AGEs to diminished bone healing in type 1 diabetes, possibly mediated by RAGE.

Matrix metalloproteinase levels and gelatinolytic activity in clinically healthy and inflamed human dental pulps.

The role of matrix metalloproteinases (MMPs) in the breakdown of pulp tissue of teeth with severe caries has not yet been directly elucidated. This study was to determine the levels of selected MMPs and the overall gelatinolytic activity in clinically healthy and inflamed human dental pulps of 29 healthy subjects, aged 10-19 yr. Seventeen pulps were collected from subjects diagnosed with symptomatic pulpitis, and 18 control pulps were obtained from 12 subjects following premolar extraction for orthodontic reasons. The levels of MMP-1, MMP-2, MMP-3 and MMP-9 were determined with enzyme-linked immunosorbent assay. Densitometric analysis of gelatin zymograms was used to assay gelatinolytic activity in pulp supernatants. The MMP-1 levels were below the detection limit for both groups. Levels of MMP-2 and MMP-3 were significantly lower in symptomatic vs. clinically healthy pulps. In contrast, levels of MMP-9 in inflamed pulps were significantly higher than those recorded in clinically normal pulps. The overall gelatinolytic activity was elevated in inflamed pulps compared with healthy counterparts. Further, the gelatinolytic activity was positively correlated with MMP-9 levels. The data obtained suggest a key role of MMP-9 in the breakdown of inflamed human dental pulp tissue.