Implications of cultured periodontal ligament cells for the clinical and experimental setting: a review.

The periodontal ligament (PDL) is a key contributor to the process of regeneration of the periodontium. The heterogeneous nature of the PDL tissue, its development during early adulthood, and the different conditions to which the PDL tissue is exposed to in vivo impart on the PDL unique characteristics that may be of consequence during its cultivation in vitro. Several factors affecting the in vivo setting influence the behaviour of PDL fibroblasts in culture. The purpose of this review is to address distinct factors that influence the behaviour of PDL fibroblasts in culture -in vivo-in vitro transitions, cell identification/isolation markers, primary PDL cultures and cell lines, tooth-specific factors, and donor-specific factors. Based on the reviewed studies, the authors recommendations include the use of several identification markers to confirm cell identity, use of primary cultures at early passage to maintain unique PDL heterogeneic characteristics, and noting donor conditions such as age, systemic health status, and tooth health status. Continued efforts will expand our understanding of the in vitro and in vivo behaviour of cells, with the goal of orchestrating optimal periodontal regeneration. This understanding will lead to improved evidence-based rationales for more individualized and predictable periodontal regenerative therapies.

Significance of the epithelial collar on the subepithelial connective tissue graft.

BACKGROUND: Most clinicians adopt two versions of the subepithelial connective tissue graft (SCTG) procedure, SCTG with or without the epithelial collar on the graft combined with a coronally advanced flap (CAF). However, limited evidence is available to determine whether a retained epithelial collar on an SCTG is needed for a better outcome. The goal of this study was to compare the clinical outcomes of the two SCTG techniques (i.e., SCTG with or without an epithelial collar). METHODS: Twenty patients with Miller Class I or II gingival defects >/=2.0 mm were recruited for the study. The patients were randomly assigned to receive an SCTG with a retained epithelial collar + CAF (SCTGE; n = 10) or an SCTG without an epithelial collar + CAF (SCTGN; n = 10). Clinical parameters, including recession depth, recession width (RW), width of keratinized gingiva (KW), clinical attachment level (CAL), probing depth (PD), gingival index (GI), and plaque index (PI), were assessed at baseline and 3 and 6 months after surgery. RESULTS: SCTGE and SCTGN groups exhibited significant root coverage at 3 and 6 months compared to baseline (P <0.05). The SCTGE group had mean root coverage of 97.50% +/- 7.90% at 6 months compared to 89.10% +/- 25.93% in the SCTGN group, with no significant difference between the groups. At 6 months, complete root coverage was seen in nine of 10 and seven of 10 subjects from SCTGE and SCTGN groups, respectively. Mean KW at 3 months for the SCTGE group was 4.10 +/- 1.10 mm, whereas in the SCTGN group it was 2.75 +/- 0.68 mm. Mean RW was 0 mm and 1.20 +/- 1.60 mm for SCTGE and SCTGN groups, respectively. KW and RW were statistically significantly different between the two groups at 3 months; however, this significance was not seen at 6 months. Other clinical parameters (CAL, PD, thickness of the recipient gingival tissue, PI, GI, and the wound healing index) showed no significant differences between the groups at any time point. CONCLUSIONS: Both SCTG techniques (with or without the epithelial collar) provided predictable and successful root coverage (>/=89%). This study suggests that a retained epithelial collar on the SCTG may not provide a significant benefit with regard to clinical parameters.

A novel decision-making process for tooth retention or extraction.

BACKGROUND: Implant-supported restorations have become the most popular therapeutic option for professionals and patients for the treatment of total and partial edentulism. When implants are placed in an ideal position, with adequate prosthetic loading and proper maintenance, they can have success rates >90% over 15 years of function. Implants may be considered a better therapeutic alternative than performing more extensive conservative procedures in an attempt to save or maintain a compromised tooth. Inadequate indication for tooth extraction has resulted in the sacrifice of many sound savable teeth. This article presents a chart that can assist clinicians in making the right decision when they are deciding which route to take. METHODS: Articles published in peer-reviewed English journals were selected using several scientific databases and subsequently reviewed. Book sources were also searched. Individual tooth- and patient-related features were thoroughly analyzed, particularly when determining if a tooth should be indicated for extraction. RESULTS: A color-based decision-making chart with six different levels, including several factors, was developed based upon available scientific literature. The rationale for including these factors is provided, and its interpretation is justified with literature support. CONCLUSION: The decision-making chart provided may serve as a reference guide for dentists when making the decision to save or extract a compromised tooth.

The effect of platelet-rich plasma on the coronally advanced flap root coverage procedure: a pilot human trial.

BACKGROUND: Coronally advanced flap (CAF) has been shown to effectively treat gingival recession. Platelet-rich plasma (PRP), containing autologous growth factors, has been shown to promote soft tissue healing. Therefore, the purpose of this study was to evaluate the effects of PRP in combination with CAF. METHODS: Twenty-four systemically healthy patients participated in this study. A single Miller's Class I buccal recession defect per patient was treated. These patients were randomly assigned into CAF or PRP + CAF groups. Clinical parameters included recession depth (RD), recession width (RW), gingival thickness (GT), width of keratinized tissue (WKT), clinical attachment level (CAL), probing depth (PD), plaque index (PI), wound healing index (WHI), and gingival index (GI). PRP was prepared from whole blood drawn prior to surgery and applied to root surfaces. Patients were followed at 2, 4, 12, and 24 weeks post-surgery. RESULTS: Twenty-three patients completed the study. The RD at 24 weeks was significantly reduced from 2.9 +/- 0.5 to 0.5 +/- 0.6 mm in the CAF group (P < 0.05) and from 2.8 +/- 0.2 to 0.5 +/- 0.7 mm in the PRP + CAF group (P < 0.05). The mean root coverage was 83.5% +/- 21.8% in the CAF group and 81.0% +/- 28.7% in the CAF + PRP group (P > 0.05). Fourteen out of 23 patients (60.9%) experienced 100% root coverage at the 24-week postoperative follow-up. CONCLUSION: Based on the results of this pilot study, the application of PRP in CAF root coverage procedure provides no clinically measurable enhancements on the final therapeutic outcomes of CAF in Miller's Class I recession defects.

The nonsurgical treatment of patients with periodontal disease: results after 6.4 years.

In a previous study involving patients at the dental clinic of the Detroit Receiving Hospital, 87% of teeth that initially had been recommended for surgery or extraction were spared either treatment through a combination of debridement and short-term usage of antimicrobial agents. The object of the present study was to determine what changes occurred to these teeth after 6.4 years in the maintenance phase of treatment. Patients were scheduled for maintenance therapy at three-month intervals over a period of 6.4 years. They were evaluated "annually" (that is, the patients were scheduled for annual visits) for surgical needs by a clinician who was not aware of the treatment received by the patients. Multivariate statistical models were used to determine which variables predicted subsequent surgical needs. The initial treatment benefits were sustained, as the majority of patients showed no increase in surgical needs after 6.4 years. When relapse occurred, those who were smoking when the study began and an increased number of sessions of debridement were predictors. Surgical needs were reduced when metronidazole was dispensed after the first and second annual examinations.

Effects of vitamin-B complex supplementation on periodontal wound healing.

BACKGROUND: Reports have demonstrated that nutrient supplements, in particular vitamin-B complex (Vit-B), can positively influence wound healing processes. However, limited information is available on the effects of Vit-B on periodontal wound healing. METHODS: A total of 30 patients (13 males, 17 females) presenting with generalized moderate to severe chronic periodontitis were enrolled in this study. All subjects presented > or = two teeth in the same sextant with probing depth (PD) > or =5 mm and bleeding upon probing (BOP) in need of access flap surgery (AFS). This study was a randomized, double-masked, placebo-controlled clinical trial. Subjects were instructed to take one capsule a day of either Vit-B (50 mg of the following: thiamine HCl, riboflavin, niacinamide, d-calcium pantothenate, and pyridoxine HCl; 50 microg each of d-biotin and cyanocobalamin; and 400 mcg of folate) or placebo for 30 days following AFS. Clinical attachment levels (CAL) and N-benzoyl-dl-arginine-2-naphthylamide (BANA) test scores were measured at baseline and at 90 and 180 days following surgical intervention. Assessments of the healing response were also performed using BOP, gingival index (GI), and plaque index (Pl) at baseline and 7, 14, 30, 90, and 180 days. The mean results of each parameter were averaged within a group. Differences between groups were analyzed by using repeated measures analysis of variance (ANOVA). RESULTS: Both groups experienced comparable levels of PD reduction following AFS (test: -1.57 +/- 0.34; control: -1.50 +/- 0.21). Changes in mean CAL were more favorable in Vit-B supplemented subjects (test: +0.41 +/- 0.12; control: -0.52 +/- 0.23; P = 0.024). Stratified data demonstrated significantly better results for the test group in both shallow (test: -0.08 +/- 0.03; control: -1.11 +/- 0.27; P = 0.032) and deep sites (test: +1.69 +/- 0.31; control: +0.74 +/- 0.23; P = 0.037). No significant differences were observed between groups regarding PI, GI, and BOP. BANA test values were significantly reduced in both groups after surgical treatment and no significant differences were noted between groups. CONCLUSION: Vitamin B-complex supplement in combination with AFS resulted in statistically significant superior CAL gains when compared to placebo.

Clinical response of azithromycin as an adjunct to non-surgical periodontal therapy in smokers.

BACKGROUND: Antibiotic therapy can be used in very specific periodontal treatment situations such as in refractory cases of periodontal disease found to be more prevalent in smokers. This study was designed to determine the efficacy of azithromycin (AZM) when combined with scaling and root planing (SRP) for the treatment of moderate to severe chronic periodontitis in smokers. METHODS: Thirty-one subjects were enrolled into a 6-month randomized, single-masked trial to evaluate clinical, microbial (using benzoyl- DL-arginine naphthylamine [BANA] assay), and gingival crevicular fluid (GCF) pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) levels in response to SRP alone or SRP + AZM. At baseline, patients who smoked > or =1 pack per day of cigarettes who presented with at least five sites with probing depths (PD) of > or =5 mm with bleeding on probing (BOP) were randomized into the test or control groups. At baseline and 3 and 6 months, clinical measurements (probing depth [PD], clinical attachment loss [CAL], and bleeding on probing [BOP]) were performed. GCF bone marker assessment (Ctelopeptide [ICTP] as well as BANA test analyses) were performed at baseline, 14 days, and 3 and 6 months. RESULTS: The results demonstrated that both groups displayed clinical improvements in PD and CAL that were sustained for 6 months. Using a subject-based analysis, patients treated with SRP + AZM showed enhanced reductions in PD and gains in CAL at moderate (4 to 6 mm) and deep sites (>6 mm) (P <0.05). Furthermore, SRP + AZM resulted in greater reductions in BANA levels compared to SRP alone (P <0.05) while rebounds in BANA levels were noted in control group at the 6-month evaluation. No statistically significant differences between groups on mean BOP and ICTP levels during the course of the study were noted. CONCLUSIONS: The utilization of AZM in combination with SRP improves the efficacy of non-surgical periodontal therapy in reducing probing depth and improving attachment levels in smokers with moderate to advanced attachment loss.

Treatment of gingival recession using a collagen membrane with or without the use of demineralized freeze-dried bone allograft for space maintenance.

BACKGROUND: Studies utilizing collagen membranes for guided tissue regeneration (GTR)-based root coverage procedures have reported promising results. However, creating and maintaining space underneath the membrane remains a challenge. Therefore, the purpose of this clinical trial was to determine whether the addition of bone graft (i.e., demineralized freeze-dried bone allograft [DFDBA]) significantly affects the outcome of collagen membrane GTR-based root coverage procedures. METHODS: Twenty patients participated. One Miller's Class I or II recession defect per patient was treated with a collagen membrane covered by a coronally positioned flap. Half of the patients also had DFDBA placed under the membrane. Clinical parameters recorded included: recession depth, recession width, width of keratinized tissue, clinical attachment level, and probing depth, measured to the nearest 0.5 mm. Presurgery and postsurgery (6-month) data were compared using Student's paired t test for parametric data and the Wilcoxon matched pairs test for non-parametric data. RESULTS: Guided tissue regeneration with collagen (COLL) and collagen + DFDBA (COBA) both resulted in statistically significant (P <0.05) reductions in recession depth (2.1 +/- 0.9 mm and 2.5 +/- 0.5 mm), recession width (1.5 +/- 1.7 mm and 2.2 +/- 1.6 mm), increase in keratinized tissue (0.7 +/- 0.8 mm and 1.2 +/- 1.0 mm), and gain of clinical attachment level (2.1 +/- 1.0 mm and 3.0 +/- 1.0 mm), when comparing 6-month data to baseline. Mean root coverage was 68.4 +/- 15.2% with COLL and 74.3 +/- 11.7% with COBA. However, there were no statistically significant differences between groups for recession depth, recession width, width of keratinized tissue, clinical attachment level, and probing depth. CONCLUSIONS: Both techniques are effective in attaining root coverage. Although root coverage tended to be better with the addition of DFDBA, the difference was not statistically significant. Further studies with a larger sample size are needed to determine whether adding DFDBA to GTR-based procedures using collagen membranes is of any benefit.

The nonsurgical treatment of patients with periodontal disease: results after five years.

BACKGROUND: In a previous study involving patients seen at the dental clinic of the Detroit Receiving Hospital, the authors found that 87 percent of teeth initially recommended for surgery or extraction were spared those treatments by a combination of debridement and short-term usage of antimicrobial agents. The objective of the present study was to determine how long the surgery-sparing benefits of less invasive treatment would persist. METHODS: Ninety of these patients were scheduled for maintenance therapy at three-month intervals over a five-year period. They were evaluated periodically for surgical needs by a clinician who was not aware of the nonsurgical periodontal treatment the patient had received. RESULTS: The initial treatment benefits were sustained, as the number of teeth needing periodontal surgery or extraction was 0.06 teeth per patient after 1.1 year, 0.22 after 2.3 years, 0.51 after 3.6 years and 0.86 after 5.1 years. CONCLUSIONS: A noninvasive treatment regimen for an anaerobic infection in teeth seriously compromised by periodontal disease resulted in a reduced need for surgery or tooth extraction for at least five years after completion of the initial treatment.