Immunohistochemical evaluation of matrix molecules associated with wound healing following treatment with an enamel matrix protein derivative in humans.

Application of enamel matrix protein derivative (EMD) onto a debrided and conditioned root surface has been shown to promote periodontal regeneration in animals and humans. However, until now there is virtually no information from humans describing the expression of different matrix molecules in the newly formed periodontal tissues following treatment with EMD. This study investigated immunohistochemically in humans the expression of matrix molecules associated with periodontal tissues reformed after treatment with EMD. Eight patients with intrabony defects were treated with EMD. Six months after surgery teeth together with some of their surrounding soft and hard tissues were removed, fixed in buffered formalin, decalcified in EDTA, and embedded in paraffin. Serial sections of 6 micro m were cut in mesiodistal direction. Sections were evaluated immunohistochemically by means of polyclonal antibodies against osteopontin, collagen I and collagen III. The original (non-treated) parts of the periodontium served as controls. In all specimens the healing resulted to a varying extent in formation of cementum, periodontal ligament and alveolar bone. In all specimens the expression of the investigated matrix molecules was stronger at the reformed than at the original sites. Osteopontin expression was most intense at the border near the newly formed cementum and bone. In the regenerated periodontal ligament, collagen I and III were localized throughout the entire periodontal ligament connective tissue. Within the newly formed PDL connective tissue the immunohistochemical staining appeared stronger for collagen III than for collagen I. The present findings suggest that (a) treatment of human intrabony defects with EMD creates an environment favourable for periodontal regeneration and, (b) in humans the healing and/or remodelling process of the reformed tissues may be followed immunohistochemically for a period of 6 months.

Effect of a toothpaste containing triclosan on dental plaque, gingivitis, and bleeding on probing--an investigation in periodontitis patients over 28 weeks.

The aim of this double-blind, 28-week study was to evaluate the plaque-inhibitory and antigingivitis efficacy of a fluoride toothpaste containing 0.3% triclosan and essential oil (Dental Kosmetik, Dresden, Germany) in comparison with a control toothpaste. One hundred twenty subjects previously treated for chronic periodontitis were included in the study. At baseline, 8, 18, and 28 weeks, plaque accumulation (PlI) and gingival status (GI) were assessed. Probing pocket depth (PD) and bleeding on probing (BOP) were measured at baseline and week 28 using a Florida probe. No professional hygiene was delivered during the study period. Mean plaque scores decreased between baseline and week 8 in both groups. At the end of the study, a significant increase of mean PlI compared to baseline could be observed in the test and in the control groups. Comparing the two groups, the PlI in the triclosan group was significantly lower than in the control group. Mean gingival scores decreased significantly during the first 8-week period in both groups. This reduction was followed by an increase of GI in the control, while the GI in the test group reached a significantly lower value than in controls after 28 weeks. Furthermore, at week 28, in both groups the PD were decreased as compared to the pre-study data. It is concluded that the triclosan/essential oil additive in a fluoride-containing dentifrice exhibited distinctive antigingivitis as well as plaque-inhibitory effects during a 28-week maintenance period in periodontitis patients.

Treatment of intrabony defects with guided tissue regeneration and enamel-matrix-proteins. An experimental study in monkeys.

BACKGROUND: Enamel matrix proteins (EMD) have recently been introduced in regenerative periodontal treatment. However, no histological data are yet available concerning the effect of treating intrabony periodontal defects with EMD, and no histological comparisons have been made comparing the result of treatment of intrabony defects with EMD with that of the treatment with guided tissue regeneration (GTR). AIM: Therefore, the aim of the present study was to evaluate histologically in monkeys the effect of treating intrabony defects with EMD, GTR or combined EMD and GTR. METHOD: Intrabony periodontal defects were produced surgically at the distal aspect of teeth 14, 11, 21, 24, 34, 31, 41 and 44 in 3 monkeys (Macaca fascicularis). In order to prevent spontaneous healing and to enhance plaque accumulation metal strips were placed into the defects. After 6 weeks the defects were exposed using a full-thickness flap procedure. The granulation tissue was removed and the root surfaces were debrided by means of hand instruments. Subsequently, the defects were treated using one of the following therapies: (i) GTR, (ii) EMD, or (iii) combination of EMD and GTR. The control defects were treated with coronally repositioned flaps. After 5 months, the animals were sacrificed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. 8 microm thick histological sections were cut and stained and subsequently examined under the light microscope. RESULTS: In the control specimens, the healing was characterized by a long junctional epithelium and limited periodontal regeneration (i.e., new periodontal ligament, new cementum with inserting connective tissue fibers and new bone) in the bottom of the defect. The GTR-treated defects consistently presented periodontal regeneration when the membranes were not exposed whereas the sites treated only with EMD presented regeneration to a varying extent. The combined therapy did not seem to improve the results. CONCLUSION: It can be concluded that all 3 treatment modalities favor periodontal regeneration.

Healing of fenestration-type defects following treatment with guided tissue regeneration or enamel matrix proteins. An experimental study in monkeys.

The aim of the present study was to evaluate histologically in monkeys the healing in acute fenestration-type defects following treatment with guided tissue regeneration (GTR) or enamel matrix proteins (EMD). Standardized "critical size" fenestration-type defects were produced surgically at the vestibular aspect of teeth 13, 23, 33, 43 in three monkeys (Macaca fascicularis). The vestibular bone plates were removed and the root surfaces were debrided by means of hand instruments in order to completely remove the root cementum. Following root conditioning with ethylenediaminetetraacetate (EDTA), the defects were treated using one of the following therapies: (1) GTR, (2) EMD, or (3) control (coronally repositioned flaps). After 5 months the animals were killed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA, and embedded in paraffin. Eight-micrometer-thick step serial histological sections were cut in a vestibulo-oral direction, stained with hematoxylin and eosin or oxone-aldehyde-fuchsin-Halmi, and subsequently examined under the light microscope. The results showed that, in the defects treated with GTR, a new connective tissue attachment (i.e., new cementum with inserting collagen fibers) and new bone formation had consistently occurred, whereas, in the defects treated with EMD or with coronally repositioned flaps, new attachment and new bone reformed to a varying extent. The quality of the cementum did not differ after EMD, GTR, or flap surgery. It was concluded that GTR treatment with bioresorbable membranes seems to predictably promote new attachment and new bone formation, whereas the application of EDTA or EMD may also enhance periodontal healing to a certain extent. Further studies with higher numbers of animals and defects are needed in order to definitely clarify the effect of root surface conditioning with EDTA and EMD on periodontal healing.

Plaque bacteria counts and vitality during chlorhexidine, meridol and listerine mouthrinses.

The aim of this double-blind study was to enumerate the total number of living and dead bacteria on defined tooth areas during the application of antibacterial mouthrinses. After prophylaxis, 40 students refrained from all oral hygiene measures for 3 d, during which they rinsed with a phenolic compound (Listerine), an amine fluoride/stannous fluoride solution (Meridol), 0.2% chlorhexidine (CHX) or a control solution (0.02% quinine-hydrochloride). The plaque index (P1I) was recorded at the start and the end of the investigation. Total bacterial counts (BC) and colony-forming units (CFU) of 1d-, 2d- and 3d-old dentogingival plaque were determined. The plating efficiency (PE) was calculated as a percentage of CFU/BC and the portion of vital microflora estimated by a vital fluorescence technique (VF). All groups started with a P1I approximating 0.1. On day 3, the P1I values were 1.21 in the control group and 0.51, 0.37 and 0.14 after Listerine, Meridol and CHX use, respectively. A tremendous variation existed between the numbers of viable bacteria found per mm2 on the enamel surface and day 3 (CHX: 0.2; Meridol: 300; Listerine; 6x10(4); control: 2x10(6)), while higher total numbers of bacteria were concomitantly present (CHX and Meridol: 1-2x10(4); Listerine: 2x10(5); control: 2x10(6)). Both vitality parameters PE and VF reached 92% in the control group at day 3, but only 7% after CHX use. With Meridol and Listerine, the corresponding PE values were 3% and 43%, respectively, while the VF values reached 48% and 54%. The PII, BC, CFU and PE values of the CHX and the Meridol groups differed significantly from those of the control group. In contrast, Listerine showed no difference as compared to the control rinse. Due to the strong antibacterial action of CHX and Meridol during their use, almost only dead or non-proliferating bacteria were found on the tooth surfaces. Thus, only a thin plaque could develop. As a clinical consequence, both substances showed retardation of plaque development as reflected by significantly reduced plaque indices.

Efficacy of Listerine, Meridol and chlorhexidine mouthrinses as supplements to regular tooth cleaning measures.

The anti-plaque, anti-gingivitis and anti-microbial efficacies of a phenolic compound (Listerine) and 2 different amine/stannous fluoride mouthwashes (Meridol I, II) were compared when these solutions were used in addition to usual tooth cleaning. A placebo preparation was utilized as a negative control and a chlorhexidine solution as a positive control in this double-blind study. After professional tooth cleaning, 49 volunteers continued their habitual, self-performed and non-supervised oral hygiene for a period of 2 weeks, in order to have a more standard baseline. At day 0, they began to rinse twice daily with 1 of the 5 mouthwashes. After 3 weeks of rinsing, plaque indices remained the lowest in the chlorhexidine and the Meridol I groups, while subjects using Listerine or Meridol II demonstrated similar indices significantly lower than that of individuals rinsing with the placebo solution. Through this period, the gingival index scores were similar in the Meridol, Listerine and chlorhexidine groups. At day 21, the mean GI scores in the chlorhexidine group were significantly lower than the scores in the placebo group. The plaque vitality scores showed a bacterial effect in vivo of chlorhexidine and, to a lesser extent, of the Meridol solutions. No substantial evidence of an antibacterial effect in vivo was found for Listerine. This study has demonstrated that when mouthrinses are used to supplement habitual mechanical oral hygiene, chlorhexidine remains the most powerful solution. Furthermore, it was also shown that a combination of habitual self-performed and non-supervised oral hygiene with Meridol or Listerine is more beneficial for plaque control than the use of mechanical oral hygiene alone.

Efficacy of Listerine, Meridol and chlorhexidine mouthrinses on plaque, gingivitis and plaque bacteria vitality.

The experimental gingivitis model was used to compare the anti-plaque, anti-gingivitis and anti-microbial efficacies of a phenolic compound (Listerine) and an amine/stannous fluoride mouthwash (Meridol), using a placebo preparation as negative control and a chlorhexidine solution as positive control in a double-blind study. After professional toothcleaning, 36 volunteers performed optimal oral hygiene for a period of 2 weeks. They then ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with 1 of the 4 mouthrinses. After 3 weeks of rinsing, plaque indices remained the lowest in the chlorhexidine group, while subjects using Listerine or Meridol harbored similar indices significantly lower than that of individuals rinsing with the placebo solution. Up to that time, the gingival index scores were equal in all groups except for the chlorhexidine group in which the values only amounted to half of these encountered in the other groups. The plaque vitality scores showed a bactericidal effect in vivo of chlorhexidine during the entire time of experimental gingivitis. In contrast, the data gave no evidence of an antibacterial effect in vivo of Listerine. The efficacy of Meridol to kill micro-organisms was similar to chlorhexidine during the early stages of plaque accumulation and, with time, became insignificant. This study has demonstrated that chlorhexidine was superior to Listerine and Meridol in its ability to maintain low plaque scores and gingival health during this 3-week period of no mechanical oral hygiene. Moreover, it was also shown that Meridol was as effective as Listerine in reducing plaque accumulation and, in contrast to Listerine, possessed a remarkable but transient antibacterial effect in vivo.