Alveolar ridge dimensional changes after two socket sealing techniques. A pilot randomized clinical trial.

OBJECTIVES: This pilot study aimed to assess dimensional changes following two different alveolar socket sealing techniques. MATERIAL AND METHODS: Twenty-one patients requiring tooth extraction and implant placement were randomly allocated to two different alveolar ridge preservation techniques. In the control group, demineralized bovine bone mineral (DBBM) and a gingival soft tissue punch were used to fill and seal the socket, whereas in the test group, the extraction socket was filled with DBBM and sealed with a hemostatic gelatin sponge. Digitalized impressions were taken before and 6 months after tooth extraction. The comparison was made on horizontal and vertical dimensional changes. RESULTS: The mean vertical loss was 0.8 ± 0.6 mm for the control group and 0.7 ± 0.5 mm for the test one. No statistical difference was found between groups for the vertical shrinkage. The horizontal dimensional narrowing of the alveolar socket was respectively 7.1/4.0/2.5 mm at levels 1, 3, and 5 mm from a coronal reference level for the control group. The test group showed dimensional changes of 4.8/2.3/1.3 mm at the three different levels, respectively. A significant difference was found at levels 3 and 5 mm. Referring to a visual analog pain scale, patients reported more severe pain in the control group (5.7/10) when compared with the test group (2.8/10). The difference was statistically highly significant (P ≤ 0.001). CONCLUSIONS: A significant difference was found between control and test groups regarding the horizontal dimensional changes and the post-operative pain. CLINICAL RELEVANCE: Regarding this primary result, the socket sealing technique with a hemostatic sponge provides an effective and inexpensive protocol with less post-operative pain.

Déterminants de la maladie parodontale en milieux hospitaliers à Kinshasa

Contexte : L'étiologie des maladies parodontales est multifactorielle. Le mode de vie, les facteurs socio-économiques, la réponse de l'hôte ainsi que l'environnement sont autant des déterminants qui influencent le développement et la progression de cette pathologie. L'identification de ces facteurs étiologiques dans un milieu hospitalier est un acquit important dans la prise en charge parodontale.Objectif : Déterminer des habitudes de vie et des paramètres cliniques ayant une influence sur le développement et la sévérité de la maladie parodontale en milieux hospitaliers de Kinshasa. Matériel et méthodes : C'était une étude analytique transversale menée auprès des patients âgés de douze ans et plus ayant consulté les services dentaires des institutions hospitalo-confessionnelles de la ville de Kinshasa au cours de la période allant de janvier à août 2015. La consommation du tabac, du sucre, de boissons sucrées et alcoolisées, les antécédents médicaux, le diabète, l'âge, le genre, l'obésité et la pression artérielle sont des variables qui ont été analysées pour identifier les déterminants des maladies parodontaux. Le Dutch Periodontal Screening Index (DPSI) a été utilisé pour évaluer le statut parodontal des patients. Les tests t de Student et de khi carré ont été appliqués pour comparer respectivement les moyennes et les pourcentages. L'analyse de régression logistique a été utilisée pour identifier les déterminants indépendants associés à la parodontite. Les Odds ratio et leurs intervalles de confiance à 95% ont été calculés pour déterminer la force d'association entre les variables dépendante et indépendantes (p < 0,05).Résultats : Sur les 642 patients examinés, 374 étaient du genre féminin. La moyenne d'âge des patients examinés était de 38,1 ± 16,3 ans avec des extrêmes allant de 12 à 92 ans. Quatre-vingt-huit virgule cinq pour cent (88,5%) des patients examinés avaient au moins un niveau secondaire. 16,7% de la population de l'étude présentaient au moins une parodontite modérée de DPSI 3+. A l'issue de l'analyse multivariée, le risque associé à la susceptibilité et la sévérité de maladie parodontale était multiplié par 5,4 (IC95%, p = 0,0001) pour les sujets âgés > 50 ans, par 3,7 (IC95%, p = 0,046) pour les sujets du genre masculin, par 2 (IC95%, p = 0,006) pour ceux qui consommaient journalièrement de boissons sucrées, par 4,26 (IC95%, p = 0,001) chez les sujets diabétiques et par 3,39 (IC95%, p = 0,025) chez les hypertendus. Ces variables indépendantes étaient liées à la variable dépendante par l'équation y = 4,2x + 1,08.Conclusion : La progression de la maladie parodontale vers la forme sévère était modulée par des nombreux facteurs notamment le vieillissement, le genre, le diabète, la consommation de boissons sucrées et l'hypertension artérielle

[Evaluation of periodontal health of Congolese in consultation in dental services of Kinshasa City]. / Evaluation de la santé parodontale des congolais admis en consultation dentaire dans la ville de Kinshasa.

Context: Periodontal diseases are multifactorial infectious pathologies. They affect tissues of support of the tooth and so end in dental losses. No sector of society is spared. Objective: To estimate the state of periodontal health of the patients admitted in consultation in the dental services of the city of Kinshasa. Material and Methods: It is a descriptive and transverse study. It was led on patients admitted in consultations in three dental services of the city of Kinshasa during the period going from January to August, 2015. The study included patients of 12 years old and more who consulted in one of the selected dental service. The selected patients supplied sociodemographic information in particular zone of residence, gender, level of education and social level. Dutch Periodontal Screening Index (DPSI) was used to estimate the periodontal state of every patient. Results: On a total of 642 patients 374 were females and 268 were males. The mean age was of 38.12 years ± 16,303. The patients of upper or more university level and those who had no employment represented successively 58.3% and 35.5%. Dental pain was the main motive for consultation. Majority of the patients had a DPSI around 3, that is 49.1%. 99.9% of the patients presented gingivitis whereas those 64% who suffered from periodontitis were subject to specialized periodontal care. Conclusion: Periodontal disease was present in all patients. The majority of the people had consulted dental surgeons only when they had pain.

Effect of N-chlorotaurine mouth rinses on plaque regrowth and plaque vitality.

The purpose of this 4-day plaque regrowth study was to assess the effect of N-chlorotaurine (NCT) mouth rinses on plaque inhibition and plaque vitality. Eighty volunteers participated in this investigator-blind, randomized, clinical controlled study in parallel groups. No oral hygiene was permitted except rinsing with a 2% or 3% NCT mouth rinse, a positive or a negative control. Primary parameters were the plaque index (Silness and Löe, Acta Odontol Scand, 22:121-135, 1964) and plaque vitality (Netuschil et al., J Clin Periodontol, 16:484-488, 1989) after the final rinse. In addition, another plaque index (Turesky et al., J Periodontol, 41:41-43, 1970), plaque area, and bleeding on probing were recorded. All parameters were taken at baseline and day 5. U test was applied on a 5% error level. No differences in plaque inhibition were found between the two NCT formulations and the negative control. However, a statistically significant reduction of plaque vitality compared to the negative and positive control was observed. Discoloration of the tongue and unpleasant taste were recorded in participants in the NCT groups. NCT mouth rinses did not inhibit plaque regrowth, but they did reduce the vitality of plaque bacteria. Methods of prolonging the substantivity of the NCT mouth rinses should be investigated to enhance the antibacterial properties of these formulations.

Stress and periodontal disease.

Stress is an association of physiological and psychological reactions of a person confronted to a change of situation he cannot face. The relationship between stress and any disease is explained by hormonal modifications and behavioural changes induced by the stress. The evidence of such an association between stress and periodontal disease will be evaluated. The purpose of the present review article is to differentiate between old feelings and knowledge, and present findings which show that a lot of prospective studies are still needed for a more defined role of stress and periodontal disease.

Effect of two new chlorhexidine mouthrinses on the development of dental plaque, gingivitis, and discolouration. A randomized, investigator-blind, placebo-controlled, 3-week experimental gingivitis study.

OBJECTIVE: The aim of this experimental gingivitis study was to assess the efficacy and safety of two new chlorhexidine (CHX) mouthrinses. MATERIAL AND METHODS: Ninety volunteers participated in this investigator-blind, randomized, clinical-controlled trial in parallel groups. During the treatment period, no oral hygiene measures except rinsing with non-alcoholic 0.2% CHX or 0.2% CHX/0.055% sodium fluoride mouthrinses, a positive control, or a negative control were permitted. The primary parameter was the gingival index; the secondary parameters were plaque index, discolouration index, and bleeding on probing. Clinical examinations were conducted 14 days before the start of the study, at baseline, and after 7, 14, and 21 days. The two sample t-test, anova, and ancova were used for the statistical analysis. RESULTS: No difference in efficacy was found between the two new CHX formulations and the positive control. On day 21, statistically significantly less gingival inflammation and plaque accumulation compared with placebo were observed. Besides discolouration and taste irritations, no adverse events were recorded. CONCLUSION: The two new CHX mouthrinses were able to inhibit plaque re-growth and gingivitis. Neither the omission of alcohol nor the supplementation with sodium fluoride had weakened the clinical efficacy of CHX with respect to the analysed clinical parameters.

A synergistic chlorhexidine/chitosan combination for improved antiplaque strategies.

BACKGROUND: The minor efficacy of chlorhexidine (CHX) on other cariogenic bacteria than mutans streptococci such as Streptococcus sanguinis may contribute to uneffective antiplaque strategies. METHODS AND RESULTS: In addition to CHX (0.1%) as positive control and saline as negative control, two chitosan derivatives (0.2%) and their CHX combinations were applied to planktonic and attached sanguinis streptococci for 2 min. In a preclinical biofilm model, the bacteria suspended in human sterile saliva were allowed to attach to human enamel slides for 60 min under flow conditions mimicking human salivation. The efficacy of the test agents on streptococci was screened by the following parameters: vitality status, colony-forming units (CFU)/ml and cell density on enamel. The first combination reduced the bacterial vitality to approximately 0% and yielded a strong CFU reduction of 2-3 log(10) units, much stronger than CHX alone. Furthermore, the first chitosan derivative showed a significant decrease of the surface coverage with these treated streptococci after attachment to enamel. CONCLUSIONS: Based on these results, a new CHX formulation would be beneficial unifying the bioadhesive properties of chitosan with the antibacterial activity of CHX synergistically resulting in a superior antiplaque effect than CHX alone.

Formation of human cementum following different modalities of regenerative therapy.

The aim of the present study was to compare newly formed cementum following different types of regenerative therapy in humans. Eighteen patients, each displaying one advanced intrabony defect around teeth scheduled for extraction, were included in this study. The defects were treated with either guided tissue regeneration (GTR), enamel matrix protein derivative (EMD), EMD plus bioactive glass, bovine-derived xenograft (BDX), BDX plus GTR, or BDX plus EMD. After healing, the teeth were removed together with their surrounding soft and hard tissues. Cellular content, presence of artifactual splits between the new cementum and the old one or the dentin surface, and thickness of the new cementum were evaluated. Irrespective of treatment, the new cementum was of a reparative, cellular, extrinsic and intrinsic fiber type. There were no differences in cementum thickness among treatments. These findings indicate that in humans, (a) the new cementum formed after different types of regenerative therapy was, irrespective of the treatment, of a reparative, cellular, extrinsic and intrinsic fiber type, and (b) the regenerative modality does not seem to influence the type of newly formed cementum.

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.

Susceptibility of planktonic versus attached Streptococcus sanguinis cells to chlorhexidine.

The effect of chlorhexidine (CHX) on the viability of Streptococcus sanguinis was investigated in a preclinical biofilm model separately on cells in the planktonic or attached life form. Saliva-coated human enamel and glass slides were exposed to the streptococci suspended in sterile saliva for 30 min and 60 min in the flow chamber system. The CHX exposition was performed in two parts: pretreatment of the planktonic bacteria before their attachment to enamel or glass, and treatment of bacteria already attached to enamel. The susceptibility measured by vitality percentages was determined by fluorescence microscopy using vital/dead cells. After CHX pretreatment of planktonic cells, the mean values of the vitality percentages after adhesion were 14-18% (enamel) and 24-25% (glass). In contrast, the mean vitality percentages of untreated attached streptococci reached 70-75% (enamel) and 68% (glass). The vitality percentages of CHX-exposed bacteria dropped markedly to 2-5%, whereas those of untreated attached cells remained at 65-66%. The exposure of initially attached streptococci to CHX resulted in greater reduction of bacterial viability than with the planktonic counterparts. This preclinical biofilm model allows the investigation of various bacterial life forms and can furthermore be used to select efficient antiplaque therapeutics which might be beneficial for clinical plaque control.

Immunohistochemical investigation on the pattern of vimentin expression in regenerated and intact monkey and human periodontal ligament.

The expression of vimentin is well documented in the intact animal and human periodontal ligament (PDL), but there is limited information on the pattern of vimentin expression in the regenerated PDL. The aim of the present study was to investigate the pattern of vimentin expression in the regenerated and intact monkey and human PDL. A total of 12 chronic recession-type defects were created in three monkeys (Macaca fascicularis) and treated either with guided tissue regeneration (GTR), or with an enamel matrix protein derivative (EMD). After 5 months, the animals were sacrificed and specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. Sections were labelled immunohistochemically by using monoclonal antibody against vimentin (VIM 3B4). Twelve patients, each of whom displayed one deep intrabony defect scheduled for extraction were treated with GTR, EMD or combination of EMD+natural bone mineral (NBM). Following a healing period of 6 months, the teeth were extracted "en block" and immunohistochemically analysed according to the same protocol as described in monkeys. The results revealed that in both monkeys and humans the newly formed PDL was labelled similarly for vimentin to the intact (non-treated) PDL. In all specimens, the newly formed PDL was in continuation with the intact parts of PDL, thus suggesting that the mesenchymal cells capable of regenerating the attachment apparatus may have their origin in the intact PDL. In conclusion, the present findings indicate that (a) the reformed PDL displayed a similar expression of vimentin to the intact (original) PDL, and (b) the cells capable of regenerating new PDL and new cementum appear to be of mesenchymal origin and their source may be in the intact PDL.

How to select the right mouthrinses in periodontal prevention and therapy. Part II. Clinical use and recommendations.

Based on scientific proof, only few mouthrinse solutions can be recommended. However, it is impossible to construct an extended table that would provide precise recommendations or advices for mouthrinse utilisation related to any possible discomfort or diseases. Only reliable information on the drugs available against periodontal disease can be offered to the therapist. By evaluation of her or his individual experiences, she or he has to judge all the armamentarium she or he possesses to react in the best possible way in each specific situation.

How to select the right mouthrinses in periodontal prevention and therapy. Part I. Test systems and clinical investigations.

The use of mouthrinses is increasing, especially as adjuncts to the daily mechanical oral hygiene. Different test systems may and can be used to test their antibacterial and clinical effects: bacteriology in vitro, substantivity in vivo, 4-day plaque re-growth, experimental gingivitis and long-term use. The plaque re-growth investigations of a few days are not only of limited use but may also be dangerous because often too extensive conclusions have been drawn from their design. The 'gold standard' test is the experimental gingivitis model to reveal the antiplaque as well as the antigingivitis effects of any mouthrinse preparation during 3 weeks. The last kind of investigations are of several months' duration, where the substances are used as supplements to mechanical oral hygiene measures.

Immunohistochemical evaluation of matrix molecules associated with wound healing following regenerative periodontal treatment in monkeys.

The aim of the study was to investigate immunohistochemically the expression of matrix molecules associated with periodontal tissues reformed after regenerative periodontal treatment. Chronic intrabony defects were treated with guided tissue regeneration, enamel matrix proteins, the combination of both, or access flap surgery. Five months after healing, the animals were killed, and the healed periodontal tissues were evaluated immunohistochemically by means of polyclonal antibodies against osteopontin, collagen I, and collagen III. The intact (nontreated) parts of the periodontium served as controls. As a general observation, the staining for all investigated matrix molecules appeared to be stronger within the regenerated tissues than in the intact ones. The results failed to reveal any differences in terms of staining intensity or distribution pattern of investigated matrix molecules between the four different treatments. Osteopontin expression was most intense at the border near the newly formed cementum and bone. In the regenerated periodontium, collagens I and III were localized throughout the entire periodontal ligament connective tissue. In the regenerated periodontal ligament, collagen III displayed more intense staining than collagen I. The present results suggest that: (1) even after a 5-month period following surgical periodontal therapy, extracellular matrix molecules associated with wound healing and/or remodelling are more strongly expressed in regenerated than in intact tissues and (2) once an environment for periodontal regeneration has been created, the expression of extracellular matrix molecules associated with the healing process seems to display the same pattern, irrespective of treatment modality.

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.

Effect of an enamel matrix protein derivative (Emdogain) on ex vivo dental plaque vitality.

BACKGROUND: A common clinical observation following surgical periodontal therapy with an enamel matrix derivative (Emdogain) is the improved healing of the soft tissues and the limited inflammation of the operated areas. These clinical observations are empirical and difficult to explain. One of the factors influencing the early wound healing might be a potential antimicrobial effect of Emdogain. AIM: To investigate the effect of Emdogain on the vitality of ex vivo supragingival dental plaque and to compare this effect to that of a standard 0.2% chlorhexidine solution. MATERIALS AND METHODS: 24 patients suffering from adult periodontitis were included in the study. At the beginning of the experiment, all participants were given a professional tooth cleaning. For the following 4 days, they had to refrain from any kind of oral hygiene measures. At day 5, from each of the volunteers, a voluminous plaque biofilm sample was taken with a sterile curette from the vestibular surfaces of the 1st lower molars and divided into 5 equal parts. Each part was mounted with 5 microl of the following solutions: (1) NaCl, (2) enamel matrix derivative dissolved in water (EMD), (3) enamel matrix derivative dissolved in the vehicle (Emdogain), (4) vehicle (propylene glycol alginate, PGA), (5) 0.2% chlorhexidine digluconate (CHX). After a reaction time of 2 min the test solutions were sucked off, and subsequently the biofilm was stained with a fluorescence dye. The vitality of the plaque flora after the treatments was evaluated under the fluorescence microscope (VF%). RESULTS: Plaque samples treated with NaCl showed a mean vitality of 76.8+/-8%. The EMD, Emdogain, PGA and CHX showed VF values of 54.4+/-9.2, 21.4+/-10.6%, 19.6+/-11.6% and 32.3+/-11.8%, respectively. Emdogain, PGA and CHX showed statistically highly significant reductions (p<0.0001) in terms of bacteria vitality when compared to water (negative control) and EMD. Both Emdogain and PGA were found to be statistically significantly different compared to CHX (p<0.001) (positive control). CONCLUSION: The results of this study indicate that Emdogain might have an antibacterial effect on the vitality of the ex vivo supragingival dental plaque flora.

Clinical controlled study on plaque and gingivitis reduction under long-term use of low-dose chlorhexidine solutions in a population exhibiting good oral hygiene.

The aim of this randomized, parallel-group, placebo-controlled, blind clinical study was to examine the dental plaque and the gingivitis inhibitory effects of two low-dose 0.06% chlorhexidine (CHX) preparations in comparison to a commercially available 0.1% CHX solution, an amine fluoride/stannous fluoride (ASF) solution and a water control as an adjunct to the daily mechanical oral-hygiene measures. After prophylaxis, 81 medical students performed their tooth cleaning and were asked to rinse for 30 s, according to the instructions given by the manufacturers with the assigned amount of the following solutions: once daily 10 ml ASF 250 ppm or twice daily each 10 ml CHX 0.06% with fluoride, 10 ml CHX 0.06% without fluoride, 15 ml CHX 0.1% or 100 ml tap water. The plaque index (PlI), the gingival index (GI) and the discoloration index (DI) were taken at day -14 and months (M) 0, 1, 2, 3 and 6. In this study group with good oral hygiene, all test products led to a reduction of the PlI scores when used as supplements to the usual mechanical hygiene measures. At M3 subjects using both the 0.1% as well as the 0.06% CHX showed significantly less plaque accumulation than those using ASF. In the GI a significant difference between the control and 0.1 % CHX was found at M3 and at M6. If a further decrease in the GI is wanted, a minimum concentration of 0.1% CHX for long-term use in association with habitual cleaning is needed, which, however, should be limited to special patients. If maintaining clinical health is the goal, the other solutions are a good alternative to 0.1% CHX because they exhibit less staining.

Patterns of cytokeratin expression in monkey and human periodontium following regenerative and conventional periodontal surgery.

The pattern of cytokeratin expression has been extensively described in the normal and inflamed periodontium. However, there is no information regarding the pattern of cytokeratin expression in the periodontium which has been reformed following regenerative periodontal surgery. The aim of the present investigation was to evaluate the pattern of cytokeratin expression in the reformed human and monkey periodontium following regenerative and conventional periodontal surgery. In 3 monkeys, acute fenestration-type and chronic intrabony defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMD), or coronally repositioned flap surgery (control). After a healing period of 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. Histological sections were cut with the microtome set at 3 microm. The sections were alternatively stained either with hematoxylin and eosin, or immunohistochemically by using one of the broad range monoclonal antibodies 34betaE 12 (for cytokeratins 1, 5, 10 and 14) or KL 1 (for cytokeratins 1, 2, 5, 6, 7, 8, 10, 11, 16 and 19), or one of the individual monoclonal antibodies LL025 (for cytokeratin 16), DC 10 (for cytokeratin 18), A53-B/A2 (for cytokeratin 19). Twelve patients, each displaying one deep intrabony defect scheduled for extraction due to advanced periodontitis or prosthetic reasons, were treated as described above. Following a healing period of 6 months, the teeth were extracted together with some of their surrounding soft and hard tissues. The histological and immunohistochemical processing of the human biopsies was identical to that described in monkeys. The results revealed that both the normal non-treated (original) monkey and human junctional epithelium stained strongly with all of the monoclonal antibodies used. The reformed junctional epithelium displayed the same cytokeratin expression pattern as the non-treated junctional epithelium. No differences regarding the cytokeratin expression pattern of the junctional epithelium were found between the treatments and types of healing (i.e. regenerative, through a new periodontal ligament, or reparative through a long junctional epithelium). In the intact periodontal ligament, the epithelial rests of Malassez displayed a comparable cytokeratin expression pattern to that of the junctional epithelium. However, no expression of cytokeratins was seen in the newly formed periodontal ligament. In such specimens, cytokeratin expression was observed only until the borderline between the regenerated cementum and the epithelial downgrowth. It was concluded that: a) the reformed junctional epithelium, following any type of surgical procedure, displays a similar pattern of cytokeratin expression to the original junctional epithelium; b) in the newly formed periodontal ligament, no expression of cytokeratins is present; and c) the epithelial rests of Malassez do not seem to reform after regenerative periodontal surgery.

Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration. A prospective controlled clinical study.

BACKGROUND: Utilisation of enamel matrix proteins (EMD) and application of the guided tissue regeneration principle (GTR) are treatment modalities which both have been shown to result in periodontal regeneration. However, it is yet unknown whether the combination of EMD and GTR may additionally favor the regeneration process. AIM: The aim of the present controlled study was to evaluate clinically the treatment effect of EMD, GTR, combination of EMD and GTR, and flap surgery (control) on intrabony defects. MATERIAL AND METHODS: 56 patients each of whom displaying one intrabony defect of a depth of at least 6 mm were randomly treated with one of the treatment modalities. Prior to surgery and at one year after, the following parameters were evaluated by a blinded examiner: Plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and clinical attachment level (CAL). No statistical significant differences between the four groups were observed at baseline for any of the investigated parameters. RESULTS: At 1 year after therapy, the sites treated with EMD demonstrated a mean PPD reduction of 4.1 +/- 1.7 mm and a mean CAL gain of 3.4 +/- 1.5 mm (p<0.001). The sites treated with GTR showed a mean PPD reduction of 4.2 +/- 1.9 mm and a mean CAL gain of 3.1 +/- 1.5 mm (p<0.001). The sites treated with the combined treatment showed a mean PPD reduction of 4.3 +/- 1.4 mm and a mean CAL gain of 3.4 +/- 1.1 mm (p<0.001). In the control group, the mean PPD reduction was 3.7 +/- 1.4 mm (p<0.001) and the mean CAL gain measured 1.7 +/- 1.5 mm (p<0.01). All 4 treatments led to statistically significant PPD reduction and CAL gain. All three regenerative treatments led to higher CAL gain than the control treatment (p<0.05). No statistical significant differences in PPD reduction and CAL gain were observed between the three regenerative treatments. CONCLUSION: It may be concluded that (a) all 3 regenerative treatment modalities may lead to higher CAL gain than the control one, and (b) the combined treatment does not seem to improve the outcome of the regenerative procedure.

Spatial distribution of vital and dead microorganisms in dental biofilms.

To examine the spatial structure of dental biofilms a vital fluorescence technique was combined with optical analysis of sections in a confocal laser scanning microscope (CLSM). Enamel slaps were worn in intraoral splints by three volunteers for five days to accumulate smooth-surface plaque. After vital staining with fluorescein diacetate and ethidium bromide the specimens were processed for CLSM examination. Optical sections 1 microm apart were analysed in the z-axis of these dental biofilms. One of the films was 15 microm high, sparse and showed low vitality, i.e. <16%, while the others were taller (25 and 31 microm) and more vital, i.e. up to 30 and 69%, respectively. In all instances the bacterial vitality increased from the enamel surface to the central part of the plaque and decreased again in the outer parts of the biofilm. The spatial arrangement of the microorganisms in the biofilm showed voids outlined by layers of vital bacteria, which themselves were packed in layers of dead material.