Biomedical subjects

M Paolantonio

Publications and source records attributed to M Paolantonio.

At least 37 records · Page 2Linked to original sources

PubMed1997

Immediate loading of titanium plasma-sprayed screw-shaped implants in man: a clinical and histological report of two cases.

THIS STUDY REPORTS ON THE histological findings of two immediately loaded titanium plasma-sprayed (TPS) implants, retrieved for a fracture of the abutment and for psychological reasons, after 8 and 9 months of loading, respectively. The microscopical analysis showed that mature, compact, cortical bone was present around both implants, with the bone implant contact percentage about 60 to 70%. No fibrous tissue or gaps were present at the interface. No resorption was present in the peri-implant bone. On both implants a few osteoblasts were found positive at the interface for alkaline phosphatase (ALP); while no cells positive for acid phosphatase (ACP) were present. Immediate loading can, perhaps, be used in very selected cases of good bone quality, with implants that have certain macro- (screw shape) and micro-interlocks (titanium plasma-sprayed surface) characteristics. Good results have been reported also for non-TPS surface (e.g., machined surface). More data about different designs (e.g., cylinders) or coatings (e.g., hydroxyapatite) are needed before any firm conclusions about immediate loading can be reached.

Aged↗

PubMed1996

Bone formation inside the material interstices of e-PTFE membranes: a light microscopical and histochemical study in man.

Membranes used in guided bone regeneration (GBR) should possibly achieve a good degree of tissue integration with neighbouring connective tissues in order to obtain a mechanically stable environment necessary for successful bone and soft tissue healing. The authors observed, in a histological study of e-PTFE membranes used for GBR and retrieved from 10 patients, inside the material interstices of the membranes, in many cases the presence of connective tissue cells and collagen fibres, and in two cases the presence of bone. The presence, inside the membrane, of connective tissue and bone could help toward a tight integration between the membrane and neighbouring tissues, with the production of a biological seal.

Bone Development↗

PubMed1996

Occurrence of Actinobacillus actinomycetemcomitans in patients wearing orthodontic appliances. A cross-sectional study.

The aim of the present study was to assess: (1) the occurrence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque from young patients undergoing orthodontic treatment with fixed appliances; (2) a possible relationship between the presence of Aa and the clinical conditions; (3) a relation between the duration of orthodontic treatment and the microbiological and clinical parameters; (4) whether differences exist when taking into consideration the different type of appliances, i.e., bands or brackets. 34 subjects aged between 12 and 20 years participated in the study. Of these, 20 subjects had worn orthodontic appliances (test group), while the remaining 14 subjects served as matched control (control group). 4 to 8 sites in each patient were available for clinical and microbiological examination. Clinical parameters consisted of presence/absence of plaque and gingival bleeding index (GBI). Microbiological sampling was performed in the same sites as in the clinical examination. A statistically significant difference was present when comparing %s of GBI positive scores between teeth from the test group (57.5%) and teeth from the control group (25%). Plaque was present in 53% of test sites and 37% of control sites, but this difference was not statistically significant. Aa was detected from at least one site in 85% of test subjects and in 15% of the control subjects (p < 0.001). Among the subjects, 41% harboured Aa at a concentration between 0.1% and 1.0%, whereas another 40% yielded Aa at a concentration greater than 1.0%. Finally, a positive correlation was noted between the % of sites positive for Aa and the % of sites displaying a positive GBI score (r = 0.41; p < 0.005). No relation was found between the duration of orthodontic treatment and the microbiological or clinical parameters; neither were statistically significant differences found when we compared results from sites wearing bands or brackets. In conclusion, the present study showed that young subjects wearing orthodontic appliances harbour Aa with a remarkable frequency of detection, although plaque levels do not significantly differ from those of a matched control group.

Adolescent↗

PubMed1996

Frequency of detection of Actinobacillus actinomycetemcomitans in young patients during fixed orthodontic therapy.

The aim of the present study was to assess the occurrence of Aa in subgingival plaques from young subjects undergoing orthodontic treatment with fixed appliances; moreover we sought a possible relationship between the presence of Aa and the clinical conditions, also taking into consideration the different types of appliances, i.e., orthodontic bands or brackets.

Actinobacillus Infections↗

PubMed1995

Flow cytometric approach to human polymorphonuclear leukocyte activation induced by gingival crevicular fluid in periodontal disease.

In gingival pockets of patients with periodontal disease, polymorphonuclear leukocytes (PMN) are in contact with a peculiar exudate, the gingival crevicular fluid (GCF). Because of the pivotal role played by PMN in periodontal disease, we evaluated the ability of GCF in modulating normal human PMN. GCF was obtained from two gingival sites with severe periodontitis (SP) and two gingival sites with only mild periodontitis (MP) in 12 patients. Purified PMN were exposed to GCF from SP and MP sites and, as a control, to sterile culture medium. GCF activity was evaluated by monitoring the modulation of membrane molecules relevant to cell function. Compared to control medium, GCF from SP and MP sites was able to induce an activation status in PMN evidenced by an increased CD11b (62 +/- 9% and 28 +/- 7%, respectively) and f-Met-Leu-Phe (56 +/- 5% and 31 +/- 7%, respectively) receptor expression, with a concomitant reduction of CD62L expression (56 +/- 8% and 23 +/- 7%, respectively). Thus, reflecting the clinical status, GCF from SP sites was significantly more efficient in affecting PMN than GCF from MP sites. Cell size modifications, evaluated as an additional indicator of PMN activation, were consistent with membrane molecule modulation. The difference in PMN-activating capacity between SP and MP was abrogated by the successful completion of an appropriate periodontal therapy that dramatically improved clinical status. This is the first direct demonstration that GCF from periodontitis has the capacity to activate normal resting PMN and that this capacity reflects the magnitude of the inflammatory process that takes place in the gingiva.

Adult↗

PubMed1995

Influence of gingival crevicular washing on the expression of polymorphonuclear leukocyte membrane receptors before and after periodontal therapy.

Extensive data demonstrate that polymorphonuclear leukocytes (PMN) are the predominant cell type involved in periodontal disease and that gingival crevicular fluid constituents are influenced by the inflamed gingiva. The aim of the present study was to evaluate the ability of gingival crevicular washing (GCW) (a dilution of gingival crevicular fluid) from periodontal sites in different clinical conditions of modulating the PMN membrane receptors involved in motility, adhesion and phagocytosis before and after periodontal treatment. 10 patients affected by adult periodontitis (AP) were selected. From each patient, 2 test sites (TS) were chosen on the basis of a probing depth > 5 mm and attachment loss, and 2 control sites (CS) with probing depth < 3 mm without. Modifications of membrane receptor density of PMN from healthy donors incubated with GCW harvested from TS and CS was evaluated using fluorescent probes and flow cytometry. Compared to CS-GCW, TS-GCW before therapy increased the expression of the beta 2 integrin CD11b and the chemotactic receptor for the oligopeptide N-formyl methionyl leucyl phenylalanine (FMLP-R) while it reduced the expression of L-selectin. GCW collected from the same TS after the successful completion of periodontal treatment did not influence PMN receptors, indicating that the clinical improvement paralleled the disappearance of the PMN modulating capability contained in TS-GCW before therapy. In conclusion, the present data illustrate the relevant modifications occurring at PMN membrane in chronic adult periodontitis exerted by GCW obtained by a simple fluid collection technique. Thus, monitoring gingival crevicular fluid PMN activating capability may help disclose the presence of chronic periodontitis and may be useful in assessing successful treatment.

Adult↗

PubMed1995

Eosinophilic granuloma of the mandible involving the periodontal tissues. A case report.

This case reports on a 14-year-old boy with multiple radiolucent lesions widely distributed in the mandible, particularly in the right side (body-angle-ascending ramus). The lesion was first diagnosed as early-onset periodontitis and treated accordingly. It continued to grow very quickly, however, over a 6-month period, resulting in involvement of the entire mandible, with complete destruction of the lingual cortical bone, erosion of the external cortex with expansion in the neighboring soft tissues, and with a periosteal reaction in some areas. This case may serve to illustrate the rapid progress of eosinophilic granuloma, the importance and the difficulties of an early diagnosis, and the consequences of late diagnosis and treatment.

Adolescent↗

PubMed1995

[The prognostic significance of the presence of Actinobacillus actinomycetemcomitans in the subgingival plaque of young orthodontic patients].

The aim of present study was to evaluate the prognostic significance of the presence of Actinobacillus actinomycetemcomitans in subgingival plaque from young patients wearing fixed orthodontic appliances. Fifteen orthodontic patients, 3 males and 12 females, aged 10 to 27, systemically healthy, participated in the study. First examination took place in the spring of 1992 (T1) and consisted in the collection of clinical (pocket depth, PD; Gingival Index, GI; Plaque Index, P1I; Gingival Bleeding Index, GBI) and microbiological (Actinobacillus actinomycetemcomitans presence) parameters in 4-8 periodontal sites in each patient. The same clinical and microbiological parameters were collected again in the spring of 1994 (T2). Results showed that the presence of Actinobacillus actinomycetemcomitans in the examined periodontal sites underwent fluctuation, 25% of sites being positive for the sought after bacterium in T2 whereas the percentage of Actinobacillus actinomycetemcomitans positivity in T1 was 47.5% with a statistically significant difference (p < 0.005). On the contrary clinical parameters did not show significant modifications through the study period T1-T2. Differential analysis of clinical parameter modifications in relation to Actinobacillus actinomycetemcomitans positivity in T1 or Actinobacillus actinomycetemcomitans-positivity fluctuations in T1-T2 period did not evidence any significant difference among various microbiological conditions. The authors conclude that the mere presence of Actinobacillus actinomycetemcomitans in subgingival plaque from specific periodontal sites in young orthodontic patients does not seem sufficient to consider those sites at risk for periodontal destruction in the medium-short term.

Adolescent↗

PubMed1995

[The effect of subgingival irrigation with acetylsalicylate on the polymorphonuclear leukocyte count in periodontal pockets of medium depth].

Considering the role played by arachidonic acid metabolites in the pathogenesis of periodontal disease and the possible beneficial effects exerted by non steroidal anti inflammatory drugs on periodontal damage, the aim of the present study was to assess the capability of a 1% acetylsalicylate solution, delivered by subgingival irrigation, in reducing the number of polymorphonuclear leukocytes (PMN) in periodontal pockets of patients affected by periodontitis. Ten patients systemically healthy, in the age between 36 and 64, participated in the study. After supragingival scaling in each patient test and two control sites were chosen among those exhibiting a pocket depth between 5 and 7 mm. The number of periodontal pocket PMN was evaluated after subgingival washing by the technique of Skapski & Lenher and Gingival Bleeding Index (GBI) score was recorded in each experimental site. Test sites then received subgingival subgingival washing by 0.5 ml of a 1% acetylsalicylate solution three times a week whereas control sites were irrigated by physiologic solution. After treatment the number of PMN and GBI scores from each test and control site was re-evaluated. Results showed that test sites exhibited a decrease in the number of pocket-PMN respect to control sites although not statistically significant (p > 0.5). At contrary GBI score did not modify through the study. In conclusion subgingival irrigation by acetylsalicylate demonstrated to be able to reduce subclinical inflammation in periodontal pockets evaluated by the number of PMN in gingival fluid.

Adult↗

PubMed1995

[The presence of Actinobacillus actinomycetemcomitans in subgingival bacterial plaque in relation to the amount of supragingival plaque].

Actinobacillus actinomycetemcomitans (Aa) is currently considered the principal bacterium involved in juvenile forms of periodontitis. Considering that supragingival and subgingival plaque are closely correlated, the aim of the present research has been to assess if a correlation can be recognized between the amount of supragingival plaque and the presence of Aa in subgingival plaque in young subjects. Thirty-three individuals participated in the study. In each subject's dentition two periodontal sites were chosen: one (test site) was randomly selected among those sites which displayed a Plaque Index (P1I) = 0; another site was similarly chosen among those which presented the highest P1I score (2 or 3). In each test and control site Gingival Bleeding Index (GBI) was recorded and a microbiological sampling of subgingival plaque was performed. After anaerobic culture of plaque samples, the occurrence of Aa in each test and control site and the proportional representation of the bacterium in total cultivable anaerobic flora were assessed. Results showed a statistically significant difference in the occurrence of Aa between test and control sites in the same oral cavity and a correlation between GBI positivity and Aa presence. In conclusion, according to other authors, Aa seems to be more frequently founded in subgingival plaque coming from periodontal sites where supragingival plaque in more abundant.

Adolescent↗

PubMed1995

Compound odontoma associated with a primary molar.

The authors describe a case of a compound odontoma located between the roots of a primary molar. It is a very unusual location. The primary tooth and the odontoma were extracted and a slide was obtained with the cutting grinding system.

Adult↗

PubMed1992

[The clinical and microbiological evaluation of the efficacy of oral irrigation on the periodontal tissues of patients wearing fixed orthodontic appliances].

The aim of the present study has been the evaluation of the effectiveness of oral irrigation with or without toothbrushing and dental flossing, in individuals treated with fixed orthodontic appliances, on controlling the development of dental plaque and, hence, of gingivitis. Eight individuals with a good general and oral status have been chosen. Before the experimental period, they received instructions about oral hygiene with toothbrushing and dental flossing and then they have been monitored to verify they were doing well. At the time T0, the upper tooth have been banded, three Periodontal Indexes (Plaque Index according to Silness and Loe, Modified Gingival Index according to Lobene and Gingival Bleeding Index according to Ainamo and Bay) registered and subgingival plaque samples from the premolars' gingival sulcus collected in order to point out the total anaerobes bacterial counts, the rates of motile bacteria, spirochetes, Gram positive and Gram negative cocci and bacteria, by means of optical and dark field microscopy and of cultural methods. For their oral hygiene, the patients had to use, in the right side toothbrush and dental floss (Control 1), in the left side the oral irrigator alone (Test 1). One month later (time T1), the lower teeth have been banded, too. In the right side the patients had to use toothbrush and dental floss (Control 2), while in the left one they used the same devices as Control 2 plus the oral irrigator (Test 2). At the time T1 Periodontal Indexes and Microbiological analyses have been extended to all the four quadrants.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[The anatomical characteristics of the root furcations in the molar teeth].

The aim of the present study has been to realize a morphometrical and morphological study on the anatomical characteristics of molar teeth root furcations. Two hundred ninety four molars (147 upper and 147 lower teeth), after extraction and elimination of periodontal ligament residuals by trypsin, have been morphometrically evaluated recording the principal anatomical characters of the furcal and radicular region (root and radicular trunk lengths, mesio-distal and vestibulo-palatal diameters at the cementum-enamel junction, inter-radicular angle width and furcal area extension). By the Pearson's correlation test data such obtained were analyzed to verify the existence of statistically significant correlations among the above mentioned anatomical characteristics. Thirty teeth, selected among the most representatives of the whole sample for their anatomical characters, have been morphologically evaluated: 10 by stereo-microscopical examination, 10 by the observation of non-demineralized histological sections and 10 by scanning electron microscopical examination. Results of the morphometrical evaluation showed that from first to second molar the radicular angle, root length and furcal area width undergo a reduction; differently radicular trunk increases his length. On the basis of this results the Authors try to explain data from recent clinical research testifying that second upper molar is the most frequently extracted tooth. In fact a long radicular trunk is associated with a more apical placement of the furcation entrance and this situation, in conjunction with a narrow inter-radicular angle, can obstruct the insertion of therapeutical instruments, justifying the bad prognosis of the second upper molar involved by periodontal disease. The statistical analysis of anatomical data showed a significant correlation (r = -0.46) among radicular trunk length and inter-radicular angle width (in upper first molars; reverse correlation), root length and inter-radicular angle width (r = 0.51) (lower first molars), vestibular-buccal diameter at the cementum-enamel junction and width of mesial and distal furcal angles (r = 0.43) (upper second molars), the extension of furcal area and the wideness of inter-radicular angle (r = 0.89/0.43). These data are in accord with those from other Authors. Morphological analysis showed the high structural complexity of furcal area in molar teeth with the common observation of cemental crests and pulpal accessory canals orifices; these structures can offer a good receptacle to the subgingival dental plaque and can cause difficulties in debridement and therapeutical treatment of the molar furcal region involved by periodontal disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Histocytological Preparation Techniques↗

PubMed1992

[The influence of the "age factor" on periodontal conditions in the diabetic patient].

Conflicting reports exist in dental literature on the relationship of diabetes mellitus to periodontal disease. Among the controversies about this relation, the role played by the age of patient has been widely investigated. Some authors, in fact, reported an increased prevalence and severity of gingivitis and periodontitis in children and young individuals with insulin dependent diabetes mellitus (IDDM) in comparison to healthy subjects, while other researchers were not able to confirm this finding. In particular some authors postulated the hypothesis that the diabetic state could influence periodontal conditions just after the age of 30-35. The aim of the present study has been to verify this hypothesis. One hundred thirty-two subjects participated in this study; among them 66 were IDDM patients and 66 were healthy controls comparable to the diabetics for the main epidemiological features. In particular, control subjects were similar to the diabetics for oral hygiene level in order not to attribute eventually occurring differences by mistake to the diabetic state instead of to a not comparable amount of bacterial plaque present on the teeth. Among 66 IDDM patients 33 were younger than 30 (medium age = 14; extremes: 6-22) and were indicated as DG (young diabetics) group; others 33 were older than 30 (medium age = 45.1; extremes: 31-66) and were indicated as DA (adult diabetics) group. A similar differentiation was made in the control group obtaining, in this way, two subgroups (CG = young controls and CA = adult controls). In the diabetic groups males were 53% while among controls they represented 58%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

[The periodontal condition of patients with insulin- and non-insulin-dependent diabetes].

The authors compared through the most common clinical indexes the periodontal conditions of a group of type I and type II diabetic patients with those of a group of healthy control subjects. Results showed the existence of statistically significant differences for each parameter considered (plaque index, gingival index, bleeding index, attachment loss). Also with comparable oral hygiene diabetics showed a worse periodontal condition in comparison with controls. In absolute terms type II diabetics presented worse clinical index scores compared to type I diabetics even if not at a statistically significant level.

Adult↗

PubMed1991

[The comparative evaluation of the efficacy of surgical and nonsurgical periodontal therapy in relation to the oral hygiene conditions and the severity of the lesions].

A retrospective longitudinal study was carried out to evaluate the efficacy of surgical and nonsurgical periodontal therapy in reducing pocket depth values. This evaluation was made in relation to the strictness with which patients observed professional and domestic oral hygiene and in relation to pretreatment pocket depth values. Results showed that the two forms of periodontal therapy offer comparable results in terms of pockets reduction of either restricted or considerable depth, whereas the most important element in order to achieve therapeutic success was the observation of an effective professional and domestic plaque control.

Adult↗

PubMed1991

General considerations in the treatment of periodontal disease: infection control, medications, and wound healing.

Although it is difficult to accurately predict the results of periodontal therapy, it may be possible to improve the success of therapy if the patient is considered from an immunologic, microbiologic, social, and behavioral point of view, as a heterogenous entity. The success or failure of a particular treatment can be related to the host's personal response to a therapeutic procedure rather than to the technique used.

Alveolar Bone Loss↗

PubMed1990

[Periodontal therapy. I. The working philosophies].

Periodontal treatment has recently been evaluated by numerous research projects which have confirmed its validity and clarified the indications and limits of treatment. In this review the authors discuss and analyse the results achieved using different techniques of periodontal therapy; moreover, attention is focused on the apparent similarity of results obtained using conservative and surgical methodologies.

Humans↗