Pontic morphology as local risk factor in root decay and periodontal disease.

INTRODUCTION: In absence of treatment, old single edentulous spaces are subjected to progressively decrease in length due to tilting and rotation of the teeth situated mesial and distal. Lately when these spaces are prosthetically restored with a bridge and these teeth are becoming abutments, sanitizing of the prosthetic restoration is achieved with difficulty, the space between the pontic and the gingival surface becoming an area rich in pathogens that can cause various complications on the abutments. AIM: Considering these aspects, in this study we wanted to highlight the presence and the types of the microorganisms that can be found under the pontic even in an ideal situation, selecting only young adult patients with a good oral hygiene and only with metal-ceramic bridges. MATERIALS AND METHODS: Determination of microorganisms was achieved by growing on BD Columbia Agar with 5% sheep blood. Incubation was done in anaerobe condition using GENbag system produced by BioMérieux Company. RESULTS: The microorganisms that we determined were Streptococcus mutans, S. mitis, S. oralis, Gram-negative bacilli (Bacteroides ovatus, B. thetaiotaomicron) and Gram-positive bacilli (Bifidobacterium spp., Actinomyces israelii, Clostridium butyricum / beijerinckii) with relevance in the carious and periodontal disease. CONCLUSIONS: In cases of single unit bridges with very narrow pontics, even in patients with a very good oral hygiene and metal-ceramic restorations, we can still find micro-organisms that can potentially generate decay or periodontal disease on the abutments, located in the gingival area underneath these pontics. These bacteria can have negative implications on the long-term prognosis of prosthetic restorations.

Enterobacteriaceae and pseudomonadaceae on the dorsum of the human tongue.

OBJECTIVE: The aim of this study was to correlate the presence of Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Xanthomonadaceae on the posterior dorsum of the human tongue with the presence of tongue coating, gender, age, smoking habit and denture use. MATERIAL AND METHODS: Bacteria were isolated from the posterior tongue dorsum of 100 individuals in MacConkey agar medium and were identified by the API 20E system (Biolab-Mérieux). RESULTS: 43% of the individuals, presented the target microorganisms on the tongue dorsum, with greater prevalence among individuals between 40 and 50 years of age (p = 0.001) and non-smokers (p=0.0485). CONCLUSIONS: A higher prevalence of Enterobacteriaceae and Pseudomonadaceae was observed on the tongue dorsum of the individuals evaluated. There was no correlation between these species and the presence and thickness of tongue coating, gender and presence of dentures.

Enterobacteriaceae and pseudomonadaceae on the dorsum of the human tongue

OBJECTIVE: The aim of this study was to correlate the presence of Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Xanthomonadaceae on the posterior dorsum of the human tongue with the presence of tongue coating, gender, age, smoking habit and denture use. MATERIAL AND METHODS: Bacteria were isolated from the posterior tongue dorsum of 100 individuals in MacConkey agar medium and were identified by the API 20E system (Biolab-Mérieux). RESULTS: 43 percent of the individuals, presented the target microorganisms on the tongue dorsum, with greater prevalence among individuals between 40 and 50 years of age (p = 0.001) and non-smokers (p=0.0485). CONCLUSIONS: A higher prevalence of Enterobacteriaceae and Pseudomonadaceae was observed on the tongue dorsum of the individuals evaluated. There was no correlation between these species and the presence and thickness of tongue coating, gender and presence of dentures.

[Microflora on mucosa under different pontics of fixed partial bridge].

OBJECTIVE: To investigate the influence of three pontic types on alveolar ridge mucosal microecosystem. METHODS: Sixty patients ready to accept three unit metal ceramic bridges were selected. The bacterial type and the cultivable flora were counted and the proportions of bacteria detected on the top of alveolar ridge mucosal contact area before tooth preparation and three months after bridge insertion. RESULTS: Type and CFU of bacteria on the alveolar ridge mucosa under modified base-type pontics and modified ridge lap pontics increased significantly (P < 0.05); while there was no significant change under the ovata pontics (P > 0.05). Before tooth preparation and 3 months after fixed prosthesis insertion, the percentages of oral Streptococci and Neisseriae changed significantly (P < 0.05). CONCLUSIONS: The ovata pontic had less influence on mucosal microecosystem than the other two pontics and is the appropriate pontic design for clinical dentist.

[A comparative study of the bacterial dental plaque formation on fixed dentures with different surface characteristics]. / Studiu comparative asupra formarii placii dentare bacteriene pe aparatele gnato-protetice conjuncte cu diverse caracteristici de suprafata.

The accumulation of dental plaque on fixed prostheses made of various biomaterials is influenced by the roughness of the surface. For the investigation of this aspects it was necessary of a method rapid, facile and cheaper in comparison with bacterial culturing and identification which is laborious and expansive. In this study we followed the accumulation of dental plaque on biomaterials like chrome-cobalt and gaudent polished and unpolished, at different periods of time (3 and 14 days). We observed that after 3 days the aspect is predominant coccoid and after 14 days is predominant bacillary. On unpolished crowns the width of dental plaque is greater and on gaudent crowns the plaque is structural organised around of filamentous organisms.

[Gram-negative anaerobic bacilli identified in the subgingival microflora associated with fixed dentures]. / Bacili gram negativi anaerobi identificati în microflora subgingivala asociata aparatelor gnato-protetice conjuncte.

The prosthodontics devices have a major role in healthy state or disease of periodontal structures. They may initiate or amplify tissues destruction when technical features or the used material are not the most appropriate. The aim of this study was to establish the influence of different materials on the evolution of chronic periodontal diseases by comparison to lesions associated with natural teeth. Lot of study was represented by 21 partial edentulous patients with periodontitis in both natural teeth and fixed prosthodontics. Periodontal pockets were sampled and then Gram stained smear and cultivation onto selective media (Schadler + 5% sheep blood + nalidixic acid + vancomycin) were done. The isolated bacteria were identified by standard methods. We observed quantitative and qualitative differences between studied patients according to the material used for making the fixed prosthodontics.

Porphyromonas gingivalis, Prevotella intermedia and Bacteroides forsythus in plaque subjacent to bridge pontics.

This study examined the distribution of P. gingivalis, P. intermedia and B. forsythus in plaque on metallic and porcelain pontics adjacent to healthy and inflamed mucosa. Subpontic plaque was collected from 33 inflamed and 31 healthy sites. Plaque suspension was incubated with specific rabbit antisera to P. gingivalis (FDC 381), P. intermedia (ATCC 25261) and B. forsythus (FDC 335), and the labelled cells disclosed with fluorescein-labelled goat-anti-rabbit IgG by indirect immunofluorescence microscopy. Mean proportions of P. gingivalis, P. intermedia, and B. forsythus at inflamed sites were 0.60+/-0.75, 2.48+/-2.28, and 0.44+/-0.64% respectively, and at healthy sites 0.21+/-0.43, 1.27+/-1.05, and 0.15+/-0.18% respectively. These differences were statistically significant. Almost all sites were positive for P. intermedia, whereas only 12/31 healthy and 21/33 inflamed sites were positive for P. gingivalis. 18/31 healthy and 28/33 inflamed sites were positive for B. forsythus. P. intermedia was recovered in higher proportions from metallic pontics adjacent to inflamed sites (MI) than healthy sites (MH) or porcelain pontics next to inflamed (PI) or healthy sites (PH). P. gingivalis is was recovered in higher proportions from MI than PH. We conclude that both the nature of the pontic material and the health status of the mucosa affect the composition of the associated microbiota.

Endodontic pathology leading to implant failure--a case report.

This case report documents both the placement of a single implant into an alveolar ridge site and the failure of the implant due to bacterial contamination from an endodontic lesion. After placement of the fixture using osteotomes, the adjacent bicuspid developed periapical pathology following prior crown preparation. This root-end inflammatory process proceeded to involve the mesial surface of the implant. Although endodontic therapy on the devitalized tooth was performed within one week, an osteitis developed around the implant. One month after placement, the fixture had to be removed to prevent additional sequela. The osteotomy site appeared to heal uneventfully, allowing for the placement of a tooth-supported, fixed, partial prosthesis.