Vol. 63 - No. 5 MINERVA STOMATOLOGICA 167 Even though we noticed a slight increase in the plaque index in patients undergoing the intermaxillary ixation phase, this decreased immediately once the phase ended and the patients managed to return to the routine oral hygiene care. This highlights the im- portance of constant motivation and oral hy- giene instruction reinforcement. KEY WORDS: Oral hygiene, prevention protocol - Gram-negative bacterial infections - Gram-positive bacterial infections. O ral health appears to be strictly cor- related to a delicate balance between bacteria within the oral cavity, good oral hygiene care and a balanced diet. Plaque is considered one of the major risk factors in oral health disease, which, without thor- ough removal, can determine the progress of caries and periodontal disease leading to early loss of teeth and consequent function- al and esthetical problems. Adequate prevention strategies may in- luence the overall oral health status of an individual. For this reason, the role of the dental hygienist is essential in promoting dental health through a speciic prevention regime. 1-3 The dental hygienist therefore has the Orthodontic Department University of Milan Milano, Italy MINERVA STOMATOL 2014;63:167-78 G. FARRONATO, L. GIANNINI, F. NOLET, G. GALBIATI, U. GARAGIOLA, C. MASPERO Qualitative and quantitative assessment of plaque bacteria in pediatric patients, patients undergoing orthodontic treatment, combined orthdontic-surgical treatment and implant-prosthetic rehabilitation Aim. The aim of this paper was to describe the qualitative and quantitative changes oc- curring within the oral bacterial lora of sev- eral groups of patients following oral preven- tion protocols during the stages of the dental treatment they required. Methods. Three hundred patients were en- rolled in the study. The selected patients were categorized into different groups to receive preventive strategies according to their needs and treatment required. Plaque samples from each patient were collected at different intervals according to the treat- ment they were undergoing. These were then assessed under a microscope to carry out a quantitative and qualitative assessment of the plaque. Results. The Mean Plaque Index Score of most patients generally decreased during the various treatment phases and hence the overall bacterial count. However, we noticed a slight increase in the plaque index in pa- tients undergoing orthodontic surgery after placement of the orthodontic appliance and patients undergoing combined orthodontic- surgical treatment during the intermaxillary ixation phase. We generally found that the coccoidal bacterial form was the most preva- lent. Conclusion. Patients who were adequately instructed and motivated through oral hy- giene prevention strategies, showed a sig- niicant decrease in the plaque levels and in the overall bacterial components between the irst visit and the successive sample taking. Corresponding author: G. Farronato, Department of Or- Department of Or- thodontics, Fondazione IRCCS Cà Granda, Ospedale Mag- giore Policlinico, University of Milan, Italy. Via Commenda 10, 20122 Milan, Italy. E-mail: giampietro.farronato@unimi.it MINERVA MEDICA COPYRIGHT® This document is protected by international copyright laws. No additional reproduction is authorized. It is permitted for personal use to download and save only one file and print only one copy of this Article. It is not permitted to make additional copies (either sporadically or systematically, either printed or electronic) of the Article for any purpose. It is not permitted to distribute the electronic copy of the article through online internet and/or intranet file sharing systems, electronic mailing or any other means which may allow access to the Article. The use of all or any part of the Article for any Commercial Use is not permitted. The creation of derivative works from the Article is not permitted. The production of reprints for personal or commercial use is not permitted. It is not permitted to remove, cover, overlay, obscure, block, or change any copyright notices or terms of use which the Publisher may post on the Article. It is not permitted to frame or use framing techniques to enclose any trademark, logo, or other proprietary information of the Publisher.