Avaliou-se o comportamento biomecânico, quanto à área de estabilidade protética, extensão de cantilever e estabilidade por análise freqüência de ressonância (AFR); parâmetros clínicos: índice de placa (IP), índice de sangramento (IS), supuração, distância da plataforma do implante-margem da mucosa (DPM), profundidade de sondagem (PS), nível de inserção (NI), sangramento à sondagem (SS), largura (LM), espessura (EM) da mucosa e análise radiográfica, em dois sistemas de reabilitações implanto-suportadas. Foram instalados 104 implantes, submetidos à ativação imediata, em 26 pacientes, divididos em dois grupos: A (n= 16, All-on-4®-Nobel Biocare) e B (n=10, Neopronto®-Neodent). As próteses foram instaladas em tempo médio de 32h. (T0), e controles realizados em seis (T6), doze (T12) e 24 meses (T24). Como resultado, a taxa de sucesso foi de 100% para o grupo A e 90% para o grupo B para implantes e próteses. Diferenças significantes (p<0,05) foram apresentadas entre o cantilever posterior 10,96mm e 18,81mm e o braço de resistência (BR) 13,87mm e 5,50mm, respectivamente para os grupos A e B. A área de estabilidade, no grupo A foi de 373,5mm2 e no B de 112,8mm2; a média da AFR (em ISQ) do grupo A T0= 68,62; T6=64,40; T12=67,07; T24=66,53 e do grupo B T0= 68,37; T6=66,29; T12=67,09; T24=67,10, com diferenças (p<0,05) entre os tempos (grupo A) e posição dos implantes (grupo B). O IP no grupo A=1,0 e 0,7; grupo B=0,6 e 0,9, o IS (0,7), supuração (ausente) e SS (presença) no grupo A=50% e 37,9%; grupo B=70,1 e 52,1%, no controle de 12 e 24 meses, não mostraram diferenças estatísticas entre os grupos. As médias (em mm) da LM para o grupo A (2,05 e 2,21) e B (2,29 e 2,40) e EM grupo A (1,53 e 1,56) e B (1,31 e 1,43), DPM do grupo A (2,54e 2,52) e B (0,18mm e -0,12mm), PS grupo A (3,52 e 3,52) e B (3,52 e 4,0), NI grupo A (0,98 e 0,99) e B (3,05 e 3,57) e perda óssea grupo A (0,45mm e 0,23mm ) grupo B(0,66mm e 0,22mm), respectivamente para 12 e 24 meses, apresentaram diferenças estatísticas entre os controles. Concluindo-se que 1- O grupo A apresentou área de estabilidade e extensão de cantilever anterior e posterior, com comportamento biomecânico mais favorável do que no grupo B; 2- A estabilidade primária e secundária (AFR) foi diferente entre os tempos (grupo A) e posição dos implantes (grupo B), mas semelhantes entre os grupos; 3- Os parâmetros clínicos de índice de placa, sangramento marginal, supuração, profundidade de sondagem (exceto para os períodos de controle no grupo B), sangramento a sondagem, largura e espessura de mucosa ceratinizada foram semelhantes entre os grupos; 4- A distância da plataforma do implante-margem da mucosa foi maior no grupo A e o nível de inserção foi maior no grupo B; 5- A perda na altura da crista óssea foi semelhante entre os grupos; 6- A perda óssea foi menor nos implantes anteriores do que nos posteriores, nos grupos. / Two implant-supported rehabilitation systems were evaluated considering their biomechanical behavior, the area of prosthetic stability, cantilever extensions, stability using resonance frequency analysis (RFA) and clinical parameters, such as: modified plaque index (PI), modified bleeding index (BI), suppuration, distance between the implant shoulder and the mucosal margin (DIM), probing pocket depth (PD), probing attachment level (PAL), bleeding on probing (BP), thickness (TM) width (WM) of keratinized mucosa and radiographic analysis. One hundred and four implants had been installed in twenty six patients, submitted to immediate loading and divided into two groups: A (n=16, All-on-4®-Nobel Biocare) e B (n=10, Neopronto®-Neodent). The prosthesis had been installed in average time of 32h (T0), and controls made in (T6), 12 (T12) and 24 months (T24). As result, the success rate was 100% for the group A and 90% for the group B for both implants and prosthesis. Significant differences (p<0,05) 10,96mm and 18,81mm had been presented between posterior cantilever and the resistance arm (RA) 13,87mm and 5,50mm, respectively for the groups A and B. The stability area, in the group A was of 373,5mm2 and in B of 112,8mm2; the average of RFA (in ISQ) of the group A T0= 68,62; T6=64,40; T12=67,07; T24=66,53 and of the group B T0= 68,37; T6=66,29; T12=67,09; T24=67,10, with differences (p<0,05) between the periods (Group A) and implant position (Group B). The PI in group A was of 1,0 and 0,7 and 0,6 and 0,9 for group B, o BI (0,7), suppuration (absent), DP (presence) in group A=50% and 37,9%; group B=70,1 and 52,1%, in the control of 12 and 24 months, did not present statistical differences between the groups. The average (in mm) of WM for the group A (2,05 and 2,21) and B (2,29 and 2,40) and TM group A (1,53 and 1,56) and B (1,31 and 1,43), DIM of group A (2,54 and 2,52) and B (0,18mm and -0,12mm), DP group.

Problématique : Les connaissances théoriques et pratiques au sujet de la mise en charge immédiate d’implants non jumelés chez les édentés sont limitées. Objectifs : Cette étude avait pour but de : (1) déterminer le taux de survie implantaire de 2 implants non jumelés supportant une prothèse totale mandibulaire suite à une mise en charge immédiate, (2) évaluer les changements des niveaux osseux et de stabilité implantaire survenus sur ces 2 implants durant une période de 4 mois et les comparer à un implant témoin, et (3) décrire les complications cliniques associées à ce mode de mise en charge. Méthodologie : Chez 18 individus édentés (âge moyen de 62±7 ans), cette étude de phase I avec un design pré/post a évalué les résultats cliniques suivant la mise en charge immédiate (<48 heures) de 2 implants non jumelés par une prothèse totale mandibulaire. À l’aide de radiographies périapicales, de sondages osseux et d’analyses de la fréquence en résonnance, les niveaux osseux péri-implantaires (en mm) et les niveaux de stabilité implantairte (en ISQ) de ces 2 implants insérés dans la région parasymphysaire ont été évalués à la chirurgie (T0) et au suivi de 4 mois (T1). Un implant non submergé et sans mise en charge inséré dans la région de la symphyse mandibulaire a été utilisé comme témoin. Les données ont été analysées avec des modèles mixtes linéaires, la méthode de Tukey ajustée, l’analyse de variance de Friedman et des tests de rang signés de Wilcoxon. Résultats : De T0 à T1, 3 implants mis en charge immédiatement ont échoué chez 2 patients. Le taux de survie implantaire obtenu était donc de 91,7% (33/36) et, par patient, de 88,9% (16/18). Aucun implant témoin n’a échoué. Les changements osseux documentés radiologiquement et par sondage autour des implants mis en charge immédiatement étaient, respectivement, de -0,2 ± 0,3 mm et de -0,5 ± 0,6 mm. Les pertes d’os de support implantaire n’ont pas été démontrées statistiquement différentes entre les implants avec mise en charge immédiate et les témoins. Les niveaux moyens de stabilité implantaire ont augmenté de 5 ISQ indépendamment de la mise en charge. Les niveaux moyens d’ISQ n’ont pas été démontrés statistiquement différents entre les implants avec mise en charge immédiate et les témoins à T0 ou T1. Cinq des 18 patients n’ont expérimenté aucune complication clinique, alors que 9 en ont eu au moins deux. Hormis les échecs implantaires, aucune de ces complications n’a entraîné de changements au protocole. Conclusion : Les résultats à court terme suggèrent que : (1) le taux de survie implantaire suite au protocole immédiat est similaire à ceux rapportés lors d’un protocole de mise en charge conventionnel (2) les changements d’os de support implantaire et de stabilité ne sont pas différents comparativement à ceux d’un implant témoin, (3) un niveau élevé d’expérience clinique et chirurgicale est requis pour effectuer les procédures et pour gérer les complications associées. Ces résultats préliminaires devraient être confirmés dans une étude clinique de phase II. / Problem: There is a theoretical and practice knowledge gap in regard to immediate loading of unsplinted implants in edentulous individuals. Objectives: This study aimed to: (1) determine the implant survival rate of 2 unsplinted implants supporting a mandibular complete overdenture following an immediate loading protocol, (2) assess marginal bone level and implant stability changes of these immediately loaded implants in a 4-month period and compared them to a control implant, and (3) describe the clinical complications associated with this mode of loading. Methods: In 18 edentate individuals (mean age 62±7 years), this phase-I trial with a pre/post design assessed the clinical outcomes following the immediate loading (<48 hours) of 2 unsplinted implants supporting a mandibular overdenture. Periapical radiograhs, bone probing measurements and resonance frequency analysis were used to assess marginal bone losses and implant stability changes of these two implants inserted in the mandibular parasymphyseal region, at baseline (T0) and 4-month follow-up (T1). A non-submerged and non-loaded implant inserted in the mandibular symphysis was used as a control. Data were analyzed using linear mixed models, adjusted Tukey tests, Friedman’s analysis of variance and Wilcoxon signed-ranks tests. Results: From T0 to T1, 3 immediately loaded implants failed in 2 patients. This resulted in an implant survival rate of 91.7% (33/36), and, per patient, of 88.9% (16/18). No control implant failed. The marginal bone losses around loaded implants were -0.2 ± 0.3 mm for radiographic measurements and -0.5 ± 0.6 mm for probing measurements. There was no statistically significant difference between immediately loaded and control implants in regard to the supporting marginal bone losses. The implant stability levels increased of 5 ISQ units regardless of loading. There was no statistically significant difference in the mean ISQ levels between immediately loaded and control implants at T0 or T1. Five out of 18 patients experienced no clinical complication, while 9 of them had at least two. Apart from implant failures, none of these clinical complications led to changes in the protocol. Conclusion: The short-term results suggest that: (1) the implant survival rate following the immediate protocol is similar to those reported during a conventional loading protocol, (2) marginal implant supporting bone and stability changes are not different compared to those of a control implant, (3) a high level of clinical and surgical experience is required to perform the procedures and to manage the associated complications. These preliminary results should be confirmed in a phase II clinical trial.

Problématique : La majorité des études publiées sur la réhabilitation par mise en charge immédiate de deux implants non jumelés avec une prothèse totale mandibulaire de recouvrement n’ont rapporté que des mesures cliniques objectives et très peu ont évalué les mesures centrées sur le patient, et ce, avec des erreurs de mesure. Aucune étude n’a évalué les attentes des patients vis-à-vis d'un tel protocole. Objectifs : Évaluer les attentes, le niveau de satisfaction ainsi que la qualité de vie reliée à la santé bucco-dentaire des édentés complets suite à un protocole de mise en charge immédiate. Méthodologie : Cet essai clinique de phase 1 utilise un design pré-post afin d’évaluer les mesures centrées sur le patient. Dix-huit individus, complètement édentés et âgés en moyenne de 62,39 ± 7,65 ans, ont reçu une prothèse totale mandibulaire de recouvrement sur deux implants non jumelés suite à un protocole de mise en charge immédiate, conjointement à une prothèse totale conventionnelle maxillaire. Un instrument adapté pour mesurer leurs attentes à l’aide d’échelles visuelles analogues, le questionnaire « McGill Denture Satisfaction Instrument » ainsi que le questionnaire OHIP-20 ont été remis aux patients avant de procéder aux traitements (T0), ainsi qu’aux rendez-vous de suivi à 2 semaines (T1), 1 mois (T2) et 4 mois (T3). De plus, l’inventaire de personnalité révisé (NÉO PI-R) ainsi qu’un questionnaire sociodémographique ont été remplis par les participants. Les « change scores » ont été calculés puis des tests non paramétriques et des analyses de variances en mesures répétées suivies de comparaisons par paires ont été utilisés afin d’analyser les données recueillies. La taille d’effet a été estimée. Résultats : Les participants avaient différentes attentes par rapport à la mise en charge immédiate. Certains s’attendaient à un effet positif à court terme par rapport à leur apparence esthétique (83,3 %) et à leur vie sociale (55,7 %), alors que d’autres avaient des craintes envers leur confort (5,6 %), leur habileté à mastiquer (11,1 %) et à nettoyer leur prothèse inférieure (11,1 %). À 4 mois, le protocole de mise en charge immédiate avait rencontré la majorité des attentes des patients par rapport à l’esthétique (94.4 %), la mastication (83.3 %), la phonétique (61.1 %), le confort (94.4 %), l’hygiène (88.9 %) et leur vie sociale (88.9 %). Une amélioration statistiquement significative de la satisfaction en générale, du confort, de l’esthétique, de la stabilité de la prothèse inférieure et de l’habileté à mastiquer a été notée à 2 semaines (p<0,001). Également, les comparaisons par paires ont révélé une diminution statistiquement significative du score total de l’OHIP-20 (p < 0,001) de même que la majorité des domaines de l’OHIP (p < 0.01), sauf pour l’handicap social qui n’a diminué significativement qu’après 1 mois (p = 0.01). Ces changements (pour la satisfaction et la qualité de vie) sont restés stables au cours des suivis subséquents. Indépendamment des traits de personnalité et des variables sociodémographiques, le protocole immédiat a satisfait 94,4 % des participants et a amélioré leur qualité de vie avec une large magnitude d’effet (d = 1.9; p < 0.001). Bien que deux patients aient perdu des implants au cours du traitement, 100 % des participants étaient d’accord pour recommander cette procédure à leurs pairs. Conclusions: Le protocole de mise en charge immédiate semble satisfaire les patients quelles que soient leurs attentes. Le protocole MCI peut améliorer, à court terme, la qualité de vie des patients totalement édentés. Les résultats prometteurs de la phase 1 devraient être corroborés lors de la 2e phase de cette étude. / Statement of problem: Most published research on the immediate loading of a mandibular 2-implant overdenture has only reported on clinical outcomes. Few studies have evaluated patients centered-outcomes but with measurement errors. Consequently, there is a need to assess clinical and patient-reported outcomes in this regard. Objectives: To examine patients’ level of satisfaction, expectations and quality of life with regard to the implants’ immediate loading protocol in edentate individuals. Methods: This phase-I trial used a pre-post design to assess patient-centered outcomes in 18 edentate individuals (mean age 62.39 ± 7.65 years) who have received a 2-implant (unsplinted) mandibular overdenture through an immediate loading protocol. The McGill Denture Satisfaction Instrument, a VAS instrument assessing expectations and the OHIP-20 questionnaire were used to evaluate patients’ outcomes at baseline, 2 weeks, 1 and 4 months. Socio-demographic and personality trait data were obtained using the Revised NEO Personality Inventory and a self-administered questionnaire. Change scores were calculated and non-parametrical tests were used to analyse the data. Repeated measures ANOVAs and paired t-tests were also conducted, and effect size was estimated. Results: The participants had a wide range of expectations regarding the immediate loading protocol. Expectations included short-term positive impact on aesthetics (83.3 %) and social life (55.7 %). Other expectations included negative effects on comfort (5.6%), the ability to chew (11.1 %) and to clean their lower denture (11.1%). At 4 months, the immediate loading protocol had met most patients’ expectations regarding aesthetics (94.4%), the ability to chew (83.3%), ability to speak (61.1%), comfort (94.4%), the ability to clean their lower denture (88.9%) and their social life (88.9%). The statistical analysis showed an overall satisfaction increase with a median change score of 66 (range=7-98), 68 (range=7- 95), and 70 (range= 17- 99), at 2 weeks, 1 month and 4 months respectively. There was a statistically significant improvement in overall satisfaction, comfort, perceived aesthetics, stability of the overdenture, and ability to chew at 2 weeks (p < 0,001). Pairwise comparison (within-subjects comparisons) revealed significant decreases in total OHIP scores (P < 0.001), as well as fewer functional limitations, physical pain, psychological discomfort, physical disability, psychological disability, and handicap (P < 0.01) from baseline to 2 weeks, 1 month and 4 months follow-up. Social disability score decrease significantly only after 1 month follow-up (p = 0.01). These changes remained stable during subsequent follow-ups. The protocol satisfied 94.4% of the participants and improve their quality of life with an estimated effect size of 1.9 (p < 0.001), regardless of socio-demographic and personality profiles. There was 100% agreement among patients on recommending this procedure to their peers. Conclusions: Immediate loading of two unsplinted implants with a mandibular overdenture seemed to fulfill patients’ satisfaction regardless of their expectations and may improve oral health-related quality life of edentate individuals in short-term. Encouraging results from phase I should be confirmed and approved in Phase II clinical trials.

Propósito: O objetivo deste estudo foi avaliar a estabilidade primária com análise de freqüência de ressonância e a resposta óssea por histomorfometria em implantes sob tratamento com carga imediata e carga precoce. Material e método: Foram colocados três implantes Replace Select (Nobel Biocare, Suécia) em cada lado da mandíbula de 8 cães, totalizando 48 implantes no estudo. Um par de implantes foi selecionado para o protocolo de carga imediata (CI). Após sete dias, o segundo par de implantes recebeu as próteses para o protocolo de carga precoce (CP). Catorze dias após a colocação dos implantes, o terceiro par de implantes recebeu as próteses para o protocolo de carga precoce tardia (CPT). Em cada período foi medida a estabilidade dos implantes por freqüência de ressonância. Após o período total de doze semanas da colocação das próteses os animais foram sacrificados e os espécimes foram preparados para análise histomorfométrica. As diferenças entre os tempos de carregamento para os seguintes parâmetros: estabilidade, contato ossoimplante (COI), densidade óssea (DO) e perda da crista óssea (PCO) foram avaliadas usando ANOVA. Resultados: Os valores iniciais de estabilidade (ISQ) dos implantes foram: 77,88 ± 4,61 para CI, 79,73 ± 3,55 para CP e 79,64 ± 3,00 para CPT, sem diferença estatisticamente significante (p=0,30). Os valores finais de estabilidade foram 80,46 ± 4,23 para CI, 81,88 ± 3,55 para CP e 81,88 ± 3,42 para CPT, também sem diferença estatística (p=0,47). Para avaliar a estabilidade dos implantes em função do tempo, foi realizada ANOVA para amostras repetidas e para cada grupo foi detectado aumento significativo da estabilidade ao final do experimento (p=0,003). A interação método de carregamento versus tempo não foi significativa (p=0,97). A porcentagem de COI para CI foi 77,9 ± 1,71%, para CP foi 79,25 ± 2,11% e para CPT foi 79,42 ± 1,49%. A porcentagem de DO para CI foi 69,97 ± 3,81%, para CP foi 69,23 ± 5,68% e para CPT foi 69,19 ± 2,90%. A PCO para CI foi 1,57 ± 0,22 mm, para CP foi 1,23 ± 0,19 mm e para CPT foi 1,17 ± 0,32 mm. Não foi observada diferença estatística para nenhum dos parâmetros avaliados (p>0,05). Conclusão: Considerando a estabilidade primária, contato osso-implante, densidade óssea ao redor do implante e perda da crista óssea em cães, conclui-se que não existem diferenças estatisticamente significantes num prazo de até 12 semanas para implantes submetidos à ativação imediata, em 7 dias ou 14 dias após a cirurgia. / Purpose: The aim of this study was to evaluate the implant stability through frequency resonance analysis and the effect that different loading time will have on the bone response around implants through a histomorphometric analysis. Material and Methods: Three Replace Select implants were placed on each side of the mandible in 8 dogs totaling 48 implants in the study. One pair of implants was selected for immediate loading protocol (IL). After seven days the second pair of implants received the prostheses for the early loading protocol (EL). In each period, the implant stability measurements were performed by means of resonance frequency. After 12 weeks, a new reading of the implant stability was performed. Fourteen days after the implant placement the third pair of implants received the prostheses for the advanced early loading (AEL). Following a period totaling twelve weeks of prosthetics, the animals were sacrificed and the specimens were prepared for histomorphometric analysis. The differences between loading time in the following parameters: bone-to-implant contact (BIC), bone density (BD) and crestal bone loss (CBL) were evaluated through ANOVA. Results: The mean values of initial stability (ISQ) in different loading times were 77.88 ± 4.61 (IL), 79.73 ± 3.55 (EL) and 79.64 ± 3.00 (AEL). The data were subject to ANOVA and a significant difference was not detected (p = 0.30). The mean values of final stability in different loading times were 80.46 ± 4.23 (IL), 81.88 ± 3.55 (EL) and 81.88 ± 3.42 (AEL). The data were subject to ANOVA and a significant difference was not detected (p = 0.47). To evaluate the implant stability in function of time, a variance analysis for repeated samples was performed, and there was significant difference (p = 0.003), indicating, for each group, a significant increase in stability at the end of the experiment. The time versus method interaction did not show significant difference (p = 0.97), indicating that the variations are similar in the studied groups. The percentage of BIC for IL was 77.9 ± 1.71%, for EL was 79.25 ± 2.11% and for AEL was 79.42 ± 1.49%. The percentage of BD for IL was 69.97 ± 3.81%, for EL was 69.23 ± 5.68% and for AEL was 69.19 ± 2.90%. The CBL for IL was 1.57 ± 0.22mm, for EL was 1.23 ± 0.19mm and for AEL was 1.17 ± 0.32mm. There was no statistical difference for any of the parameters evaluated (p>0.05). Conclusion: Considering primary stability, bone-to-implant contact, bone density around the implants and crestal bone loss, there are no significant differences until 12 weeks after surgery for the stability of immediate, 7 or 14 days after placement activated implants.

Problématique : Les connaissances théoriques et pratiques au sujet de la mise en charge immédiate d’implants non jumelés chez les édentés sont limitées. Objectifs : Cette étude avait pour but de : (1) déterminer le taux de survie implantaire de 2 implants non jumelés supportant une prothèse totale mandibulaire suite à une mise en charge immédiate, (2) évaluer les changements des niveaux osseux et de stabilité implantaire survenus sur ces 2 implants durant une période de 4 mois et les comparer à un implant témoin, et (3) décrire les complications cliniques associées à ce mode de mise en charge. Méthodologie : Chez 18 individus édentés (âge moyen de 62±7 ans), cette étude de phase I avec un design pré/post a évalué les résultats cliniques suivant la mise en charge immédiate (<48 heures) de 2 implants non jumelés par une prothèse totale mandibulaire. À l’aide de radiographies périapicales, de sondages osseux et d’analyses de la fréquence en résonnance, les niveaux osseux péri-implantaires (en mm) et les niveaux de stabilité implantairte (en ISQ) de ces 2 implants insérés dans la région parasymphysaire ont été évalués à la chirurgie (T0) et au suivi de 4 mois (T1). Un implant non submergé et sans mise en charge inséré dans la région de la symphyse mandibulaire a été utilisé comme témoin. Les données ont été analysées avec des modèles mixtes linéaires, la méthode de Tukey ajustée, l’analyse de variance de Friedman et des tests de rang signés de Wilcoxon. Résultats : De T0 à T1, 3 implants mis en charge immédiatement ont échoué chez 2 patients. Le taux de survie implantaire obtenu était donc de 91,7% (33/36) et, par patient, de 88,9% (16/18). Aucun implant témoin n’a échoué. Les changements osseux documentés radiologiquement et par sondage autour des implants mis en charge immédiatement étaient, respectivement, de -0,2 ± 0,3 mm et de -0,5 ± 0,6 mm. Les pertes d’os de support implantaire n’ont pas été démontrées statistiquement différentes entre les implants avec mise en charge immédiate et les témoins. Les niveaux moyens de stabilité implantaire ont augmenté de 5 ISQ indépendamment de la mise en charge. Les niveaux moyens d’ISQ n’ont pas été démontrés statistiquement différents entre les implants avec mise en charge immédiate et les témoins à T0 ou T1. Cinq des 18 patients n’ont expérimenté aucune complication clinique, alors que 9 en ont eu au moins deux. Hormis les échecs implantaires, aucune de ces complications n’a entraîné de changements au protocole. Conclusion : Les résultats à court terme suggèrent que : (1) le taux de survie implantaire suite au protocole immédiat est similaire à ceux rapportés lors d’un protocole de mise en charge conventionnel (2) les changements d’os de support implantaire et de stabilité ne sont pas différents comparativement à ceux d’un implant témoin, (3) un niveau élevé d’expérience clinique et chirurgicale est requis pour effectuer les procédures et pour gérer les complications associées. Ces résultats préliminaires devraient être confirmés dans une étude clinique de phase II. / Problem: There is a theoretical and practice knowledge gap in regard to immediate loading of unsplinted implants in edentulous individuals. Objectives: This study aimed to: (1) determine the implant survival rate of 2 unsplinted implants supporting a mandibular complete overdenture following an immediate loading protocol, (2) assess marginal bone level and implant stability changes of these immediately loaded implants in a 4-month period and compared them to a control implant, and (3) describe the clinical complications associated with this mode of loading. Methods: In 18 edentate individuals (mean age 62±7 years), this phase-I trial with a pre/post design assessed the clinical outcomes following the immediate loading (<48 hours) of 2 unsplinted implants supporting a mandibular overdenture. Periapical radiograhs, bone probing measurements and resonance frequency analysis were used to assess marginal bone losses and implant stability changes of these two implants inserted in the mandibular parasymphyseal region, at baseline (T0) and 4-month follow-up (T1). A non-submerged and non-loaded implant inserted in the mandibular symphysis was used as a control. Data were analyzed using linear mixed models, adjusted Tukey tests, Friedman’s analysis of variance and Wilcoxon signed-ranks tests. Results: From T0 to T1, 3 immediately loaded implants failed in 2 patients. This resulted in an implant survival rate of 91.7% (33/36), and, per patient, of 88.9% (16/18). No control implant failed. The marginal bone losses around loaded implants were -0.2 ± 0.3 mm for radiographic measurements and -0.5 ± 0.6 mm for probing measurements. There was no statistically significant difference between immediately loaded and control implants in regard to the supporting marginal bone losses. The implant stability levels increased of 5 ISQ units regardless of loading. There was no statistically significant difference in the mean ISQ levels between immediately loaded and control implants at T0 or T1. Five out of 18 patients experienced no clinical complication, while 9 of them had at least two. Apart from implant failures, none of these clinical complications led to changes in the protocol. Conclusion: The short-term results suggest that: (1) the implant survival rate following the immediate protocol is similar to those reported during a conventional loading protocol, (2) marginal implant supporting bone and stability changes are not different compared to those of a control implant, (3) a high level of clinical and surgical experience is required to perform the procedures and to manage the associated complications. These preliminary results should be confirmed in a phase II clinical trial.

Problématique : La majorité des études publiées sur la réhabilitation par mise en charge immédiate de deux implants non jumelés avec une prothèse totale mandibulaire de recouvrement n’ont rapporté que des mesures cliniques objectives et très peu ont évalué les mesures centrées sur le patient, et ce, avec des erreurs de mesure. Aucune étude n’a évalué les attentes des patients vis-à-vis d'un tel protocole. Objectifs : Évaluer les attentes, le niveau de satisfaction ainsi que la qualité de vie reliée à la santé bucco-dentaire des édentés complets suite à un protocole de mise en charge immédiate. Méthodologie : Cet essai clinique de phase 1 utilise un design pré-post afin d’évaluer les mesures centrées sur le patient. Dix-huit individus, complètement édentés et âgés en moyenne de 62,39 ± 7,65 ans, ont reçu une prothèse totale mandibulaire de recouvrement sur deux implants non jumelés suite à un protocole de mise en charge immédiate, conjointement à une prothèse totale conventionnelle maxillaire. Un instrument adapté pour mesurer leurs attentes à l’aide d’échelles visuelles analogues, le questionnaire « McGill Denture Satisfaction Instrument » ainsi que le questionnaire OHIP-20 ont été remis aux patients avant de procéder aux traitements (T0), ainsi qu’aux rendez-vous de suivi à 2 semaines (T1), 1 mois (T2) et 4 mois (T3). De plus, l’inventaire de personnalité révisé (NÉO PI-R) ainsi qu’un questionnaire sociodémographique ont été remplis par les participants. Les « change scores » ont été calculés puis des tests non paramétriques et des analyses de variances en mesures répétées suivies de comparaisons par paires ont été utilisés afin d’analyser les données recueillies. La taille d’effet a été estimée. Résultats : Les participants avaient différentes attentes par rapport à la mise en charge immédiate. Certains s’attendaient à un effet positif à court terme par rapport à leur apparence esthétique (83,3 %) et à leur vie sociale (55,7 %), alors que d’autres avaient des craintes envers leur confort (5,6 %), leur habileté à mastiquer (11,1 %) et à nettoyer leur prothèse inférieure (11,1 %). À 4 mois, le protocole de mise en charge immédiate avait rencontré la majorité des attentes des patients par rapport à l’esthétique (94.4 %), la mastication (83.3 %), la phonétique (61.1 %), le confort (94.4 %), l’hygiène (88.9 %) et leur vie sociale (88.9 %). Une amélioration statistiquement significative de la satisfaction en générale, du confort, de l’esthétique, de la stabilité de la prothèse inférieure et de l’habileté à mastiquer a été notée à 2 semaines (p<0,001). Également, les comparaisons par paires ont révélé une diminution statistiquement significative du score total de l’OHIP-20 (p < 0,001) de même que la majorité des domaines de l’OHIP (p < 0.01), sauf pour l’handicap social qui n’a diminué significativement qu’après 1 mois (p = 0.01). Ces changements (pour la satisfaction et la qualité de vie) sont restés stables au cours des suivis subséquents. Indépendamment des traits de personnalité et des variables sociodémographiques, le protocole immédiat a satisfait 94,4 % des participants et a amélioré leur qualité de vie avec une large magnitude d’effet (d = 1.9; p < 0.001). Bien que deux patients aient perdu des implants au cours du traitement, 100 % des participants étaient d’accord pour recommander cette procédure à leurs pairs. Conclusions: Le protocole de mise en charge immédiate semble satisfaire les patients quelles que soient leurs attentes. Le protocole MCI peut améliorer, à court terme, la qualité de vie des patients totalement édentés. Les résultats prometteurs de la phase 1 devraient être corroborés lors de la 2e phase de cette étude. / Statement of problem: Most published research on the immediate loading of a mandibular 2-implant overdenture has only reported on clinical outcomes. Few studies have evaluated patients centered-outcomes but with measurement errors. Consequently, there is a need to assess clinical and patient-reported outcomes in this regard. Objectives: To examine patients’ level of satisfaction, expectations and quality of life with regard to the implants’ immediate loading protocol in edentate individuals. Methods: This phase-I trial used a pre-post design to assess patient-centered outcomes in 18 edentate individuals (mean age 62.39 ± 7.65 years) who have received a 2-implant (unsplinted) mandibular overdenture through an immediate loading protocol. The McGill Denture Satisfaction Instrument, a VAS instrument assessing expectations and the OHIP-20 questionnaire were used to evaluate patients’ outcomes at baseline, 2 weeks, 1 and 4 months. Socio-demographic and personality trait data were obtained using the Revised NEO Personality Inventory and a self-administered questionnaire. Change scores were calculated and non-parametrical tests were used to analyse the data. Repeated measures ANOVAs and paired t-tests were also conducted, and effect size was estimated. Results: The participants had a wide range of expectations regarding the immediate loading protocol. Expectations included short-term positive impact on aesthetics (83.3 %) and social life (55.7 %). Other expectations included negative effects on comfort (5.6%), the ability to chew (11.1 %) and to clean their lower denture (11.1%). At 4 months, the immediate loading protocol had met most patients’ expectations regarding aesthetics (94.4%), the ability to chew (83.3%), ability to speak (61.1%), comfort (94.4%), the ability to clean their lower denture (88.9%) and their social life (88.9%). The statistical analysis showed an overall satisfaction increase with a median change score of 66 (range=7-98), 68 (range=7- 95), and 70 (range= 17- 99), at 2 weeks, 1 month and 4 months respectively. There was a statistically significant improvement in overall satisfaction, comfort, perceived aesthetics, stability of the overdenture, and ability to chew at 2 weeks (p < 0,001). Pairwise comparison (within-subjects comparisons) revealed significant decreases in total OHIP scores (P < 0.001), as well as fewer functional limitations, physical pain, psychological discomfort, physical disability, psychological disability, and handicap (P < 0.01) from baseline to 2 weeks, 1 month and 4 months follow-up. Social disability score decrease significantly only after 1 month follow-up (p = 0.01). These changes remained stable during subsequent follow-ups. The protocol satisfied 94.4% of the participants and improve their quality of life with an estimated effect size of 1.9 (p < 0.001), regardless of socio-demographic and personality profiles. There was 100% agreement among patients on recommending this procedure to their peers. Conclusions: Immediate loading of two unsplinted implants with a mandibular overdenture seemed to fulfill patients’ satisfaction regardless of their expectations and may improve oral health-related quality life of edentate individuals in short-term. Encouraging results from phase I should be confirmed and approved in Phase II clinical trials.

Propósito: O objetivo deste estudo foi avaliar a estabilidade primária com análise de freqüência de ressonância e a resposta óssea por histomorfometria em implantes sob tratamento com carga imediata e carga precoce. Material e método: Foram colocados três implantes Replace Select (Nobel Biocare, Suécia) em cada lado da mandíbula de 8 cães, totalizando 48 implantes no estudo. Um par de implantes foi selecionado para o protocolo de carga imediata (CI). Após sete dias, o segundo par de implantes recebeu as próteses para o protocolo de carga precoce (CP). Catorze dias após a colocação dos implantes, o terceiro par de implantes recebeu as próteses para o protocolo de carga precoce tardia (CPT). Em cada período foi medida a estabilidade dos implantes por freqüência de ressonância. Após o período total de doze semanas da colocação das próteses os animais foram sacrificados e os espécimes foram preparados para análise histomorfométrica. As diferenças entre os tempos de carregamento para os seguintes parâmetros: estabilidade, contato ossoimplante (COI), densidade óssea (DO) e perda da crista óssea (PCO) foram avaliadas usando ANOVA. Resultados: Os valores iniciais de estabilidade (ISQ) dos implantes foram: 77,88 ± 4,61 para CI, 79,73 ± 3,55 para CP e 79,64 ± 3,00 para CPT, sem diferença estatisticamente significante (p=0,30). Os valores finais de estabilidade foram 80,46 ± 4,23 para CI, 81,88 ± 3,55 para CP e 81,88 ± 3,42 para CPT, também sem diferença estatística (p=0,47). Para avaliar a estabilidade dos implantes em função do tempo, foi realizada ANOVA para amostras repetidas e para cada grupo foi detectado aumento significativo da estabilidade ao final do experimento (p=0,003). A interação método de carregamento versus tempo não foi significativa (p=0,97). A porcentagem de COI para CI foi 77,9 ± 1,71%, para CP foi 79,25 ± 2,11% e para CPT foi 79,42 ± 1,49%. A porcentagem de DO para CI foi 69,97 ± 3,81%, para CP foi 69,23 ± 5,68% e para CPT foi 69,19 ± 2,90%. A PCO para CI foi 1,57 ± 0,22 mm, para CP foi 1,23 ± 0,19 mm e para CPT foi 1,17 ± 0,32 mm. Não foi observada diferença estatística para nenhum dos parâmetros avaliados (p>0,05). Conclusão: Considerando a estabilidade primária, contato osso-implante, densidade óssea ao redor do implante e perda da crista óssea em cães, conclui-se que não existem diferenças estatisticamente significantes num prazo de até 12 semanas para implantes submetidos à ativação imediata, em 7 dias ou 14 dias após a cirurgia. / Purpose: The aim of this study was to evaluate the implant stability through frequency resonance analysis and the effect that different loading time will have on the bone response around implants through a histomorphometric analysis. Material and Methods: Three Replace Select implants were placed on each side of the mandible in 8 dogs totaling 48 implants in the study. One pair of implants was selected for immediate loading protocol (IL). After seven days the second pair of implants received the prostheses for the early loading protocol (EL). In each period, the implant stability measurements were performed by means of resonance frequency. After 12 weeks, a new reading of the implant stability was performed. Fourteen days after the implant placement the third pair of implants received the prostheses for the advanced early loading (AEL). Following a period totaling twelve weeks of prosthetics, the animals were sacrificed and the specimens were prepared for histomorphometric analysis. The differences between loading time in the following parameters: bone-to-implant contact (BIC), bone density (BD) and crestal bone loss (CBL) were evaluated through ANOVA. Results: The mean values of initial stability (ISQ) in different loading times were 77.88 ± 4.61 (IL), 79.73 ± 3.55 (EL) and 79.64 ± 3.00 (AEL). The data were subject to ANOVA and a significant difference was not detected (p = 0.30). The mean values of final stability in different loading times were 80.46 ± 4.23 (IL), 81.88 ± 3.55 (EL) and 81.88 ± 3.42 (AEL). The data were subject to ANOVA and a significant difference was not detected (p = 0.47). To evaluate the implant stability in function of time, a variance analysis for repeated samples was performed, and there was significant difference (p = 0.003), indicating, for each group, a significant increase in stability at the end of the experiment. The time versus method interaction did not show significant difference (p = 0.97), indicating that the variations are similar in the studied groups. The percentage of BIC for IL was 77.9 ± 1.71%, for EL was 79.25 ± 2.11% and for AEL was 79.42 ± 1.49%. The percentage of BD for IL was 69.97 ± 3.81%, for EL was 69.23 ± 5.68% and for AEL was 69.19 ± 2.90%. The CBL for IL was 1.57 ± 0.22mm, for EL was 1.23 ± 0.19mm and for AEL was 1.17 ± 0.32mm. There was no statistical difference for any of the parameters evaluated (p>0.05). Conclusion: Considering primary stability, bone-to-implant contact, bone density around the implants and crestal bone loss, there are no significant differences until 12 weeks after surgery for the stability of immediate, 7 or 14 days after placement activated implants.