Student Theses, Dissertations and Capstones

Document Type


Degree Name

Master of Science (M.S.) in Dentistry


College of Dental Medicine

First Advisor

Saynur Vardar-Sengul

Publication Date / Copyright Date



Nova Southeastern University


Dental implants have revolutionized the world of dentistry since their discovery by Branemark (5). Millions of dental implants are being placed in the United States every year. Dental implants are the best option for many people to replace missing teeth in a predictable fashion. In spite of the high success and survival rates of dental implants, complications and failures can occur. Peri-implantitis generates an inflammatory response that involves both soft tissue inflammation and progressive loss of supporting bone beyond biologic remodelling (AAP consensus paper 2013 (2)). A recent meta-analysis by Decks in 2016 (13) reported the prevalence of peri-implantitis to be 45% in patients. The statistical analyses suggest that hundreds of thousands of implants are affected by peri-implantitis. The increasing number of implants placed increases the need for treatment of implants affected by peri-implantitis. The cost of losing an implant due to peri-implantitis is tremendous financially and emotionally for the patient. The progression rate of peri-implantitis is very fast; therefore, early detection and early treatment is crucial. Current treatment strategies report about 50% success rate (Froum, Froum and Rosen 2015 (43)). In 2009, Romanos, Froum and Tarnow (56) presented a surgical protocol for implant surface decontamination using the CO2 laser and found the results to be promising. Therefore, the purpose of this study is i) to evaluate the effect of CO2 laser in combination with hydrogen peroxide in the treatment of peri-implantitis lesions in humans and ii) to compare clinically, microbiologically and radiographically the effects of this new treatment to the conventional approach. Our study design innovatively targets decontamination of the implant surface for regeneration and also potentially may create a surface that could allow for re-osseointegration. This approach is new in the field of implant dentistry. A total of ten (n= 10) patients, who were diagnosed with peri-implantitis after one year of implant loading were selected. They were randomly divided into two groups: Test Group (n=5) and Control Group (n=5). The test Group underwent a new proposed protocol, which consists of using CO2 laser in combination with H2O2 along with citric acid decontamination and bone grafting. The Control Group underwent a similar treatment without the use of the CO2 laser in combination with H2O2. One week, 1 month, 3 months and 6 months post-operative appointments followed to compare clinical, radiographic and microbiological outcomes of each group. Before we proceeded, we tested the laser on expired implants to insure the CO2 laser was safe to use at the recommended settings. The SEM was used at 250 X and 38X magnifications and it was concluded that we could proceed with our protocol since the surface was unaffected. The microbiologic samples were analyzed at the OMTS Laboratory at the Kornberg School of Dentistry of Temple University, Pennsylvania. The radiographic bone fill were compare using the standard radiographs with periapical and bitewings registrations in PVS. The resulting digitized images of the radiographs were analyzed using the measurement options of the computer software of the XDR program. A computer- assisted calibration was carried out for each implant. For each implant, the distance between the implant shoulder, which was the chosen landmark, and the most coronal aspect of the alveolar crest at mesial (M) and distal aspects (D) was measured separately. Bone loss or bone gain was calculated by comparing measurements made with the radiographs from the baseline of the study and from the 6 months post-operative radiographs. The clinical measurements included: probing depth (PD), clinical attachment levels (CAL), plaque score (PI), bleeding score (mBoP), keratinized gingiva (KG), mucosal recession and were examined by 2 operators for better standardization. The clinical measurements were analyzed using pairwise comparisons with a Bonferroni adjustment. The analysis revealed interesting results. It can be concluded that: 1. Smokers had a statistically significant less bone fill after the six-months post-op appointment (P = 0.042). Smokers had 2.40 times lower levels of bone fill compare to non-smokers. Furthermore, the smokers had residual probing depth of ≥ 6mm and only 13% of the non-smokers had ≥ 6mm probing depth. Thus, tobacco consumption seems to have a negative impact on healing and regenerative outcomes and smoking is a risk factor for peri-implantitis. 2. All patients who smoked cigarettes were associated with a higher level of Fusobacterium Nucleatum and Parvirmonas Micra and also linked with Prevotella Intermedia and Tannerella forsythia. One patient also had Enteric Gram-Negative rods. The non-smokers had a more diverse microbiome consisting of Streptococcus constellatus, Campylobacter rectus, Staphylococcus aureus, Tannerella forsythia, Fusobacterium Nucleatum, Parvirmonas Micra and Prevotella Intermedia. 3. Most of the bacteria harboured around the implants affected by peri-implantitis were from the orange complex and included: Campylobacter rectus Fusobacterium Nucleatum, Parvirmonas Micra and Prevotella Intermedia. Removal of plaque and bacteria is imperative in order to have peri-implant health. 4. Plaque was statistically positively correlated to the prosthesis type (P < 0.001), meaning there was more plaque with hybrid prosthesis than with a single unit crown on implant. The flanges on the buccal of the prosthesis make the flossing and the brushing around the implants difficult. Hybrid prostheses have a higher prevalence of peri-implantitis. 5. Clinical, microbiological and radiographic improvements were noted in both groups post-operatively. The test group showed a tendency for higher increase in clinical attachment level gain and decrease in probing depth while not increasing recession. Both groups showed better BOP scores after treatment. 6. Radiographic bone fill wasn’t successful in all patients. Some patients were refractory to the surgical procedure. These patients had similar characteristics including smoking tobacco, presence of Enteric gram negative rods and 50% of bone loss pre-operatively. 7. The treatment of peri-implantitis must include a surgical procedure. It is necessary for the proper access to the implant and visualization of the defect to open a flap.




CO2 laser, Dental implants, Hydrogen peroxide, Microorganisms, Peri-implantitis



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