| research Fig. 6: Change in cross-sectional area of the defect as a percentage of the baseline area for seven implants from Group 1. Black circles = success. Case 4 is among the lost implant cases (Fig. 5). The pa- tient was an 81-year-old immunocompromised man with several medical conditions, including cardiovascular dis- ease and a drug-resistant systemic infection. An implant (Nobel Biocare Tapered; 5 × 13 mm) had been placed in position #46, and he was seen six months later with an aPD of 6.8 mm, bleeding at four sites, erythema and radio- graphic evidence of bone loss. At the five-month follow- up visit, bleeding had resolved, and the aPD was reduced to 5.5 mm, but there was still redness and suppuration. By the 18-month visit, the condition had deteriorated. The aPD had increased to 8 mm, and there was bleeding and suppuration. At that time, the patient received a second LAPIP treatment. At 30 months, one PD was 11 mm and the rest were 12 mm, and there was an increase in the ra- diographic size of the defect. A third treatment was per- formed, and the laser dose was increased to 305 J at Pass 1 and 180 J at Pass 2 for that treatment. However, the implant was finally removed 31 months after the first treatment. Change in radiographic density Radiographs from all 299 implants were reviewed to identify interproximal vertical defects at baseline indicat- ing bone loss. Many patients had panoramic radiographs of low resolution, and most bone loss was restricted to the buccal plate, which is not visible in transmission (peri- apical and panoramic) radiography. Only 21 cases were identified, and of these, ten provided measurable base- line and follow-up radiographs. Radiographic data re- flected a similar proportion of outcomes to the PD and clinical sign data. Out of the ten cases, one was from Group 3 (lost implant), two were from Group 2 (partial re- 14 2 2024 sponse) and seven were from Group 1 (successful cases). The cross-sectional areas of the seven successful cases were converted to a percentage of the baseline areas, and those values were plotted at their respective follow- up times (Fig. 6). The data fitted well to a decaying expo- nential function, y=e–0.1x, which suggested that regenera- tion approached 98% by 36 months. Discussion The LAPIP utilises the advantages of laser sulcular de- bridement (e.g. selective tissue removal, bacterial reduc- tion, haemostasis, minimally invasive method) and em- beds the laser components into a medically sound protocol that also includes implant debridement, occlusal adjustment, and detailed pretreatment and post-treatment procedures. Because of these additional therapeutic measures, the outcomes reported here may not be di- rectly comparable with those of many controlled laser studies. PD and clinical signs were analysed. Analysis of the short-term data from 116 patients with complete baseline and follow-up data determined that there was a statisti- cally significant reduction in PD and clinical signs at the first follow-up visit (median: 7.6 months) after a single treatment. The aPD was reduced by 2.0 mm (5.4 mm reduced to 3.4 mm, P < 0.001), and clinical signs of erythema, bleeding and suppuration were reduced by 78–85% (P < 0.001). A recent prospective controlled trial of ten patients who were treated with the LAPIP found similar results: a 1.9 mm PD reduction and decreased bleeding and suppuration.12 Several patients had follow-up visits after the short-term study had concluded. By the time of this long-term anal- ysis, there were 155 patients with 299 implants available to determine long-term survival and response to therapy. The initial survival rate was 94% at 13.1 months (15 were lost out of the 264 implants). The long-term survival rate matched and surpassed the previous results, being 95% at 28.8 months (16 of the 299 implants were lost). In the long term, PD remained ≤ 4 mm, and clinical signs re- mained absent for 68% of the 299 implants. An additional 11% were initially successful, but then presented with a relapse at about two years post-treatment. Sixteen per cent of the 299 implants never achieved success but re- mained intact at 22 months. The clinical healing curve indicated by the average rate of increase in radiographic density for successful cases demonstrated that, on average, bone fill is expected to be 25% complete by three months, 70% complete at one year, 90% complete by two years and 98% complete af- ter three years. It is important to note that this study only sampled interproximal defects, and the analysis may thus not accurately reflect changes to labial bone.