*3.4. Clinical Trial*

All patients selected for inclusion in the study received a comprehensive periodontal examination and radiographs. The study patients were comprised of seven men and eight women with an age range of 35-65 years (mean age: 53 years). Among the seven patients who used Epi-Guide®, two patients collected more than one site due to their severity in periodontal disease (7 + 2 = 9 results). Among the eight patients who used ES PLA95/β-TCP GTR membrane, three patients collected more than one site due to their severity in periodontal disease (8 + 3 = 11 results). In patient response, four patients of the control group had a sore tooth at the surgical sites six months after the surgery, while the ES PLA95/β-TCP membrane group did not. In clinical observation, ES PLA95/β-TCP membrane did not show early exposure, implying that the hydrophilic membrane might help gingival tissue adhesion. Six months after the surgery, the clinical indices of each site were measured and re-recorded, such as PI, GI, PI, GI, BOP, PD, GR, MOB, and CAL. Furthermore, pre-surgery and post-surgery radiographies were observed, and reconstruction of bony defect was compared (Figure 7). Several new bone tissues were detected in the defect, indicating that the surgery had good bone-material compatibility outcome.

**Figure 7.** The patient A is with (**A**) pre-surgical radiograph (Tooth No. 36), (**B**) post-surgical radiograph with Epi-Guide® membrane after 6 months. The patent B is with (**C**) pre-surgical radiograph (Tooth No. 37), (**D**) post-surgical radiograph with ES PLA95/β-TCP membrane after 6 months. Arrow (white) indicates the bone regeneration.

The clinical indices for the commercial Epi-Guide® group in PD, GI, BOP, and CAL, showed statistically significant differences (*p* < 0.05; Table 3) after treatment, while the experimental group of the ES PLA95/β-TCP membrane showed statistically significant differences for PD, GI, GR, and CAL indices (*p* < 0.05; Table 4) after treatment. The results showed significantly more attachment gain (Epi-Guide®, 2 mm; PLA95/β-TCP GTR group, 3 mm; *p* =0.28) and shallower probing depths (Epi-Guide®, 3.3 mm; PLA95/β-TCP GTR group, 2.25 mm; *p* =0.85) than the empty control group. The change of clinical indices indicated direct improvement of periodontal inflammation and the efficacy for both the Epi-Guide® and the ES PLA95/β-TCP GTR membrane groups. However, these results did not show statistically significant differences between them (Table 5).


**Table 3.** Clinical indices before and after treatment for Epi-Guide® group by Wilcoxon signed-rank test.

\*: Differences were considered statistically significant when *p* < 0.05.

**Table 4.** Clinical indices before and after treatment for ES PLA95/β-TCP group by Wilcoxon signed-rank test.


\*: Differences were considered statistically significant when *p* < 0.05.

**Table 5.** Itemized clinical index differences between the Epi-Guide® and ES PLA95/β-TCP groups after treatment.


Mann–Whitney *U* test, \*: Differences were considered statistically significant when *p* < 0.05.

In the clinical study, a few patients of the control group showed soreness at the surgical sites 6 months after the surgery, while the ES PLA95/β-TCP membrane did not. We conjectured that the small amount of β-TCP in this membrane acts as a buffer to reduce the acid releasing during the hydrolysis of ES PLA95 membrane. Therefore, the ES technique is suitable for manufacturing the ES PLA95/β-TCP GTR membrane.

#### **4. Conclusions**

In this study, ES PLA95/β-TCP membranes were prepared by ES technology. Their effectiveness and safety with regards to cytotoxicity, in vivo animal, and clinical studies were investigated. The ES PLA95/β-TCP membrane did not show cytotoxicity, nor did it result in any inflammation. Significant difference was observed in cementum and bone height before and after surgery using the ES PLA95/β-TCP membrane in animal study. Furthermore, the ES PLA95/β-TCP membrane have a hydrophilic property would prevent early exposure and healing efficacy in this study. In intrabony defects, the use of Epi-Guide® or ES PLA95/β-TCP membranes in GTR procedures yielded comparable clinical results in reducing the probing depth and increasing attachment gain for periodontal patients. The results extended the data bank of resorbable polymer for medical applications where contradictory use of current commercial solution due to clinical condition/preexisting condition of patients

**Author Contributions:** The contributions for each author are as follows: Conceptualization by S.-Y.L. and J.-C.Y.; methodology by N.-C.T.; validation by C.-C.C. and J.-C.Y.; investigation by H.-T.H.; clinical study and data curation by P.-C.H.; writing—original draft preparation by C.-C.C. and H.-T.H.; writing—review and editing by J.-C.Y.; project administration by S.-Y.L.

**Funding:** This research was funded by National Science Council (NSC) under grant number of NSC99-2321-B038-002.

**Acknowledgments:** The bone grafts (BonaGraft™) used in this clinical study were kindly donated by BioTech One Inc., Taiwan.

**Conflicts of Interest:** The authors declare no conflicts of interest.
