**3.2 Zirconia implants**

Statistically significant difference was observed among the groups. This was the case for both the total number of bacteria and each bacteria separately (p < 0.0001). Every group showed vast bacterial reduction with statistically significant difference when compared to the negative control (NC). These results are shown in **Table 6** in logarithmic form.

The PDT1, PDT2 and PDT3 had the largest bacterial reduction for each bacterium separately, as well as for the total count of bacteria. There was a reduction of more than 99% in comparison to NC. However, between these three groups the differences in bacterial reduction were not statistically significant difference neither for each of the bacteria separately nor for the total number of bacteria (p > 0.05).

The lowest bacterial reduction for each bacteria separately and also for the total number of bacteria was observed in the TB group. The PC group had lower bacterial reduction compared to PDT1, PDT2 and PDT3 without statistically significant differences among them. It also did not differ significantly compared to the TB in terms of the total bacterial count, *P. gingivalis* and *P. intermedia*. It had a significant difference compared to the TB only for *A. actinomycetemcomitans*.

### **3.3 Scanning electron microscope analysis**

The SEM images from the PDT1, PDT2, and PDT3 groups did not show any surface alterations, cracks, or damage when compared to the images obtained for the sterile implants. Visually, their surface appeared to be very similar to the surface of the sterile implant, for both titanium and zirconia implants (**Figures 9**–**12**).

**161**

**Group**

PDT1 PDT2 PDT3

TB PC NC **Group**

PDT1 PDT2 PDT3

TB PC NC *\*p-value for ANOVA test.*

**Table 5.**

*Results of ANOVA and Tukey's post hoc test for the titanium implants.*

12

7.0

2.2 *abc - result of post-hoc comparison (Tukey test). Having the same letter means that there is no statistically significant difference.*

a

12

4.9

2.7

ab

12

6.7

2.4

a

12

5.4

3.1

ab

12

3.6

2.4

b

12

4.3

2.4

ab

**0.0096**

12 12 12 12 12 12

7.4

1.8

a

5.4

2.6

abc

7.0

2.2

ab

6.1

2.5

abc

3.9

2.3

c

4.7

2.3

bc

**0.0022**

N

mean

st.d.

p\*

N

mean

st.d.

p\*

p

**0.0026**

12

6.5

1.7 *Prevotella intermedia*

a

12

4.7

2.7

ab

12

6.2

2.3

a

12

5.4

2.3

ab

12

3.1

2.0

b

12

3.3

2.2

b

**0.0006**

12 12 12 12 12 12

6.8

1.9 **Total number of bacteria**

Wilks' lambda

a

4.7

2.3

abc

6.2

2.0

ab

5.2

2.2

abc

2.8

2.4

c

3.7

2.5

bc

**0.0003**

N

mean

st.d.

**Aggregatibacter actynomycetemcomitans**

p\*

N

mean

st.d.

p\*

p

**0.0026**

**Porphyromonas gingivalis**

**Wilks' lambda**

*Evaluation of the Antimicrobial Efficacy of Different Types of Photodynamic Therapy…*

*DOI: http://dx.doi.org/10.5772/intechopen.94268*


**Table 5.**

*Results of ANOVA and Tukey's post hoc test for the titanium implants.*

*Evaluation of the Antimicrobial Efficacy of Different Types of Photodynamic Therapy… DOI: http://dx.doi.org/10.5772/intechopen.94268*

**161**

*Photodynamic Therapy - From Basic Science to Clinical Research*

*The number of P. intermedia in logarithmic form for both types of implants and the study groups.*

the total number nor for each bacteria separately.

As for *P.intermedia* the PDT1 group showed no significant difference compared to NC group. On the other hand the PDT2 group was significantly more effective in the elimination of each of the bacteria separately when compared to the NC group

The least effective among the groups, when compared to the NC group, was the TB group (62.4%). Compared to NC there was no significant difference neither for

Statistically significant difference was observed among the groups. This was the case for both the total number of bacteria and each bacteria separately (p < 0.0001). Every group showed vast bacterial reduction with statistically significant difference when compared to the negative control (NC). These results are shown in **Table 6** in

The PDT1, PDT2 and PDT3 had the largest bacterial reduction for each bacterium separately, as well as for the total count of bacteria. There was a reduction of more than 99% in comparison to NC. However, between these three groups the differences in bacterial reduction were not statistically significant difference neither for each of the bacteria separately nor for the total number of bacteria

The lowest bacterial reduction for each bacteria separately and also for the total number of bacteria was observed in the TB group. The PC group had lower bacterial reduction compared to PDT1, PDT2 and PDT3 without statistically significant differences among them. It also did not differ significantly compared to the TB in terms of the total bacterial count, *P. gingivalis* and *P. intermedia*. It had a significant

The SEM images from the PDT1, PDT2, and PDT3 groups did not show any surface alterations, cracks, or damage when compared to the images obtained for the sterile implants. Visually, their surface appeared to be very similar to the surface of the sterile implant, for both titanium and zirconia implants

difference compared to the TB only for *A. actinomycetemcomitans*.

**3.3 Scanning electron microscope analysis**

**160**

(**Figures 9**–**12**).

**Figure 8.**

(p < 0.05).

**3.2 Zirconia implants**

logarithmic form.

(p > 0.05).

